CRYSTAL STRUCTURE OF 2-(BENZOYLMETHYLENE)HEXAHYDROPYHIMIDINE

<正> INTNDDUCTION. In our study on ketene aminals, it has been discovered that there are some differences between 2-(benzoylmethylene)imidazolidine and 2-(benzoylmethylene)hexahydropyrimidine in their reactivities and spectral data of NMR and IR. The crystal structure of the title compound was determined in order to carry out a systematic investigation on these problems.     

Microwave-assisted Syntheses and Crystal Structures of Benzimidazole Thiazolinone Derivatives

A rapid and efficient microwave-assisted synthesis method for the preparation of 3-(1H-benzo[d]imidazol-2-yl)-2-substituted phenyl thiazolidin-4-one (4a, 4b) was described. The structures of 4a and 4b were determined by elemental analyses, IR, 1H NMR and X-ray diffraction. In the crystals of compounds 4a and 4b, the imidazole ring and two benzene rings are planar. Interestingly, the dihedral angle between two benzene rings is 71.5° in 4a, while it is almost perpendicular in 4b due to the different benzene substituents. Meanwhile, the thiazolidinone ring is planar in 4a while slightly distorted with an r.m.s deviation of 0.1494(2) in 4b. The hydrogen bonding interactions observed link the molecules to form a dimeric unit, which may be effective in the stabilization of the structure.     

Rotation dynamics of C_(60) molecules in organic superconductor K_3C_(60)

The rotation dynamics of C60 molecules in organic superconductor K3C60 has been investigated from the viewpoint of intramolecular interaction.It is determined that the rotation of C60 at room temperature has been frozen up within a small region of rotation angle (0→50°),and pointed out that the reason for the freeze is the physical interaction rather than the geometrical hindrance.The computations of the interactions for alkali-doped compounds A3-xAxC60(x=1,2,3;A,A'= K,Rb,Cs) other than K3C60 have also been carried out.From the obtained results,it is seen that the superconducting transition temperatures Tc are strongly connected with the interactions in them,and this observation is consistent with the discovery of the correlation between Tc and lattice constants a     

CRYSTAL STRUCTURE OF 2-METHYL-4-(ρ-)PLUOROPHENYL-2,3,4,5 TETRAHYDRO-BENZO-(l,5)-THIAZEPINE(C16H16SNF)

<正> INTRODUCTION. In our systematic investigation on the 2, 4-substituted derivatives of dihydro- and tetrahydro-benzo-(1,5)-thiazepines, it has been discovered that there are large differences between dihydro- and tetrahydro- compounds in their conformation and in their spectral splits of proton     

Coordination polyhedron growth mechanism model and growth habit of crystals

A new growth mechanism model, coordination polyhedron growth mechanism model, is introduced from the angle of the coordination of anion and cation to each other at the interface. It is pointed out that the force driving the growth unit to enter the crystal lattice is the electrostatic attraction force between ions, whose relative size can be approximately measured by the electrostatic bond strength (EBS) that reaches a nearest neighbor anion (or cation) in the parent phase from a cation (or anion) at the interface. The growth habits of NaCI, ZnS, CaF2 and Csl crystals are discussed, and a new growth habit rule is proposed as follows. When the growth rate of a crystal is determined by the step generation rate, the growth habit of this crystal is related to the coordination number of the ion with the smallest coordination rate at the interface of various crystal faces. The smaller the coordination number of the ion at the interface, the faster the growth rate of corresponding crystal face. When the growth     

异吲唑硝基取代衍生物的HEI2光电子能谱——-"轨道换向"现象的又一例证

The HeIα PES of indazole (1a), 3-bromoindazole (2a) and their isomeric nitro derivatives 1b-e and 2b-e have been recorded. It has been found that the lowest π^-^1 ionization energies (I1)^m, (I2)^m are moved towards higher energies under the influence of the nitro group, but that there is no significant dependence of the size of the shifts (ΔI1)^m, (ΔI2)^m on the position of the group. The result, which is at variance with the predications derived from a naive perturbation treatment based on the π orbitals of 1a, has been explained as being due to "orbital switching" in the substituted derivatives.     

Co-crystallization of glycine anhydride with the hydroxybenzoic acids: Controlled formation of dimers via synthons cooperation and structural characterization

The results of crystallographic analyses on 1:1 and 1:4 well-defined co-crystals formed between glycine anhydride and each of 4-hydroxybenzoic acid and 3,5-dihydroxybenzoic acid are described. Neutral molecules are connected via heteromeric O-H···O and N-H···O contacts leading to different packing arrangements of supramolecular chains. On the basis of the molecular structures of glycine anhydride and carboxylic acid guests, the hydrogen bonds are arranged to give centrosymmetric synthons V and VII which are noteworthy for their robustness. Hydrogen-bond interactions between glycine anhydride and aromatic acid provide sufficient driving force to direct molecular recognition and crystal packing. Utilization of the orientation of functional groups of the building blocks, the acidity, and weak interactions provides a route for the creation of novel supra- molecular architectures in the crystal lattice. Both two co-crystals contain the expected hydrogen-bonded motifs, and there has been no proton transfer from either of the two carboxylic acids to the aza compound moiety. This demonstrates that glycine anhydride is very capable of affecting the construction of binary co-crystals in a predictable and rationale manner. It is noted that synthons VⅢ and IX are fairly large, but the real challenge in crystal engineering is to find a big enough synthon that occurs often enough. Thermal stability of these compounds has been investigated by thermogravimetric analysis (TGA) of mass loss.     

EFFECT OF IONIC RADII ON UNIT-CELL VOLUMES OF ISOSTRUCTURAL COMPOUNDS

The relation between cell-edges or unit-cell volumes of isostructural compounds and theionic radii has wide applications in crystal chemistry. The authors have proved: (1) For a series of multiple isostructural compounds such as A_mB_n…X_p, when the anionand other cations are fixed, there exists the following relation between the unit-cell volume Vand the radius r_A of a certain cation such as A: V = (a + br_A)(r_X + r_A)~3 (a and b are constants). (2) For binary isostructural compounds A_mX_p, the above relation is reduced to V = k(r_X + r_A)~3 (k is a constant). (3) For binary isostructural compounds the relation between V and r_A~3 is approximatelylinear, and for multiple compounds, it is often curvilinear but still approximately linear whenthe variation of r_A is slight. As another approximation, a linear relation also exists betweenV and r_A for isostructural compounds. (4) The relation of ce1l-edge a vs. r_A is linear for binary isostructural compounds. Butno such a good linear relation exists fo     

Synthesis,Characterization and X-ray Structure of N-(4-bromobutanoyl-N’-(2-3- and 4-methylphenyl)thiourea

N-4-(bromobutanoyl)-N'-(o-, m- and p-tolyl)thioureas 3a, 3b and 3c respectively, were synthesized by the reaction of 4-bromobutanoylisothiocyanate with p-, m- and o-toludine. The products were characterized by IR, and NMR spectroscopic techniques. The two carbonoylthiourea isomers N-(4-bromobutanoyl)-N'-(3-methylphenyl)thiourea(3b) and N-(4-bromobutanoyl)-N'-(4-methylphenyl)thiourea(3c) were obtained in crystalline form by recrystallization from DMSO. Xray crystallographic studies showed that both compounds 3b and 3c crystallize in triclinic system with space group of P1. The molecules adopt trans-cis configuration with respect to the positions of 4-bromobutanoyl and tolyl groups respectively, against the thiono C=S bond across their C–N bonds. The configuration is attributed by the intrahydrogen bond between the carbonyl oxygen and amide hydrogen atoms. Both crystal structures are stabilized by N–H···S intermolecular hydrogen bonds to form dimers and arranged along the b axis.     

STUDY ON FACTORS AFFECTING ROOM TEMPERATURE TRANSITION OF POLYTETRAFLUOROETHYLENE

In the X-ray diffiaction intensity distribution diagram of PTFE, three diffraction peaks exist inthe range of Bragg angle 30--45°, which are very sensitive to the Crystal trausition at room temperature.At 15℃, the crystal is triclinic and the "small spikes" along with the main peaks appear on the dif-fraction scans due to the distortion of the unit cell, while at 23℃, distortion no longer exists, "smallspikes" disappear completely. When the temperature is raised to 34℃, the hexagonal crystal fur-ther randomizes and the peak at Bragg angle 42°vanishes. We assigned correctly Miller index (108) tothis peak and used 2θ=30--45°region ("sensitive region") as a criterion to characterize qualita-tively the crystal transition. It has been found that some factors such as γ-irradiation, cold press-ing, drawing, calendering and copolymerization which are usually encountered in the fabrication orapplication of PTFE articles have profound effect on the crystal transition as evidenced by X-raydiffraction patterns and DSC thermograms. The information obtained in the present work isbeneficial to the use of PTFE articles.     

2-芳亚胺基噻唑烷类化合物的晶体结构研究

2-芳亚胺基噻唑烷类化合物具有良好的农用杀菌活性 [1] ,对于其双键异构问题 ,文献观点不一 [2 ,3] .另外 ,芳环上取代基的位置对化合物的杀菌活性影响较大 ,如苯环邻位甲基取代 ( a)及对位甲基取代 ( b)的化合物在 50 mg/L浓度时对某些致病菌的活性有较大差异 (见表 1 ) .本文以苯环上甲基取代的化合物为代表 ,测定了该类化合物的晶体结构 .Table1　Fungicidal activity( % ) of a and b( Dose:50 mg/L)Com pd. Gibberella zeae Phoma asparagi Cercospora beticola Alternaria solani Physalospora piricola a 6 0 .0 6 3.6 5 3.3 2 …     

Electrochemical synthesis of metal complexes of schiff bases: The crystal structure of bis{2-[(4-methylphenyl)iminomethyl]pyrrolato}copper(II)

The electrochemical oxidation of anodic nickel, copper, zinc or cadmium in acetonitrile solutions of Schiff bases (HL) derived from H-pyrrole-2-carbaldehyde and substituted anilines gives compounds of general formula ML₂. The crystal structure of bis{2-[(4-methylphenyl)iminomethyl]pyrrolato}copper(II) has been determined by X-ray diffraction. The compound crystallizes in the monoclinic space group P2₁/n with a = 9.356(2), b = 16.697(2), c = 14.145(2) Å and β = 108.47(2)°. The crystal structure consists of monomeric molecules in which the central CuN₄ unit has distorted square-planar geometry with a dihedral angle of 25.8(3)° between the coordination planes. The IR, ¹H NMR and UV-visible spectra of the complexes are discussed and related to the structure.     

新型三唑醇衍生物的合成及抗真菌活性

依据三唑醇类化合物的构效关系, 保留基本药效团三唑环、叔醇羟基和2,4-二氟苯基, 引入新的含哌嗪侧链结构, 设计合成了12个1-(1H-1,2,4-三唑-1-基)-2-(2,4-二氟苯基)-3-取代-2-丙醇类化合物.     

The synthesis and transformations of some 3-thiocarbamoylthiazolidines

In connection with our studies on potential bioactive compounds some new polysubstituted 3-thiocarbamoylthiazolidines 5, 6, 7, 9 and 10 were prepared in the reaction between 2-(2-methoxy-phenyl)iminothiazolidine (2) and sulfamoylphenyl isothiocyanates 3 and 4a-c. The structures for compounds 2 and 5 were established by X-ray analyses, showing that the reaction is taking place at the endo-cyclic nitrogen atom of thiazolidine ring.     

5,5'-双(4-甲基苯)-2,2-联恶唑的晶体结构及构象

本文报道5,5'-双(4-甲基苯基)-2,2'-联恶唑(POOP)的晶体结构,并辅以分子力学法(MM-X程序)计算,探讨了POOP分子的基态构象.     

Isomere Tritolylphosphine und deren Derivate. UV-Spektren und Dipolmomente

The UV spectra of tris(2-methylphenyl)phosphine (I), tris(3-methylphenyl)phosphine (II), tris(4-methylphenyl)phosphine (III), and of their phosphine oxides, phosphine sulfides, and methyl phosphonium iodides are given. The dipole moments of I–III in benzene at 20° C were also determined. I absorbs at the longest wavelength and this result may be interpreted by a broadening of the angle on phosphorus in I. This results also from the measured dipole moment, assuming a constant phosphorus ring moment and neglecting other ortho-effects.     

Structural characterization of two oxadiazolic systems used as spacers for potential angiotensin II receptor antagonists

The structures of two oxadiazole derivatives, methyl 2-[5-(4-methylphenyl)-1,3,4-oxadiazol-2-yl]benzoate (1) and methyl 2-[3-(4-methylphenyl)-1,2,4-oxadiazol-5-yl]benzoate2, used as spacers in the synthesis of new potential non-peptide angiotensin receptor antagonists have been determined by X-ray crystallography. In both compounds π-π interactions were observed between the oxadiazole rings and the phenyl rings of neighboring molecules. In the crystal packing of the oxadiazole 2 two C-H?O interactions are present.     

Synthesis and biological evaluation of some new substituted benzoxazepine and benzothiazepine as antipsychotic as well as anticonvulsant agents

Various 2-((2-((5-benzylideneamino)-1,3,4-oxa/thiadiazol-2-yl)methyl)hydrazinyl) methyl)benzo[b][1,4]oxa/thiazepin-4(5H)-ones (4a–4l), 2-((2-((5-(4-oxo-2-substitutedphenyl thiazolidin-3-yl)-1,3,4-oxa/thiadiazol-2-yl)methyl)hydrazinyl)methyl)benzo [b] [1,4]oxa/thiazepin-4(5H)-ones (5a–5l) and 2-((2-((5-(3-chloro-2-(substitutedphenyl)-4-oxoazetidin-1-yl)-1,3,4-oxa/thia diazol-2-yl)methyl)hydrazinyl)methyl)benzo[b][1,4]oxa/thiazepin-4(5H)-ones (6a–6l) have been synthesized. The structures of these compounds have been established by elemental (C, H, N) and spectral (IR, ¹H-NMR and Mass) analysis. The synthesized compounds were screened for their antipsychotic and anticonvulsant activities. Compound 5l was found to be the most active compound of this series.     

Synthesis, Characterization, Spectroscopic and Electro-chemical Properties of New Mono- and Binuclear Copper(I) Complexes with Substituted 2,2''''-Bipyridine

Introduction Copper(I) complexes have received much attention for their being less expensive and environmentally friendly, various coordination geometry, rich photo-chemical and photophysical properties.1-7 It is well known that copper complexes with diimine (2,2'-bipy- ridine, 1,10-phenanthroline and their substituted deriva-tives designated as diimine) generally exhibit low en-ergy metal-to-ligand charge-transfer (MLCT) states lo-cated in the regions of 350650 nm (e ≈ 103—104 dm3昺ol-1昪…     

3-甲基-4-对甲苯基-5-(2-吡啶基)-1，2，4-三唑-铜(Ⅱ)配合物

A copper(Ⅱ) complex [CuL(H₂O)(Sal)]·0.5H₂O was obtained by the reaction of copper(Ⅱ) salicylate with 3-methyl-4-(4-methylphenyl)-5-(2-pyridyl)-1,2,4-triazole (L) in ethanol-water solution at room temperature. The crystal belongs to triclinic system with space group P1, and a=0.913 6(4) nm, b=1.122 2(5) nm, c=1.263 3(7) nm, α=67.10(2)°, β=76.31(3)°, γ=68.17(2)°, V= 1.101(1) nm³, Z=2. The final refinement gave R₁=0.039 8 and wR₂=0.106 0 for 3 453 reflections with I>2σ(I). This complex is a good purple fluorescent material in solid state at room temperat-ure. CCDC: 685713.