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

• 294 nm and 315 nm (aggregated solid state). This was also observed for T2, which illustrated that π–π interactions and H-aggregation occurred with the increase in concentration [22][23][24]. To further study the driving forces for the self-assembly of T1 and T2, FTIR spectra were also measured (Figure

• C=O stretching vibration (around 1720 cm−1) suggested that strong hydrogen bonds between urethane groups were formed [25][26]. These results indicated that π–π interactions and hydrogen bonding were the main driving forces behind the self-assembly. In addition, UV−vis and FTIR spectra were measured

The simple production of nonsymmetric quaterpyridines through Kröhnke pyridine synthesis

• Isabelle Sasaki,
• Jean-Claude Daran and
• Gérard Commenges

Beilstein J. Org. Chem. 2015, 11, 1781–1785, doi:10.3762/bjoc.11.193

• -chair conformation. The packing is stabilised by van der Waals contacts and weak π–π interactions between symmetry related N2-C21-C22-C23-C24-C25 and N4-C41-C42-C43-C44-C45 pyridine rings (1+x, y, z) with a centroid-to-centroid distance of 3.761(2) Å, and an average interatomic distance between planes

Polythiophene and oligothiophene systems modified by TTF electroactive units for organic electronics

• Alexander L. Kanibolotsky,
• Neil J. Findlay and
• Peter J. Skabara

Beilstein J. Org. Chem. 2015, 11, 1749–1766, doi:10.3762/bjoc.11.191

• , with the optical band gap being in the range of 1.7–1.9 eV. When comparing the spectra in CH2Cl2 solutions to those of the solid film, the red shift in absorption is due to the emergence of π–π interactions in the solid state. Compared to the aforementioned polymers, poly(thienylenevinylene) (PTV) 39

Are D-manno-configured Amadori products ligands of the bacterial lectin FimH?

• Tobias-Elias Gloe,
• Insa Stamer,
• Cornelia Hojnik,
• Tanja M. Wrodnigg and
• Thisbe K. Lindhorst

Beilstein J. Org. Chem. 2015, 11, 1096–1104, doi:10.3762/bjoc.11.123

• (1). A somewhat weaker complexation is predicted for 9 and 10 than for 1. We had expected 10 to score clearly better than 9, owing to the possibility of π–π interactions between the phenyl substituent in 10 and the tyrosine gate at the entrance of the FimH CRD. However, this seems not to be the case

• Amadori products are tilted in comparison to MeMan and somewhat lifted from the binding site (Figure 3B and C). When the respective anomeric centres are taken as a reference, 9 is lifted by 0.5 Å and 10 by 0.7 Å in comparison with complexed MeMan. The tilting effect apparently also prevents effective π–π

• interactions between the FimH tyrosine gate and Amadori product 10. The effect of tilting of Amadori products 9 and 10 upon FimH complexation can also be analyzed by comparison of hydrogen bonding in the complex. Close inspection of the H-bond network reveals that the average length of H-bonds established with

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

• recognition of aromatic guest molecules through π–π interactions [16][17]. We recently described various glycoluril-based molecular clips 1–4 [18][19] (Figure 1) for which the structure varies by: i) the nature of connection between the glycoluril spacer and the TTF sidewalls, ii) the nature of the peripheral

Copper ion salts of arylthiotetrathiafulvalenes: synthesis, structure diversity and magnetic properties

• Longfei Ma,
• Jibin Sun,
• Xiaofeng Lu,
• Shangxi Zhang,
• Hui Qi,
• Lei Liu,
• Yongliang Shao and
• Xiangfeng Shao

Beilstein J. Org. Chem. 2015, 11, 850–859, doi:10.3762/bjoc.11.95

• discussed in the crystal structure section. On the other hand, the antiferromagnetic interaction of radical cations in 7·CuBr2 could be due to the π–π interactions, because the neighbouring donor molecules have a S···S contact (3.30 Å) along the a-axis. Figure 6a shows the magnetic susceptibility of 1·CuBr4

Mechanical stability of bivalent transition metal complexes analyzed by single-molecule force spectroscopy

• Manuel Gensler,
• Christian Eidamshaus,
• Maurice Taszarek,
• Hans-Ulrich Reissig and
• Jürgen P. Rabe

Beilstein J. Org. Chem. 2015, 11, 817–827, doi:10.3762/bjoc.11.91

• UPy dimers (DDAA–AADD pairs) in hexadecane. The UPy dimers exhibit shorter rupture lengths of 0.20 nm compared to 0.29 nm, resulting in much higher rupture forces from 150 to 250 pN compared to 50–100 pN for UAT dimers. Another model system probing π–π-interactions associated with van-der-Waals forces

Trifluoromethyl-substituted tetrathiafulvalenes

• Olivier Jeannin,
• Frédéric Barrière and
• Marc Fourmigué

Beilstein J. Org. Chem. 2015, 11, 647–658, doi:10.3762/bjoc.11.73

• comparison, in the neutral donor molecule 1c, the folding angles amount to 20.59(5) and 19.00(5)° respectively [31]. Such π–π interactions have been shown to derive from quadrupolar interactions between the π systems of both donor and acceptor moieties [47], and their geometrical characteristics to favor the

Highly selective generation of vanillin by anodic degradation of lignin: a combined approach of electrochemistry and product isolation by adsorption

• Dominik Schmitt,
• Carolin Regenbrecht,
• Marius Hartmer,
• Florian Stecker and
• Siegfried R. Waldvogel

Beilstein J. Org. Chem. 2015, 11, 473–480, doi:10.3762/bjoc.11.53

• polymeric backbone has a very important influence on the adsorption behavior (Figure 7). The polystyrene backbones appear to be especially well suited for the adsorption of 1 from alkaline solutions. This can be explained by attractive π–π interactions between the backbone and the adsorptive phase. All

Molecular ordering at electrified interfaces: Template and potential effects

• Thanh Hai Phan and
• Klaus Wandelt

Beilstein J. Org. Chem. 2014, 10, 2243–2254, doi:10.3762/bjoc.10.233

• and the benzyl groups. In addition π–π-interactions between all π-systems of adjacent molecules will play a role with the stipulation that the benzyl groups take up a trans-conformation [6] as shown in Figure 2 and Figure 8b and in the structural models in Figure 11. In particular, the π–π

• interactions between neighboring monocation radicals are important which, by spin-pairing, are known to lead to the formation of dimers in solution [5]. The adsorbate–substrate interactions are obviously dominated by electrostatic interactions between the doubly (DBV2+) or singly (DBV+•) charged bipyridinium

Scalable synthesis of 5,11-diethynylated indeno[1,2-b]fluorene-6,12-diones and exploration of their solid state packing

• Bradley D. Rose,
• Peter J. Santa Maria,
• Aaron G. Fix,
• Chris L. Vonnegut,
• Lev N. Zakharov,
• Sean R. Parkin and
• Michael M. Haley

Beilstein J. Org. Chem. 2014, 10, 2122–2130, doi:10.3762/bjoc.10.219

• )°, giving a variant of the common herringbone motif, despite the lack of a crystallographic glide plane. In addition to the IF-dione π-stacking, inversion-related phenyl groups on the solubilizing groups are paired by π–π interactions. The stacking in compounds 8c and 8d (Si(n-Pr)3 and Si(iPr)3, vol. ~278

Chiral phosphines in nucleophilic organocatalysis

• Yumei Xiao,
• Zhanhu Sun,
• Hongchao Guo and
• Ohyun Kwon

Beilstein J. Org. Chem. 2014, 10, 2089–2121, doi:10.3762/bjoc.10.218

• polyfunctionalized spirocyclopenteneoxindoles in good yields (63–85%) and with excellent enantioselectivities (91–99% ee). In contrast, the ee was fairly low (46%) when using a methyl-substituted MHB carbonate at the allylic site. It was rationalized that the aromatic π–π interactions between the catalyst and the

Expeditive synthesis of trithiotriazine-cored glycoclusters and inhibition of Pseudomonas aeruginosa biofilm formation

• Meriem Smadhi,
• Sophie de Bentzmann,
• Anne Imberty,
• Marc Gingras,
• Raoudha Abderrahim and
• Peter G. Goekjian

Beilstein J. Org. Chem. 2014, 10, 1981–1990, doi:10.3762/bjoc.10.206

• modifying π–π-interactions and by favoring hydrogen-bonding to water. These compounds also lack the hydrophobic peripheral benzene units of the previous glycoasterisk ligands. They were replaced with a methylene-triazole linker in order to increase water solubility and to modulate the degree of flexibility

Supercritical carbon dioxide: a solvent like no other

• Jocelyn Peach and
• Julian Eastoe

Beilstein J. Org. Chem. 2014, 10, 1878–1895, doi:10.3762/bjoc.10.196

• intermolecular π–π interactions. Highly ordered macroscale structures were formed through surfactant self-assembly with the addition of the hydrotropic salt benzylamine hydrochloride (BnNH2∙HCl) to a sodium sulfonate surfactant (sodium dodecylbenzene sulfonate, SDBS) [109]. With hydrotrope addition, self

• dimensional fibre growth is attributed to directional forces arising from π–π interactions between the phenyl groups present in both the surfactant and the hydrotrope. Conclusions – viscosity enhancers in dense CO2 There is a range of approaches to help develop viscosity in scCO2, most of which surround the

• phenomena [32][41]. The addition of low molecular weight polymers has shown some promise, with viscosity increases being observed in polymer containing CO2 in comparison to pure CO2, which are attributed to strong intermolecular forces arising from π–π interactions of phenyl groups in the polymeric

Aryl substitution of pentacenes

• Andreas R. Waterloo,
• Anna-Chiara Sale,
• Dan Lehnherr,
• Frank Hampel and
• Rik R. Tykwinski

Beilstein J. Org. Chem. 2014, 10, 1692–1705, doi:10.3762/bjoc.10.178

• stability, processability, and semiconductor device performance. Intermolecular π–π-interactions between chromophores can be dramatically improved upon functionalization at the 6- and 13-positions of pentacene, as demonstrated by the two-dimensional (2D) bricklayer-packing motif for TIPSPc [13][14]. A

Columnar/herringbone dual crystal packing of pyrenylsumanene and its photophysical properties

• Binod Babu Shrestha,
• Shuhei Higashibayashi and
• Hidehiro Sakurai

Beilstein J. Org. Chem. 2014, 10, 841–847, doi:10.3762/bjoc.10.80

• molecules are stacked in a convex-to-concave fashion, since this particular pattern results in more highly favored intermolecular π–π interactions [1][2][3][4][5][6][7][8][9][10][11][12][13]. The columnar packing structures of buckybowls typically occur in two forms which are differentiated by the stacking

• –π interaction is 3.0 Å which is sufficiently close to form an excimer (Figure 2f). The angle of the pyrene moieties resulting from the CH–π interaction is approximately 40° (Figure 2f), which enables the partial π–π interactions. Judging from the crystal features of 1, the red-shifted emission of 1

• columnar structure of buckybowl crystals resulting from convex–concave intermolecular π–π interactions is expected to be quite predictable and to serve as a directing force to provide specific crystal structures [16][17]. The present study demonstrates the promising possibility of utilizing the sumanene

Triphenylene discotic liquid crystal trimers synthesized by Co₂(CO)₈-catalyzed terminal alkyne [2 + 2 + 2] cycloaddition

• Bin Han,
• Ping Hu,
• Bi-Qin Wang,
• Carl Redshaw and
• Ke-Qing Zhao

Beilstein J. Org. Chem. 2013, 9, 2852–2861, doi:10.3762/bjoc.9.321

• 3.57Å than that of 5b and 5c, due to the stronger π–π interactions between the triphenylene discogens with mono-ester group. The columnar parameter values of the trimers decreased with the spacer length shortened. So we deduced that the benzene cores were among the alkyl chains in the columnar stacking

Structure of 1,5-benzodiazepinones in the solid state and in solution: Effect of the fluorination in the six-membered ring

• Marta Pérez-Torralba,
• Rosa M. Claramunt,
• M. Ángeles García,
• Concepción López,
• M. Carmen Torralba,
• M. Rosario Torres,
• Ibon Alkorta and
• José Elguero

Beilstein J. Org. Chem. 2013, 9, 2156–2167, doi:10.3762/bjoc.9.253

• % probability) of 1, showing the X-ray labeling of the asymmetric unit. View of the zigzag chain formed in 1, showing the H-bond and F–F interactions. ORTEP plot (20% probability) of 2, showing the X-ray labeling of the asymmetric unit. Packing of 2 showing the F–F contacts along the chain (orange) and the π–π

• interactions that form the double chain (violet). The different tautomers in the 1H and 1-methyl series. 2-Methoxy-4-methyl-3H-1,5-benzodiazepine (7). 1H–19F coupling constant values either through-bond or through-space. The optimized geometry of the TS of 2a inversion. Equations used to transform absolute

Synthesis and testing of the first azobenzene mannobioside as photoswitchable ligand for the bacterial lectin FimH

• Vijayanand Chandrasekaran,
• Katharina Kolbe,
• Femke Beiroth and
• Thisbe K. Lindhorst

Beilstein J. Org. Chem. 2013, 9, 223–233, doi:10.3762/bjoc.9.26

• the CRD of the lectin, as expected, and furthermore, that in both cases the azobenzene moiety exerts effective interactions with the tyrosine gate involving both benzene rings. Regardless of whether the (E)- or the (Z)-form of 2 is complexed with FimH, favourable π–π interactions can be formed between

Synthesis of 5-(ethylsulfonyl)-2-methoxyaniline: An important pharmacological fragment of VEGFR2 and other inhibitors

• Miroslav Murár,
• Gabriela Addová and
• Andrej Boháč

Beilstein J. Org. Chem. 2013, 9, 173–179, doi:10.3762/bjoc.9.20

• ; S, 14.77%. The AAZ ligand conformer from PDB complex 1Y6A and its VEGFR2 intermolecular interaction map depicting three hydrogen bonds and two stacked (π,π) interactions. No lipophilic interactions are shown here. The part of the skeleton AAZ in bold represents the fragment originating from the

Organocatalytic asymmetric addition of malonates to unsaturated 1,4-diketones

• Sergei Žari,
• Tiiu Kailas,
• Marina Kudrjashova,
• Mario Öeren,
• Ivar Järving,
• Toomas Tamm,
• Margus Lopp and
• Tõnis Kanger

Beilstein J. Org. Chem. 2012, 8, 1452–1457, doi:10.3762/bjoc.8.165

• -containing esters could be the aromatic nature of the squaramide functional group in catalyst IX, allowing additional π–π-interactions. The properties of the enone double bond of the substrate depend on the nature of the substituents in the phenyl ring. Therefore, the electronic effect of the para

Self-assembly of Ru₄ and Ru₈ assemblies by coordination using organometallic Ru(II)₂ precursors: Synthesis, characterization and properties

• Sankarasekaran Shanmugaraju,
• Dipak Samanta and
• Partha Sarathi Mukherjee

Beilstein J. Org. Chem. 2012, 8, 313–322, doi:10.3762/bjoc.8.34

• , respectively. The four donor sites of L are coordinated to four different Ru(II) metal centers and thereby it adopts a tetranuclear rectangular geometry. The solid-state packing of macrocycle 2a along the crystallographic c-axis results in a highly porous structure with square-type channels due to the π–π

• interactions between the adjacent macrocycles (Figure S8, Supporting Information File 1). Triflate (O3SCF3−) counter anions are located outside of the porous channel (Figure S8, Supporting Information File 1). Synthesis and characterization of the octanuclear cage The construction of an octanuclear macrocyclic

Anion–π interactions influence pK_a values

• Christopher J. Cadman and
• Anna K. Croft

Beilstein J. Org. Chem. 2011, 7, 320–328, doi:10.3762/bjoc.7.42

• biological, medical and environmental chemistry [1]. Cation–π and π–π interactions are perhaps the best known of these non-covalent forces and are driven by attractions between the quadrupole moments of the aromatic species in question, with either a cation or other aromatic, respectively. In a similar

• model systems 1–5, based on 1,8-disubstituted naphthalene (Figure 1). Such model systems have already been utilised to great effect by Cozzi and co-workers to probe π–π interactions [25][26]. Related models have also proven effective in exploring neighbouring group interactions in reactive systems, such

Protonation and deprotonation induced organo/hydrogelation: Bile acid derived gelators containing a basic side chain

• Uday Maitra and
• Arkajyoti Chakrabarty

Beilstein J. Org. Chem. 2011, 7, 304–309, doi:10.3762/bjoc.7.40

• -assembled structures form mainly due to weak non-covalent interactions such as hydrogen-bonding, van der Waals forces, π–π interactions, charge-transfer interactions etc. in organogels, whereas, in aqueous gels, the major driving force for aggregation is hydrophobic interaction [2]. A number of

Synthesis and self-assembly of 1-deoxyglucose derivatives as low molecular weight organogelators

• Guijun Wang,
• Hao Yang,
• Sherwin Cheuk and
• Sherman Coleman

Beilstein J. Org. Chem. 2011, 7, 234–242, doi:10.3762/bjoc.7.31

• gelators for water or aqueous ethanol mixtures. The monoesters presumably form an extended hydrogen bonding array between the ring oxygen and the free hydroxy groups [36]. For these compounds, the main forces that influence gelation include phenyl ring π–π interactions, hydrogen bonding, and hydrophobic