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Search for "nanostructure" in Full Text gives 21 result(s) in Beilstein Journal of Organic Chemistry.
Applications of microscopy and small angle scattering techniques for the characterisation of supramolecular gels
- Connor R. M. MacDonald and
- Emily R. Draper
Beilstein J. Org. Chem. 2024, 20, 2608–2634, doi:10.3762/bjoc.20.220
- highly sensitive cantilever to measure the nanometre to sub-millimetre surface morphology. Attractive or repulsive interactions between the surface and the cantilever induce a bending force in the cantilever providing a mechanical means of probing the surface nanostructure [11]. There are various modes
- liquid nitrogen, in the order of 210 MPa, and has been reported to improve the preservation of cryo-SEM specimen nanostructure [35][36]. While allowing thicker samples to be investigated avoids artifacts introduced by preparing thinner samples, cryo-SEM is limited to investigating the surface topology
- opportunity for the directed tailoring of the nanostructure topology. To further characterise the structures of the self-assembled hollow cylinders, additional investigations are required. We discuss later how these structures can be further elucidated by using scattering and microscopy in tandem. SAS is also
Graphical Abstract
Figure 1: Hierarchical assembly occurring across length scales. Molecular interactions result in fibres which...
Figure 2: Three-dimensional CLSM image of a multicomponent supramolecular structure. The three-dimensional CL...
Figure 3: AFM images of air-dried aqueous Fmoc-FF, Fmoc-S, and 1:1 Fmoc-FF:Fmoc-S solutions. Figure 3 was reprinted f...
Figure 4: (a) 3D CLSM images of macroscopically a self-sorting gel network, where all fibres were stained gre...
Figure 5: (a) 3D AFM topographic image of dried elastin fibre. (b) Indicative height and diameter profile plo...
Figure 6: The nano-to-micro imaging range of SEM and TEM [30]. Cartoons represent the nanoparticles, pores, nanow...
Figure 7: Cartoon of artifacts caused by blotting and thinning. a) Alignment of threadlike micelles (left) [32] a...
Figure 8: (a) Chemical structures of monomer compounds and a schematic of the resulting chiral helical struct...
Figure 9: Commonly observed entanglements of urea-based supramolecular helices. (a) Double helix, (b) quadrup...
Figure 10: (a) SEM image of a single three-stranded braid showing a defect in which the braid separates into s...
Figure 11: Visualization of individual atoms at 1.25 Å resolution. Three apoferritin residues are shown at hig...
Figure 12: Cartoon of a general small-angle scattering setup.
Figure 13: (a) SAXS data and fits for solution in H2O (open symbols) and D2O (closed symbols). Cryo-TEM data f...
Figure 14: (a) A cartoon illustrating the orientation phases caused by shear alignment of WLMs. (b) Rheologica...
Figure 15: (a) Chemical structure of 2NapFF and (b) a cartoon cross-section of the hollow cylinder structure f...
Figure 16: Length scales of scattering and imaging techniques [16,54,55].
Figure 17: A schematic of a hydrogel network showing the significance of various parameters extracted from SAN...
Figure 18: The morphologies of a co-assembled complex dependent on the solvent composition. Figure 18 is from [89] and was ...
Figure 19: Allowed and forbidden crossings of entangled helices. Figure 19 is from [44] and was adapted by permission from ...
Figure 20: (a) Cryo-TEM density map of self-assembled (ʟ,ʟ)-2NapFF. (b) Computational model fit to cryo-TEM ma...
Figure 21: Map showing an incomplete list of global scientific centres providing access to (a) cryo-EM in red ...
Figure 22: SANS at a range of times. Solid lines are fits to a hollow cylinder model (T = 114 min and T = 202 ...
Figure 23: SAXS data of 5 mg/mL alanine-functionalised perylene bisimide (PBI-A) in 20 v/v % MeOH at pH (a) 2;...
Figure 24: Cryo-TEM sample prepared using plunge freezing in liquid nitrogen slush and sublimed for 30 minutes...
Structure–property relationships in dicyanopyrazinoquinoxalines and their hydrogen-bonding-capable dihydropyrazinoquinoxalinedione derivatives
- Tural N. Akhmedov,
- Ajeet Kumar,
- Daken J. Starkenburg,
- Kyle J. Chesney,
- Khalil A. Abboud,
- Novruz G. Akhmedov,
- Jiangeng Xue and
- Ronald K. Castellano
Beilstein J. Org. Chem. 2024, 20, 1037–1052, doi:10.3762/bjoc.20.92
- -crystal X-ray analysis of 2b, and its important structural parameters were compared with that of 2a (#CCDC 227464) reported in the literature [25]. An improved 2D nanostructure through highly ordered organization facilitated by H-bonding is revealed. Notably, the C–C distance between two carbonyl groups
Graphical Abstract
Figure 1: Chemical structures of H-bonding N-heteroacenes synthesized by Miao et al. and Bunz et al. (a) [22,23]. Pr...
Scheme 1: Synthesis of dicyanopyrazinoquinoxaline derivatives 1a–7a.
Scheme 2: Synthesis of bis-alkoxy-substituted π-conjugated phenanthrolines 16a, 16b, 16c, and 16d.
Scheme 3: An alternative synthetic route to access 7a.
Scheme 4: Synthesis of DPQDs 1b–7b from their corresponding DCPQs 1a–7a. *THF/H2O/1,4-dioxane (4:5:1). **in s...
Figure 2: TGA of 1a–6a (a) and 1b–7b (b) obtained at 10 °C/min under nitrogen.
Figure 3: Absorption spectra (20 μM) for a) DCPQs 1a–6a and b) DPQDs 1b–7b in dimethyl sulfoxide.
Figure 4: Calculated HOMO (below) and LUMO (above) energies by DFT analysis (B3LYP/6-31+G* level of theory), ...
Figure 5: Calculated HOMO (below) and LUMO (above) energies by DFT analysis (B3LYP/6-31+G* level of theory), ...
Figure 6: Asymmetric unit of DPQD 2b with important bond lengths highlighted (a). Torsion angles of 4.33° and...
Green and sustainable approaches for the Friedel–Crafts reaction between aldehydes and indoles
- Periklis X. Kolagkis,
- Eirini M. Galathri and
- Christoforos G. Kokotos
Beilstein J. Org. Chem. 2024, 20, 379–426, doi:10.3762/bjoc.20.36
- his research group developed a novel sulfonic graphitic carbon nitride (g-C3N4-SO3H) as a nanosheet ionic liquid for the one-pot synthesis of BIMs [125]. Graphitic carbon nitride is a non-metal and non-toxic chemically stable nanostructure, which is obtained through a facile pyrolysis process that has
- effect on reaction times or yields. The nanostructure could be recovered by simple filtration, where it could be reemployed upwards of 5 times before a drop in catalytic activity was noticed. The low reactivity exhibited by ketones, the use of ethanol as a solvent and the need for conventional heating
Graphical Abstract
Scheme 1: Examples of BIMs used for their medicinal properties.
Scheme 2: Mechanisms for the synthesis of BIMs using protic or Lewis acids as catalysts.
Scheme 3: Synthesis of bis(indolyl)methanes using DBDMH.
Scheme 4: Competition experiments and synthesis of bis(indolyl)methanes using DBDMH.
Scheme 5: Proposed mechanism for formation of BIM of using DBDMH.
Scheme 6: Synthesis of bis(indolyl)methanes using I2.
Scheme 7: General reaction mechanism upon halogen bonding.
Scheme 8: Synthesis of bis(indolyl)methanes using I2, introduced by Ji.
Scheme 9: Synthesis of bis(indolyl)methanes using Br2 in CH3CN.
Scheme 10: Βidentate halogen-bond donors.
Scheme 11: Synthesis of bis(indolyl)methanes using bidentate halogen-bond donor 26.
Scheme 12: Proposed reaction mechanism.
Scheme 13: Synthesis of bis(indolyl)methanes using iodoalkyne as catalyst.
Scheme 14: Proposed reaction mechanism.
Scheme 15: Optimized reaction conditions used by Ramshini.
Scheme 16: Activation of the carbonyl group by HPA/TPI-Fe3O4.
Scheme 17: Synthesis of BIMs in the presence of nanoAg-Pt/SiO2-doped silicate.
Scheme 18: Mechanism of action proposed by Khalafi-Nezhad et al.
Scheme 19: Activation of the carbonyl group by the Cu–isatin Schiff base complex.
Scheme 20: Optimum reaction conditions published by Jain.
Scheme 21: Organocatalytic protocol utilizing nanoparticles introduced by Bankar.
Scheme 22: Activation of the carbonyl group by the AlCl3·6H2O-SDS-SiO2 complex.
Scheme 23: Optimal reaction conditions for the aforementioned nano-Fe3O4 based catalysts.
Scheme 24: Nanocatalytic protocol proposed by Kaur et al.
Scheme 25: Microwave approach introduced by Yuan.
Scheme 26: Microwave approach introduced by Zahran et al.
Scheme 27: Microwave irradiation protocol introduced by Bindu.
Scheme 28: Silica-supported microwave irradiation protocol.
Scheme 29: Proposed mechanism for formation of BIM by Nongkhlaw.
Scheme 30: Microwave-assisted synthesis of BIMs catalyzed by succinic acid.
Scheme 31: Proposed mechanism of action of MMO-4.
Scheme 32: Catalytic approach introduced by Muhammadpoor-Baltork et al.
Scheme 33: Reaction conditions used by Xiao-Ming.
Scheme 34: Ultrasonic irradiation-based protocol published by Saeednia.
Scheme 35: Pyruvic acid-mediated synthesis of BIMs proposed by Thopate.
Scheme 36: Synthesis of BIMs using [bmim]BF4 or [bmim]PF6 ionic liquids.
Scheme 37: Synthesis of BIMs utilizing In(OTf)3 in octylmethylimidazolium hexafluorophosphate as ionic liquid.
Scheme 38: FeCl3·6H2O-catalyzed synthesis of BIMs with use of ionic liquid.
Scheme 39: Synthesis of BIMs utilizing the [hmim]HSO4/EtOH catalytic system.
Scheme 40: Synthesis of BIMs utilizing acidic ionic liquid immobilized on silica gel (ILIS-SO2Cl).
Scheme 41: The [bmim][MeSO4]-catalyzed reaction of indole with various aldehydes.
Scheme 42: The role of [bmim][MeSO4] in catalyzing the reaction of indole with aldehydes.
Scheme 43: Synthesis of BIMs utilizing FeCl3-based ionic liquid ([BTBAC]Cl-FeCl3) as catalyst.
Scheme 44: Synthesis of BIMs using [Msim]Cl at room temperature.
Scheme 45: [Et3NH][H2PO4]-catalyzed synthesis of bis(indolyl)methanes.
Scheme 46: PILs-catalyzed synthesis of bis(indolyl)methanes.
Scheme 47: FSILs-mediated synthesis of bis(indolyl)methanes.
Scheme 48: Possible “release and catch” catalytic process.
Scheme 49: Synthesis of bis(indolyl)methanes by [DABCO-H][HSO4].
Scheme 50: Synthesis of bis(indolyl)methanes by [(THA)(SO4)].
Scheme 51: Synthesis of BBSI-Cl and BBSI-HSO4.
Scheme 52: Synthesis of BIMs in the presence of BBSI-Cl and BBSI-HSO4.
Scheme 53: Chemoselectivity of the present method.
Scheme 54: Synthesis of BIMs catalyzed by chitosan-supported ionic liquid.
Scheme 55: Proposed mechanism of action of CSIL.
Scheme 56: Optimization of the reaction in DESs.
Scheme 57: Synthesis of BIMs using ChCl/SnCl2 as DES.
Scheme 58: Synthesis of BIMs derivatives in presence of DES.
Scheme 59: BIMs synthesis in choline chloride/urea (CC/U).
Scheme 60: Flow chemistry-based synthesis of BIMs by Ley.
Scheme 61: Flow chemistry-based synthesis of BIMs proposed by Nam et al.
Scheme 62: Amino-catalyzed reaction of indole with propionaldehyde.
Scheme 63: Aminocatalytic synthesis of BIMs.
Scheme 64: Proposed mechanism for the aminocatalytic synthesis of BIMs.
Scheme 65: Enzymatic reaction of indole with aldehydes.
Scheme 66: Proposed mechanism for the synthesis of BIMs catalyzed by TLIM.
Scheme 67: Proposed reaction mechanism by Badsara.
Scheme 68: Mechanism proposed by D’Auria.
Scheme 69: Photoinduced thiourea catalysis.
Scheme 70: Proposed mechanism of photoacid activation.
Scheme 71: Proposed mechanism of action for CF3SO2Na.
Scheme 72: Proposed mechanism for the synthesis of BIMs by Mandawad.
Scheme 73: Proposed mechanism for the (a) acid generation and (b) synthesis of BIMs.
Scheme 74: a) Reaction conditions employed by Khaksar and b) activation of the carbonyl group by HFIP.
Scheme 75: Activation of the carbonyl group by the PPy@CH2Br through the formation of a halogen bond.
Scheme 76: Reaction conditions utilized by Mhaldar et al.
Scheme 77: a) Reaction conditions employed by López and b) activation of the carbonyl group by thiourea.
Scheme 78: Infrared irradiation approach introduced by Luna-Mora and his research group.
Scheme 79: Synthesis of BIMs with the use of the Fe–Zn BMOF.
Perspectives on push–pull chromophores derived from click-type [2 + 2] cycloaddition–retroelectrocyclization reactions of electron-rich alkynes and electron-deficient alkenes
- Michio Yamada
Beilstein J. Org. Chem. 2024, 20, 125–154, doi:10.3762/bjoc.20.13
- solution as well as contradictory propensity to form luminescent nanostructure suspensions in hexane (Figure 5) [137]. It was posited that 65 features hollow vesicles, with vesicle fusion releasing curvature energy, leading to a thermodynamically more stable tubular structure. Such aggregation-induced
Graphical Abstract
Scheme 1: Pathway of the [2 + 2] CA–RE reaction of an electron-rich alkyne with TCNE or TCNQ. EDG = electron-...
Scheme 2: Reaction pathway for DMA-appended acetylene and TCNEO.
Scheme 3: Pathway of the [2 + 2] CA–RE reaction between 1 and DCFs.
Scheme 4: Sequential double [2 + 2] CA–RE reactions between 1 and TCNE.
Scheme 5: Divergent chemical transformation pathways of TCBD 6.
Scheme 6: Synthesis of 12.
Scheme 7: [2 + 2] CA–RE reaction of 1 with 14. TCE = 1,1,2,2-tetrachloroethane.
Scheme 8: Autocatalytic model proposed by Nielsen et al.
Scheme 9: Synthesis of anthracene-embedded TCBD compound 19.
Scheme 10: Sequence of the [2 + 2] CA–RE reaction between dibenzo-fused cyclooctyne or cyclooctadiyne and TCNE...
Scheme 11: [2 + 2] CA–RE reaction between the CPP derivatives and TCNE. THF = tetrahydrofuran.
Scheme 12: [2 + 2] CA–RE reaction between ethynylfullerenes 31 and TCNE and subsequent thermal rearrangement.
Scheme 13: Pathway of the [2 + 2] CA–RE reaction between TCNE and 34, followed by additional skeletal transfor...
Scheme 14: Synthesis scheme for heterocycle 38 from the reaction between TCNE and 1 in water and a surfactant.
Scheme 15: Synthesis scheme of the CDA product 41.
Scheme 16: Synthesis of rotaxanes 44 and 46 via the [2 + 2] CA–RE reaction.
Scheme 17: Synthesis of a CuI bisphenanthroline-based rotaxane 50.
Figure 1: Structures of the chiral push–pull chromophores 51–56.
Figure 2: Structures of the axially chiral TCBD 57 and DCNQ 58 bearing a C60 core.
Figure 3: Structures of the axially chiral SubPc–TCBD–aniline conjugates 59 and 60 and the subporphyrin–TCBD–...
Figure 4: Structures of 63 and the TCBD 64.
Figure 5: Structures of the fluorophore-containing TCBDs 65–67.
Figure 6: Structures of the fluorophore-containing TCBDs 68–72.
Figure 7: Structures of the urea-containing TCBDs 73–75.
Figure 8: Structures of the fullerene–TCBD and DCNQ conjugates 76–79 and their reference compounds 80–83.
Figure 9: Structures of the ZnPc–TCBD–aniline conjugates 84 and 85.
Figure 10: Structures of the ZnP–PCBD and TCBD conjugates 86–88.
Figure 11: Structures of the porphyrin-based donor–acceptor conjugates (89–104).
Figure 12: Structures of the porphyrin–PTZ or DMA conjugates 105–112.
Figure 13: Structures of the BODIPY–Acceptor–TPA or PTZ conjugates 113–116.
Figure 14: Structures of the corrole–TCBD conjugates 117 and 118.
Figure 15: Structure of the dendritic TCBD 119.
Figure 16: Structures of the TCBDs 120–126.
Figure 17: Structures of the precursor 127 and TCBDs 128–130.
Figure 18: Structures of 131–134 utilized for BHJ OSCs.
Tetraphenylethylene-embedded pillar[5]arene-based orthogonal self-assembly for efficient photocatalysis in water
- Zhihang Bai,
- Krishnasamy Velmurugan,
- Xueqi Tian,
- Minzan Zuo,
- Kaiya Wang and
- Xiao-Yu Hu
Beilstein J. Org. Chem. 2022, 18, 429–437, doi:10.3762/bjoc.18.45
- phenyl-ring rotations thus enhancing the AIE property. The resulting m-TPEWP5G self-assembled worm-like nanosystem acts as an ideal donor and loading EsY as acceptor on the surface of the worm-like nanostructure, leads to the generation of a nanorod assembly via electrostatic interactions. The final AIE
- -like nanostructure (diameter = 748 nm). After the loading of EsY into m-TPEWP5G, the worm-like structure changed into a nanorod (diameter = 652 nm) assembly via electrostatic interactions. In comparison, the diameter and length of the m-TPEWP5G assembly were slightly higher than that of m-TPEWP5G-EsY
Graphical Abstract
Scheme 1:
Graphical representation of the fabrication of supramolecular m-TPEWP5![[Graphic 5]](/bjoc/content/inline/1860-5397-18-45-i7.svg?max-width=637&scale=1.18182)
G-EsY self-assembled photocat...
Figure 1: 1H NMR (400 MHz, D2O, 298 K) spectra of m-TPEWP5 (1.0 mM), m-TPEWP5 (1.0 mM) + G (1.0 mM), and G (1...
Figure 2: (a) Fluorescence spectra of m-TPEWP5 (1 × 10−5 M) with different concentrations of G (0 to 1.2 equi...
Figure 3:
TEM images of (a) m-TPEWP5![[Graphic 15]](/bjoc/content/inline/1860-5397-18-45-i17.svg?max-width=637&scale=1.18182)
G; (b) m-TPEWP5![[Graphic 16]](/bjoc/content/inline/1860-5397-18-45-i18.svg?max-width=637&scale=1.18182)
G-EsY. [m-TPEWP5] = 1 × 10−4 M, [G] = 1 × 10−4 M, [EsY] = ...
Figure 4:
(a) Normalized absorption and emission spectra of the EsY acceptor and the m-TPEWP5![[Graphic 25]](/bjoc/content/inline/1860-5397-18-45-i27.svg?max-width=637&scale=1.18182)
G donor assembly...
Scheme 2:
Products from 2-bromo-1-phenylethanone dehalogenation reactions in the presence of m-TPEWP5![[Graphic 43]](/bjoc/content/inline/1860-5397-18-45-i45.svg?max-width=637&scale=1.18182)
G-EsY na...
Figure 5:
Proposed mechanism for the 2-bromo-1-phenylethanone dehalogenation reaction mediated by m-TPEWP5![[Graphic 48]](/bjoc/content/inline/1860-5397-18-45-i50.svg?max-width=637&scale=1.18182)
G-E...
Constrained thermoresponsive polymers – new insights into fundamentals and applications
- Patricia Flemming,
- Alexander S. Münch,
- Andreas Fery and
- Petra Uhlmann
Beilstein J. Org. Chem. 2021, 17, 2123–2163, doi:10.3762/bjoc.17.138
Graphical Abstract
Figure 1: (a) Schematic representation of the phase stability of a binary mixture based on the free enthalpy ...
Figure 2: Illustration of the relationship between the type of miscibility gap and the temperature dependence...
Figure 3: Schematically pictured phase diagram of a binary mixture composed of a dissolved polymer with a LCS...
Figure 4: Schematic illustration of a thermo-induced swelling behavior of a star polymer composed of responsi...
Figure 5: Schematic illustration of self-assembly of block copolymer amphiphiles in a polar medium.
Figure 6: Schematic comparison of the size and conformation between free polymer chains (a), grafted polymer ...
Figure 7: Comparison of the possible phase diagrams of a polymer in solution with partially miscibility and t...
Figure 8: Selection of polymers exhibiting UCST behavior due to hydrogen bonding (blue) divided into homo- (a...
Figure 9: Part A shows the molecular structure of PDMAPS stars synthesized by Li et al. (left) demonstrating ...
Figure 10: Part A contains a schematic demonstration of conformational transitions of dual-thermoresponsive bl...
Figure 11: Part A pictures zwitterionic brushes grafted from silicon substrates obtaining a nonassociated, hyd...
Figure 12: Part A pictures the UCST phase transition of zwitterionic polymers grafted on the surface of mesopo...
Multiswitchable photoacid–hydroxyflavylium–polyelectrolyte nano-assemblies
- Alexander Zika and
- Franziska Gröhn
Beilstein J. Org. Chem. 2021, 17, 166–185, doi:10.3762/bjoc.17.17
- applied in aqueous solution, with the Schmuck binding motif – the guanidiniocarbonyl‐pyrrole zwitterion binding motif – representing a most versatile binding motif with potential from nanostructure design to biomedicine [22][23][24][25]. In addition, it is desirable to establish general concepts that do
Graphical Abstract
Scheme 1: The chemical network of reactions for 4-hydroxyflavylium (left) and the write-lock-erase cycle (rig...
Scheme 2: The building blocks used for the self-assembly in this study: pelargonidin chloride (Flavy), 1-naph...
Scheme 3: Overview of the different states of the multi-switchable system consisting of Flavy, 1N36S, and pol...
Figure 1: Top: pelargonidin cation (Flavy) and network of chemical reactions; bottom: corresponding UV–vis sp...
Figure 2: Characterization of Flavy: a) 1H NMR spectrum at pH 7.0 (form A) before and after irradiation; b) 13...
Scheme 4: Overview of the different states of the two main cycles switching the system consisting of 1N36S, F...
Figure 3: UV–vis spectroscopy of the ternary nano-assemblies for cycle I (a) and cycle II (b).
Figure 4: Dynamic light scattering: Electric field autocorrelation function g1(τ) and distribution of relaxat...
Figure 5: Static light scattering data from the assemblies of cycle I; a) A, non-irradiated, spherical partic...
Figure 6: Comparison of cycle I and cycle II in AFM.
Figure 7: a) ζ-Potential and b) effective surface charge density for cycle I; c) ζ-potential and d) effective...
Figure 8: Isothermal titration calorimetry of poly(allylamine) into the cell containing Flavy and 1N36S in aq...
Figure 9: Polar surface area of Flavy in form of A (left) and B (right).
Figure 10: Hydrodynamic radii of the nano-assemblies as function of the loading ratio: a) cycle I, b) cycle II....
Figure 11: UV–vis spectra of the nano-assemblies of cycle II at l = 0.75.
Figure 12: ζ-Potential of the nano-assemblies of cycle II depending on the concentration ratio.
Scheme 5: Different mixing orders of the assemblies. The major part of this study focuses on route i.
Heterogeneous photocatalysis in flow chemical reactors
- Christopher G. Thomson,
- Ai-Lan Lee and
- Filipe Vilela
Beilstein J. Org. Chem. 2020, 16, 1495–1549, doi:10.3762/bjoc.16.125
Graphical Abstract
Figure 1: A) Bar chart of the publications per year for the topics “Photocatalysis” (49,662 instances) and “P...
Figure 2: A) Professor Giacomo Ciamician and Dr. Paolo Silber on their roof laboratory at the University of B...
Scheme 1: PRC trifluoromethylation of N-methylpyrrole (1) using hazardous gaseous CF3I safely in a flow react...
Figure 3: A) Unit cells of the three most common crystal structures of TiO2: rutile, brookite, and anatase. R...
Figure 4: Illustration of the key semiconductor photocatalysis events: 1) A photon with a frequency exceeding...
Figure 5: Photocatalytic splitting of water by oxygen vacancies on a TiO2(110) surface. Reprinted with permis...
Figure 6: Proposed adsorption modes of A) benzene, B) chlorobenzene, C) toluene, D) phenol, E) anisole, and F...
Figure 7: Structures of the sulfonate-containing organic dyes RB5 (3) and MX-5B (4) and the adsorption isothe...
Figure 8: Idealised triclinic unit cell of a g-C3N4 type polymer, displaying possible hopping transport scena...
Figure 9: Idealised structure of a perfect g-C3N4 sheet. The central unit highlighted in red represents one t...
Figure 10: Timeline of the key processes of charge transport following the photoexcitation of g-C3N4, leading ...
Scheme 2: Photocatalytic bifunctionalisation of heteroarenes using mpg-C3N4, with the selected examples 5 and ...
Figure 11: A) Structure of four linear conjugated polymer photocatalysts for hydrogen evolution, displaying th...
Figure 12: Graphical representation of the common methods used to immobilise molecular photocatalysts (PC) ont...
Figure 13: Wireless light emitter-supported TiO2 (TiO2@WLE) HPCat spheres powered by resonant inductive coupli...
Figure 14: Graphical representation of zinc–perylene diimide (Zn-PDI) supramolecular assembly photocatalysis v...
Scheme 3: Upconversion of NIR photons to the UV frequency by NaYF4:Yb,Tm nanocrystals sequentially coated wit...
Figure 15: Types of reactors employed in heterogeneous photocatalysis in flow. A) Fixed bed reactors and the s...
Figure 16: Electrochemical potential of common semiconductor, transition metal, and organic dye-based photocat...
Scheme 4: Possible mechanisms of an immobilised molecular photoredox catalyst by oxidative or reductive quenc...
Scheme 5: Scheme of the CMB-C3N4 photocatalytic decarboxylative fluorination of aryloxyacetic acids, with the...
Scheme 6: Scheme of the g-C3N4 photocatalytic desilylative coupling reaction in flow and proposed mechanism [208].
Scheme 7: Proposed mechanism of the radical cyclisation of unsaturated alkyl 2-bromo-1,3-dicarbonyl compounds...
Scheme 8: N-alkylation of benzylamine and schematic of the TiO2-coated microfluidic device [213].
Scheme 9: Proposed mechanism of the Pt@TiO2 photocatalytic deaminitive cyclisation of ʟ-lysine (23) to ʟ-pipe...
Scheme 10: A) Proposed mechanism for the photocatalytic oxidation of phenylboronic acid (24). B) Photos and SE...
Scheme 11: Proposed mechanism for the DA-CMP3 photocatalytic aza-Henry reaction performed in a continuous flow...
Scheme 12: Proposed mechanism for the formation of the cyclic product 32 by TiO2-NC HPCats in a slurry flow re...
Scheme 13: Reaction scheme for the photocatalytic synthesis of homo and hetero disulfides in flow and scope of...
Scheme 14: Reaction scheme for the MoOx/TiO2 HPCat oxidation of cyclohexane (34) to benzene. The graph shows t...
Scheme 15: Proposed mechanism of the TiO2 HPC heteroarene C–H functionalisation via aryl radicals generated fr...
Scheme 16: Scheme of the oxidative coupling of benzylamines with the HOTT-HATN HPCat and selected examples of ...
Scheme 17: Photocatalysis oxidation of benzyl alcohol (40) to benzaldehyde (41) in a microflow reactor coated ...
Figure 17: Mechanisms of Dexter and Forster energy transfer.
Scheme 18: Continuous flow process for the isomerisation of alkenes with an ionic liquid-immobilised photocata...
Scheme 19: Singlet oxygen synthetic step in the total synthesis of canataxpropellane [265].
Scheme 20: Scheme and proposed mechanism of the singlet oxygen photosensitisation by CMP_X HPCats, with the st...
Scheme 21: Structures of CMP HPCat materials applied by Vilela and co-workers for the singlet oxygen photosens...
Scheme 22: Polyvinylchloride resin-supported TDCPP photosensitisers applied for singlet oxygen photosensitisat...
Scheme 23: Structure of the ionically immobilised TPP photosensitiser on amberlyst-15 ion exchange resins (TPP...
Scheme 24: Photosensitised singlet oxygen oxidation of citronellol (46) in scCO2, with automatic phase separat...
Scheme 25: Schematic of PS-Est-BDP-Cl2 being applied for singlet oxygen photosensitisation in flow. A) Pseudo-...
Scheme 26: Reaction scheme of the singlet oxygen oxidation of furoic acid (54) using a 3D-printed microfluidic...
Figure 18: A) Photocatalytic bactericidal mechanism by ROS oxidative cleavage of membrane lipids (R = H, amino...
Figure 19: A) Suggested mechanisms for the aqueous pollutant degradation by TiO2 in a slurry flow reactor [284-287]. B)...
Figure 20: Schematic of the flow system used for the degradation of aqueous oxytetracycline (56) solutions [215]. M...
Scheme 27: Degradation of a salicylic acid (57) solution by a coupled solar photoelectro-Fenton (SPEF) process...
Figure 21: A) Schematic flow diagram using the TiO2-coated NETmix microfluidic device for an efficient mass tr...
Functionalization of graphene: does the organic chemistry matter?
- Artur Kasprzak,
- Agnieszka Zuchowska and
- Magdalena Poplawska
Beilstein J. Org. Chem. 2018, 14, 2018–2026, doi:10.3762/bjoc.14.177
- ; Introduction In 2004, Geim and Novoselov reported the first experimental isolation of the graphene sheet and the measurement of its properties [1]. Since then, the researchers have presented many different applications of this special carbon nanostructure [2][3]. Graphene oxide (GO) and reduced graphene oxide
- material applies for the derivatization of GO and RGO based on heating or mixing a carbon nanostructure with an amine or hydroxy-containing component [24][25][26]. For example [24], it is not clear whether the word “amination” refers to the formation of the amide (NH–CO) bond or to the reaction that the
Graphical Abstract
Figure 1: Partial structure [7,8] of the (a) graphene oxide (GO) and (b) reduced graphene oxide (RGO).
Figure 2: Mechanism of the amidation/esterification-type reactions with the GO/RGO using carbodiimide and N-h...
Figure 3: Mechanism of the Steglich esterification with the GO/RGO: (a) acid–base reaction of the carboxyl gr...
Figure 4: Mechanism of the epoxide ring opening reaction with the GO/RGO.
Figure 5: Generation of the free amine (nucleophile) from the corresponding amine hydrohalide using an acid–b...
Figure 6: Mechanism of amidation/esterification-type reactions with the GO/RGO using 1,1’-carbonyldiimidazole...
Figure 7: Mechanism of the covalent functionalization of graphene-family material applying diazonium salts ch...
A self-assembled photoresponsive gel consisting of chiral nanofibers
- Lei Zou,
- Dan Han,
- Zhiyi Yuan,
- Dongdong Chang and
- Xiang Ma
Beilstein J. Org. Chem. 2018, 14, 1994–2001, doi:10.3762/bjoc.14.174
- absorption spectroscopy, circular dichroism, scanning electron microscopy and rheological techniques. This work provides a new method for facile synthesis of chiro-optical gels. Keywords: chirality; nanostructure; organogel; photoresponse; self-assembly; Introduction Supramolecular gels [1][2] immobilized
- process of the nanostructure is proposed as well. It is found that compound 3 is able to form a gel in nonpolar solvents. The assembled structures of 3 in different solvents were also investigated. The photoresponsiveness of the formed nanostructure was investigated concomitantly as well. Results and
- microscopy (SEM, Figure 4). The samples were prepared by evaporating the solution of compound 3 on a surface of mica, and the differences in various solvents were also investigated. The sample in DMSO did not show a chiral self-assembled nanostructure owing to the destruction of quadruple hydrogen bonding
Graphical Abstract
Scheme 1: The preparation of compound 3.
Figure 1: The chemical structure and the schematic representation of compound 3 as well as the proposed assem...
Figure 2: UV–vis absorbance spectra of a) compound 3 and b) irradiated by a light source of 365 nm and c) the...
Figure 3: CD spectrum of compound 3 in solutions of a) benzene, toluene, p-xylene, chloroform, tetrachloromet...
Figure 4: SEM images of the microstructure a) obtained by the self-assembled compound 3 in CHCl3 on the surfa...
Figure 5: a) The gel-to-sol transformation of the samples via different routes. b) Dynamic frequency sweep of...
Nanoreactors for green catalysis
- M. Teresa De Martino,
- Loai K. E. A. Abdelmohsen,
- Floris P. J. T. Rutjes and
- Jan C. M. van Hest
Beilstein J. Org. Chem. 2018, 14, 716–733, doi:10.3762/bjoc.14.61
- confined catalysis, (c) the nanostructure shell may regulate the access of substrates to the catalyst-containing micelle core. Reprinted with permission from reference [29]. PQS (4a), PQS attached proline catalyst 4b. Adapted from reference [26]. Copyright 2012 American Chemical Society. 3a) Schematic
Graphical Abstract
Figure 1: Assembly of catalyst-functionalized amphiphilic block copolymers into polymer micelles and vesicles...
Scheme 1: C–N bond formation under micellar catalyst conditions, no organic solvent involved. Adapted from re...
Scheme 2: Suzuki−Miyaura couplings with, or without, ppm Pd. Conditions: ArI 0.5 mmol 3a, Ar’B(OH)2 (0.75–1.0...
Figure 2: PQS (4a), PQS attached proline catalyst 4b. Adapted from reference [26]. Copyright 2012 American Chemic...
Figure 3: 3a) Schematic representation of a Pickering emulsion with the enzyme in the water phase (i), or wit...
Scheme 3: Cascade reaction with GOx and Myo. Adapted from reference [82].
Figure 4: Cross-linked polymersomes with Cu(OTf)2 catalyst. Reprinted with permission from [15].
Figure 5: Schematic representation of enzymatic polymerization in polymersomes. (A) CALB in the aqueous compa...
Figure 6: Representation of DSN-G0. Reprinted with permission from [100].
Figure 7: The multivalent esterase dendrimer 5 catalyzes the hydrolysis of 8-acyloxypyrene 1,3,6-trisulfonate...
Figure 8: Conversion of 4-NP in five successive cycles of reduction, catalyzed by Au@citrate, Au@PEG and Au@P...
Mechanochemical synthesis of graphene oxide-supported transition metal catalysts for the oxidation of isoeugenol to vanillin
- Ana Franco,
- Sudipta De,
- Alina M. Balu,
- Araceli Garcia and
- Rafael Luque
Beilstein J. Org. Chem. 2017, 13, 1439–1445, doi:10.3762/bjoc.13.141
- areas result from the superposition of several graphene oxide and/or graphene layers containing oxygen functional groups. Most transparent areas are from thinner films composed of a few layers of reduced graphene oxide from stacking nanostructure exfoliation. A significant collapse of the structure
Graphical Abstract
Figure 1: N2 isotherms of (a) RGO, (b) Fe/RGO, and (c) Co/RGO.
Figure 2: SEM images of (a and b) RGO, (c) 1% Fe/RGO, and (d) 1% Co/RGO.
Figure 3: TEM micrographs at different magnifications of (a and b) RGO, (c and d) 1% Fe/RGO, and (e and f) 1%...
Figure 4: Powder XRD patterns of RGO supported Fe and Co NPs.
Figure 5: IR spectra of 1% Fe/RGO and 1% Co/RGO catalysts collected by using diffuse reflectance infrared tra...
Effects of solvent additive on “s-shaped” curves in solution-processed small molecule solar cells
- John A. Love,
- Shu-Hua Chou,
- Ye Huang,
- Guilllermo C. Bazan and
- Thuc-Quyen Nguyen
Beilstein J. Org. Chem. 2016, 12, 2543–2555, doi:10.3762/bjoc.12.249
- extraction, it significantly reduces the magnitude of the effects, removing the dramatic s-shape of the curve. Thin film X-ray diffraction Changes in device performance upon addition of solvent additives are typically ascribed to improvements in the BHJ nanostructure by affecting the thermodynamics and
Graphical Abstract
Figure 1: a) Molecular structures and b) energy levels of p-SIDT(FBTTh2)2 and p-SIDT(FBTThCA8)2 highlighting ...
Scheme 1: Synthetic route towards p-SIDT(FBTThCA8)2. (i) Sn2Me6, Pd(PPh3)4, toluene, 85 °C; (ii) 4,7-dibromo-...
Figure 2: a) Solid-state absorption profiles of neat p-SIDT(FBTThCA8)2 (dashed line) and p-SIDT(FBTThCA8)2:PC...
Figure 3: Light intensity dependence of photocurrent as a function of the effective voltage, V0 − V, for devi...
Figure 4: Current voltage curves for devices cast from pure chlorobenzene (yellow) and with 1.5% DIO (blue) w...
Figure 5: Dynamic secondary ion mass spectrometry (DSIMS) profile showing scaled nitrogen (solid) and deuteri...
Figure 6: a) A schematic diagram of inverted architecture and b) J–V curves of device cast with no DIO in the...
A direct method for the N-tetraalkylation of azamacrocycles
- Andrew J. Counsell,
- Angus T. Jones,
- Matthew H. Todd and
- Peter J. Rutledge
Beilstein J. Org. Chem. 2016, 12, 2457–2461, doi:10.3762/bjoc.12.239
- their system is controlled by the influence of mechanical motion on nanostructure formation (the assembly of β-sheet-based fibres from the peptide building blocks in this example). Given the rapid precipitation of 3 at the phase interface observed in our N-tetrapropargylation reaction, it seems
- plausible that mechanical motion is influencing nanostructure formation and thence reaction outcomes in this context too, when shaking versus stirring the system. Alternatively the difference may be due to cavitation effects at play in the shaken system [50]. However, further work is required to determine
Graphical Abstract
Scheme 1: N-Tetraalkylation of cyclam (1) and cyclen (2) with alkyl halides in partially miscible aqueous–org...
Figure 1: Ball-and-stick depiction of the crystal structure obtained for [(3)H2](ClO4)2, generated with X-See...
Separation and identification of indene–C70 bisadduct isomers
- Bolong Zhang,
- Jegadesan Subbiah,
- David J. Jones and
- Wallace W. H. Wong
Beilstein J. Org. Chem. 2016, 12, 903–911, doi:10.3762/bjoc.12.88
- thin film nanostructure are key factors in determining the performance of these fullerene derivatives in BHJ solar cell devices. With the observations in this study, it can be argued that the success of IC70BA (and in extension, IC60BA) as the electron acceptor component in BHJ solar cells is
- electron donor and an electron acceptor) with the film nanostructure being extremely important for the device performance. Molecular structure of IC60BA and IC70BA. a) Schlegel diagram of C70; b) illustrations of three regioisomers of IC70BA and their geometrical isomers. Chromatograms of IC70BA mixture
Graphical Abstract
Figure 1: Molecular structure of IC60BA and IC70BA.
Figure 2: a) Schlegel diagram of C70; b) illustrations of three regioisomers of IC70BA and their geometrical ...
Figure 3: Chromatograms of IC70BA mixture and fractions 1, 4 and 9 separated by HPLC (Cosmosil Buckyprep-D co...
Figure 4: 1H NMR spectrum of IC70BA fractions containing a major isomer species.
Figure 5: The retention time of the first species in fraction 10 is shorter than the species in fraction 11 o...
Figure 6: The UV–vis spectrum of each fraction of IC70BA as well as known C70 bisadducts: a) fraction 1, 2, 3...
Figure 7: Schematic diagram of the architecture of BHJ solar cell devices (a) and J−V curves of the devices c...
Enabling technologies and green processes in cyclodextrin chemistry
- Giancarlo Cravotto,
- Marina Caporaso,
- Laszlo Jicsinszky and
- Katia Martina
Beilstein J. Org. Chem. 2016, 12, 278–294, doi:10.3762/bjoc.12.30
- , while nanostructure size and shape were regulated according to the structure of the CD-PG dendrons [75]. CD-based polymers can be easily prepared under MW. Biswas et al. have prepared a number of macromolecular structures from α-, β-, γ-CDs by crosslinking reactions with toluene diisocyanate and
Graphical Abstract
Figure 1: (a) Multihorn-flow US reactor, (b) Cavitational turbine, (c) Pilot-scale BM, (d) High-pressure MW r...
Figure 2: Trends in CD papers and CD use in green chemical processes.
Figure 3: Distribution of energy efficient methods in CD publications.
Figure 4: Document type dealing with CD chemistry under non-conventional techniques (conference proceedings a...
Figure 5: Document type dealing with sustainable technologies in CD publications.
Scheme 1: Synthesis of 6I-(p-toluenesulfonyl)-β-CD.
Scheme 2: Example of CuAAC with 6I-azido-6I-deoxy-β-CD and phenylacetylene.
Scheme 3: Synthesis of 6I-benzylureido-6I-deoxy-per-O-acetyl-β-CD.
Scheme 4: Synthesis of 3I-azido-3I-deoxy-altro-α, β- and γ-CD.
Scheme 5: Synthesis of 2-2’ bridged bis(β-CDs). Reaction conditions: 1) TBDMSCl, imidazole, dry pyridine, sti...
Scheme 6: Insoluble reticulated CD polymer.
Scheme 7: CD-HDI cross linked polymers.
Scheme 8: Derivatization of 6I-(p-toluenesulfonyl)-β-CD by tosyl displacement.
Scheme 9: Synthetic scheme for the preparation of heptakis(6-amino-6-deoxy)-β-CD, heptakis(6-deoxy-6-ureido)-...
Scheme 10: Structure of CD derivatives obtained via MW-assisted CuAAC.
Scheme 11: Preparation of SWCN CD-DOTA carrier.
Aggregation behaviour of amphiphilic cyclodextrins: the nucleation stage by atomistic molecular dynamics simulations
- Giuseppina Raffaini,
- Antonino Mazzaglia and
- Fabio Ganazzoli
Beilstein J. Org. Chem. 2015, 11, 2459–2473, doi:10.3762/bjoc.11.267
- nanostructure could be viewed as the building block of a vesicle surface [37]. In any case, the radius of gyration of the two clusters are essentially equal, since they amount to 12.01 Å and 12.09 Å, respectively, showing again the relatively loose association achieved in water in this stage. It should be
Graphical Abstract
Scheme 1: Structure of an aCD functionalized with hydrophobic thioalkyl C2 (R = C2H5) or C6 (R = C6H13) chain...
Figure 1: The final optimized geometry of the aCD molecule in vacuo (panel a) and in explicit water (panel b)...
Figure 2: Some relevant PDF’s calculated along the runs for the isolated aCD. a) The PDF of the glycosidic ox...
Figure 3: The distance between the oxygen atoms of two water molecules and the c.o.m. of the aCD plotted as a...
Figure 4: The PDF of the oxygen and of the hydrogen atoms of the water molecules (in red and in blue, respect...
Figure 5: The pairwise initial arrangements of two amphiphilic molecules that face the two hydrophobic H grou...
Figure 6: Final optimized geometries at equilibrium after the 30 ns MD runs obtained both in vacuo and in wat...
Figure 7: The starting arrangements (a–c) of the four α-CD molecules (top row) and the final arrangement afte...
Figure 8: The optimized geometry achieved by four aCD molecules in water by four molecules after the MD run. ...
Figure 9: a) The initial random arrangement of eight molecules of the model aCD in a space-filling representa...
Figure 10: The two aggregates obtained in water, each comprising three molecules of the model aCD, cluster A (...
Figure 11: The PDF of the S atoms of the H groups at the primary rim (black symbols) and of the oxygen atoms o...
Figure 12: The time change of the potential energy and of the van der Waals energy due to the dispersion and c...
Figure 13: a) The PDF of the eight molecules of the model aCD in water as a function of their distance r from ...
Star-shaped tetrathiafulvalene oligomers towards the construction of conducting supramolecular assembly
- Masahiko Iyoda and
- Masashi Hasegawa
Beilstein J. Org. Chem. 2015, 11, 1596–1613, doi:10.3762/bjoc.11.175
- showed two reversible two-electron redox waves at −0.03 and 0.38 V vs Fc/Fc+ in benzonitrile under normal conditions [25][60]. Conducting nanostructure formation from star-shaped oligo-TTFs Although pristine TTF does not self-associate in solution due to the low association constant for dimerization, the
Graphical Abstract
Figure 1: Radially expanded TTF oligomers 1 and 2a,b.
Figure 2: TTF-calix[4]pyrrole 3 and its TNT and C60 complexes 4 and 5.
Figure 3: C3-symmetric TTF derivatives 6a,b and 7a–c.
Figure 4: Radially expanded TTF derivatives 8, 9, and 10a,b.
Figure 5: Amphiphilic TTFs 11–14 and 15a,b.
Figure 6: TTF dimers linked by σ-bond (16) and conjugated π-systems (17–19).
Scheme 1: Synthesis of star-shaped TTF trimers 22 and 23.
Figure 7: Projections of the molecular array of 22 in crystal structure (a) along with the c axis and (b) fro...
Figure 8: UV–vis/NIR spectra of 23, 23•+, 233+, and 236+.
Scheme 2: Synthesis of tris(TTF)[12]annulenes 28 and 29 and tris(TTF)[18]annulenes 30 and 31, together with h...
Figure 9: TTF-fused annulene 33 and radiannulenes 34 and 35.
Figure 10: Colors of 30 solutions a–d in toluene (0.025 mM) at various temperatures. (a) λmax: 511 nm, (b) λmax...
Figure 11: Solutions of 33. (a) In CS2, λmax: 608 nm. (b) In CH2Cl2, λmax: 577 nm. Reprinted with permission f...
Figure 12: Optical micrographs (1000× magnified) of fibers, prepared from 30 in THF–H2O 1:1, on a glass plate ...
Scheme 3: Star-shaped TTF oligomers 38–43.
Figure 13: Star-shaped TTF 10-mer 44.
Figure 14: Cyclic voltammograms of 38, 40, and 42 (0.1 mM) in benzonitrile with 0.1 M n-Bu4PF6 as a supporting...
Figure 15: Stepwise oxidation of (a) 38 (0.02 mM), (b) 40 (0.05 mM), and (c) 42 (0.03 mM) with incremental add...
Scheme 4: Pyridazine-3,6-diol-TTF 45 and its trimer 46.
Figure 16: CT-complex of 47 with TCNQF4.
Figure 17: (a) Star-shaped TTF hexamer 48. (b) Optical image of 48 fiber with a hexagonal structure. (c) Optic...
Synthesis and evaluation of the biostability and cell compatibility of novel conjugates of nucleobase, peptidic epitope, and saccharide
- Dan Yuan,
- Xuewen Du,
- Junfeng Shi,
- Ning Zhou,
- Abdulgader Ahmed Baoum,
- Khalid Omar Al Footy,
- Khadija Omar Badahdah and
- Bing Xu
Beilstein J. Org. Chem. 2015, 11, 1352–1359, doi:10.3762/bjoc.11.145
- nanostructure (Figure 1C). This result implies that the base pair interactions between thymine and adenine likely play a critical role for the hydrogelation of the mixture of 5 + 8. In addition, we did gelation tests for 4 + 5 and 4 + 7. Both mixtures are unable to self-assemble to form hydrogels at the same
Graphical Abstract
Scheme 1: Chemical structures of the conjugates (nucleobase–amino acids–saccharide (NAS)), and nucleopeptides...
Scheme 2: The representative synthesis route of conjugates NAS (1, including solid-phase peptide synthesis an...
Figure 1: TEM images of (A) solution of 1 + 8; (B) hydrogel of 5 + 8; (C) solution of 7 + 8. Each component i...
Figure 2: (A) Strain sweep and (B) frequency sweep of the solution of 1 + 8, the hydrogel of 5 + 8, and the s...
Figure 3: Compounds remained after incubating with proteinase K (3.2 U/mL) for 24 h at 37 °C. (A) Each conjug...
Figure 4: Cell viability of HeLa cells incubated with (A) 1, (B) 2, (C) 3, (D) 4, (E) 5, (F) 6, (G) 7, (H) 8 ...
Figure 5: Cell viability of PC12 cells incubated with (A) 1, (B) 2, (C) 3, (D) 4, (E) 5, (F) 6, (G) 7, (H) 8 ...
Figure 6: Cell viability of (A) HeLa and (B) PC12 cells incubated with 5 + 8 at different concentrations.
Cyanoethylation of the glucans dextran and pullulan: Substitution pattern and formation of nanostructures and entrapment of magnetic nanoparticles
- Kathrin Fiege,
- Heinrich Lünsdorf,
- Sevil Atarijabarzadeh and
- Petra Mischnick
Beilstein J. Org. Chem. 2012, 8, 551–566, doi:10.3762/bjoc.8.63
- when a solution of the polymer material is dialyzed against the poorer solvent water. A certain degree of hydrophobicity and amphiphilic balance is necessary to form stable particles [11][12][13][14]. We also observed nanostructure formation of alkynyldextrans [15]. Embedding magnetic iron cores in the
Graphical Abstract
Figure 1: Polysaccharide structures of pullulan and dextran cyanoethylation with acrylonitrile and NaOH as ca...
Figure 2: ATR–IR spectra of (a) dextran, 6 kDa, and cyanoethyldextrans (b–d) CED-1–3.
Figure 3: ATR–IR spectra of (a) pullulan, 100 kDa, and cyanoethylpullulans (b–d) CEP-1–3.
Figure 4: 1H NMR spectra (300 MHz) of (a) CED-2 (DSNMR(1) = 1.81) in D2O; (b) dextran, native in D2O; (c) CED...
Figure 5: 1H NMR spectra (400 MHz) of (a) CEP-2 (DSNMR(3) = 1.31) in D2O; (b) pullulan, native in D2O; (c) CE...
Figure 6: Gas chromatogram of hydrolyzed and trimethylsilylated cyanoethylglucans; (a) CED-1 (DSGC = 0.74); (...
Figure 7: Experimentally determined substituent distribution in the glucosyl units (glc) of cyanoethyldextran...
Figure 8: Experimentally determined substituent distribution in the glucosyl units (glc) of cyanoethylpullula...
Figure 9: TEM micrograph of iron oxide nanoparticles prepared from an aqueous dispersion.
Figure 10: SEM micrographs of CEP-3 with iron oxide nanoparticles, (Table 3, entry 2).
Figure 11: TEM micrograph of (a) uncoated iron oxide nanoparticles; (b) of CEP-3 + iron oxide nanoparticles (n...
Figure 12: ESI Fe distribution maps of CEP-3 with iron oxide nanoparticle (Table 3, entry 1). (A) Net Fe, shown in re...
Molecular recognition of organic ammonium ions in solution using synthetic receptors
- Andreas Späth and
- Burkhard König
Beilstein J. Org. Chem. 2010, 6, No. 32, doi:10.3762/bjoc.6.32
- . This indicates that the actual binding conformation of the bis-crown ether-diammonium ion aggregates may be more complex under the experimental conditions. Recently, they reported the application of a similar peptide forming an α-helical amphiphilic peptide nanostructure with cytolytic activity. A
Graphical Abstract
Figure 1: Biologically important amines and quaternary ammonium salts: histamine (1), dopamine (2) and acetyl...
Figure 2: Crown ether 18-crown-6.
Figure 3: Conformations of 18-crown-6 (4) in solvents of different polarity.
Figure 4: Binding topologies of the ammonium ion depending on the crown ring size.
Figure 5: A “pseudorotaxane” structure consisting of 24-crown-8 and a secondary ammonium ion (5); R = Ph.
Figure 6: Typical examples of azacrown ethers, cryptands and related aza macrocycles.
Figure 7: Binding of ammonium to azacrown ethers and cryptands [111-113].
Figure 8: A 19-crown-6-ether with decalino blocking groups (11) and a thiazole-dibenzo-18-crown-6-ether (12).
Figure 9: 1,3-Bis(6-oxopyridazin-1-yl)propane derivatives 13 and 14 by Campayo et al.
Figure 10: Fluorescent azacrown-PET-sensors based on coumarin.
Figure 11: Two different pyridino-cryptands (17 and 18) compared to a pyridino-crown (19); chiral ammonium ion...
Figure 12: Pyridino-18-crown-6 ligand (21), a similar acridino-18-crown-6 ligand (22) and a structurally relat...
Figure 13: Ciral pyridine-azacrown ether receptors 24.
Figure 14: Chiral 15-crown-5 receptors 26 and an analogue 18-crown-6 ligand 27 derived from amino alcohols.
Figure 15: C2-symmetric chiral 18-crown-6 amino alcohol derivatives 28 and related macrocycles.
Figure 16: Macrocycles with diamide-diester groups (30).
Figure 17: C2-symmetric chiral aza-18-crown-6 ethers (31) with phenethylamine residues.
Figure 18: Chiral C-pivot p-methoxy-phenoxy-lariat ethers.
Figure 19: Chiral lariat crown ether 34.
Figure 20: Sucrose-based chiral crown ether receptors 36.
Figure 21: Permethylated fructooligosaccharide 37 showing induced-fit chiral recognition.
Figure 22: Biphenanthryl-18-crown-6 derivative 38.
Figure 23: Chiral lariat crown ethers derived from binol by Fuji et al.
Figure 24: Chiral phenolic crown ether 41 with “aryl chiral barriers” and guest amines.
Figure 25: Chiral bis-crown receptor 43 with a meso-ternaphthalene backbone.
Figure 26: Chromogenic pH-dependent bis-crown chemosensor 44 for diamines.
Figure 27: Triamine guests for binding to receptor 44.
Figure 28: Chiral bis-crown phenolphthalein chemosensors 46.
Figure 29: Crown ether amino acid 47.
Figure 30: Luminescent receptor 48 for bis-alkylammonium guests.
Figure 31: Luminescent CEAA (49a), a bis-CEAA receptor for amino acids (49b) and the structure of lysine bindi...
Figure 32: Luminescent CEAA tripeptide for binding small peptides.
Figure 33: Bis crown ether 51a self assembles co-operatively with C60-ammonium ion 51b.
Figure 34: Triptycene-based macrotricyclic dibenzo-[24]-crown-8 ether host 52 and guests.
Figure 35: Copper imido diacetic acid azacrown receptor 53a and the suggested His-Lys binding motif; a copper ...
Figure 36: Urea (54) and thiourea (55) benzo crown receptor for transport and extraction of amino acids.
Figure 37: Crown pyryliums ion receptors 56 for amino acids.
Figure 38: Ditopic sulfonamide bridged crown ether receptor 57.
Figure 39: Luminescent peptide receptor 58.
Figure 40: Luminescent receptor 59 for the detection of D-glucosamine hydrochloride in water/ethanol and lumin...
Figure 41: Guanidinium azacrown receptor 61 for simple amino acids and ditopic receptor 62 with crown ether an...
Figure 42: Chiral bicyclic guanidinium azacrown receptor 63 and similar receptor 64 for the enantioselective t...
Figure 43: Receptors for zwitterionic species based on luminescent CEAAs.
Figure 44: 1,10-Azacrown ethers with sugar podand arms and the anticancer agent busulfan.
Figure 45: Benzo-18-crown-6 modified β-cyclodextrin 69 and β-cyclodextrin functionalized with diaza-18-crown-6...
Figure 46: Receptors for colorimetric detection of primary and secondary ammonium ions.
Figure 47: Porphyrine-crown-receptors 72.
Figure 48: Porphyrin-crown ether conjugate 73 and fullerene-ammonium ion guest 74.
Figure 49: Calix[4]arene (75a), homooxocalix[4]arene (75b) and resorcin[4]arene (75c) compared (R = H, alkyl c...
Figure 50: Calix[4]arene and ammonium ion guest (R = H, alkyl, OAcyl etc.), possible binding sites; A: co-ordi...
Figure 51: Typical guests for studies with calixarenes and related molecules.
Figure 52: Lower rim modified p-tert-butylcalix[5]arenes 82.
Figure 53: The first example of a water soluble calixarene.
Figure 54: Sulfonated water soluble calix[n]arenes that bind ammonium ions.
Figure 55: Displacement assay for acetylcholine (3) with a sulfonato-calix[6]arene (84b).
Figure 56: Amino acid inclusion in p-sulfonatocalix[4]arene (84a).
Figure 57: Calixarene receptor family 86 with upper and lower rim functionalization.
Figure 58: Calix[6]arenes 87 with one carboxylic acid functionality.
Figure 59: Sulfonated calix[n]arenes with mono-substitution at the lower rim systematically studied on their r...
Figure 60: Cyclotetrachromotropylene host (91) and its binding to lysine (81c).
Figure 61: Calixarenes 92 and 93 with phosphonic acids groups.
Figure 62: Calix[4]arene tetraphosphonic acid (94a) and a double bridged analogue (94b).
Figure 63: Calix[4]arene tetraphosphonic acid ester (92c) for surface recognition experiments.
Figure 64: Calixarene receptors 95 with α-aminophosphonate groups.
Figure 65: A bridged homocalix[3]arene 95 and a distally bridged homocalix[4]crown 96.
Figure 66: Homocalix[3]arene ammonium ion receptor 97a and the Reichardt’s dye (97b) for colorimetric assays.
Figure 67: Chromogenic diazo-bridged calix[4]arene 98.
Figure 68: Calixarene receptor 99 by Huang et al.
Figure 69: Calixarenes 100 reported by Parisi et al.
Figure 70: Guest molecules for inclusion in calixarenes 100: DAP × 2 HCl (101a), APA (101b) and Lys-OMe × 2 HC...
Figure 71: Different N-linked peptido-calixarenes open and with glycol chain bridges.
Figure 72: (S)-1,1′-Bi-2-naphthol calixarene derivative 104 published by Kubo et al.
Figure 73: A chiral ammonium-ion receptor 105 based on the calix[4]arene skeleton.
Figure 74: R-/S-phenylalaninol functionalized calix[6]arenes 106a and 106b.
Figure 75: Capped homocalix[3]arene ammonium ion receptor 107.
Figure 76: Two C3 symmetric capped calix[6]arenes 108 and 109.
Figure 77: Phosphorous-containing rigidified calix[6]arene 110.
Figure 78: Calix[6]azacryptand 111.
Figure 79: Further substituted calix[6]azacryptands 112.
Figure 80: Resorcin[4]arene (75c) and the cavitands (113).
Figure 81: Tetrasulfonatomethylcalix[4]resorcinarene (114).
Figure 82: Resorcin[4]arenes (115a/b) and pyrogallo[4]arenes (115c, 116).
Figure 83: Displacement assay for acetylcholine (3) with tetracyanoresorcin[4]arene (117).
Figure 84: Tetramethoxy resorcinarene mono-crown-5 (118).
Figure 85: Components of a resorcinarene based displacement assay for ammonium ions.
Figure 86: Chiral basket resorcin[4]arenas 121.
Figure 87: Resorcinarenes with deeper cavitand structure (122).
Figure 88: Resorcinarene with partially open deeper cavitand structure (123).
Figure 89: Water-stabilized deep cavitands with partially structure (124, 125).
Figure 90: Charged cavitands 126 for tetralkylammonium ions.
Figure 91: Ditopic calix[4]arene receptor 127 capped with glycol chains.
Figure 92: A calix[5]arene dimer for diammonium salt recognition.
Figure 93: Calixarene parts 92c and 129 for the formation molecular capsules.
Figure 94: Encapsulation of a quaternary ammonium cation by two resorcin[4]arene molecules (NMe4+@[75c]2 × Cl−...
Figure 95: Encapsulation of a quaternary ammonium cation by six resorcin[4]arene molecules (NMe3D+@[130]6 × Cl−...
Figure 96: Structure and schematic of cucurbit[6]uril (CB[6], 131a).
Figure 97: Cyclohexanocucurbit[6]uril (CB′[6], 132) and the guest molecule spermine (133).
Figure 98: α,α,δ,δ-Tetramethylcucurbit[6]uril (134).
Figure 99: Structure of the cucurbituril-phthalhydrazide analogue 135.
Figure 100: Organic cavities for the displacement assay for amine differentiation.
Figure 101: Displacement assay methodology for diammonium- and related guests involving cucurbiturils and some ...
Figure 102: Nor-seco-Cucurbituril (±)-bis-ns-CB[6] (140) and guest molecules.
Figure 103: The cucurbit[6]uril based complexes 141 for chiral discrimination.
Figure 104: Cucurbit[7]uril (131c) and its ferrocene guests (142) opposed.
Figure 105: Cucurbit[7]uril (131c) guest inclusion and representative guests.
Figure 106: Cucurbit[7]uril (131c) binding to succinylcholine (145) and different bis-ammonium and bis-phosphon...
Figure 107: Paraquat-cucurbit[8]uril complex 149.
Figure 108: Gluconuril-based ammonium receptors 150.
Figure 109: Examples of clefts (151a), tweezers (151b, 151c, 151d) and clips (151e).
Figure 110: Kemp’s triacid (152a), on example of Rebek’s receptors (152b) and guests.
Figure 111: Amino acid receptor (154) by Rebek et al.
Figure 112: Hexagonal lattice designed hosts by Bell et al.
Figure 113: Bell’s amidinium receptor (156) and the amidinium ion (157).
Figure 114: Aromatic phosphonic acids.
Figure 115: Xylene phosphonates 159 and 160a/b for recognition of amines and amino alcohols.
Figure 116: Bisphosphonate recognition motif 161 for a colorimetric assay with alizarin complexone (163) for ca...
Figure 117: Bisphosphonate/phosphate clip 164 and bisphosphonate cleft 165.
Figure 118: N-Methylpyrazine 166a, N-methylnicotinamide iodide (166b) and NAD+ (166c).
Figure 119: Bisphosphate cavitands.
Figure 120: Bisphosphonate 167 of Schrader and Finocchiaro.
Figure 121: Tweezer 168 for noradrenaline (80b).
Figure 122: Different tripods and heparin (170).
Figure 123: Squaramide based receptors 172.
Figure 124: Cage like NH4+ receptor 173 of Kim et al.
Figure 125: Ammonium receptors 174 of Chin et al.
Figure 126: 2-Oxazolin-based ammonium receptors 175a–d and 176 by Ahn et al.
Figure 127: Racemic guest molecules 177.
Figure 128: Tripods based on a imidazole containing macrocycle (178) and the guest molecules employed in the st...
Figure 129: Ammonium ion receptor 180.
Figure 130: Tetraoxa[3.3.3.3]paracyclophanes 181 and a cyclophanic tetraester (182).
Figure 131: Peptidic bridged paraquat-cyclophane.
Figure 132: Shape-selective noradrenaline host.
Figure 133: Receptor 185 for binding of noradrenaline on surface layers from Schrader et al.
Figure 134: Tetraphosphonate receptor for binding of noradrenaline.
Figure 135: Tetraphosphonate 187 of Schrader and Finocchiaro.
Figure 136: Zinc-Porphyrin ammonium-ion receptors 188 and 189 of Mizutani et al.
Figure 137: Zinc porphyrin receptor 190.
Figure 138: Zinc porphyrin receptors 191 capable of amino acid binding.
Figure 139: Zinc-porphyrins with amino acid side chains for stereoinduction.
Figure 140: Bis-zinc-bis-porphyrin based on Tröger’s base 193.
Figure 141: BINAP-zinc-prophyrin derivative 194 and it’s guests.
Figure 142: Bisaryl-linked-zinc-porphyrin receptors.
Figure 143: Bis-zinc-porphyrin 199 for diamine recognition and guests.
Figure 144: Bis-zinc-porphyrin crown ether 201.
Figure 145: Bis-zinc-porphyrin 202 for stereodiscrimination (L = large substituent; S = small substituent).
Figure 146: Bis-zinc-porphyrin[3]rotaxane and its copper complex and guests.
Figure 147: Dien-bipyridyl ligand 206 for co-ordination of two metal atoms.
Figure 148: The ligand and corresponding tetradentate co-complex 207 serving as enantioselective receptor for a...
Figure 149: Bis(oxazoline)–copper(II) complex 208 for the recognition of amino acids in aqueous solution.
Figure 150: Zinc-salen-complexes 209 for the recognition tertiary amines.
Figure 151: Bis(oxazoline)–copper(II) 211 for the recognition of amino acids in aqueous solution.
Figure 152: Zn(II)-complex of a C2 terpyridine crown ether.
Figure 153: Displacement assay and receptor for aspartate over glutamate.
Figure 154: Chiral complex 214 for a colorimetric displacement assay for amino acids.
Figure 155: Metal complex receptor 215 with tripeptide side arms.
Figure 156: A sandwich complex 216 and its displaceable dye 217.
Figure 157: Lanthanide complexes 218–220 for amino acid recognition.
Figure 158: Nonactin (221), valinomycin (222) and vancomycin (223).
Figure 159: Monesin (224a) and a chiral analogue for enantiodiscrimination of ammonium guests (224b).
Figure 160: Chiral podands (226) compared to pentaglyme-dimethylether (225) and 18-crown-6 (4).
Figure 161: Lasalocid A (228).
Figure 162: Lasalocid derivatives (230) of Sessler et al.
Figure 163: The Coporphyrin I tetraanion (231).
Figure 164: Linear and cyclic peptides for ammonium ion recognition.
Figure 165: Cyclic and bicyclic depsipeptides for ammonium ion recognition.
Figure 166: α-Cyclodextrin (136a) and novocaine (236).
Figure 167: Helical diol receptor 237 by Reetz and Sostmann.
Figure 168: Ammonium binding spherand by Cram et al. (238a) and the cyclic[6]metaphenylacetylene 238b in compar...
Figure 169: Receptor for peptide backbone and ammonium binding (239).
Figure 170: Anion sensor principle with 3-hydroxy-2-naphthanilide of Jiang et al.
Figure 171: 7-bromo-3-hydroxy-N-(2-hydroxyphenyl)naphthalene 2-carboxamide (241) and its amine binding.
Figure 172: Naturally occurring catechins with affinity to quaternary ammonium ions.
Figure 173: Spiropyran (244) and merocyanine form (244a) of the amino acid receptors of Fuji et al.
Figure 174: Coumarin aldehyde (245) and its iminium species with amino acid bound (245a) by Glass et al.
Figure 175: Coumarin aldehyde appended with boronic acid.
Figure 176: Quinolone aldehyde dimers by Glass et al.
Figure 177: Chromogenic ammonium ion receptors with trifluoroacetophenone recognition motifs.
Figure 178: Chromogenic ammonium ion receptor with trifluoroacetophenone recognition motif bound on different m...
