Art, auto-mechanics, and supramolecular chemistry. A merging of hobbies and career

• Eric V. Anslyn

Beilstein J. Org. Chem. 2016, 12, 362–376, doi:10.3762/bjoc.12.40

• the creation of synthetic receptors and self-assembly. For synthetic ease, the receptors and assemblies routinely possess a high degree of symmetry, which lends them an aspect of aesthetic beauty. Pictures of electron orbitals similarly can be seen as akin to works of art. This similarity was an early

My maize and blue brick road to physical organic chemistry in materials

• Anne J. McNeil

Beilstein J. Org. Chem. 2016, 12, 229–238, doi:10.3762/bjoc.12.24

• perspective concludes with some predictions about where molecular gels, as well as my personal and professional life, are headed. Keywords: molecular gel; organic chemistry; organic materials; self-assembly; supramolecular chemistry; Review One of my earliest memories involves pouring water down our

• providing a portable and potentially inexpensive method for sensing. Considering how naïve my understanding of gelation was at the time, I am still surprised that my proposal idea worked almost exactly as described. Molecular gels form through the self-assembly of small molecules into supramolecular

• triggers gel formation? One of my first graduate students, Jing Chen, evaluated the use of an oxidation reaction to convert a nonplanar molecule into a planar one [25]. We hypothesized that this conformational change, combined with an increase in conjugation length, would facilitate self-assembly and

A journey in bioinspired supramolecular chemistry: from molecular tweezers to small molecules that target myotonic dystrophy

• Steven C. Zimmerman

Beilstein J. Org. Chem. 2016, 12, 125–138, doi:10.3762/bjoc.12.14

• reports on molecular-recognition-driven self-assembly. The grand challenge was to design small subunits that would spontaneously form complex structures noncovalently, ultimately with some particular function. So we began in earnest to develop such systems, focusing primarily on hydrogen bonding. This

• ], revealed clear opportunities for a rational design approach. The stem-loop structure adopts an overall A-form structure but with little distortion in the backbone that would allow the U–U mismatches to form hydrogen bonds. Our early experience with Janus bases in self-assembly [61][63][77] suggested the

Supramolecular structures based on regioisomers of cinnamyl-α-cyclodextrins – new media for capillary separation techniques

• Gabor Benkovics,
• Ondrej Hodek,
• Martina Havlikova,
• Zuzana Bosakova,
• Pavel Coufal,
• Milo Malanga,
• Eva Fenyvesi,
• Andras Darcsi,
• Szabolcs Beni and
• Jindrich Jindrich

Beilstein J. Org. Chem. 2016, 12, 97–109, doi:10.3762/bjoc.12.11

• held together by non-covalent interactions, such as electrostatic interactions, coordination bonds, hydrogen bonds, hydrophobic interactions and host–guest interactions [1]. Their formation is spontaneous and reversible by self-assembly of the monomer units. Because of this special non-covalent

Aggregation behavior of amphiphilic cyclodextrins in a nonpolar solvent: evidence of large-scale structures by atomistic molecular dynamics simulations and solution studies

• Giuseppina Raffaini,
• Fabio Ganazzoli and
• Antonino Mazzaglia

Beilstein J. Org. Chem. 2016, 12, 73–80, doi:10.3762/bjoc.12.8

• nanoaggregates even in apolar solvents. Keywords: aggregation; amphiphilic cyclodextrins; molecular dynamics; nanoparticles; self-assembly; simulations; Introduction Amphiphilic cyclodextrins (aCD) are a class of molecules highly investigated for their self-assembly properties and inherent potential

Recent advances in metathesis-derived polymers containing transition metals in the side chain

• Ileana Dragutan,
• Valerian Dragutan,
• Bogdan C. Simionescu,
• Albert Demonceau and
• Helmut Fischer

Beilstein J. Org. Chem. 2015, 11, 2747–2762, doi:10.3762/bjoc.11.296

• = BPh4 or Cl). Self-assembly of these block copolymers into core–shell spherical micelles was successfully conducted and, by UV/ozonolysis or thermal pyrolysis generating antiferromagnetic CoO species, some of these micelles could be converted into inorganic nanoparticles. With the aim at extending the

• recent study, Tang and coworkers [52] performed a quantitative analysis of counterion exchange in cobaltocene-containing polyelectrolytes that are accessible by an initial ROMP, and subsequently derivatized with cobalt motifs. These results appear to be relevant for self-assembly and drug-delivery

• the self-assembly of transition metal-containing polymers, Sleiman et al. [60] expanded the field by preparing ROMP-able oxanorbornene monomers having iridium and osmium bipyridines attached by an extended organic linker (Scheme 14). The triblock copolymers obtained through a sequential ROMP of the

Learning from the unexpected in life and DNA self-assembly

• Jennifer M. Heemstra

Beilstein J. Org. Chem. 2015, 11, 2713–2720, doi:10.3762/bjoc.11.292

• self-assembly; nucleic acids; Introduction “Jennifer is not skilled at science.” This judgment was delivered upon me at the age of fourteen by my eighth grade science teacher, and was part of a recommendation that I not be placed on the science-intensive track of study as I entered high school. The

• research choices throughout my career. Much like a negative judgment about my aptitude for science unexpectedly led me to a career in chemistry, my lab has found that our greatest insights into the molecular recognition and self-assembly properties of DNA have come from unexpected results or failed

• my Ph.D. studies, I had tremendous fun designing and studying organic foldamers, but I also began to be attracted to the especially privileged molecular recognition and self-assembly properties of nucleic acids. I think that Jeff actually recognized this before I did, as he chose the additional

Rhodium, iridium and nickel complexes with a 1,3,5-triphenylbenzene tris-MIC ligand. Study of the electronic properties and catalytic activities

• Carmen Mejuto,
• Beatriz Royo,
• Gregorio Guisado-Barrios and
• Eduardo Peris

Beilstein J. Org. Chem. 2015, 11, 2584–2590, doi:10.3762/bjoc.11.278

• interested in the design of several types of C3v-symmetric tris-NHCs, both for the preparation of self-assembly molecular cages [12][13][27] and for the design of discrete trimetallic molecules whose catalytic performances were explored [23][25][28][29]. Among these ligands, we found those featuring a

Smart molecules for imaging, sensing and health (SMITH)

• Bradley D. Smith

Beilstein J. Org. Chem. 2015, 11, 2540–2548, doi:10.3762/bjoc.11.274

• a remarkable self-assembly process that we call Synthavidin (synthetic avidin). A simple example is illustrated in Scheme 5 [44]. A water soluble tetralactam macrocycle with anthracene sidewalls is threaded by squaraine dyes that are flanked by long PEG chains to give highly stable complexes with

• and there is coplanar stacking of the squaraine aromatic surfaces with the anthracene sidewalls of the macrocycle. We are beginning to use Synthavidin technology as a self-assembly platform to rapidly fabricate libraries of targeted multivalent probes for fluorescence imaging of over-expressed

• and self-assembly processes that are crucial for cell growth and signaling. These precisely controlled association systems have been refined over billions of years of evolution. The selective recognition is driven by protein–protein interactions that operate at an interface with a surface area that is

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

• correlating their structures with the pharmaceutical properties. Keywords: aggregation; amphiphilic cyclodextrins; micelles; molecular dynamics simulations; nanoparticles; self-assembly; Introduction Inclusion complexes with supramolecular structures formed by native or modified cyclodextrins (CDs) are

• recognize cells by exposing receptor-targeting groups on the surface of the nanoassembly [30]. Because of these promising results, we have begun to investigate the aggregation behaviour of an aCD model compound by atomistic computer simulation to clarify the early stages of self-assembly, in particular the

• portion of a whole vesicle [37]. Otherwise, coarse-grained Monte Carlo simulations in two dimensions modelled the self-assembly of aCD [38]. It should be underlined, however, that in the atomistic simulations a manually pre-assembled system was generally assumed, while the spontaneous formation of

Size-controlled and redox-responsive supramolecular nanoparticles

• Raquel Mejia-Ariza,
• Gavin A. Kronig and
• Jurriaan Huskens

Beilstein J. Org. Chem. 2015, 11, 2388–2399, doi:10.3762/bjoc.11.260

• core of the SNPs. Keywords: host–guest interactions; nanoparticles; self-assembly; stimulus-responsive; supramolecular chemistry; Introduction Self-assembly and molecular recognition are two core concepts underlying supramolecular chemistry. These offer convenient and versatile pathways to

• between the multivalent guest-functionalized dendrimers and host-functionalized polymers. At higher ionic strengths, the increased charge screening led to a loss of electrostatic repulsion and therefore to larger aggregates. Optimal self-assembly of the multivalent components was observed at a 1:1

• from Ad8-PAMAM) and [Ad] = 62.5 µM (from Ad-PEG) (control) in 0.2 M NaCl. 10 equiv of Ce4+relative to Fc was added to the SNPs. Experimental d measurements (markers) and trendlines (line, guide to the eye). a) Schematic representation of the supramolecular nanoparticle (SNP) self-assembly and redox

Preparation of Pickering emulsions through interfacial adsorption by soft cyclodextrin nanogels

• Shintaro Kawano,
• Toshiyuki Kida,
• Mitsuru Akashi,
• Hirofumi Sato,
• Motohiro Shizuma and
• Daisuke Ono

Beilstein J. Org. Chem. 2015, 11, 2355–2364, doi:10.3762/bjoc.11.257

• particle size of the primary CD nanogel and the appearance of a new peak at a larger diameter (120 nm) may be due to the self-assembly of the primary CD nanogels at 0.1 wt % concentration in water. The scanning electron microscopy (SEM) measurement was carried out in order to observe the self-assembled

Life lessons

• Jonathan R. Nitschke

Beilstein J. Org. Chem. 2015, 11, 2350–2354, doi:10.3762/bjoc.11.256

• Learner Keywords: autobiography; host–guest; self-assembly; supramolecular; Review I was raised in Syracuse, New York (USA), and went to a series of state schools of varying quality. Only the faces of the bad teachers stick with me, but I remember the names, too, of a few of the good ones – Karen Curry

• kindness for which I remain grateful – and the next proposal I wrote obtained modest funding. This proposal, and the research programme that followed, involved the use of old chemistry – Daryle Busch’s metal-templated imine-bond forming reaction [6] – in new ways. We called it subcomponent self-assembly to

• . Ultimate success in attracting funding from the European Research Council (ERC) and EPSRC was the sweeter for the many failures that had preceded it. It has also been a delight to see others making use of subcomponent self-assembly to solve new puzzles, citing our development of the technique [12][13][14

Urethane tetrathiafulvalene derivatives: synthesis, self-assembly and electrochemical properties

• Xiang Sun,
• Guoqiao Lai,
• Zhifang Li,
• Yuwen Ma,
• Xiao Yuan,
• Yongjia Shen and
• Chengyun Wang

Beilstein J. Org. Chem. 2015, 11, 2343–2349, doi:10.3762/bjoc.11.255

• Technology of Ministry of Education, Hangzhou Normal University, Hangzhou 310012, China 10.3762/bjoc.11.255 Abstract This paper reports the self-assembly of two new tetrathiafulvalene (TTF) derivatives that contain one or two urethane groups. The formation of nanoribbons was evidenced by scanning electron

• microscopy (SEM) and X-ray diffraction (XRD), which showed that the self-assembly ability of T1 was better than that of T2. The results revealed that more urethane groups in a molecule did not necessarily instigate self-assembly. UV–vis and FTIR spectra were measured to explore noncovalent interactions. The

• driving forces for self-assembly of TTF derivatives were mainly hydrogen bond interactions and π–π stacking interactions. The electronic conductivity of the T1 and T2 films was tested by a four-probe method. Keywords: hydrogen bond; nanoribbon; self-assembly; tetrathiafulvalene; urethane; Introduction

Self-assemblies of γ-CDs with pentablock copolymers PMA-PPO-PEO-PPO-PMA and endcapping via atom transfer radical polymerization of 2-methacryloyloxyethyl phosphorylcholine

• Jing Lin,
• Tao Kong,
• Lin Ye,
• Ai-ying Zhang and
• Zeng-guo Feng

Beilstein J. Org. Chem. 2015, 11, 2267–2277, doi:10.3762/bjoc.11.247

• pentablock copolymer chain to generate single-chain-stranded loose-fit PPRs and showed no characteristic channel-like crystal structure. All the self-assembly processes of the pentablock copolymers resulted in the formation of hydrogels. After endcapping via in situ ATRP of 2-methacryloyloxyethyl

• character and deformable cavity size allow for the self-assembly or inclusion of various polymer chains to generate poly(pseudorotaxanes) (PPRs) or polyrotaxanes (PRs) after endcapping with bulky stoppers. Since Harada et al. first reported the α-CD-based single-chain-stranded PPRs constructed from the

• more flexible main chain and smaller cross-sectional area as compared with PHEMA. Attaching PMA to two ends of PPO-PEO-PPO imparts the resulting amphiphilic copolymers with a unique core–shell micellar structure, showing different self-assembly behavior as compared with that of PHEMA-PPO-PEO-PPO-PHEMA

Supramolecular chemistry: from aromatic foldamers to solution-phase supramolecular organic frameworks

• Zhan-Ting Li

Beilstein J. Org. Chem. 2015, 11, 2057–2071, doi:10.3762/bjoc.11.222

• : applications for molecular recognition and self-assembly Donor–acceptor interaction and π-stacking for folding. In January 2001, I returned to SIOC again. When I left SIOC for Urbana in 2000, I had built a small research group with two graduates. Thanks to the persistence of Professor Xi-Kui Jiang [19][20

• be induced by discrete noncovalent forces. In 2014, Jia Tian further extended the concept of solution-phase SOF to 3D space from the self-assembly of tetrahedral 34 and CB[8] [86] (Scheme 18). The 1:2 mixture in water generated a 3D, homogeneous SOF of diamond topology. The pores of the 3D SOF could

Synthesis, antimicrobial and cytotoxicity evaluation of new cholesterol congeners

• Mohamed Ramadan El Sayed Aly,
• Hosam Ali Saad and
• Shams Hashim Abdel-Hafez

Beilstein J. Org. Chem. 2015, 11, 1922–1932, doi:10.3762/bjoc.11.208

• their immunostimulant activities [21]. Finally, the ability of cholesterol derivatives to self-assembly and gelation as supramolecular gels was reviewed [22]. They are beneficially applicable in materials science, reaction media, sensing and responsive materials, energy supply, biomedicine, and tissue

Asymmetric 1,4-bis(ethynyl)bicyclo[2.2.2]octane rotators via monocarbinol functionalization. Ready access to polyrotors

• Cyprien Lemouchi and
• Patrick Batail

Beilstein J. Org. Chem. 2015, 11, 1881–1885, doi:10.3762/bjoc.11.202

• )bicyclo[2.2.2]octane rotators. The good yields allow the large amounts required for self-assembly and subsequent investigations of the dynamics of the rotors in the solid state to be readily prepare. The chemistry, physical chemistry and materials chemistry and physics of asymmetric rotors and their

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

• , and particles, amphiphilic TTFs having a rigid core and long alkyl chains are one of the best molecular systems. The self-assembly of TTF derivatives in solid and on surface gives rise to a long-distance dynamic ordering as compared with single crystals. Among the recent researches on TTF and its

• conducting liquid. Radially expanded TTF oligomers with a large central π-surface can be expected to show effective intra- and intermolecular delocalization of electrons in the neutral and mixed-valence states. Furthermore, the supramolecular self-assembly of these large molecules having nanophase separation

• derived from the self-assembly of TTF-appended dipeptides were reported [77]. Conductivity measurements performed on the nanofibers of TTF-appended dipeptides indicate a remarkable enhancement in the conductivity after doping with TCNQ (σrt = 1 × 10−5 S cm−1). Conducting nanostructures prepared from

Tetrathiafulvalene-based azine ligands for anion and metal cation coordination

• Awatef Ayadi,
• Aziz El Alamy,
• Olivier Alévêque,
• Magali Allain,
• Nabil Zouari,
• Mohammed Bouachrine and
• Abdelkrim El-Ghayoury

Beilstein J. Org. Chem. 2015, 11, 1379–1391, doi:10.3762/bjoc.11.149

• dinitrophenyl ring coplanar with the hydrazone unit and also by an intramolecular short contact S4···N1 (2.824(6) Å) that makes the TTF unit and the pyridine ring coplanar. In the solid state, the packing arrangement in L1 is characterized by the self-assembly between the TTF donor unit and the dinitrophenyl

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

• able to act as hydrogelators [4]. Besides the properties of self-assembly, these conjugates are cell compatible [3][4]. Moreover, the NAS conjugates promote the proliferation of mES cells [5] and deliver the oligonucleotide into living cells [6]. Particularly, the incorporation of the functional

• chromatography (HPLC) to purify the target conjugates. Gelation properties Supramolecular hydrogels [18][19][20][21][22][23][24] formed by self-assembly of small molecules in water, as demonstrated previously by us and other researchers, have numerous potential applications, such as encapsulation and delivery of

• conditions used for 5 + 8. These results illustrate that the subtle change in the molecular structures of the conjugates is able to cause drastically different behaviour of self-assembly [37][38]. We also investigated the rheological properties of the three mixtures, 1 + 8, 5 + 8, and 7 + 8 in PBS buffer. As

Synthesis of photoresponsive cholesterol-based azobenzene organogels: dependence on different spacer lengths

• Yuchun Ren,
• Bin Wang and
• Xiuqing Zhang

Beilstein J. Org. Chem. 2015, 11, 1089–1095, doi:10.3762/bjoc.11.122

• ; organogel; photoresponsive; Introduction In the past few decades, low molecular mass organic gelators (LMOGs) have attracted increasing attention not only for basic self-assembly behavior but also for their potential application in areas such as templates [1], light harvesting [2], fluorescent scensing [3

• shifted to 2933 and 2859 cm−1. The above mentioned FTIR spectral changes demonstrated sufficiently that van der Waals interaction between the alkyl chains plays an important role in the self-assembly process of organogels. The XRD studies To reveal the detailed changes in gel molecular of M6, XRD analyses

• another two solvents, corresponding to d values of 5.10 and 3.50 nm, respectively. The different self-assembly modes of gelator in various solvents cause the values changing. The XRD results described above also demonstrated that the molecular interaction and the solvents had a significant impact on the

Glycoluril–tetrathiafulvalene molecular clips: on the influence of electronic and spatial properties for binding neutral accepting guests

• Yoann Cotelle,
• Marie Hardouin-Lerouge,
• Stéphanie Legoupy,
• Olivier Alévêque,
• Eric Levillain and
• Piétrick Hudhomme

Beilstein J. Org. Chem. 2015, 11, 1023–1036, doi:10.3762/bjoc.11.115

• clip with two radical cations stack with and/or without self-assembly affording mixed-valence or π-dimer interactions. At higher potential, the tetracation is provided by another one-electron process on each TTF unit leading to a clip bearing two dications. The graphical representation can be simulated

• ]+ mixed-valence dimer [47][48] and the absorption bands centered around 600 nm to the (TTF˙+)2 π-dimer [49]. The band close to 825 nm could be assigned to cation radicals stack with self-assembly affording mixed-valence. Nevertheless, at this stage, it would be premature to conclude with certainty. The

• bulky groups at the periphery of the TTF moieties does not provide an advantage for the self-assembly of dimers. Moreover, this dimerization phenomenon which is driven by the inclusion of one sidewall into the cavity of the opposing clip is not observed in the solid state for clips 2 and 3 (Figure 8

Tuning the size of a redox-active tetrathiafulvalene-based self-assembled ring

• Sébastien Bivaud,
• Sébastien Goeb,
• Vincent Croué,
• Magali Allain,
• Flavia Pop and
• Marc Sallé

Beilstein J. Org. Chem. 2015, 11, 966–971, doi:10.3762/bjoc.11.108

• allows for modulating the size and the shape of the resulting discrete self-assembly, which therefore incorporate two (M4L2) or three (M6L3) electroactive exTTF sidewalls. Keywords: coordination; metal-driven; redox; self-assembly; tetrathiafulvalene; Findings The coordination-driven approach is a well

• modulating the bulkiness of the ancillary group on the metal complex precursor. The tetrapyridyl-exTTF ligand L1 (Scheme 1, Figure 1a) was synthesized through a palladium catalysed C–H arylation from the naked exTTF [39]. We already reported that the self-assembly process of this tetratopic ligand with cis-M

• acetonitrile containing 0.1 M NBu4PF6 (Figure 5). Compared to ligand L1 which presents the usual electrochemical behavior of exTTF derivatives, i.e. one poorly electrochemically reversible two-electrons oxidation process, the oxidation of exTTF in self-assembly M6L3 is shifted to higher potential (+0.26 V

Is organic chemistry science – and does this question make any sense at all?

• Andreas Kirschning and
• Thomas A. C. Reydon

Beilstein J. Org. Chem. 2015, 11, 893–896, doi:10.3762/bjoc.11.100

• conditions (molecular recognition, self-assembly and dynamic combinatorial chemistry) and how their molecular composition would be; the question why nature developed DNA and RNA that utilize ribose and 2-deoxyribose as central nucleotide building blocks instead of the more abundant and readily available