Query: Hydrogen Bonding

title: Fabrication of strong hydrogen bonding induced coacervate adhesive hydrogels with antibacterial and hemostatic activities.
abstract: In this work, a biocompatible poly(N hydroxyethyl acrylamide) (PHEAA) polymer with hydrogen bonding acceptors and donors in its side chains is prepared and mixed with tannic acid (TA) to form a supramolecular coacervate hydrogel (TAHE) due to multiple hydrogen bonding interactions between TA and PHEAA. The coacervate TAHE hydrogel exhibits not only self healing and antibacterial properties, but also strong adhesion to various substrates, with average adhesion strengths of 722 kPa, 522 kPa, 484 kPa, and 322 kPa to the substrates of iron, PMMA, ceramics, and glass, respectively. Notably, the hydrogel reformed by the rehydration of freeze dried and ground TAHE hydrogel powder retains the initial adhesive performance and exhibits an excellent hemostatic ability. This novel adhesive hydrogel holds great potential as an adhesive hemostatic material for self rescue in emergency situations.

title: Hydrogen bonding induces dual porous types with microporous and mesoporous covalent organic frameworks based on bicarbazole units
abstract: Although the topologies of covalent organic frameworks (COFs) can be controlled mainly by varying the symmetries of the building blocks condensed to form the structures, another approach is to change the structures of blocks but retain the same symmetries. The construction of a single COF featuring pores of different sizes from two symmetrical building blocks remains extremely difficult. In this paper, we report an investigation into the effect of hydrogen bonding on the topological regulation of two dimensional COFs as a new approach for managing their properties. Our strategy involved introducing pristine and substituted diamine monomers benzidine (BD) and 1,4 dihydroxybenzidine (DHBD) into the skeleton of bicarbazole based COFs. The constructed bicarbazole based COFs, Cz BD and Cz DHBD, were designed using a (C2 C2) geometry strategy and synthesized through Schiff base condensations of bicarbazole 4CHO and the benzidine derivatives. The resulting COFs featured two different topologies: Cz BD COF possessing a single type of pore having a tetragonal structure, and Cz DHBD COF possessing a Kagome structure featuring two types of pores (one hexagonal and the other triangular with mesoporous and microporous structure, induced by intramolecular OHN hydrogen bonding) These COFs exhibited high crystallinity, great thermal stability, and large surface areas, as well as synergistic structural effects and high performance CO2 uptake.

title: Transparent, mechanically robust, and ultrastable ionogels enabled by hydrogen bonding between elastomers and ionic liquids
abstract: Nonvolatile ionogels have recently emerged as promising soft electrolyte materials for use in flexible electronics. However, it remains challenging to fabricate highly robust and stable transparent ionogels. Here, high performance ionogels with excellent transparency, mechanical robustness, and ultrahigh stability are designed by virtue of hydrogen bonding between poly(ethyl acrylate) based elastomers and room temperature ionic liquids (ILs) Through rationally tuning the chemical structures of ILs and thus achieving good compatibility of ILs with elastomers, the transparent hydrophobic ionogels exhibit super strong mechanical properties (favorable elasticity of 15 484 kPa, ultrahigh stretchability of more than 5000% and record high fracture toughness of up to 4.7 kJ m 2) and high stability (high thermal stability, high voltage stability, air stability, humidity resistance, strong self adhesion, and non corrosive stability) In particular, it is demonstrated that a skin like sensor fabricated using the ionogel directly not only exhibits outstanding durability (10 000 cycles at 100% strain) but is also capable of operation under harsh environmental conditions, including high vacuum, high/low temperatures, and high humidity. It is believed that this work provides new prospects for sophisticated wearable optoelectronic devices.

title: Twist Bend Nematogenic Supramolecular Dimers and Trimers Formed by Hydrogen Bonding
abstract: A selection of novel non symmetric supramolecular liquid crystal dimers and trimers formed by hydrogen bonding have been prepared and their phase behaviour characterised by polarised optical microscopy, X ray diffraction and temperature dependent Fourier transform infrared spectroscopy. We mix the bent twist bend nematogen 4 [6 (4' cyanobiphenyl 4 yl) hexyloxy] benzoic acid (CB6OBA) with a series of small stilbazole based compounds 4 (E) 2 (n alkoxyphenyl)ethenyl]pyridines (nOS) of varying terminal chain length (n) to obtain the CB6OBA:nOS complexes. Complexes with n 7 exhibit nematic and twist bend nematic behaviour, followed on cooling by a smectic C phase for n 4 7, and finally, a hexatic type smectic X phase for n 3 7. Mixtures with n 8 10 exhibit a smectic A phase below the conventional nematic phase, and on further cooling, a biaxial smectic Ab phase and the same hexatic type SmX phase. Supramolecular trimers, CB6OBA:CB6OS and CB6OBA:1OB6OS, formed between CB6OBA and dimeric stilbazoles (E) 2 (4 [6 (4' methoxy[1,1' biphenyl] 4 yl)hexyl]oxy}phenyl)ethenyl]pyridine (1OB6OS) or 4 (E) 4' (6 {4 (E) 2 (pyridin 4 yl)ethenyl]phenoxy}hexyl)[1,1' biphenyl] 4 carbonitrile (CB6OS) exhibit nematic and twist bend nematic phases, and are the first hydrogen bonded trimers consisting of unlike donor and acceptor fragments to do so.

title: Weighted persistent homology for osmolyte molecular aggregation and hydrogen bonding network analysis
abstract: It has long been observed that trimethylamine N oxide (TMAO) and urea demonstrate dramatically different properties in a protein folding process. Even with the enormous theoretical and experimental research work on these two osmolytes, various aspects of their underlying mechanisms still remain largely elusive. In this paper, we propose to use the weighted persistent homology to systematically study the osmolytes molecular aggregation and their hydrogen bonding network from a local topological perspective. We consider two weighted models, i.e. localized persistent homology (LPH) and interactive persistent homology (IPH) Boltzmann persistent entropy (BPE) is proposed to quantitatively characterize the topological features from LPH and IPH, together with persistent Betti number (PBN) More specifically, from the localized persistent homology models, we have found that TMAO and urea have very different local topology. TMAO is found to exhibit a local network structure. With the concentration increase, the circle elements in these networks show a clear increase in their total numbers and a decrease in their relative sizes. In contrast, urea shows two types of local topological patterns, i.e. local clusters around 6 A and a few global circle elements at around 12 A. From the interactive persistent homology models, it has been found that our persistent radial distribution function (PRDF) from the global scale IPH has same physical properties as the traditional radial distribution function. Moreover, PRDFs from the local scale IPH can also be generated and used to characterize the local interaction information. Other than the clear difference of the first peak value of PRDFs at filtration size 4 A, TMAO and urea also shows very different behaviors at the second peak region from filtration size 5 A to 10 A. These differences are also reflected in the PBNs and BPEs of the local scale IPH. These localized topological information has never been revealed before. Since graphs can be transferred into simplicial complexes by the clique complex, our weighted persistent homology models can be used in the analysis of various networks and graphs from any molecular structures and aggregation systems.

title: Glycolipids from natural sources: dry liquid crystal properties, hydrogen bonding and molecular mobility of Palm Kernel oil mannosides
abstract: Glycolipids prepared from palm kernel oil, PKO, in tropical regions represent an excellent opportunity to develop new surfactant formulations for cosmeceutical and pharmaceutical applications while contributing to sustainable economies. Here we report the synthesis of a new mannoside obtained from palm kernel oil, aManPKO, and we characterise its thermotropic properties by using DSC, POM, SAXS, WAXS, FT IR and broadband dielectric spectroscopy. aManPKO exhibits a monotropic smectic phase with a partially interdigitated bilayer structure, similar to its major unsaturated component, the oleyl mannoside with a C18:1 monounsaturated alkyl chain. The smectic phase of aManPKO vitrifies below room temperature, which is associated to the C18:1 component, but also to the activation of short range motions, ~4 A, by cleavage of strong hydrogen bonding between the polar heads of the mannosides. The stability of the liquid crystal phase, on the other hand, is linked to the presence of weak hydrogen bonding, whose breakage leads to the activation of long rate motions in the range of the layer distances, ~39 A. Graphical Abstract

title: Hydrogen bonding interactions in single component molecular conductors based on metal (Ni, Au) bis(dithiolene) complexes.
abstract: Introduction of hydrogen bonding (HB) interactions in single component conductors derived from nickel and gold bis(dithiolene) complexes is explored with the 2 alkylthio 1,3 thiazole 4,5 dithiolate (RS tzdt) with R CH2CH2OH through the preparation of the neutral [Ni(HOEtS tzdt)2]0 (closed shell) and [Au(HOEtS tzdt)2] (radical) complexes. At variance with many other radical gold dithiolene complexes which have a strong tendency to dimerize in the solid state, [Au(HOEtS tzdt)2] crystallizes into uniform stacks interconnected by strong O HN HB involving the nitrogen atom of the thiazole ring.

title: Lasagna like supramolecular polymers derived from the PdII osazone complexes via C(sp2) HHal hydrogen bonding
abstract: Preparation of the novel PdII osazone complex and its self assembly into lasagna like arrays in the solid state via rare C(sp2) HHal hydrogen bonding, as well as N HPh weak contact is reported. The rare PdII osazone complex was characterized using elemental analyses (C, H, N) ESI MS, IR, 1H and 13C NMR techniques and X ray diffraction analysis. The intermolecular non covalent interactions C HCl and N HPh responsible for the formation of 1D supramolecular polymeric chains in the crystal were detected and studied by DFT calculations and topological analysis of the electron density distribution within the framework of Bader's theory (QTAIM method) Estimated strength of these non covalent interactions is 1.3 1.6 kcal/mol.

title: Intramolecular hydrogen bonding stabilizes trans configuration in a mixed carbene/isocyanide PdII complexes
abstract: Aromatic amidines 1a e undergo facile reaction with one isocyanide in PdCl2(CNBut)2 giving carbene complexes 2b d (Scheme 2) in high isolated yields (79 95% The structures of 2b d were confirmed by the 1H and 13C NMR spectroscopies, high resolution electrospray ionization mass spectrometry (HRESI MS) IR, the elemental analyses (C, H, N) and X ray diffraction analysis for 2c, which revealed that the carbene and unreacted isocyanide ligands were located in a mutually trans position. Such arrangement was unexpected since it did not fit trans effect rule. Stabilization of the unfavorable isomer was rationalized by intramolecular hydrogen bonding. The nature of the intramolecular non covalent interactions, which were responsible for the stabilization of the trans isomer, was studied theoretically using DFT calculations and topological analysis of the electron density distribution within the framework of Bader's theory (QTAIM method)

title: Hydrogen Bonding Reinforced Hydrogel Electrolyte for Flexible, Robust and All In One Supercapacitor with Excellent Low Temperature Tolerance.
abstract: Flexible supercapacitors are promising energy storage devices for emerging wearable electronics. However, due to the poor mechanical strength, complicated device manufacturing process and unsatisfactory low temperature tolerance, their overall performance for practical applications is hindered. Herein we report a hydrogen bonding reinforced, dual crosslinked poly (vinyl alcohol) acrylic acid and H2SO4 (PVA AA S) hydrogel electrolyte for all in one flexible supercapacitors. The PVA AA S hydrogel demonstrates excellent compressive/tensile properties and high ionic conductivity. It tolerates a compressive stress of 0.53 MPa and is stretchable up to 500% The PVA AA S hydrogel based all in one supercapacitor shows promising electrochemical performance under various harsh conditions. The device energy density and power density reach up to 14.2 uWh cm 2 and 0.94 mW cm 2, respectively. Furthermore, it retains nearly 80% capacitance after being stored at 35 for 23 days. The excellent performance of the hydrogel electrolyte originates from its abundant strong hydrogen bonding between the polymer chains and water molecules.