Facile synthesis and characterization of novel thermo-chromism cholesteryl-containing hydrogen-bonded liquid crystals

Two series of novel cholesteryl-containing H-bonded liquid crystals were prepared through facile self-assembly between cholesteryl isonicotinate （proton acceptor） exhibiting a monotropic cholesteric phase, and the 4-alkoxy-benzoic acid or 4-alkoxy cinnamic acid （proton donor）. It was found that the increase of the conjugate length as well as the terminal length can contribute to enhance the interaction of molecules and thus significantly influenced the thermal behaviors of H-bonded LCs. The cholesteric reflection spectra of the induced mesogenic complexes were located in the visible region with the color tuneable thermo-sensitivity, which could be used for display application.

Forming of A New Liquid Crystalline through Hydrogen Bonding

A stable Sc phase is formed through hydrogen bonding between side-chain aromatic acid groups of polysiloxane: Bending of polysiloxane with N-Acetyl Latimic acid (NAA) gives a chiral S c * phase; The influence of polymerism and hydrogen bond induction effect over mesophase is discussed. The influence of NAA over mesophase is studied.

Syntheses and Crystal Structures of Two 3D Zinc(II) Compounds Involving Coordination and Hydrogen Bonds

Two zinc（Ⅱ） compounds, [Zn（L）（H2O）2]n 1 and [Zn（4,4＇-bpy）（H2O）4]（L） 2 （H2L = trans,trans-1,3 butadiene 1,4-dicarboxylic acid）, were synthesized by hydrothermal methods and characterized by single-crystal X-ray diffraction analyses. Compound 1 crystallizes in monoclinic, space group C2/c with a=15.4970（16）, b = 5.4976（6）, c = 10.7113（12） A, β=96.298（6）°, C6H8O6Zn, Mr = 241.50, V = 907.06（17） A^3, Z = 4, D, = 1.768 g/cm^3, F（000） = 488,μ = 2.703 mm^-1, S = 1.060, the final R = 0.0256 and wR = 0.0660 for 968 observed reflections with Ⅰ 〉 2σ（Ⅰ）. Compound 2 crystallizes in triclinic, space group P1^- with a = 6.915（2）, b = 7.166（2）, c = 10.363（3） A, α = 73.250（4）, β = 84.429（4）, γ = 61.605（3）°, C16H2ON2O8Zn, Mr = 433.70, V = 432.1 （2） A^3, Z = 1, D, = 1.667 g/cm^3, F（000） = 224 and μ= 1.471 mm^-1, S = 1.118, the final R = 0.0486 and wR = 0.1077 for 1352 observed reflections with Ⅰ〉 2σ（Ⅰ）. Upon using the assembly strategy of combination of coordination polymer chains with intermolecular hydrogen bonds, three-dimensional frameworks of complexes 1 and 2 were formed.

Syntheses, Crystal Structures and Hydrogen-bonding Motif of Two Glycoluril Derivatives

The synthesis and aggregation behavior of two glycoluril derivatives were descrybed.The crystal of compound 1 belongs to the triclinic system,space group ■,with a=8.946（1）,b=13.445（2）,c=20.361（3）?,α=89.517（3）,β=84.405（3）,γ=86.325（3）°,Z=2,V=2432.1（6）?3,Dc=1.293 g·cm-3,C48H34N6O6·2DMSO,Mr=947.07,F（000）=992,μ=0.170 mm-1,the final R=0.1606 and wR=0.2410 for 4382 observed reflections（Ⅰ>2σ（Ⅰ））.The crystal of compound 2belongs to the monoclinic system,space group P21/c,with a=9.500（3）,b=24.522（8）,c=17.997（6）?,Z=2,V=4054（2）?3,Dc=1.296 g·cm-3,C48H34N6O6,Mr=790.81,F（000）=1648,μ=0.087mm-1,the final R=0.2146 and wR=0.2535 for 2878 observed reflections（Ⅰ>2σ（Ⅰ））.Unlike the highly conserved R22（8）hydrogen-bonding amide···amide homosynthon,the structural analysis indicated that compound 1 selected the C（20）hydrogen-bonding motif and 2 selected the R22（34）hydrogen-bonding motif,which revealed the competition from remote solvent molecule and the interference of the molecular hydrocarbon core in crystal packing.The supramolecular structure revealed molecule 1 is further linked into a one-dimensional chain and 2 into a two-dimensional interwoven plane by N–H···N hydrogen bonds.

Hydrogen-bond mediated and concentrate-dependent NaHCO_(3) crystal morphology in NaHCO3–Na2CO3 aqueous solution: Experiments and computer simulations

Adding Na_(2)CO_(3) to the NaHCO_(3) cooling crystallizer, using the common ion effect to promote crystallization and improve product morphology, is a new process recently proposed in the literature. However, the mechanism of the impact of Na_(2)CO_(3)on the crystal morphology is still indeterminate. In this work, the crystallization of NaHCO_(3)in water and Na_(2)CO_(3)–NaHCO_(3) aqueous solution was investigated by experiments and molecular dynamics simulations(MD). The crystallization results demonstrate that the morphology of NaHCO_(3) crystal changed gradually from needle-like to flake structure with the addition of Na_(2)CO_(3). The simulation results indicate that the layer docking model and the modified attachment energy formula without considering the roughness of crystal surface can obtain the crystal morphology in agreement with the experimental results, but the lower molecules of the crystal layer have to be fixed during MD. Thermodynamic calculation of the NaHCO_(3) crystallization process verifies that the common ion effect from Na^(+)and the ionization equilibrium transformation from CO_(3)^(2-) jointly promote the precipitation of NaHCO_(3) crystal. The radial distribution function analysis indicates that the oxygen atoms of Na_(2)CO_(3) formed strong hydrogen bonds with the hydrogen atoms of the(0 1 1) face, which weakened the hydration of water molecules at the crystal surface, resulting in a significant change in the attachment energy of this crystal surface. In addition, Na+and CO_(3)^(2-) are more likely to accumulate on the(011) face,resulting in the fastest growth rate on this crystal surface, which eventually leads to a change in crystal morphology from needle-like to flake-like.

Synthesis and Crystal Structure of a Three-dimensional Manganese(Ⅱ)Complex Constructed via Covalent and Hydrogen Bonds

The assembly of 1,4-benzenedicarboxylic acid (H2bdc), 4,4?bipyridine (4,4?bipy), trimethyltin chloride and MnBr24H2O in hydrothermal conditions gave rise to a hydrogen-bonded three-dimensional complex {[Mn(4,4?bipy)4H2O](bdc)}n which has been characterized by single- crystal X-ray diffraction. The complex crystallizes in the monoclinic system, space group P2/n with a = 7.0001(2), b = 11.5540(3), c = 11.4192(1) ? = 101.754(2)? V = 904.21(4) 3, Z = 2, C18H20MnN2O8, Mr = 447.30, Dc = 1.643 g/cm3, F(000) = 462 and m(MoK? = 0.783 mm-1. The final R and wR are 0.0499 and 0.1301, respectively for 1335 observed reflections with I ≥ 2(I). The Mn (Ⅱ) is six-coordinated in a distorted octahedral geometry. 4,4?Bipyridine in a m-bridge mode links [Mn(H2O)4]2+ into a linear cation chain. bdc acts as a counter anion and links the linear chains into a three-dimensional structure through hydrogen bonds.

C-H…O Hydrogen Bonds and π…π Interaction and the Crystal and Molecular Structures of 3-Nitro-benzylideneaniline-methyl-2’

The title compound (C14H12N2O2, Mr = 240.26) crystallizes in the monoclinic system, space group P21/a with a = 7.394(1), b = 21.334(3), c = 7.423(1) ? b = 89.82(1)? V = 1170.8(3) ?, Z = 4, Dc = 1.363 g/cm3, m(MoKa) = 0.93 cm-1 and F(000) = 504.00. The final R and wR are 0.0440 and 0.1370 for 2153 observed reflections (I > 2s(I)), respectively. The dihedral angle between the two phenyl rings is 52.9 and that between the NO2 group and its attached ring is 3.0. In the crystal, molecules are stacked along [100] through p…p interactions. The CH…O hydrogen bond (3.403 ? 120.4? laterally connects the stacks along [010] to form networks (001) which are further anti- parallelly connected by CH…O (3.382 ? 142.9) and p…p interactions extending along [001]. Also presented here is a brief study on the CH…O hydrogen bonds in nitro-substituted benzyl-ideneanilines which can be classified into five types, namely, )5(12R, )4(21R, )8(22R, )6(12R and )7(22R, with the first three occurring more often.

Synthesis and Crystal Structure of a 3-D Hydrogen-bonded Supramolecular Decavanadate Compound [Habo]_6[V_(10)O_(28)]·2C_3H_7OH·2H_2O

A new inorganic-organic hybrid supramolecular compound [Habo]6[V10O28]·2C3H7OH·2H2O 1 （abo = R（-）-2-amino-1-butanol） has been synthesized from VO2^＋ in organic solvents and its crystal structure was reported as follows： monoclinic, space group P21/n, a = 11.419（9）, b = 16.811（16）, c = 15.521（12） A, β= 102.98（2）°, V= 2903（4） A^3, Z = 4, C15H46N3O19V5, Mr = 827.25, Dc = 1.893 g/cm^3, 2（MoKα） = 0.71073 A, μ = 1.636 mm^-1, F（000） = 1696, the final R = 0.0696 and wR = 0.1361 for 4641 observed reflections with I 〉 2σ（I）. The compound is based on decavanadate clusters [V10O28]^6-. The hydrogen bonding interactions among Habo^＋ cations, solvents and decavanadate clusters extend 1 into a three-dimensional supramolecular architecture.

Crystal Structure Determination and Hydrogen-Bonding Patterns in 2-Pyridinecarboxamide

The title compound, 2-pyridinecarboxamide, C6H6N2O, crystallize in the monoclinic system with space group P21/n (No14), Z = 4, and unit cell parameters a = 5.2074(1) , b = 7.1004(1) , c = 16.2531(3) , = 100.260(1)o. The crystal structure of the title compound, was reported previously from Weissenberg photographic data with R = 0.127. It has now been redetermined, providing a significant increase in the precision of the derived geometric parameters. The crystal packing is governed by N--HO hydrogen bond-type intermolecular interactions, forming infinite one-dimensional chains with graph-set notation C(4), R22(8) and R24(8).

π-π Stacking, Hydrogen Bonding and Magnetic Coupling Mechanism on a Mono-nuclear Cu^Ⅱ Complex

A new mono-nuclear CuII complex [Cu（DPP）（DP）Br]（ClO4）H2O （DPP = 2-（3,5- dimethyl-1H-pyrazol-1-yl）-1,10-phenanthroline, DP = 3,5-dimethyl-1H-pyrazole） has been syn- thesized with 2-（3,5-dimethyl-1H-pyrazol-1-yl）-1,10-phenanthroline and 3,5-dimethyl-1H-pyrazole as ligands, and its crystal structure was determined by X-ray crystallography. The crystal is of monoclinic system, space group P21/c with a = 13.765（2）, b = 17.044（3）, c = 10.9044（16）, β= 97.112（2）°, V = 2538.5（6）3, Z = 4, C22H24BrClCuN6O5, Mr = 631.37, Dc = 1.652 g/cm3, F（000） = 1276 and μ= 2.585 mm-1. In the crystal, DPP functions as a tridentate ligand and CuII ions assume a distorted square pyramidal geometry with Br atom lying on the apex, and at the same time, there is π-π stacking between adjacent complexes, which deals with two 1,10-phenanthroline plane rings. In addition to the π-π stacking, there are C-H···Br non-classic hydrogen bonds between adjacent complexes. The theoretical calculations reveal that the π-π stacking and C-H···Br non-classic hydrogen bond result in a weak anti-ferromagnetic interaction with 2J = -5.34 cm-1 and a weak ferromagnetic 2J = 5.92 cm-1, respectively. The magnetic coupling sign from the π-π stacking could be explained with McConnell I spin-polarization mechanism.

Solvothermal Synthesis and Structure Characterization of a 3D Hydrogen-bonded Copper Compound [Cu(H_2dhpmc)_2]·2H_2O

The solvothermal reaction of H3dhpmc (H3dhpmc = 2, 4-dihydroxypyrimidine- 5-carboxylic acid), CuCl2稨2O and NaVO3 results in the formation of a discrete mononuclear Cu(Ⅱ) complex [Cu(H2dhpmc)2]?H2O. It crystallizes in monoclinic system, space group P21/c with a = 5.0497(9), b = 10.0196(6), c = 13.715(2) ? b = 96.237(1)? V = 689.8(2) 3, Z = 2, Dc = 1.973 g/cm3, ?= 1.654 mm-1, F(000) = 414, R = 0.0736 and wR = 0.1351. Each Cu(Ⅱ) is coordinated to four oxygen atoms of two 2, 4-dihydroxypyrimidine-5-carboxylic acid ligands in the equatorial position and two oxygen atoms of two water molecules in the axial position to form an axially elongated octahedral geometry. The title complex is further linked into a three-dimensional structure through the weak interactions of hydrogen bonds between the oxygen atoms and the nitrogen atoms.

Layered Lanthanum Complex with 3-Nitrophthalic Acid Assembled via Hydrogen Bonds-Synthesis, Structure and Characterization of [LaL(HL)(H_2O)_3]_2·2H_2O (H_2L=3-NO_2C_6H_3(CO_2H)_2)

A new dinuclear centrosymmetric complex [LaL（HL）（H2O）3]2（2H2O （H2L = 3-nitrophthalic acid, NPA） was synthesized in water/ethanol solution and characterized by X-ray diffraction, IR spectrum and TGA-DTA. The complex crystallizes in triclinic system, space group P1^- with a = 8.1549（16）, b = 8.8856（18）, c = 15.277（3）A,α= 100.93（3）,α= 90.81（3）, γ= 104.56（3）°, V = 1049.8（4）A^3, Z = 1,μ= 2.125 mm^-1, Dc=1.994 g/cm^3, R = 0.0259 and wR = 0.0679. Two 3-nitrophthalates（2-） coordinate with the La3＋ ions in a bridging mode, and two monohydrogen- 3-nitrophthates（1-） and three waters in terminal ways, respectively. Each La^3＋ ion is nine-coordinated to exhibit a distorted tricapped trigonal prism coordination polyhedron. Both the coordinated and crystal waters are involved in the inter- and intramolecular hydrogen bonds. The dinuclear units are linked into a 2D network structure in the ab plane via intermolecular hydrogen bonds along the axes a and b. Two crystal waters fill each rhombic pore of the network. The networks are further packed along the c axis forming a layered supramolecular structure through the C-H…O weak forces between the adjacent sheets. TGA analysis shows the complex undergoes the loss of waters of crystallization and coordination and the decomposition of ligands sequentially.

Syntheses and Crystal Structures of Two Gd(Ⅲ) Hydrogen Supramolecules Based on p-Sulfonatothiacalix[4]arene

Two novel polymeric complexes, [Gd（HsTCAS）（H2O）7]·4H2O 1 and [Gd（HsTCAS） （CH3COCH3）（H2O）6]·6H2O 2 （H4TCAS = p-sulfonatothiacalix[4]arene）, have been synthesized and characterized by single-crystal X-ray diffraction analyses. Complex 1 crystallizes in monoclinic, space group C2/m with a = 20.2308（12）, b = 19.0894（10）, c = 12.2448（7）A, β = 101.847（3）°, V = 4628.1（5）A^3, C24H43GdO27S8, Mr = 1169.25, Z = 4, Dc = 1.690 g/cm^3, F（000） = 2380,μ = 1.879 mm^-1, the final R = 0.0404 and wR = 0.1038 for 5127 observed reflections with I 〉 2σ（I）. Complex 2 is pseudo-isostructural with complex 1.

Synthesis and Structure of a Hydrogen-bonding Assembled Three-dimensional Supramolecular Indium(III) Compound Involving One-dimensional Helices

The title compound [In（H2ip）（pdc）（H2O）] （H3ip = 5-hydroxyisophthalic acid, H2Pdc = pyridine-2,6-dicarboxylic acid） has been synthesized and characterized by single-crystal X-ray diffraction analysis. It crystallizes in monoclinic, space group P21/c with a = 13.830（8）, b = 6.488（4）, c = 17.632（10）A^°, β = 92.510（10）°, C15H10InNO10, Mr= 479.06, V = 1580.6（15）A^°3, Z = 4, De= 2.013 g/cm^3, F（000） = 944,μ = 1.557 mm^-1, the final R = 0.0413 and wR = 0.0793 for 2950 observed reflections with I 〉 2σ（I）. The In（Ⅲ） ion is seven-coordinated in a slightly distorted penta-bipyramidal geometry. The mixed ligands connect the In（Ⅲ） ions into 21 helical chains along the [010] direction, and the hydrogen bonds assemble the chains into a three-dimensional supramolecular network.

A Novel Luminescent Tetranuclear-copper(Ⅰ) Complex with Cavities Formed through Hydrogen Bonds

The solvothermal reaction of CuI with 5-amino-2-benzimidazolethiol in acetonitrile condition affords complex [Cuz（5-amino-2-benzimidazolethiol）2]2 which has been characterized by elemental analysis, infrared spectrum and single-crystal X-ray diffraction analysis. Crystal data for C28H24N12S4Cu4： monoclinic, space group C2/c with a = 15.970（5）, b = 12.365（4）, c = 16.293（5） A, fl = 91.977（6）°, V = 3215.5（18）, Z = 4, Mr= 910.99, Dc= 1.882 g/cm3 , F（000） = 1824, p = 2.913 mm-1, λ（MoKa） = 0.71073A, T= 293（2） K, the final R = 0.0527 and wR = 0.1342. X-ray diffraction analysis revealed that the title complex exhibits a l D channel constructed from tetranuclear-copper（I） motifs connected by hydrogen bonds and shows strong photoluminescence in the solid state at room temperature.

A New Cadmium(Ⅱ) Coordination Polymer Extended through Hydrogen Bonds and π-π Stacking Interactions: Synthesis and Photoluminescence Property

A new coordination polymer, {[Cd(OPY)(tdc)(HO)]·H2 O}n(OPY = 4,4?-(oxybis(4,1-phenylene))dipyridine, H2 tdc = thiophene-2,5-dicarboxylic acid), has been synthesized hydrothermally based on a V-shaped ligand OPY. The structure was fully characterized by elemental analysis, FT-IR spectroscopy, and X-ray single-crystal diffraction analysis. In1, two OPY ligands and one water molecule acted as terminal ligands coordinating to Cdcation to form [Cd(OPY)HO]units, which are then linked by tdc2-ligands to generate a one-dimensional chain. Every two adjacent chains linked by extensive O–H···O hydrogen bonds constitute one-dimensional double-chains, and such chains are extended into two-dimensional layers via O–H···N hydrogen bonds. These layers are further connected to form a three-dimensional supramolecular architecture via π-π stacking interactions. In addition, the thermal stability and solid state fluorescence property of 1 were also investigated.

Synthesis and Characterization of a Two-dimensional Cadmium(II) Compound Involving Covalent and Hydrogen Bonds

A two-dimensional hydrogen-bonded cadmium(II) compound [Cd(dapm)2- (CH3COO)2(H2O)2] (dapm = diaminodiphenylmethane) has been synthesized and characterized by single-crystal X-ray diffraction analysis. It crystallizes in monoclinic, space group C2/c with a = 27.572(3), b = 5.5064(5), c = 23.310(2) , = 124.785(1)o, C15H19Cdo.5ON2O3, Mr =331.52, V = 2906.6(5) ?, Z = 4, Dc = 1.515 g/cm3, F(000) = 1368 and = 0.801 mm-1. The final R = 0.0403 and wR = 0.1014 for 1795 observed reflections with I≥4(I). The centrosymmetric Cd(II) is six- coordinated in a distorted octahedral geometry, and the dapm in a trans mode acts as a monoden- tate ligand. The intermolecular hydrogen bonds among coordinated aqua molecules with coordi- nated acetate oxygen atoms and uncoordinated dapm nitrogen atoms form a two-dimensional supramolecular framework.

Analysis of Intra-and Intermolecular Hydrogen Bonds and Quantum Chemical Calculations on 1-(3-Fluorobenzoyl)-3-(4-trifluoromethylphenyl)thiourea

1-（3-Fluorobenzoyl）-3-（4-trifluoromethylphenyl）thiourea, C15H10F4N2OS, has been synthesized firstly and determined by single-crystal X-ray diffraction analysis. The title compound crystallizes in monoclinic system, space group C2/c with a = 31.87（3）, b = 7.705（9）, c = 12.591（14） A°, b = 106.06（2）°, V = 2971（6） A°^3, Z = 8, Dc=1.530 g·cm^-1, F（000） = 1392, m = 0.266 mm^–1, S = 1.06, the final R = 0.070 and w R（I 〉 2s（I）） = 0.249. The crystal structure revealed that the carbonyl thiourea unit in the determined compound was mostly planar due in part to the formation of intramolecular N–H···O=C and C–H···S=C hydrogen bonds that form two S（6） rings. The intermolecular contacts of the crystal structure have been preformed based on the Hirshfeld surface and their associated 2D fingerprint plots. In the packing diagram of the synthesized compound, the C=S group formed two types of intermolecular hydrogen bonds by the H–N（C=O） group and the H–C of the phenyl ring, respectively, and they formed R2^2（8） and R2^2（14） ring motifs, respectively. The crystal packing form was also stabilized by the intermolecular hydrogen bonds C–H···O（1–x, y, 0.5–z） with the R2^2（10） ring motifs. In addition, supramolecular layers sustained by π-π stacking interactions（between the C（2）～C（7） rings with the C（10）～C（15） rings） are formed in the crystal structure of the title compound. The electronic and reactivity were assessed by the natural bond orbital（NBO） analysis in this study.

Hydrogen-bonded Supramolecular Rosette Ribbon Constructed from Melamine with Isophthalic Acid

The new complex of melamine （MA） with isophthalic acid （H2IA）, [（HMA^＋）- （HIA^-）]·2H2O, has been prepared and its structure was characterized by X-ray crystallography. The crystal is of triclinic, space group P^-1 with a = 7.0228（6）, b = 9.1706（8）, c = 12.170（1） A, α = 95.337（2）, β = 105.247（2）, γ = 97.813（2）^o, V = 742.3（1） A ^3, Mr= 328.30, Z = 2, Dc = 1.469 g/cm^3, ;λ = 0.71073 A,μ（MoKa） = 0.121 mm^-1 and F（000） = 344. The structure was refined to R = 0.0389 and wR = 0.1093 for 2513 observed reflections with I 〉 2σ（I）. Melamine dimer and isophthalic acid anion are interlinked by N-H…N and N-H…O hydrogen bonds, resulting in a 1D rosette ribbon in which water molecules and amino groups are self-assembled into quasihexagonal patterns.

Primary Organicamine Templated Indium Iodate (H_2en)KIn(IO_3)_6·2(H_2O) with Hydrogen-bonded Helices

The first primary organicamine templated indium iodate with the formula （H2en）KIn（IO3）6-2（H2O） was hydrothermally synthesized via reaction at 100 ℃ for 7 d and characterized by single-crystal X-ray diffraction and thermal analysis. The compound crystallized in a triclinic system with space group P1, a=0.69803（14） nm, b=0.70863（14） nm, c=1.2091（2） nm, a=76.417（4）°,β=79.953（4）°, γ=72.206（3）°, V=0.55012（19） nm3. Structure determination indicates that it is made up of zero-dimensional units each of which consists of [In（IO3）6]3 anion, potassium, water and ethylenediamine cation. The most striking feature of the compound is that it possesses helical hydrogen bonds formed by organic amine template, water molecules and inorganic network.