Crystal structure of 2-selenobenzyl-1-benzoic acid.

C14H12O2Se is monoclinic, P2(1)/c. Unit-cell dimensions at 293 K are a = 8.1055(7), b = 5.8403(11), c = 26.0302(17)A, beta = 94.560(5) degrees, V = 1228.3(3)A3, Dx = 1.575 g/cm3, and Z = 4. The R value is 0.048 for 2144 observed reflections. The dihedral angle between the phenyl rings is 74.9(2)degrees. There is an intermolecular hydrogen bond between two symmetry related carboxyl groups with an O1-O2 distance of 2.668(6)A. The molecules in the crystal are packed at normal van der Waals distances.     

Molecular and crystal structure of 2-(2-methyl-2-propenyl)-1,3-cyclopentanedione (C9H12O2)

An x-ray crystal structure study of 2-(2-methyl-2-propenyl)-1,3-cyclopentane-dione (C₉H₁₂O₂) has been carried out. It has been shown that in the solid this compound occurs exclusively in the enol form. The molecules are bound together by strong hydrogen bonds and form infinite chains along the b-axis. According to the spectroscopic data (¹H and¹³C NMR), the same compound in solution has a mesomeric structure.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 8, pp. 1794–1797, August, 1991.     

Synthesis and modification of 4-hydroxy-2-methyl-3-(2-chloro-2-propenyl)quinoline

4-Hydroxy-2-methyl-3-(2-chloro-2-propenyl)quinoline was prepared by O-allylation of 4-hydroxy-2-methylquinoline followed by the Claisen rearrangement of the 2-methyl-4-(2-chloro-2-propenyloxy)quinoline obtained. Chemical modifications of 4-hydroxy-2-methyl-3-(2-chloro-2-propenyl)quinoline resulted in the synthesis of 4-amino-2-methyl-3-(2-methyl-3-indolyl)quinoline.     

Crystal structure of diacetato-bis(2-methyl-2-propylamine)zinc(II)

The diacetato-bis(2-methyl-2-propylamine)zinc(II) compound crystallizes in the triclinic system, space group P-1 with unit cell parameters a = 10.0144(10)Å, b = 10.2687(10)Å, c = 10.5149(10)Å. α = 115.184(2)°, β = 97.489(2)°, γ = 114.066(2)°, ν = 830.85(14)ų. The obtained solid state structure of (^tBuNH₂)₂Zn(OOCCH₃)₂ shows both inter- and intramolecular NH—O hydrogen bond interactions which are analyzed.     

离子液体中脂肪酶催化拆分外消旋烯丙酮醇反应

 以离子液体为溶剂,考察了溶剂类型、水活度、温度、 pH值和共溶剂等因素对脂肪酶催化拆分外消旋烯丙酮醇(R,S)-4-羟基-3-甲基-2-(2-丙烯基)-2-环戊烯-1-酮反应的影响,并与常用于外消旋烯丙酮醇拆分的有机溶剂乙酸乙烯酯进行了比较. 结果表明,在离子液体［bmim］PF6中脂肪酶的催化性能较好,酶初始反应速率为18.48 μmol/(g·min), 半衰期为74.53 h, 高于在乙酸乙烯酯中的相应值(9.18 μmol/(g·min)和64.29 h). 但离子液体中拆分反应的转化率低于在乙酸乙烯酯中的转化率,可以通过向离子液体中补加酰基供体来提高外消旋烯丙酮醇的转化率. 两种反应介质中最佳酶反应条件均为水活度0.17, 温度40 ℃和pH=7, 但加入共溶剂后,离子液体中脂肪酶催化拆分外消旋烯丙酮醇的效率降低,而在乙酸乙烯酯中则有所提高.     

Crystal Structure of Diethyl 1-(6-methyl-2-benzothia-zolylamino)-2, 4-dichlorophenylmethylphosphonate

１ＩＮＴＲＯＤＵＣＴＩＯＮα Ａｍｉｎｏｐｈｏｓｐｈｏｎｉｃａｃｉｄｓ,ｂｉｏｉｓｏｓｔｅｒｅｓｏｆｎａｔｕｒａｌａｍｉｎｏａｃｉｄｓ,ｈａｖｅａｔｒａｃｔｅｄｍｕｃｈａｔｅｎｔｉｏｎｂｅｃａｕｓｅｔｈｅｙｓｈｏｗｗｉｄｅｂｉｏｌｏｇｉｃａｌａｃｔｉ...     

Crystal structure of isotactic poly(4-methyl-1-pentene)

The crystal structure of isotactic poly(4-methyl-1-pentene) was determined by x-ray analysis. The unit cell is tetragonal, P4 b2, with α = 18.70 Å and c (fiber axis) = 13.68 Å; it contains four molecular chains each consisting of seven monomeric units in the fiber period. The molecular conformation is essentially a (7/2) helix, but deviates slightly from the uniform (7/2) helix. The unusual low density is discussed from the structural point of view.     

Crystal and molecular structure of 2-(p-tolylimino)-4-methyl-4-ethyl-5-methylenethiazolidine

It was found by an x-ray diffraction study of 2-(p-tolylimino)-4-methyl-4-ethyl-5-methylenethiazolidine that the thiazolidine molecules in the crystal are joined together to form centrosymmetric dimers due to the formation of N-H...N hydrogen bonds. The structure of the dimer and the bond lengths and angles of the thiazolidine are presented. The study confirmed the imino structure of the investigated compound. The pathway of fragmentation of the alkyl groups attached to C₄ during mass-spectroscopic analysis was analyzed thoroughly.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 12, pp. 1617–1619, December, 1981.