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Search for "photoacid" in Full Text gives 9 result(s) in Beilstein Journal of Organic Chemistry.
Photoswitches beyond azobenzene: a beginner’s guide
- Michela Marcon,
- Christoph Haag and
- Burkhard König
Beilstein J. Org. Chem. 2025, 21, 1808–1853, doi:10.3762/bjoc.21.143
Graphical Abstract
Figure 1: Energy diagram of a two-state photoswitch. Figure 1 was redrawn from [2].
Figure 2: Example of the absorption spectra of the isomers of a photoswitch with most efficient irradiation w...
Scheme 1: Photoswitch classes described in this review.
Figure 3: Azoheteroarenes.
Scheme 2: E–Z Isomerisation (top) and mechanisms of thermal Z–E isomerisation (bottom).
Scheme 3: Rotation mechanism favoured by the electron displacement in push–pull systems. Selected examples of...
Figure 4: A) T-shaped and twisted Z-isomers determine the thermal stability and the Z–E-PSS (selected example...
Figure 5: Effect of di-ortho-substitution on thermal half-life and PSS.
Figure 6: Selected thermal lifetimes of azoindoles in different solvents and concentrations. aConcentration o...
Figure 7: Aryliminopyrazoles: N-pyrazoles (top) and N-phenyl (bottom).
Scheme 4: Synthesis of symmetrical heteroarenes through oxidation (A), reduction (B), and the Bayer–Mills rea...
Scheme 5: Synthesis of diazonium salt (A); different strategies of azo-coupling: with a nucleophilic ring (B)...
Scheme 6: Synthesis of arylazothiazoles 25 (A) and heteroaryltriazoles 28 (B).
Scheme 7: Synthesis of heteroarylimines 31a,b [36-38].
Figure 8: Push–pull non-ionic azo dye developed by Velasco and co-workers [45].
Scheme 8: Azopyridine reported by Herges and co-workers [46].
Scheme 9: Photoinduced phase transitioning azobispyrazoles [47].
Figure 9: Diazocines.
Scheme 10: Isomers, conformers and enantiomers of diazocine.
Scheme 11: Partial overlap of the ππ* band with electron-donating substituents and effect on the PSS. Scheme 11 was ada...
Figure 10: Main properties of diazocines with different bridges. aMeasured in n-hexane [56]. bMeasured in THF. cMe...
Scheme 12: Synthesis of symmetric diazocines.
Scheme 13: Synthesis of asymmetric diazocines.
Scheme 14: Synthesis of O- and S-heterodiazocines.
Scheme 15: Synthesis of N-heterodiazocines.
Scheme 16: Puromycin diazocine photoswitch [60].
Figure 11: Indigoids.
Figure 12: The main representatives of the indigoid photoswitch class.
Scheme 17: Deactivation process that prevents Z-isomerisation of indigo.
Figure 13: Stable Z-indigo derivative synthesised by Wyman and Zenhäusern [67].
Figure 14: Selected examples of indigos with aliphatic and aromatic substituents [68]. Dashed box: proposed π–π in...
Scheme 18: Resonance structures of indigo and thioindigo involving the phenyl ring.
Scheme 19: Possible deactivation mechanism for 4,4'-dihydroxythioindigo [76].
Scheme 20: Effect of different heteroaryl rings on the stability and the photophysical properties of hemiindig...
Figure 15: Thermal half-lives of red-shifted hemithioindigos in toluene [79]. aMeasured in toluene-d8.
Scheme 21: Structures of pyrrole [81] and imidazole hemithioindigo [64].
Figure 16: Examples of fully substituted double bond hemithioindigo (left), oxidised hemithioindigos (centre),...
Scheme 22: Structure of iminothioindoxyl 72 (top) and acylated phenyliminoindolinone photoswitch 73 (bottom). ...
Scheme 23: (top) Transition states of iminothioindoxyl 72. The planar transition state is associated with a lo...
Scheme 24: Baeyer–Drewsen synthesis of indigo (top) and N-functionalisation strategies (bottom).
Scheme 25: Synthesis of hemiindigo.
Scheme 26: Synthesis of hemithioindigo and iminothioindoxyl.
Scheme 27: Synthesis of double-bond-substituted hemithioindigos.
Scheme 28: Synthesis of phenyliminoindolinone.
Scheme 29: Hemithioindigo molecular motor [85].
Figure 17: Arylhydrazones.
Scheme 30: Switching of arylhydrazones. Note: The definitions of stator and rotor are arbitrary.
Scheme 31: Photo- and acidochromism of pyridine-based phenylhydrazones.
Scheme 32: A) E–Z thermal inversion of a thermally stable push–pull hydrazone [109]. B) Rotation mechanism favoured...
Scheme 33: Effect of planarisation on the half-life.
Scheme 34: The longest thermally stable hydrazone switches reported so far (left). Modulation of thermal half-...
Figure 18: Dependency of t1/2 on concentration and hypothesised aggregation-induced isomerisation.
Figure 19: Structure–property relationship of acylhydrazones.
Scheme 35: Synthesis of arylhydrazones.
Scheme 36: Synthesis of acylhydrazones.
Scheme 37: Photoswitchable fluorophore by Aprahamian et al. [115].
Scheme 38: The four-state photoswitch synthesised by the Cigáň group [116].
Figure 20: Diarylethenes.
Scheme 39: Isomerisation and oxidation pathway of E-stilbene to phenanthrene.
Scheme 40: Strategies adapted to avoid E–Z isomerisation and oxidation.
Scheme 41: Molecular orbitals and mechanism of electrocyclisation for a 6π system.
Figure 21: Aromatic stabilisation energy correlated with the thermal stability of the diarylethenes [127,129].
Figure 22: Half-lives of diarylethenes with increasing electron-withdrawing groups [128,129].
Scheme 42: Photochemical degradation pathway promoted by electron-donating groups [130].
Figure 23: The diarylethenes studied by Hanazawa et al. [134]. Increased rigidity leads to bathochromic shift.
Scheme 43: The dithienylethene synthesised by Nakatani's group [135].
Scheme 44: Synthesis of perfluoroalkylated diarylethenes.
Scheme 45: Synthesis of 139 and 142 via McMurry coupling.
Scheme 46: Synthesis of symmetrical derivatives 145 via Suzuki–Miyaura coupling.
Scheme 47: Synthesis of acyclic 148, malonic anhydride 149, and maleimide derivatives 154.
Figure 24: Gramicidin S (top left) and two of the modified diarylethene derivatives: first generation (bottom ...
Scheme 48: Pyridoxal 5'-phosphate and its reaction with an amino acid (top). The analogous dithienylethene der...
Figure 25: Fulgides.
Scheme 49: The three isomers of fulgides.
Scheme 50: Thermal and photochemical side products of unsubstituted fulgide [150].
Figure 26: Maximum absorption λc of the closed isomer compared with the nature of the aromatic ring and the su...
Scheme 51: Possible rearrangement of the excited state of 5-dimethylaminoindolylfulgide [153].
Figure 27: Quantum yields of ring closure (ΦE→C) and E–Z isomerisation (ΦE→Z) correlated with the increasing s...
Scheme 52: Active (Eα) and inactive (Eβ) conformers (left) and the bicyclic sterically blocked fulgide 169 (ri...
Scheme 53: Quantum yield of ring-opening (ΦC→E) and E–Z isomerisation (ΦE→Z) for different substitution patter...
Scheme 54: Stobbe condensation pathway for the synthesis of fulgides 179, fulgimides 181 and fulgenates 178.
Scheme 55: Alternative synthesis of fulgides through Pd-catalysed carbonylation.
Scheme 56: Optimised synthesis of fulgimides [166].
Scheme 57: Photoswitchable FRET with a fulgimide photoswitch [167].
Scheme 58: Three-state fulgimide strategy by Slanina's group.
Figure 28: Spiropyrans.
Scheme 59: Photochemical (left) and thermal (right) ring-opening mechanisms for an exemplary spiropyran with a...
Figure 29: Eight possible isomers of the open merocyanine according to the E/Z configurations of the bonds hig...
Scheme 60: pH-Controlled photoisomerisation between the closed spiropyran 191-SP and the open E-merocyanine 19...
Scheme 61: Behaviour of spiropyran in water buffer according to Andréasson and co-workers [180]. 192-SP in an aqueo...
Scheme 62: (left box) Proposed mechanism of basic hydrolysis of MC [184]. (right box) Introduction of electron-dona...
Scheme 63: Photochemical interconversion of naphthopyran 194 (top) and spirooxazine 195 (bottom) photoswitches...
Scheme 64: Synthesis of spiropyrans and spirooxazines 198 and the dicondensation by-product 199.
Scheme 65: Alternative synthesis of spiropyrans and spirooxazines with indolenylium salt 200.
Scheme 66: Synthesis of 4’-substituted spiropyrans 203 by condensation of an acylated methylene indoline 201 w...
Scheme 67: Synthesis of spironaphthopyrans 210 by acid-catalysed condensation of naphthols and diarylpropargyl...
Scheme 68: Photoswitchable surface wettability [194].
Figure 30: Some guiding principles for the choice of the most suitable photoswitch. Note that this guide is ve...
Biobased carbon dots as photoreductants – an investigation by using triarylsulfonium salts
- Valentina Benazzi,
- Arianna Bini,
- Ilaria Bertuol,
- Mariangela Novello,
- Federica Baldi,
- Matteo Hoch,
- Alvise Perosa and
- Stefano Protti
Beilstein J. Org. Chem. 2025, 21, 1024–1030, doi:10.3762/bjoc.21.84
- photoreductants, and we considered triarylsulfonium salts Ar3S+X− as suitable probes. Such derivatives are photoreactive molecules characterized by a positively charged sulfur atom bonded to three aromatic moieties [20][21][22][23], mainly employed as photoacid generators in cationic polymerization [19]. Apart
Graphical Abstract
Scheme 1: a) CDs-mediated 1,2-difunctionalization of alkenes by alkyl halides R–Y and b) light-driven reducti...
Figure 1: UV–vis spectra of the CDs. All the measurements have been performed in water, except for CD-a-GLU, ...
Auxiliary strategy for the general and practical synthesis of diaryliodonium(III) salts with diverse organocarboxylate counterions
- Naoki Miyamoto,
- Daichi Koseki,
- Kohei Sumida,
- Elghareeb E. Elboray,
- Naoko Takenaga,
- Ravi Kumar and
- Toshifumi Dohi
Beilstein J. Org. Chem. 2024, 20, 1020–1028, doi:10.3762/bjoc.20.90
- presence or absence of transition metal catalysts under thermal or photochemical conditions [2][3][4][5]. Furthermore, these compounds have practical applications in the synthesis of radiochemicals utilized in positron emission tomography (PET) imaging [6], as well as serving as photoacid generators for
Graphical Abstract
Scheme 1: Synthetic approaches of diaryliodonium(III) trifluoroacetates.
Scheme 2: Synthesis of diaryliodonium(III) carboxylates.
Scheme 3: Scope of dummy ligands.
Scheme 4: Substrate scope of aryl(TMP)iodonium(III) acetates. a) 0.50 mmol scale of 1i. b) 1,3,5-Trimethoxybe...
Scheme 5: Substrate scope of the carboxylic acids and iodosylarenes. a) The reaction was conducted for 4 h. b...
Scheme 6: Representative applications of aryl(TMP)iodonium(III) carboxylates.
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
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.
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
- pH-responsive nano-assemblies with switchable size and structure are formed by the association of a photoacid, anthocyanidin, and a linear polyelectrolyte in aqueous solution. Specifically, anionic disulfonated naphthol derivatives, neutral hydroxyflavylium, and cationic poly(allylamine) are used as
- building blocks for the ternary electrostatic self-assembly, forming well-defined supramolecular assemblies with tunable sizes of 50 to 500 nm. Due to the network of possible chemical reactions for the anthocyanidin and the excited-state dissociation of the photoacid upon irradiation, different ways to
- ; multiswitchable; photoacid; polyelectrolyte; Introduction Supramolecular nanoscale assemblies responding to multiple stimuli are highly desirable in various fields including transport systems, sensors, and optoelectronic applications [1][2][3][4][5][6][7][8]. Self-assembly into supramolecular structures and
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.
p-Pyridinyl oxime carbamates: synthesis, DNA binding, DNA photocleaving activity and theoretical photodegradation studies
- Panagiotis S. Gritzapis,
- Panayiotis C. Varras,
- Nikolaos-Panagiotis Andreou,
- Katerina R. Katsani,
- Konstantinos Dafnopoulos,
- George Psomas,
- Zisis V. Peitsinis,
- Alexandros E. Koumbis and
- Konstantina C. Fylaktakidou
Beilstein J. Org. Chem. 2020, 16, 337–350, doi:10.3762/bjoc.16.33
- the DNA photocleavage from sulfonylamidoximes and ethanone oximes (IV and V, Figure 1), which were found to attack DNA via sulfonyloxyl radicals (SRs) [10][11]. All the above radical species exhibit photoreactivity towards DNA. Those oxime derivatives are considered photoacid generators (PAGs) since
Graphical Abstract
Figure 1: General structures of oxime derivatives with possible DNA photocleavage ability. Left: Oxime carbox...
Scheme 1: Synthesis of O-carbamoyl amidoximes (8–13), ethanone oximes (15–20) and aldoximes (22–27). Oxime 1 ...
Figure 2: UV–vis spectra of CT DNA ([DNA] = 1.1 × 10−4 M) in buffer solution in the absence or presence of in...
Figure 3: Relative viscosity (η/η0)1/3 of CT DNA (0.1 mM) in buffer solution in the presence of compounds 11 ...
Figure 4: Plot of EB-DNA relative fluorescence emission intensity at λ = 592 nm (I/I0, %) vs r (= [compound]/...
Figure 5: DNA photocleavage of amidoxime carbamates at a concentration of 500 μM and mechanistic studies of a...
Figure 6: Potential energy curve for the dissociation of 12 in the first excited triplet state, T1. For compo...
Scheme 2: Photodissociation reaction of the derivative 12 in the T1 state and the formation of ground state r...
Scheme 3: Decarboxylation reaction of the p-chlorophenylcarbamoyloxyl radical.
Figure 7: Proposed scheme showing a possible energy transfer from acetophenone sensitizer to oxime carbamate ...
Figure 8: DNA photocleavage of compounds 8–10 and 12–13 at concentration of 500 μM, at 365 nm, in the absence...
Figure 9: DNA photocleavage of compound 12 at a concentration of 500 μM, at 312 nm, in the absence and presen...
Interactions between photoacidic 3-hydroxynaphtho[1,2-b]quinolizinium and cucurbit[7]uril: Influence on acidity in the ground and excited state
- Jonas Becher,
- Daria V. Berdnikova,
- Darinka Dzubiel,
- Heiko Ihmels and
- Phil M. Pithan
Beilstein J. Org. Chem. 2017, 13, 203–212, doi:10.3762/bjoc.13.23
- photoacid (pKa = 7.2; pKa* < 0) [35]. Furthermore, it was observed that quinolizinium derivatives 1b and 1c bind to cucurbiturils with high affinity [36][37]. Therefore, it seemed possible that the available range of pKa and pKa* values of this class of compounds can be extended by complexation with an
- deeply embedded in the host cavity, so that it is no longer available [28]. Hence, hydroxynaphthoquinolizinium 2 is one of the few reported examples of a photoacid whose acidity decreases upon association with CB[7]. In analogy to the behavior of reported CB[7]-bound photoacids, it is assumed that the
- ]. Conclusion In summary we introduced a novel quinolizinium-based photoacid whose acidity in the ground and excited state can be changed by the association with CB[7]. With this result we demonstrated that in general the acidic functionality as well as the photophysical properties of hydroxyquinolizinium
Graphical Abstract
Figure 1: Structures of quinolizinium derivatives 1a–c and 2.
Scheme 1: Synthesis of 3-hydroxynaphtho[1,2-b]quinolizinium bromide (2).
Figure 2: Absorption (A, c = 100 µM) and normalized emission spectra (B, c = 10 µM or Abs. = 0.1 at λex) of d...
Figure 3: Photometric (A) and fluorimetric (B) acid–base titration (λex = 380 nm) of naphthoquinolizinium 2 (c...
Figure 4: Absorption spectra of 2 (c = 100 µM) in MeOH (A) and MeCN (B). Black lines: without additive, red: ...
Figure 5: Normalized emission spectra of 2 (c = 10 µM) in MeOH (A, λex = 400 nm) and MeCN (B, λex = 398 nm). ...
Figure 6: Photometric titration of CB[7] (c = 0.45 mM) to 2 (c = 15 µM) in BPE buffer (with 10% v/v DMSO) at ...
Figure 7: Photometric (A) and fluorimetric (B) acid–base titration (λex = 380 nm) of 2 (c = 15 µM) in the pre...
Scheme 2: Acid–base equilibrium of hydroxynaphthoquinolizinium 2.
Figure 8: Structures of quinolizinium derivatives 6–8.
Bright molecules for sensing, computing and imaging: a tale of two once-troubled cities
- A. Prasanna de Silva
Beilstein J. Org. Chem. 2015, 11, 2774–2784, doi:10.3762/bjoc.11.298
- interface somewhat akin to those found in a touch-screen of a mobile telephone or in a mouse-driven screen of a stored-program computer. The treated paper could build an image after receiving a projection of the object. We do this by using a photoacid generator 6 (used to sculpt features in silicon chips
Graphical Abstract
Figure 1: Approximate world maps of sources of fluorescent PET sensors/switches. Only the names of correspond...
Figure 2: OPTITM cassettes sold by Optimedical Inc. (http://www.optimedical.com). Photograph is reprinted fro...
Figure 3: Structural formulae of the molecules discussed in this paper.
Figure 4: Approximate world maps of the sources of molecular logic devices. Only the names of corresponding a...
Figure 5: Fluorescence micrographs (excited at 366 nm) of 0.1 mm polymer beads carrying MCID tags. The beads ...
Figure 6: Photographs of fluorescent images (excited at 366 nm) after writing with 254 nm light through a ‘sq...
Figure 7: Backlit shamrock object and fluorescence image (excited at 366 nm) on paper containing 6, 9 and Na2...
Figure 8: Comparison of how a child, a computer and the molecules 7 and 9 draw the outline of a shamrock obje...
Light-induced olefin metathesis
- Yuval Vidavsky and
- N. Gabriel Lemcoff
Beilstein J. Org. Chem. 2010, 6, 1106–1119, doi:10.3762/bjoc.6.127
- photoinitiated metathesis is indirect activation. Grubbs et al. [79] demonstrated the use of photoacid generators (PAG) 34 and 35 (Figure 13) for the sub-300 nm UV activation of metathesis precatalysts 36 and 37 (Scheme 8). Thus, an acid sensitive olefin metathesis catalyst can be photoactivated by using a PAG
- . Ruthenium complexes with p-cymene and NHC ligands. Photoactivated cationic ROMP precatalysts. Different monomers for PROMP. Light-induced cationic catalysts for ROMP. Sulfur chelated ruthenium benzylidene pre-catalysts for olefin metathesis. Photoacid generators for photoinduced metathesis. Encapsulated 39
Graphical Abstract
Scheme 1: Light activated metathesis of trans-2-pentene.
Scheme 2: Light induced generation of metathesis active species 2.
Figure 1: Well-defined tungsten photoactive catalysts.
Figure 2: The first ruthenium based complexes for PROMP.
Figure 3: Cyclic strained alkenes for PROMP.
Scheme 3: Proposed mechanism for photoactivation of sandwich complexes.
Figure 4: Ruthenium and osmium complexes with p-cymene and phosphane ligands for PROMP.
Figure 5: Commercially available photoactive ruthenium precatalyst.
Figure 6: Some of the rings produced by photo-RCM.
Scheme 4: Photopromoted ene-yne RCM by cationic allenylidene ruthenium complex 14.
Figure 7: Dihydrofurans synthesised by photopromoted ene-yne RCM.
Figure 8: Ruthenium complexes with p-cymene and NHC ligands.
Scheme 5: Ruthenium NHC complexes for PROMP containing p-cymene and trifluroacetate (17, 19) or phenylisonitr...
Figure 9: Photoactivated cationic ROMP precatalysts.
Figure 10: Different monomers for PROMP.
Scheme 6: Proposed mechanism for photoinitiated polymerisation by 22 and 23.
Figure 11: Light-induced cationic catalysts for ROMP.
Figure 12: Sulfur chelated ruthenium benzylidene pre-catalysts for olefin metathesis.
Scheme 7: Proposed mechanism for the photoactivation of sulfur-chelated ruthenium benzylidene.
Figure 13: Photoacid generators for photoinduced metathesis.
Scheme 8: Synthesis of precatalysts 36 and 37.
Scheme 9: Trapping of proposed intermediate 41.
Figure 14: Encapsulated 39, isolated from the monomer.
