Halogen-bonding-induced diverse aggregation of 4,5-diiodo-1,2,3-triazolium salts with different anions

• Xingyu Xu,
• Shiqing Huang,
• Zengyu Zhang,
• Lei Cao and
• Xiaoyu Yan

Beilstein J. Org. Chem. 2020, 16, 78–87, doi:10.3762/bjoc.16.10

• ], diiodoacetylene [15] and iodo/bromoethynyl moieties [16] have revealed that the XB-donors interacting with XB-acceptors (a nucleophilic region) are in approximately linear orientation. Besides, linearity, tunability and hydrophobicity (features of the XB ) are widely applied in crystal engineering, supramolecular

The interaction between cucurbit[8]uril and baicalein and the effect on baicalein properties

• Xiaodong Zhang,
• Jun Xie,
• Zhiling Xu,
• Zhu Tao and
• Qianjun Zhang

Beilstein J. Org. Chem. 2020, 16, 71–77, doi:10.3762/bjoc.16.9

• Xiaodong Zhang Jun Xie Zhiling Xu Zhu Tao Qianjun Zhang Key Laboratory of Macrocyclic and Supramolecular Chemistry of Guizhou Province, Guizhou University, Guiyang 550025, China 10.3762/bjoc.16.9 Abstract The host–guest interactions between baicalein (BALE) and cucurbit[8]uril (Q[8]) and the

Photocontrolled DNA minor groove interactions of imidazole/pyrrole polyamides

• Sabrina Müller,
• Jannik Paulus,
• Jochen Mattay,
• Heiko Ihmels,
• Veronica I. Dodero and
• Norbert Sewald

Beilstein J. Org. Chem. 2020, 16, 60–70, doi:10.3762/bjoc.16.8

• -isomer [35]. The photostationary state depends on the nature of the azobenzene, but also on the concentration, as the azobenzene is known to form supramolecular assemblies at high concentration, compromising photoconversion [11][12]. When the concentration of polyamide P1 was reduced to 0.8 mM, 80% of

Influence of the cis/trans configuration on the supramolecular aggregation of aryltriazoles

• Sara Tejera,
• Giada Caniglia,
• Rosa L. Dorta,
• Andrea Favero,
• Javier González-Platas and
• Jesús T. Vázquez

Beilstein J. Org. Chem. 2019, 15, 2881–2888, doi:10.3762/bjoc.15.282

• stabilization of the supramolecular aggregation of bis(4-bromophenyl)triazoles. The trans or cis spatial disposition of the triazole rings is highly important for gelation, with the cis configuration having higher propensity. Keywords: circular dichroism; cis/trans configuration; gels; triazole; X-ray

• diffraction; Introduction Structures self-assembled by noncovalent interactions give rise to supramolecular architectures with specific physical and/or chemical properties. Gels are colloid systems in which the dispersed phase has combined with the dispersion medium to yield a semisolid material. Gels from

• supramolecular studies and report herein the ability of ditriazoles to form gels, their physical properties, as well as the dependence of these properties on the cis/trans relative configuration. Results and Discussion A large set of mono- and ditriazoles was synthesized using cycloaddition reactions based on

Preparation of anthracene-based tetraperimidine hexafluorophosphate and selective recognition of chromium(III) ions

• Qing-Xiang Liu,
• Feng Yang,
• Zhi-Xiang Zhao,
• Shao-Cong Yu and
• Yue Ding

Beilstein J. Org. Chem. 2019, 15, 2847–2855, doi:10.3762/bjoc.15.278

• intermolecular π–π interactions between perimidine moieties (with a face-to-face distance of 3.558(4) Å and a center-to-center distance of 3.566(1) Å), as shown in Supporting Information File 1, Figure S1a. Besides, a 2D supramolecular layer was formed by the 1D supramolecular chains through two types of C–H···F

Photoreversible stretching of a BAPTA chelator marshalling Ca²⁺-binding in aqueous media

• Aurélien Ducrot,
• Arnaud Tron,
• Robin Bofinger,
• Ingrid Sanz Beguer,
• Jean-Luc Pozzo and
• Nathan D. McClenaghan

Beilstein J. Org. Chem. 2019, 15, 2801–2811, doi:10.3762/bjoc.15.273

• , as elucidated by the crystallographic structure of a 1:1 host–guest BAPTA system [2]. This moiety has been exploited in the development of various fluorescent supramolecular chemosensor systems and even molecular logic systems [3][4][5][6][7][8][9][10][11]. Equally, the incorporation of

• state (PSS) for the E→Z photoisomerization at 365 nm was 88:12 in favor of the cis-form (Figure 4). The reversibility of the photoswitching of the supramolecular host was tested over several isomerization cycles with little evidence of fatigue (Figure 5). Thermal isomerization Z→E resulted in the

A chiral self-sorting photoresponsive coordination cage based on overcrowded alkenes

• Constantin Stuckhardt,
• Diederik Roke,
• Wojciech Danowski,
• Edwin Otten,
• Sander J. Wezenberg and
• Ben L. Feringa

Beilstein J. Org. Chem. 2019, 15, 2767–2773, doi:10.3762/bjoc.15.268

• , Germany Leiden Institute of Chemistry, Leiden University, Einsteinweg 55, 2333 CC, Leiden, The Netherlands 10.3762/bjoc.15.268 Abstract In recent years, increasing efforts have been devoted to designing new functional stimuli-responsive supramolecular assemblies. Here, we present three isomeric

• supramolecular coordination complexes consisting of a Pd2L4 stoichiometry. As shown by NMR, CD and X-ray studies, as well as DFT calculations, these complexes form cage-like structures by chiral self-sorting. Photochromic ligands derived from first generation molecular motors enable light-driven interconversion

• between the three isomers. Two of the isomers were able to form host–guest complexes opening up new prospects toward stimuli-controlled substrate binding and release. Keywords: coordination cages; molecular motors; molecular switches; overcrowded alkene; palladium; Introduction Supramolecular

A combinatorial approach to improving the performance of azoarene photoswitches

• Joaquin Calbo,
• Aditya R. Thawani,
• Rosina S. L. Gibson,
• Andrew J. P. White and
• Matthew J. Fuchter

Beilstein J. Org. Chem. 2019, 15, 2753–2764, doi:10.3762/bjoc.15.266

• including imaging applications [20], photopharmacology [21], supramolecular chemistry [22][23], responsive foams [24], coordination chemistry [25] and DNA nanotechnology [26][27]. Whilst the azopyrazoles have excellent properties for use in a variety of photo-addressable applications, it remains frustrating

• -fluoroazopyrazole as part of their study of the supramolecular chemistry of these systems. Irradiating their compound at 365 nm enables near quantitative E→Z conversion, however, the 520 nm PSS provides 55% of the E-isomer. In water, this compound possesses a thermal half-life of >11 days. Herein, we present

Emission solvatochromic, solid-state and aggregation-induced emissive α-pyrones and emission-tuneable 1H-pyridines by Michael addition–cyclocondensation sequences

• Natascha Breuer,
• Irina Gruber,
• Christoph Janiak and
• Thomas J. J. Müller

Beilstein J. Org. Chem. 2019, 15, 2684–2703, doi:10.3762/bjoc.15.262

• ) Å, H···O1 1.87(2) Å, N1···O2 2.624(2) Å, O1–H···O2 140(1)°. Supramolecular C–H···N [36][37][38][39] and C–H···π [40][41][42][43][44][45][46][47][48][49] interactions around the 6-positioned phenyl ring in 5a. Details of C–H···N bond (dashed orange line) C11–H 0.95 Å, H···N2 2.61 Å, C11···N2 3.263(2

Formation of alkyne-bridged ferrocenophanes using ring-closing alkyne metathesis on 1,1’-diacetylenic ferrocenes

• Celine Bittner,
• Dirk Bockfeld and
• Matthias Tamm

Beilstein J. Org. Chem. 2019, 15, 2534–2543, doi:10.3762/bjoc.15.246

• of conjugated diynes (DYCM) is promoted by the benzylidyne tungsten complex II with silanolate ligands (X = OSi(Ot-Bu)3) [21][22]; this catalyst is also active in classical alkyne metathesis [23]. Complex III with chelating phenoxide ligands [24][25][26][27] is mostly applied in supramolecular

• can be found in the literature [54][55][56][57], including the formation of olefinic metallocenophanes via ring-closing olefin metathesis [58][59][60][61], and the preparation of supramolecular structures using template synthesis [62][63][64][65][66][67][68][69]. However, only few cases are

Anion-driven encapsulation of cationic guests inside pyridine[4]arene dimers

• Anniina Kiesilä,
• Jani O. Moilanen,
• Anneli Kruve,
• Christoph A. Schalley,
• Perdita Barran and
• Elina Kalenius

Beilstein J. Org. Chem. 2019, 15, 2486–2492, doi:10.3762/bjoc.15.241

• vital importance to understand the supramolecular chemistry of pyridinearenes. Interestingly, ternary complexes of 12 containing both cation and solvent are not observed in either of the ESI-MS modes, even though in earlier studies such complexes were observed with solvent and anion [11]. This points to

• an endo location of the cation. Ion mobility mass spectrometry (IM-MS) is a powerful tool to study structural features such as the endo/exo complexation of supramolecular complexes [11][15][16][17][18]. Drift tube ion mobility mass spectrometry (DT-IMMS) enables the determination of structure-related

• complementary information, the ternary complex ions [12 + Me4N + 2A]− (A = PF6−, BF4−, I−) were further investigated by infrared multiphoton dissociation (IRMPD). IRMPD is an MS/MS technique, which can be utilized to study the fragmentation of supramolecular complexes [23]. In these experiments, the [12 + Me4N

Self-assembled coordination thioether silver(I) macrocyclic complexes for homogeneous catalysis

• Zhen Cao,
• Aline Lacoudre,
• Cybille Rossy and
• Brigitte Bibal

Beilstein J. Org. Chem. 2019, 15, 2465–2472, doi:10.3762/bjoc.15.239

• -diphenylanthracene [56][57]. The silver(I) coordination on the ligand and the formation of supramolecular systems does not seem to affect the spectroscopic properties of the 9,10-diphenylanthracene system. Silver catalysis As silver(I) salts exhibit a high alkynophilicity [11][12][13][14][15][16][17], the new

Photochromic diarylethene ligands featuring 2-(imidazol-2-yl)pyridine coordination site and their iron(II) complexes

• Andrey G. Lvov,
• Max Mörtel,
• Anton V. Yadykov,
• Frank W. Heinemann,
• Valerii Z. Shirinian and
• Marat M. Khusniyarov

Beilstein J. Org. Chem. 2019, 15, 2428–2437, doi:10.3762/bjoc.15.235

• for realization of light-triggered guest uptake/release [52] and light-controlled interconversion between distinct supramolecular assemblies [53]. Ligand 6 featuring two coordination sites in the heteroaryl moiety and bridge provides unique opportunities to construct novel macrocyclic systems. Our

Reversible switching of arylazopyrazole within a metal–organic cage

• Anton I. Hanopolskyi,
• Soumen De,
• Michał J. Białek,
• Yael Diskin-Posner,
• Liat Avram,
• Moran Feller and
• Rafal Klajn

Beilstein J. Org. Chem. 2019, 15, 2398–2407, doi:10.3762/bjoc.15.232

• photochromism in the spiropyran switch [18]. Other recent studies of photochromic systems within macrocyclic and supramolecular hosts [19] include dihydroazulene switches [20] and red-shifted azobenzenes [21][22] inside cucurbiturils and cyclodextrins. The behavior of light-responsive compounds can also be

Perspective isomorphs – a new classification of molecular structures based on artistic and chemical concepts

• Jannis Neumann,
• Ansgar Schnurr and
• Hermann A. Wegner

Beilstein J. Org. Chem. 2019, 15, 2319–2326, doi:10.3762/bjoc.15.224

• ] between molecules or specific parts within molecules, are highly dependent on the orientation of the interacting entities. In contrast, considerations of space on a supramolecular scale [7][8] or even the integration of an actual human viewer are mostly excluded in models of chemical concepts. The

Small anion-assisted electrochemical potential splitting in a new series of bistriarylamine derivatives: organic mixed valency across a urea bridge and zwitterionization

• Keishiro Tahara,
• Tetsufumi Nakakita,
• Alyona A. Starikova,
• Takashi Ikeda,
• Masaaki Abe and
• Jun-ichi Kikuchi

Beilstein J. Org. Chem. 2019, 15, 2277–2286, doi:10.3762/bjoc.15.220

• used for anion recognition [27][28][29]. In the oxidized state, the enhanced acidity of NH protons can increase the strength of H-bonds and give them more dynamic properties, which can be useful for refined designs of supramolecular systems [30] and proton-coupled electron-transfer systems [31][32][33

• characteristics and fabricating sophisticated molecular devices through supramolecular methods. Experimental Materials and general measurements All solvents and chemicals of reagent grade were used without purification except tetra-n-butylammonium phosphate (n-Bu4NPF6), which was recrystallized from methanol. 4

1,2,3-Triazolium macrocycles in supramolecular chemistry

• Mastaneh Safarnejad Shad,
• Pulikkal Veettil Santhini and
• Wim Dehaen

Beilstein J. Org. Chem. 2019, 15, 2142–2155, doi:10.3762/bjoc.15.211

• macrocycles and focus on their application in different areas of supramolecular chemistry. The synthesis is mostly relying on the well-known “click reaction” (CuAAC) leading to 1,4-disubstituted 1,2,3-triazoles that then can be quaternized. Applications of triazolium macrocycles thus prepared include

• receptors for molecular recognition of anionic species, pH sensors, mechanically interlocked molecules, molecular machines, and molecular reactors. Keywords: anion recognition; catenane; chalcogen bonding; click reaction; molecular reactor; hydrogen bonding; pH sensor; rotaxane; supramolecular; 1,2,3

• -triazolium macrocycles; Review 1. Introduction Supramolecular chemistry – “The chemistry beyond the molecule” [1] – is an ever growing interdisciplinary area has emerged from the early host–guest chemistry to more elaborate bio-inspired supramolecular aggregates by exploiting various noncovalent

Multiple threading of a triple-calix[6]arene host

• Veronica Iuliano,
• Roberta Ciao,
• Emanuele Vignola,
• Carmen Talotta,
• Patrizia Iannece,
• Margherita De Rosa,
• Annunziata Soriente,
• Carmine Gaeta and
• Placido Neri

Beilstein J. Org. Chem. 2019, 15, 2092–2104, doi:10.3762/bjoc.15.207

• Veronica Iuliano Roberta Ciao Emanuele Vignola Carmen Talotta Patrizia Iannece Margherita De Rosa Annunziata Soriente Carmine Gaeta Placido Neri Laboratory of Supramolecular Chemistry, Dipartimento di Chimica e Biologia " A. Zambelli", Università di Salerno, Via Giovanni Paolo II 132, 84084

• stereoselective formation of endo-alkyl pseudo[n]rotaxane stereoisomers. Keywords: calixarene; multiple-threading; pseudo[n]rotaxane; stereoisomers; Introduction The self-assembly [1] of smaller components to larger aggregates represents one of the most spectacular phenomena in supramolecular chemistry [2][3][4

• ]. Among the self-assembly processes, those that lead to the formation of interlocked and/or interpenetrated supramolecular structures have inspired many scientists [5][6][7][8]. The synthesis of interlocked molecules such as rotaxanes, catenanes, and high-order architectures (e.g., polyrotaxanes, suitanes

1,2,3,4-Tetrahydro-1,4,5,8-tetraazaanthracene revisited: properties and structural evidence of aromaticity loss

• Arnault Heynderickx,
• Sébastien Nénon,
• Olivier Siri,
• Vladimir Lokshin and
• Vladimir Khodorkovsky

Beilstein J. Org. Chem. 2019, 15, 2059–2068, doi:10.3762/bjoc.15.203

• moieties allows further modifications at these units to achieve fine-tuning of the light absorption and redox properties. In the course of this study, we also expected that these derivatives could serve as interesting components of supramolecular structures that can assemble in a predictable way owing to

• hydroquinones or chloranilic acid as the H-bond donors (the O–H···N=C H-bonds) are known [15][16], the examples of the N–H···N=C bonds are less numerous and involve mostly aminopyrimidines and imidazoles [13][14]. Derivatives of 3 can be of special interest as flexible supramolecular synthons [14][17] owing to

• , 6a forms a 2D supramolecular network involving the chloride anion Cl1 as an intermolecular connector between the molecules. Each anion interacts with the two N–H protons of the associated dications (Figure 10). In spite of the asymmetrical structure, the X-ray structure of 7a exhibits the same trend

Fluorinated azobenzenes as supramolecular halogen-bonding building blocks

• Esther Nieland,
• Oliver Weingart and
• Bernd M. Schmidt

Beilstein J. Org. Chem. 2019, 15, 2013–2019, doi:10.3762/bjoc.15.197

• , Universitätsstraße 1, D-40225 Düsseldorf, Germany 10.3762/bjoc.15.197 Abstract ortho-Fluoroazobenzenes are a remarkable example of bistable photoswitches, addressable by visible light. Symmetrical, highly fluorinated azobenzenes bearing an iodine substituent in para-position were shown to be suitable supramolecular

• bond donor, R is covalently bound to X, and Y is the Lewis basic halogen bond acceptor [1]. In recent years, halogen bonding was used to assemble molecules, leading to a variety of supramolecular architectures [8][9][10][11][12][13][14][15][16][17][18][19], as well as discrete supermolecules [20][21

• in the field of crystal engineering [1]. Only few supramolecular capsules were reported so far [29], including the resorcin[4]arene capsules of Diederich and co-workers [21][23], triangular macrocycles assembled by self-complemented halogen bonding [20] and halogen bond templated, polyfluorinated

Synthesis and anion binding properties of phthalimide-containing corona[6]arenes

• Meng-Di Gu,
• Yao Lu and
• Mei-Xiang Wang

Beilstein J. Org. Chem. 2019, 15, 1976–1983, doi:10.3762/bjoc.15.193

• [1][2][11][12]. Moreover, the designed macrocycles are useful molecular tools in the investigation of supramolecular catalysis and reaction mechanisms [1][2][13][14][15][16]. Heteracalixaromatics or heteroatom-bridged calix(het)arenes [17][18][19][20][21] are synthetic macrocycles composed of

• heteroatoms and meta-(het)arenes in an alternative manner. Because of the interplay between heteroatoms and aromatic rings, heteracalixaromatics possess versatile molecular recognition properties and have found wide supramolecular applications. Very recently, we have devised coronarenes [22] simply through

• ]tetrazines a useful macrocyclic platform for the study of supramolecular chemistry. Applications of the phthalimide-containing functionalized O6-corona[3]arene[3]tetrazines are being actively perused and results will be reported in due course. Experimental General procedure for the synthesis of 3a–e. To a

Morphology-tunable and pH-responsive supramolecular self-assemblies based on AB₂-type host–guest-conjugated amphiphilic molecules for controlled drug delivery

• Yang Bai,
• Cai-ping Liu,
• Di Chen,
• Long-hai Zhuo,
• Huai-tian Bu and
• Wei Tian

Beilstein J. Org. Chem. 2019, 15, 1925–1932, doi:10.3762/bjoc.15.188

• -responsive supramolecular self-assemblies have been constructed, the controlled drug delivery induced by morphology transitions of these supramolecular self-assemblies on the basis of host–guest-conjugated monomers (HGCMs) are few reported. In this paper, the self-assembly behaviors of AB2-type HGCMs, e.g

• ., β-cyclodextrin-benzimidazole2 (β-CD-BM2), were investigated at neutral and acidic pH conditions, respectively. Specifically, β-CD-BM2 first self-assembled into fan-shaped supramolecular self-assemblies with a hydrodynamic diameter of 163 nm at neutral pH, whereas they were further dissociated into

• spherical supramolecular self-assemblies with a size of 52 nm under acidic conditions. This morphology transition process was utilized to conduct a two-stage DOX delivery under neutral and acidic pH. Basic cell experiments demonstrated that the drug-loaded β-CD-BM2-based supramolecular self-assemblies with

Complexation of chiral amines by resorcin[4]arene sulfonic acids in polar media – circular dichroism and diffusion studies of chirality transfer and solvent dependence

• Bartosz Setner and
• Agnieszka Szumna

Beilstein J. Org. Chem. 2019, 15, 1913–1924, doi:10.3762/bjoc.15.187

• Bartosz Setner Agnieszka Szumna Institute of Organic Chemistry, Polish Academy of Sciences, Kasprzaka 44/52, 01-224 Warsaw, Poland 10.3762/bjoc.15.187 Abstract Directional self‐assembly of conformationally well-defined complexes in polar environment is still a major challenge in supramolecular

• disintegrative for these complexes. This result is quite non-intuitive and worth attention in the context of formation of supramolecular complexes in polar environment, for which DMSO is most often a first-choice solvent. Keywords: cavitands; chirality; macrocycle; resorcin[4]arene; self-assembly

• ; supramolecular chemistry; Introduction Despite of the great progress that has been made in supramolecular chemistry in polar and aqueous media, formation of discrete ordered supramolecular associates with precise patterns of noncovalent interactions still presents a challenge [1][2]. Especially self-assembly

Nanopatterns of arylene–alkynylene squares on graphite: self-sorting and intercalation

• Tristan J. Keller,
• Joshua Bahr,
• Kristin Gratzfeld,
• Nina Schönfelder,
• Marcin A. Majewski,
• Marcin Stępień,
• Sigurd Höger and
• Stefan-S. Jester

Beilstein J. Org. Chem. 2019, 15, 1848–1855, doi:10.3762/bjoc.15.180

• , Uniwersytet Wrocławski, ul. F. Joliot-Curie 14, 50-383 Wrocław, Poland 10.3762/bjoc.15.180 Abstract Supramolecular nanopatterns of arylene–alkynylene squares with side chains of different lengths are investigated by scanning tunneling microscopy at the solid/liquid interface of highly oriented pyrolytic

• other words, either alkyl/alkoxy chains of the same or different length(s) will interdigitate, which corresponds to narcisstic self-sorting or social self-sorting, respectively [26]. Results and Discussion Here, we report on the synthesis and supramolecular nanopatterns of shape-persistent arylene

• compounds 1a/b (see Supporting Information File 1). Details, including the full compound characterization (NMR and MS), are given in Supporting Information File 1. Supramolecular nanopatterns of 1a/b at the solid/liquid interface of HOPG and 1,2,4-trichlorobenzene (TCB) were investigated by scanning

Novel macrocycles – and old ones doing new tricks

• Wei Jiang and
• Christoph A. Schalley

Beilstein J. Org. Chem. 2019, 15, 1838–1839, doi:10.3762/bjoc.15.178

• 10.3762/bjoc.15.178 Keywords: macrocycles; supramolecular chemistry; Macrocycles [1] are the workhorses in supramolecular chemistry. Many basic supramolecular concepts have been developed through studying crown ethers, cryptands, podands and spherands in the 1970s and 1980s. For these contributions

• , macrocycles played a central role for the fundamental science that established supramolecular chemistry as an independent field of chemical research as well as for its applications in contemporary research on functional supramolecules and materials. Nowadays, the use of macrocycles has significantly

• diversified. They are not only tools for studying molecular recognition and molecular machines, but are also key components for sensing, supramolecular catalysis, (chiral) separation, drug delivery, or smart materials. Many new macrocycles have recently been reported, with pillararenes being one of the most