Nano/Micro-Structural Supramolecular Biopolymers: Innovative Networks with the Boundless Potential in Sustainable Agriculture

Sustainable agriculture plays a crucial role in meeting the growing global demand for food while minimizing adverse environmental impacts from the overuse of synthetic pesticides and conventional fertilizers.In this context,renewable biopolymers being more sustainable offer a viable solution to improve agricultural sustainability and production.Nano/micro-structural supramolecular biopolymers are among these innovative biopolymers that are much sought after for their unique features.These biomaterials have complex hierarchical structures,great stability,adjustable mechanical strength,stimuli-responsiveness,and self-healing attributes.Functional molecules may be added to their flexible structure,for enabling novel agricultural uses.This overview scrutinizes how nano/micro-structural supramolecular biopolymers may radically alter farming practices and solve lingering problems in agricultural sector namely improve agricultural production,soil health,and resource efficiency.Controlled bioactive ingredient released from biopolymers allows the tailored administration of agrochemicals,bioactive agents,and biostimulators as they enhance nutrient absorption,moisture retention,and root growth.Nano/micro-structural supramolecular biopolymers may protect crops by appending antimicrobials and biosensing entities while their eco-friendliness supports sustainable agriculture.Despite their potential,further studies are warranted to understand and optimize their usage in agricultural domain.This effort seeks to bridge the knowledge gap by investigating their applications,challenges,and future prospects in the agricultural sector.Through experimental investigations and theoretical modeling,this overview aims to provide valuable insights into the practical implementation and optimization of supramolecular biopolymers in sustainable agriculture,ultimately contributing to the development of innovative and eco-friendly solutions to enhance agricultural productivity while minimizing environmental impact.

Enhanced Ion-Selective Diffusion Achieved by Supramolecular Interaction for High Thermovoltage and Thermal Stability

Thermoelectric(TE)generators capable of converting thermal energy into applicable electricity have gained great popularity among emerging energy conversion technologies.Biopolymer-based ionic thermoelectric(i-TE)materials are promising candidates for energy conversion systems because of their wide sources,innocuity,and low manufacturing cost.However,common physically crosslinked biopolymer gels induced by single hydrogen bonding or hydrophobic interaction suffer from low differential thermal voltage and poor thermodynamic stability.Here,we develop a novel i-TE gel with supramolecular structures through multiple noncovalent interactions between ionic liquids(ILs)and gelatin molecular chains.The thermopower and thermoelectric power factor of the ionic gels are as high as 2.83 mV K-1 and 18.33μW m^(-1)K^(-2),respectively.The quasi-solid-state gelatin-[EMIM]DCA i-TE cells achieve ultrahigh 2 h output energy density(E_(2h)=9.9 mJ m^(-2))under an optimal temperature range.Meanwhile,the remarkable stability of the supramolecular structure provides the i-TE hydrogels with a thermal stability of up to 80℃.It breaks the limitation that biopolymer-based i-TE gels can only be applied in the low temperature range and enables biopolymer-based i-TE materials to pursue better performance in a higher temperature range.

Supramolecular polymer-based gel fracturing fluid with a double network applied in ultra-deep hydraulic fracturing

A gel based on polyacrylamide,exhibiting delayed crosslinking characteristics,emerges as the preferred solution for mitigating degradation under conditions of high temperature and extended shear in ultralong wellbores.High viscosity/viscoelasticity of the fracturing fluid was required to maintain excellent proppant suspension properties before gelling.Taking into account both the cost and the potential damage to reservoirs,polymers with lower concentrations and molecular weights are generally preferred.In this work,the supramolecular action was integrated into the polymer,resulting in significant increases in the viscosity and viscoelasticity of the synthesized supramolecular polymer system.The double network gel,which is formed by the combination of the supramolecular polymer system and a small quantity of Zr-crosslinker,effectively resists temperature while minimizing permeability damage to the reservoir.The results indicate that the supramolecular polymer system with a molecular weight of(268—380)×10^(4)g/mol can achieve the same viscosity and viscoelasticity at 0.4 wt%due to the supramolecular interaction between polymers,compared to the 0.6 wt%traditional polymer(hydrolyzed polyacrylamide,molecular weight of 1078×10^(4)g/mol).The supramolecular polymer system possessed excellent proppant suspension properties with a 0.55 cm/min sedimentation rate at 0.4 wt%,whereas the0.6 wt%traditional polymer had a rate of 0.57 cm/min.In comparison to the traditional gel with a Zrcrosslinker concentration of 0.6 wt%and an elastic modulus of 7.77 Pa,the double network gel with a higher elastic modulus(9.00 Pa)could be formed only at 0.1 wt%Zr-crosslinker,which greatly reduced the amount of residue of the fluid after gel-breaking.The viscosity of the double network gel was66 m Pa s after 2 h shearing,whereas the traditional gel only reached 27 m Pa s.

Construction and Properties of the Me_(10)Q[5]/2,7-diaminofluorenedihydrochloride Supramolecular Hydrogel

Compared to traditional polymer hydrogels,supramolecular hydrogels exhibits superior reversibility and stimulus response due to the instantaneous and reversible nature of non-covalent bonds.In this paper,we utilized the host-guest exclusion interaction between Decamethylcucurbit[5]uril(Me_(10)Q[5])and the 2,7-diaminofluorenedihydrochloride(DAF·HCl)to construct a Q[n]-based hydrogel system.The composition,structure,and properties of the hydrogel were compre-hensively characterized using rheometer,nuclear magnetic resonance,scanning electron microscope.This cost-effective and straightforward hydrogel synthesis method paves the way for the scalable production of practical and commercially viable Q[n]-based hydrogels.

Catalytic epoxidation of olefin over supramolecular compounds of molybdenum oxide clusters and a copper complex

The catalytic epoxidation of olefin was investigated on two copper complex-modified molybdenum oxides with a 3D supramolecular structure, [Cu（bipy）]4[Mo15O47].2H2O （1） and [Cu1（bix）][（Cu1bix） （δ-MoVl8O26）0.5] （2） （bipy = 4,4＇-bipyridine, bix = 1,4-bis（imidazole-1-ylmethyl）benzene）. Both compounds were catalytically active and stable for the epoxidation of cyclooctene, 1-octene, and styrene with tert-butyl hydroperoxide （t-BuOOH） as oxidant. The excellent catalytic performance was attributed to the presence of stable coordination bonds between the molybdenum oxide and copper complex, which resulted in the formation of easily accessible Mo species with high electropositivity. In addition, the copper complex also acted as an active site for the activation of t-BuOOH, thus im- proving these copper complex-modified polyoxometalates.

Effects of Doubled_CO_2 Concentration on Ultrastructure, Supramolecular Architecture and Spectral Characteristics of Chloroplasts from Wheat

Wheat ( Triticum aestivum L.) plants were grown under ambient and doubled_CO 2(plus 350 μL/L) concentration in cylindrical open_top chamber to examine their effects on the ultrastructure, supramolecular architecture, absorption spectrum and low temperature (77 K) fluorescence emission spectrum of the chloroplasts from wheat leaves. The results were briefly summarized as follows: (1) The wheat leaves possessed normally developed chloroplasts with intact grana and stroma thylakoid membranes; The grana intertwined with stroma thylakoid membranes and increased slightly in stacking degree and the width of granum, in spite of more accumulated starch grains within the chloroplasts than those in control; (2) The particle density in the stacked region of the endoplasmic fracture face (EFs) and protoplasmic fracture face (PFs) and in the unstacked region the endoplasmic fracture face (EFu) and the protoplasmic fracture face (PFu) was significantly higher than that of control. Furthermore, in some cases many more particles on EFs faces of thylakoid membranes appeared as a paracrystalline particle array; (3) The variations in the structure of chloroplasts were consistent with the absorption spectra and the low temperature (77 K) fluorescence emission spectra of the chloroplasts developed under the doubled_CO 2 concentration. Results indicate that the capability of light energy absorption of chloroplasts and regulative capability of excitation energy distribution between PSⅡ and PSⅠ were raised by doubled_CO 2 concentration. This is very favorable for final productivity of wheat.

Supramolecular Fixation of Three Amines using Cobalt Tetraphenyl- porphyrin for SO2 Removal

In this work, supramolecular fixation of three amines, including aniline, ethylenediamine, and diethylamine, using cobalt tetraphenylporphyrin （CoTPP） for SO2 removal was studied using UV-Vis and fluorescence measurements. The UV-Vis spectra showed that increasing amines concentrations resulted in bathochromic shift for CoTPP Soret absorption band （B band）. Once SO2 was introduced, it competed with CoTPP for aniline, ethylenediamine, and diethylamine, which eventually led to the release of CoTPP and the change of solution colour/absorption band. After that, the CoTPP was regenerated and got back to the first state. The fluorescence spectra offered that CoTPP interacted with aniline, ethylenediamine, and diethylamine to form 1：1 molecular adducts. The interactions of CoTPP with aniline, ethylenediamine, and diethylamine were entropy-driven. The interaction of CoTPP with aniline and diethylamine was endothermic, and that with ethylenediamine was exothermic. Ethylenediamine presented a stronger binding constant value for CoTPP, so it was considered as a potential agent for SO2 removal.

Hydrothermal Synthesis,Crystal Structure and Fluorescence Spectrum Studies of a Supramolecular Compound {[2-(2-Pyridyl)benzimidazoleH_2]^(2+)·[SbCl_5]^(2-)}_2

A new supramolecular compound, { [2-（2-pyridyl）benzimidazoleH2]2＋.[SBC15]2-}2, was synthesized by the hydrothermal reaction of o-diaminobenzene, 2-pyridinecarboxylie acid and SbCl3 in 1：1 HC1 solution, and characterized by chemical analysis, elemental analysis, IR spectra, thermogravimetfic analysis and fluorescence spectra. The crystal structure was deter- mined by X-ray single-crystal diffraction. The crystal belongs to the monoclinic system, space group P211c, with a = 16.0397（13）, b = 14.3189（12）, c = 15.6370（13） A, β = 105.8980（10）°, V = 3454.0（5） A3, Z = 4, C24H22Cl10N6Sb2, Mr = 992.48, Dc = 1.909 g/cm3,/z = 2.366 mm-1, S = 1.010, F（000） = 1920, R = 0.0254 and wR = 0.0555. The coordination anion, [SbCl5]2- which is a distorted tetragonal pyramid, is composed by coordinating action with Sb3＋ ion and five adjacent chloride ions. Every four coordination anions of [SbCl5]2- form a biquaternion ring structure through the secondary bonding of Sb...Cl. Moreover, the compound adopts a three-dimensional network supramolecular structure because of the hydrogen bonds and π-π stacking between the rings and the 2-（2-pyridyl）benzimidazole divalent cations. The title compound also shows good fluorescent behaviors.

Synthesis of a New Porphyrin-fluorescein Hybrid and its Supramolecular Self-assembly with Amino-porphyrinatomanganese(Ⅲ) by Hydrogen-bonding

A new porphyrin-fluorescein hybrid 2 (Fl-PPTPP) has been synthesized and characterized by UV-Vis, IR, H-NMR, ESI-MS and elemental analysis. The supramolecular 1 self-assembly of Fl-PPTPP with amino-porphyrinatomanganese [Mn (p-APTPP)Cl] by hydrogen-bonding was studied using fluorescence spectroscopic titration and ESI-MS.

Syntheses and Crystal Structures of Four Cobalt Supramolecular Architectures with Hmtyaa Ligand

Four cobalt supramolecular architectures with Hmtyaa（2-（5-methyl-1,3,4-thiadiazol-2-ylthio）acetic acid） ligand have been synthesized.[Co（mtyaa）2（H2O）4]·4（H2O）（1）：triclinic,space group P1 with a = 6.7537（18）,b = 8.591（2）,c = 10.615（3） ,α = 96.495（4）,β = 99.955（5）,γ = 103.615（5）°,V = 581.9（3） 3,Z = 1,Mr = 581.52,Dc = 1.659 g/m3,μ = 1.158 mm-1,F（000） = 301,Rint = 0.0557,R = 0.0377 and wR = 0.1056 for 1854 observed reflections with Ⅰ 〉 2σ（Ⅰ）;{[Co（4,4＇-bipy）（H2O）4]·2（mtyaa）·2（H2O）}n（2）：triclinic,space group P1 with a = 7.669（2）,b = 8.840（3）,c = 11.521（4） ,α = 79.912（5）,β = 73.954（5）,γ = 86.612（6）°,V = 738.9（4） 3,Z = 1,Mr = 701.67,Dc = 1.577 g/m3,μ = 0.924 mm-1,F（000） = 363,Rint = 0.0636,R = 0.0498 and wR = 0.1311 for 2155 observed reflections with Ⅰ 〉 2σ（Ⅰ）;{[Co（4,4＇-bipy）（mtyaa）（H2O）3]（mtyaa）·2（H2O）}（3）：monoclinic,space group Pc with a = 7.7832（17）,b = 11.527（3）,c = 31.483（7） ,β = 91.952（4）°,V = 2822.9（11） 3,Z = 4,Mr = 683.65,Dc = 1.609 g/m3,μ = 0.963 mm-1,F（000） = 1412,Rint = 0.0758,R = 0.0609 and wR = 0.1095 for 5841 observed reflections with I 〉 2σ（I）;{[Co（bpe）（mtyaa）2（H2O）2]}n（4）：monoclinic,space group C2/c with a = 19.290（11）,b = 12.027（7）,c = 14.865（8） ,β = 125.648（8）°,V = 2802（3）3,Z = 4,Mr = 657.66,Dc = 1.559 g/m3,μ = 0.959 mm-1,F（000） = 1356,Rint = 0.0456,R = 0.0332 and wR = 0.0985 for 2299 observed reflections with Ⅰ 〉 2σ（Ⅰ）.

A pH-sensitive supramolecular nanosystem with chlorin e6 and triptolide co-delivery for chemo-photodynamic combination therapy

The combination of Ce6,an acknowledged photosensitizer,and TPL,a natural anticancer agent,has been demonstrated as a useful strategy to reinforce the tumor growth suppression,as well as decrease the systemic side effects compared with their monotherapy.However,in view of the optimal chemo-photodynamic combination efficiency,there is still short of the feasible nanovehicle to steadily co-deliver Ce6 and TPL,and stimuli-responsively burst release drugs in tumor site.Herein,we described the synergistic antitumor performance of a pH-sensitive supramolecular nanosystem,mediated by the host–guest complexing betweenβ-CD and acid pH-responsive amphiphilic co-polymer mPEG-PBAE-mPEG,showing the shell–core structural micelles with the tightβ-CD layer coating.Both Ce6 and TPLwere facilely co-loaded into the spherical supramolecular NPs(TPL+Ce6/NPs)by one-step nanoprecipitation method,with an ideal particle size(156.0 nm),acid pH-responsive drug release profile,and enhanced cellular internalization capacity.In view of the combination benefit of photodynamic therapy and chemotherapy,as well as co-encapsulation in the fabricated pH-sensitive supramolecular NPs,TPL+Ce6/NPs exhibited significant efficacy to suppress cellular proliferation,boost ROS level,lower MMP,and promote cellular apoptosis in vitro.Particularly,fluorescence imaging revealed that TPL+Ce6/NPs preferentially accumulated in the tumor tissue area,with higher intensity than that of free Ce6.As expected,upon 650-nm laser irradiation,TPL+Ce6/NPs exhibited a cascade of amplified synergistic chemo-photodynamic therapeutic benefits to suppress tumor progression in both hepatoma H22 tumor-bearingmice and B16 tumor-bearingmice.More importantly,lower systemic toxicitywas found in the tumor-bearingmice treated with TPL+Ce6/NPs.Overall,the designed supramolecular TPL+Ce6/NPs provided a promising alternative approach for chemo-photodynamic therapy in tumor treatment.

Intercalation Assembly, Characterization and Luminescent Properties of Novel Supramolecular Composite Materials, Tb(Ⅲ) Complex with Tetrapodal Ligand-Montmorillonite

Two kinds of Tb（ Ⅲ ） complexes with tetrapodal ligand, [TbL（NO3）]^3＋ and [TbL]^3＋ （L： 1,1, 1＇, 1＇-tera （ 2-pyridinecarboxylester ）-di （ trimethylpropane）） were intercalated into the interlayer space of montmorillonite （MT） by ion exchange and coordination reaction of L with the Tb^3＋ ion existing in the interlayer space of Tb-MT respectively. The obtained luminescent supramolecular composite materials, [ TbL （NO3） ]^2＋-MT and [TbL]^3＋-MT were characterized by elemental analysis, XRD, FT-IR, UV-vis and thermal analysis. At the same time, the luminescent properties of the materials were also studied. The results show that the intercalated materials with regular layered structure, good thermal stability and the interlayer spacing （d001） approximates to the size of the complex ions which are located in the interlayer space of MT in the form of a monolayer.

A New Three-dimensional Supramolecular Polymer Built from Non-covalent Bonding Interactions

A new complex, [Ni2（L）4（H2O）8]（1, L1 = 4-（1H-imidazol-4-yl）benzoic acid）, has been hydrothermally prepared and characterized by single-crystal X-ray diffraction, IR spectroscopy, elemental analysis and PXRD. Complex 1 crystallizes in monoclinic, space group P21/c with α = 22.281（2）, b = 7.3959（7）, c = 24.978（3） ？, β = 90.876（10）, V = 4115.6（7） ？3, Z = 8, C20H22N4O8Ni, Mr = 505.13, Dc = 1.630 g/cm3, μ = 1.001 mm-1, S = 1.080, F（000） = 2096, the final R = 0.452 and wR = 0.1152 for 9380 observed reflections （I 〉 2σ（I））. The result of X-ray diffraction analysis revealed three different kinds of Ni（II） centre mononuclear molecules in the asymmetric unit. The independent mononuclear units are bridged to form a three-dimensional supramolecular polymer by extensive hydrogen bonds and C–H… non-covalent bonding interactions.

A Photoluminescent Bimetallic Zinc-pyridinedicarboxylate:Diverse Supramolecular Motifs from Distinct Hydrogen Bonds

A cyclic bimetallic metal-organic complex [Zn（C）（H-fmpdc）（H2O）]2·2H2O （fmpdc = 4-（furan-2-yl）-2,6-dimethylpyridine-3,5-dicarboxylate） was synthesized and characterized by single-crystal X-ray analysis. The compound crystallizes in orthorhombic, space group Pbca with a = 12.905（2）, b = 14.774（3）, c = 16.833（3）A, V= 3029.4（10）A^3 Z = 4, Dc = 1.644 g/cm^3, F（000） = 1616, R = 0.0347 and wR = 0.0956 （I 〉 2σ（I））. There exist diverse supramolecular motifs （1-D, 2-D and 3-D） from distinct hydrogen bonds in the crystal structure of the title compound. The furanyl group has obvious contribution to the red-shift in the photoluminescent spectrum of the H2fmpdc ligand. The title compound 1 shows strong photoluminescence with emission maximum at 2 = 402 nm （λex.max = 367 nm）.

π-CONJUGATED OLIGOMERS IN SUPRAMOLECULAR CRYSTALS AND THEIR OPTOELECTRONIC FUNCTIONS

Functional organic molecular materials and conjugated oligomers or polymers now allow the low-cost fabrication of thin films for insertion into new generations of electronic and optoelectronic devices. The performance of these devices relies on the understanding and optimization of several complementary processes. Our goal is to discuss the relationship between the molecular stacking structures and their optoelectronic properties that are of importance in all these areas. The concept of intermolecular interaction should be taken here in the special sense that is inter-dipole coupling. Specifically, we will address the impact of inter-dipole interaction between adjacent molecules in aggregate state on the solid-state emission properties.

Ultrasound assisted multicomponent reactions:A green method for the synthesis of N-substituted 1,8-dioxo-decahydroacridines usingβ-cyclodextrin as a supramolecular reusable catalyst in water

We demonstrate a superficial method for the synthesis of N-substituted 1,8-dioxo-decahydroacridines using β-cyclodextrin as a supramolecular,biodegradable,and reusable catalyst in aqueous medium.The reaction product is in excellent yield with moderate to excellent selectivity.The mechanistic transformation presumably proceeds via a one-pot,multicomponent cyclization of dimedone in the presence of aromatic aldehydes and aromatic amines/INH,undergoing a tandem Michael addition reaction.The proposed approach in this study provides a highly efficient and environmentally benign route to N-substituted 1,8-dioxo-decahydroacridines.

Synthesis and Crystal Structure of New Supramolecular Adducts of[PtCl_6]^(2-) with Cucurbit [7] uril:[(H_3O)_2 [PtCl_6]_3 [C_(42)H_(42)N_(28)O_ (14)_2·H_2O

A novel supramolecular adduct 3(C 42H 42N 28O 14) 2·H 2O (1) was synthesized by mixing 2- and cucurbit uril in solution of hydrochloric acid. The crystal structure was determined by single crystal X-ray diffraction analysis. The crystal belongs to orthorhombic system and space group F dd2 with cell dimensions: a=4.705 33 (5) nm, b=7.153 80 (6) nm, c= 1.894 61 (2) nm, Z=16, V=63.7744 (11) nm3, D c= 1.534 g/cm3, μ=3.007 mm -1, F(000)=29 120, R 1= 0.070 7, wR 2=0.169 2. In crystal, the cucurb uril molecules form two zig-zag chains.

Synthesis, Crystal Structure and Property of a Series of Supramolecular Polymers Based on Novel 3,5-Dimethyl- 2,6-bis(3-(pyrid-2-yl)-1,2,4-triazolyl)pyridine Ligand

Solvothermal reactions of 3,5-dimethyl-2,6-bis（3-（pyrid-2-yl）-1,2,4-triazolyl） pyridine （L）, 1,4-benzendicarboxylic acid （H2bdc）, and transitional metal cations of M11 （M = Mn, Co, Cd） in the presence of oxalic acid （H2ox） afford three novel supramolecular polymers （CPs）, namely, {[M2（ox）（L）2][bdc][M2（Hox）2（OH）（H2O）4]·3H2O}n （M = Mn for 1, Co for 2, Cd for 3）. Single-crystal X-ray diffraction analysis reveals that complexes 1-3 are isostructural and the 3D supramolecular structure was connected through non-covalent interactions. With the help of H2ox, the L ligands cheated with center atoms forming a butterfly [M2（ox）（L）2]2＋ building block. The bdc2- ligand linked with the unprecedented [M2（Hox）2（OH）2（H2O）4] units through strong O-H...O hydrogen bonds forming a zigzag chain, which are further connected through π-π interactions between L and bdc2- ligands to form a 3D supramolecular structure. Moreover, elemental analyses, IR, thermogravimetric, PXRD and luminescence have been investigated.

Preparation and characterization of supramolecular gel suitable for fractured formations

The excellent mechanical properties of supramolecular gel could adapt to the complex reservoir environment and had broad application prospects in the field of oil and gas drilling and production engineering.In this paper,a supramolecular gel based on hydrophobic association and hydrogen bonding was prepared by micellar copolymerization,which could be used to plug fractures and pores in formations.Supramolecular gel was a gel network system with high performance characteristics formed by self-assembly of non-covalent bond interaction.The rheological properties,mechanical mechanics,temperature resistance and swelling ability of supramolecular gel were studied.The results showed that the supramolecular gel had a dense three-dimensional network structure with open and interconnected pore structures,which could exhibit good rheological properties and strong viscoelastic recovery ability.The mechanical properties of the supramolecular gel were excellent,it had a tensile stress of 0.703 MPa and an elongation at break of 1803%.When the compressive strain was 96%,the compressive stress could reach 14.5 MPa.Supramolecular gel also showed good temperature resistance and swelling properties.At the aging temperature of 135℃,supramolecular gels still maintained good gel strength,and it only took 12 h to reach the equilibrium swelling ratio of 35.87 in 1%NaCl solution.It was also found that supramolecular gel in low concentration saline(1%NaCl solution)showed relatively faster swelling than high concentration saline(25%NaCl solution).The swelling process of the supramolecular gel was non-Fick diffusion(typeⅡ).This indicated that the organic/inorganic permeability network was well formed.Therefore,the diffusion rate of small molecules could be guaranteed to be equal to the relaxation rate of large molecules before and after the phase transition temperature.In addition to the diffusion of water molecules,the swelling process of the supramolecular gel was also affected by the relaxation of gel network and polymer chain segment,the interaction between water molecules and polymer network and the groups of polymer network and other factors.Supramolecular gel particles could be used as plugging materials for drilling fluids,which had excellent ability to plug formation fractures and pores.The plugging ability of the supramolecular gel was up to 6.7 MPa for 0.5 mm fracture width,and 9.6 MPa for porous media with 5 mD permeability.Compared with HT-PPG gel particles commonly used in oil fields,supramolecular gel particles had better plugging ability on fractures and porous media.The development and application of supramolecular gel had far-reaching significance for promoting the functional application of polymer materials in drilling and production engineering.

Highly stable supramolecular hydrogels formed from 1,3,5-benzenetricarboxylic acid and hydroxyl pyridines

New supramolecular hydrogels with the maximal sol-gel transition temperature （Tgel） of 95 ℃ were obtained by using gelators formed from 1,3,5-benzenetricarboxylic acid （BTA） and para-hydroxyl pyridine （PHP） or meta-hydroxyl pyridine （MHP）. The single crystal structure of the complex formed from BTA and ortho-hydroxyl pyridine （OHP） indicated that the molecules assembled into superstructure via both hydrogen bonds and π--π stacking interaction.