Synthesis and Structure Analysis of N-（Dehydroabietyl）maleamic Acid

N-(Dehydroabietyl)maleamic acid was synthesized from dehydroabietylamine and maleic anhydride.Its structure was characterized by IR,1 H-and 13 C-NMR spectra.The stereo structure of the title compound was also unambiguously confirmed by X-ray crystal structure analysis.The white crystal crystallizes in the monoclinic system,space group P2 1 with a=12.075(2),b=10.377(2),c=17.840(4),β=100.31(3) °,V=2199.3(8) 3,R=0.0618 and wR=0.1437.Two crystallographically independent molecules with different conformations co-exist in the unit.In each molecule,the two cyclohexane rings form a trans ring junction with chair and half-chair conformations,respectively.The C=C double bond between two carbonyl groups is in a Z configuration.Intermolecular and intramolecular hydrogen bonds coexist to stabilize the structure.     

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, C_(15)H_(10)F_4N_2OS, 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) ?, b = 106.06(2)°, V = 2971(6) ?~3, Z = 8, D_c=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 R_2~2(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 R_2~2(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.     

Structure of cis-[Pt(NH_3)(2-picoline)]~(2+) and DNA adduct and its bonding characteristics

Several methods including molecular mechanics, molecular dynamics, ONIOM that combines quantum chemistry with molecular mechanics and standard quantum chemistry are used to study the configuration and electron structures of an adduct of the DMA segment d(ATACATG*G*TACATA)-d(TATGTACCATGTAT) with cis-[Pt(NH3)(2-Picoline)]2+. The investigation shows that the configuration optimized by ONIOM is similar to that determined by NMR. Strong chemical bonds between Pt of the complex and two N7s of neighboring guanines in the DNA duplex and hydrogen bond between the NH3of the complex and O6 of a nearby guanine have a large impact on the configuration of the adduct. Chemical bonds, the aforementioned hydrogen bond, and the interaction between a methyl of the complex and a methyl of the base in close proximity are critical for the complex to specifically recognize DNA.     

CRYSTAL AND MOLECULAR STRUCTURE OF N, N-PLATINUM-DIETHYL-DICHLORIDEDI-L-ASPARTATE

This paper reports the crystal and molecular structure of title compound. 3978 three-dimensional independent reflections were collected by Syntex R3 four circle diffractometer. The crystal is monoclinic with space group P2_1, a=8.074(1), b=11.309(4), c=27.793(9), β=106.84°(2), Z=4. The molecular formula is Pt(C_8 H_(15)O_4N)_a Cl_2. The crystal structure was solved by Patterson method and refined by block matrix least squares refinement techniques. The final R factor is 0.039.The result of crystal structure analysis shows that Pt(Ⅱ) has a dsp~2 hybrid orbital and square coordination. Two C1 atoms are located oppositely to two diethyi-dichloride-di-L-aspartare. N atoms have sp~3 tetrahedral hybrid configurations and form the coordinate bonds with Pt(Ⅱ) atom using their lone pair electrons. By reason of molecular packing and due to the formation of inner hydrogen bonds in the complex molecule, the configuration of L-aspartic acid in the title complex is more twisted than that of L-and DL-aspartic acid     

Syntheses,Crystal Structures and Antibacterial Activities of Cobalt(Ⅱ) and Manganese(Ⅱ) Complexes with Schiff Base Ligand Derived from Tryptamine

Two new mononuclear complexes, namely [Co(L)_2](1) and [Mn(L)_2](2)(HL = N-(3-methylsalicylidene)tryptamine), have been synthesized by the reactions of the ligand with cobalt acetate or manganese acetate in anhydrous ethanol. The crystal structures of the complexes were characterized by IR spectrum, elemental analysis, PXRD and single-crystal X-ray diffraction analysis. Complex 1 crystallizes in monoclinic, space group C2/c, with a = 23.146(2), b = 9.4864(10), c = 13.9261(15) ?, β = 102.898(2)°, V = 2980.6(5) ?3, Z = 4, Dc = 1.367 g/cm3, F(000) = 1284 and μ = 0.616 mm-1. Complex 2 crystallizes in monoclinic, space group P21/n, with a = 14.807(11), b = 13.118(10), c = 16.663(13) ?, β = 111.237(14)°, V = 3017(4) ?3, Z = 4, Dc = 1.342 g/cm~3, F(000) = 1276 and μ = 0.477 mm-1. The units of complex 1 are linked by intermolecular N–H···π hydrogen bonds into infinite 1D chains, which are further extended into a 3D supramolecular structure by a series of π···π stacking interactions. The units of complex 2 are linked by intermolecular N–H···π hydrogen bonds and C–H···π hydrogen bonds into an infinite 3D supramolecular structure. Meanwhile, the antibacterial activities of the ligand and its complexes have been tested against four kinds of bacteria. The results show that the three compounds all have excellent antibacterial activities and that 1 and 2 possess stronger inhibiting effects against the bacteria than the Schiff base.     

The open-close mechanism of M2 channel protein in influenza A virus:A computational study on the hydrogen bonds and cation-π interactions among His37 and Trp41

The M2 protein from influenza A virus is a tetrameric ion channel. It was reported that the permeation of the ion channel is correlated with the hydrogen bond network among His37 residues and the cation-π interactions between His37 and Trp41. In the present study,the hydrogen bonding network of 4-methyl-imidazoles was built to mimic the hydrogen bonds between His37 residues,and the cation-π interactions between 4-methyl-imidazolium and indole systems were selected to represent the interac-tions between His37 and Trp41. Then,quantum chemistry calculations at the MP2/6-311G level were carried out to explore the properties of the hydrogen bonds and the cation-π interactions. The calcula-tion results indicate that the binding strength of the N-H···N hydrogen bond between imidazole rings is up to -6.22 kcal·mol-1,and the binding strength of the strongest cation-π interaction is up to -18.8 kcal·mol-1(T-shaped interaction) or -12.3 kcal·mol-1(parallel stacking interaction). Thus,the calcu-lated binding energies indicate that it is possible to control the permeation of the M2 ion channel through the hydrogen bond network and the cation-π interactions by altering the pH values.     

Structures of N—（2,3,4,6—Tetra—O—acetyl—β—D—glycosyl） thiocarbamic Benzoyl Hydrazine

The crystal structure of N-(2,3,4,6-tetra-O-acetyl-β-D-gly-cosyl)-thiocarbamic benzoyl hydrazine(C22H27N3O9S) was determined by X-ray diffracton method.The hexopyranosyl ring adopts a chair conformation.All the ring substituents are in the equatorial positions.The acetoxyl-methyl group is in synclinal conformation.The S atom is in synperiplanar conformation while the benzoyl hydrazine moiety is anti-periplanar.The thiocarbamic moiety is almost companar with the benzoyl hydrazine group.There are two intramolecular hydrogen bonds and one intermolecular hydrogen bond for each molecule in the crystal structure.The molecules form a network structure through intermolecular hydrogen bonds.     

Synthesis,Crystal Structure and Flame Retardance of 2-(3-Silatranylpropylamino)-4-phenyl-5,5-dimethyl-1,3,2-dioxaphosphorinane-2-oxide

The title compound, 2-(3-silatranylpropylamino)-4-dichlorophenyl-5,5-dimethyl-1,3,2-dioxaphosphorinane-2-oxide(2(C_(20)H_(33)N_2O_6Psi)·C_2H_6O·CH_4O, Mr = 991.20), has been synthesized by the nucleophilic substitution reaction of 2-chloro-4-phenyl-5,5-dimethyl-1,3,2-dioxaphosphorinane-2-oxide with γ-aminopropylsilatrane, and its crystal structure was determined by single-crystal X-ray diffraction. The crystal belongs to the triclinic system, space group P1 with a = 10.3783(15), b = 11.2402(17), c = 12.1675(18) ?, a = 70.653(4), b = 82.908(4), g = 85.690(4)°, V = 1328.1(3) ?3, Z = 1, Dc = 1.239 g/cm~3, μ = 0.19 mm~(-1), F(000) = 532, the final R = 0.0640 and wR = 0.2090 for 3615 observed reflections with I 2s(I). The cyclic dioxaphosphorinane ring in the molecule adopts a thermodynamically stable cis conformation, while the silatrane fragment forms a cage-like structure in which there exists an intramolecular Si?N donor-acceptor bond. In the crystal structure, centrosymmetrically related molecules are linked by pairs of N–H···O hydrogen bonds into dimers, generating rings with graph-set motif R22(8). Furthermore, a couple of O(7)–H(10)···O(3) hydrogen bonds were formed by O atom of P=O and H atom from hydroxyl in the solvent ethanol. Thermal property of the compound was also studied by means of thermogravimetry(TGA). The thermal analysis and preliminary fireproofing test show that the title compound has good flame retardance.     

Theoretical Investigation on Interaction between Guanine and Luteolin

The interacting patterns of the luteolin and guanine have been investigated by using the density functional theory B3LYP method with 6-31＋G＊ basis set. Eighteen stable structures for the luteolin-guanine complexes have been found respectively. The results indicate that the complexes are mainly stabilized by the hydrogen bonding interactions. Meanwhile, both the number and strength of hydrogen bond play important roles in determining the stability of the complexes which can form two or more hydrogen bonds. Theories of atoms in molecules and natural bond orbital have also been utilized to investigate the hydrogen bonds involved in all the systems. The interaction energies of all the complexes which were corrected by basis set superposition error are 6.04-56.94 kJ/mol. The calculation results indicate that there are strong hydrogen bonding interactions in the luteolin-guanine complexes. We compared the interaction between luteolin and four bases of DNA, and found luteolin-thymine was the strongest and luteolin-adenine was the weakest. The interaction between luteolin and DNA bases are all stronger than luteolin-water.     

Aminolysis reaction of calix [ 4 ] arene esters and crystal structures and conformational behaviors of calix[4]arene amides

We first make use of aminolysis of calix[4]arene esters to synthesize calix[4]arene amides. When the two ethyl esters of the calix[4]arene esters are aminolysized, the 1, 3-amide derivative is formed selectively. The crystal structures of the calix-[4]arene with two butyl amide (3b) and four butyl amide moieties (4b) were determined. The intermolecular hydrogen bonds make 4b form two-dimensional net work insolid state. The 1H NMR spectra prove that 3b is of a pinched cone conformation, while 4b and tetraheptylamide-calix[4]arene (6b) take fast interconversion between two C2v isomers in solution and appear an apparent cone conformation at room temperature. As decreasing temperature, the interconversion rate decreases gradually and, finally, the interconversion process is frozen at Tc = -10℃, which makes both conformations of 4b and 6b the pinched cone structures. The hydrogen bond improves the interconversion barrier, and the large different values of the potential barrier between 6b and 4b (or 6b) may     

Synthesis,Crystal Structure and Antifungal Activities of 3-Methyl-1-(4-methylphenyl)-4-(N-4-trifluoromethylphenyl)-aminomethyl-5-(4-methoxyphenylthio)-1H-pyrazole

The title compound 3-methyl-1-(4-methylphenyl)-4-(N-4-trifluoromethylphenyl) aminomethyl-5-(4-methoxyphenylthio)-1H-pyrazole has been synthesized via a four-step reaction and characterized by IR,1H NMR,elemental analysis and X-ray crystallography.The compound crystallizes in monoclinic,space group P21/c with a = 8.7170(15),b = 18.355(3),c = 15.292(3) ,β = 103.445(3)°,V = 2379.7(7) 3,Dc = 1.350 g/cm3,Z = 4,μ = 0.184,F(000) = 1008,and the final R = 0.0491 and wR = 0.1339 for 4160 observed reflections(I 2σ(I)).The results demonstrate that there is a face-to-face π-π stacking interaction between one benzene ring(C(19)~C(24)) and another(C(13)~C(18)) at a plane-plane distance of 3.3539 .The ring normal and vector between the ring centroids form an angle of 18.2o up to the centroid-to-centroid distance of 3.5273 .The crystal structure is stabilized by the intermolecular hydrogen bond of N(3)-H(3A)···N(2)(symmetry code:A –x+1,–y+1,–z).The preliminary biological test shows that the title compound has a moderate antifungal activity.     

STEREOCHEMICAL STUDIES ON CYCLOHEXANONE SEMICARBAZONE DERIVATIVES II. CRYSTAL AND MOLECULAR STRUCTURES OF 4-METHYL-CYCLOHEXANONE SEMICARBAZONE AND 4-CYCLOHEXYL-CYCLOHEXANONE SEMICARBAZONE

<正> The crystal and molecular structures of 4-methyl-cyclohexanone semicarbazone (MCSC) and 4-cyclohexyl-cyclohexanone semicarbazone (CHCSC) have been determined by X-ray diffraction methods. MCSC, monoclinic, space group C2/c with a=19. 788(5), b=8.328(2), c=14. 372(4) A , β=127. 44(1)°, final R = 0. 051, Rw = 0. 057 for 801 unique reflections. CHCSC, triclinic, space group P1 with a = 5. 874(5), b = 7. 026(3), c=17. 93(1)A, α=88. 57(4)°,β = 83.08(5)°,γ=111. 66(5)°, final R = 0. 063, Rw = 0. 057 for 2144 unique reflections. The cyclohexane ring of both compounds has a slightly distorted chair conformation. The NH CONH group in both molecules shows a configuration with the C = O bonds trans to the N-NH bond with respect to the C-NH bond. The molecules in the crystals interacted with each other forming infinite ribbons through the O....H -N hydrogen bonds.     

Crystal Structure and Biological Activities of N-(5-(4-Chloro-2-(trifluoromethyl)phenyl)furan-2- carbonyl)-N'-(4,6-dimethylpyrimidin-2-yl)thiourea

The new title compound N-(5-(4-chloro-2-(trifluoromethyl)phenyl)furan-2-carbon-yl)- N?-(4,6-dimethylpyrimidin-2-yl)thiourea (C19H14ClF3N4O2S) has been synthesized, and its crystal structure and biological behaviors were studied. The title compound crystallizes in the monoclinic system, space group P21/c with a = 7.932(5), b = 33.46(2), c = 7.556(5) , β = 98.058(9)°, V = 1986(2) 3, Mr = 454.85, Z = 4, Dc = 1.521 g/cm3, μ = 0.349 mm–1 and F(000) = 928. The structure was solved by direct methods and refined to R = 0.0724 and wR = 0.1429 for 3494 observed reflections (I > 2σ(I)). Intermolecular hydrogen bonds along the b axis together with the continuous π-π interactions construct the three-dimensional architecture of the title compound. The preliminary biological tests show definite herbicidal activity for the title compound.     

A Cell Solid Structure of cis-1,3-Cyclohexanedicarboxylic Acid and Its Complex Crystal with 4,4''''-Dipyridine

Carboxylic acids are important in crystal engineering because they can form strong and directional O-H…O hydrogen bonds as dimmer and catmer.[1] The dicarboxylic acids (not containing other hydrogen bonding groups) generally form the extended line structure interlinked through dimmer,[2] except that oxalic acid forms both the β-oxalic acid linked by dimmer (finite synthon) and the a-oxalic acid by catmer[3] (infinite synthon). A new molecular packing structure of cis-1,3-cyclohexanedicarboxylic acid (CHDA), which is different from line structure,[4] was gotten (P1/2, Figure 1). The novel structure has dimmer and catmer hydrogen bond pairs in the crystal and the hydrogen bond length of O-H…O is 0.268 nm in catmer and 0.264 nm in dimmer. The bond angles of O=C-O vary from 123.1° to 123.8° in catmer and from 123.1° to 122.0° in dimmer comparing with the ones in line structure.     

Theoretical Investigations on the Structure,Density, Thermodynamic and Performance Properties of Bis（2,2-dinitropropyl） formal

Density functional method was used to investigate the IR spectrum,heat of formation and thermal stability of a new energetic material bis(2,2-dinitropropyl) formal(BDNPF).The detonation velocity and pressure were evaluated by using the Kamlet-Jacobs equations based on the theoretical density and heat of formation.The bond dissociation energies for the weakest bonds were analyzed to investigate the thermal stability of the title compound.The results show that the C(1)-N(1) bond is predicted to be the trigger bond during pyrolysis.The crystal structure obtained by molecular mechanics belongs to the P21 space group,with the lattice parameters to be Z = 2,a = 11.5254,b = 6.2168,c = 9.5000  and ρ= 1.66 g/cm3.     

Synthesis and Crystal Structure of a Copper(Ⅱ) Compound Constructed by N-(4,6-Dimethoxylpyrimidin)-N'-(ethoxycarbonyl)thiourea

A copper(Ⅱ ) complex Cu(L)2(NO3)2 constructed by the L (L = N-(4,6-dime- thoxylpyrimidin)-N'-(ethoxycarbonyl)thiourea) ligand crystallizes in monoclinic, space group C2/c with a = 16.2416(16), b = 9.1385(7), c = 22.0008(18) , β = 108.077(2)o, V = 3104.3(5)3, Dc = 1.627 g/cm3, Z = 4, C20H28CuN10O14S2, Mr = 760.18, μ(MoKα) = 0.920 mm–1, F(000) = 1564, R = 0.0471 and wR = 0.1284 for 2239 observed reflections (I > 2σ(I)). X-ray diffraction shows the existence of weak complementary intramolecular N–H…O (DA) hydrogen bonds which further strengthen the coordination from the two L ligands with the Cu(II) ion, intermolecular C–H…O hydrogen bonds and weak π…π stacking interactions, leading to the formation of a multi-dimen- sional supramolecular network.     

Synthesis and Crystal Structure of a Copper(II) Compound Constructed by N-(4,6- Dimethoxylpyrimidin)-N'-(ethoxycarbonyl)thiourea

A copper(Ⅱ) complex Cu(L)2(NO3)2 constructed by the L (L = N-(4,6-dime- thoxylpyrimidin)-N'-(ethoxycarbonyl)thiourea) ligand crystallizes in monoclinic, space group C2/c with a = 16.2416(16), b = 9.1385(7), c = 22.0008(18) (A),β = 108.077(2)°, V ＝ 3104.3(5)(A)3, Dc = 1.627 g/cm3, Z = 4, C20H28CuN10O14S2, Mr = 760.18, μ(MoKα) = 0.920 mm-1, F(000) = 1564, R = 0.0471 and wR = 0.1284 for 2239 observed reflections (I > 2σ(I)). X-ray diffraction shows the existence of weak complementary intramolecular N-H…O (DA) hydrogen bonds which further strengthen the coordination from the two L ligands with the Cu(II) ion, intermolecular C-H…O hydrogen bonds and weak π…π stacking interactions, leading to the formation of a multi-dimen- sional supramolecular network.     

Synthesis,Crystal Structure and Biological Activity of N-（2,6-Difluorobenzoyl）-N＇-[5-（4-trifluoromethyl-phenyl）-1,3,4-thiadiazol-2-yl]ure

The title compound N-(2,6-difluorobenzoyl)-N'-[5-(4-trifluoromethylphenyl)-1,3,4-thiadiazol-2-yl]urea(C17H9F5N4O2S,Mr = 428.34) has been synthesized by the reaction of 2-amino-5-(4-trifluoromethylphenyl)-1,3,4-thiadiazole with 2,6-difluorobenzoyl isocyanate,and its crystal structure was determined by single-crystal X-ray diffraction.The crystal belongs to monoclinic,space group P21/n with a = 10.7316(13),b = 10.5617(13),c = 16.037(2) ,β = 106.408(2)°,V = 1743.6(4) 3,Z = 4,Dc = 1.632 g/cm3,μ = 0.260 mm-1,F(000) = 864,the final R = 0.0599 and wR = 0.1420 for 3467 observed reflections with I > 2σ(I).The urea group,which adopts a planar configuration mediated by the intramolecular N-H...O hydrogen bond,is nearly coplanar with the thiadiazole and 4-trifluoromethylbenzene rings.The title compound was found to exhibit good fungicidal activity against Rhizoctonia solani and Botrytis cinerea.     

Synthesis,Crystal Structure and Electrochemical Properties of a Cobalt Compound Based on N-（4-pyridylmethyl）imidazole Ligand①

One compound with N-(4-pyridylmethyl)imidazole liand, [Co(pyim)2(N3)2]n 1(pyim = N-(4-pyridylmethyl)imidazole), was synthesized and structurally characterized. Compound 1 crystallizes in triclinic, space group P21/c with a = 8.090(3), b = 16.109(3), c = 8.590(3), B= 117.800(12)o, V = 990.3(5) A3, Z = 2, Mr = 461.37, Dc = 1.547 g/cm3, F(000) = 474, μ = 0.901 mm-1, the final R = 0.0381 and wR = 0.0950 for 1581 observed reflections with I 2A(I). In this compound, the unique Co(Ⅱ) resides at a crystallographic inversion center and exhibits an octahedral coordination geometry. The adjacent Co(Ⅱ) ions are connected by the pyim ligands to form a 2D layer structure. The layers are stacked in an ABAB mode and reinforced by the weak interlayer C–H···N hydrogen bonds and π-π stacking to give a 3D architecture. The thermal property and electrochemical property of compound 1 have also been studied.     

Synthesis and Crystal Structure of Ethyl 4-（2-Chloro-4-fluorophenyl）-6-hydroxy-3-oxo-1,3-dihydro-5-isobenzofurancarboxylate

The crystal structure of the title compound(C17H12ClFO5,Mr=350.72) was determined by single-crystal X-ray diffraction.The crystal belongs to monoclinic,space group P21/c,with a=7.693(1),b=15.767(1),c=12.986(1),β=97.23(1)°,V=1562.6(2)3,Z=4,Dc= 1.491 g/cm3,λ(MoKα)=0.71073,F(000)=720,μ(MoKα)=0.280 mm-1,R=0.0563 and wR=0.1674.A total of 3592 unique reflections were collected,of which 2462 with Ⅰ2σ(Ⅰ) were observed.Five-membered lactone rings and hydroxyl-substituted phenyl rings are approximately coplanar with their dihedral angle of 4.1°.The dihedral angle between two different phenyl rings is 71.3°.To our interest,intramolecular O(1)-H(1)···O(4) hydrogen bonds could be found in each molecule.Intramolecular hydrogen bonds and intermolecular van der Waals force contribute to the stability of the structure.