Crystal structure of 4,5-bis(4-dimethylaminophenyl)-2-(4-nitrophenyl)imidazole.

A nonlinear optical chromophore, 4,5-bis(4-dimethylaminophenyl)-2-(4-nitrophenyl)imidazole, was investigated by X-ray crystallography. The study focused on coplanarity among several aromatic rings, including phenyls and imidazole. Two phenyl rings with NMe2 groups are twisted by 46.39(3) degrees from each other. However, they are twisted by 23.05(5) degrees and 46.84(3) degrees from the imidazole, respectively. These unequal twists were elucidated by different conjugation pathways from the donors to the acceptor. The phenyl ring with the NO2 group is twisted by only 6.76(6) degrees from the imidazole.     

Crystal and molecular structure of (2)-4-(3-trifluormethyl-phenyl)-1-hydroxyadamantane

Moscow State University Translated from Zhurnal Strukturnoi Khimii, Vol. 32, No. 5, pp. 153–158, September–October, 1991.     

Molecular and Crystal Structure of 1-(4-Chlorophenyl)-3-(2-nitrophenyl)-1-triazene

1　ＩＮＴＲＯＤＵＣＴＩＯＮＩｔｈａｓｂｅｅｎｒｅｐｏｒｔｅｄｔｈａｔ1,3ｄｉｐｈｅｎｙｌｔｒｉａｚｅｎｅｓｈｏｗｓａｎｔｉｔｕｍｏｕｒａｃｔｉｖｉｔｙｃｏｍｐａｒａｂｌｅｔｏｔｈａｔｏｆ3,3ｄｉｍｅｔｈｙｌ1ａｒｙｌｔｒｉａｚｅｎｅｓ.1,3Ｄｉａｒｙｌｔｒｉａｚｅｎｅｓｃａｎａｃｔａｓｐｒｏｄｒｕｇｓ,ｏｒ‘ｃａｒｒｉｅｒｓ’ｏｆｄｉａｚｏｎｉｕｍｃｏｍｐｏｕｎｄｓ,ｓｉｎｃｅｔｈｅｙｕｎｄｅｒｇｏｈｙｄｒｏｌｙｓｉｓｔｏｆｏｒｍａｒｙｌｄｉａｚｏｎｉｕｍｃｏｍｐｏｕｎｄｓ[1,2].Ａｎｄｓｏｍｅｏｎｅｈ…     

Synthesis and Crystal Structure of 1-（2,6-Dichloro-4-nitrophenyl）-5-amino-4-cyanopyrazole

The crystal structure of 1-（2,6-dichloro-4-nitrophenyl）-5-amino-4-cyanopyrazole （C10H10Cl2N5O2, Mr = 298.09） has been determined by single-crystal X-ray diffraction. It crystallizes in the triclinic system, space group P1^- with a = 8.1258（10）, b = 8.6460（10）, c = 10.0214（12） A, α = 68.986（2）, β = 71.598（2）, γ = 85.181（2）°, V = 623.26（13） A3, Z = 2, Dc = 1.588 g/cm^3,μ = 0.525 mm^-1, F（000） = 300, R = 0.0613 and wR = 0.1524 for 1890 observed reflections, and the extinction coefficient = 0.010（5）. The crystal structure is stabilized by N-H...N hydrogen bonds.     

Crystal and molecular structure of 1-(trimethylsilylmethyl)benzotriazole

The crystal and molecular structure of 1-(trimethylsilylmethyl)benzotriazole has been established by X-ray diffraction (XRD) analysis. The coordination polyhedron of the silicon atom in this molecule is a tetrahedron. The bond lengths and angles of the 1-(trimethylsilylmethyl)benzotriazole molecule were compared with those of related crystal structures.     

Laser photolysis of 1-(4-nitrophenyl)-3-methylpyrazole and 1-ethyl-3-(4-nitrophenyl)-5-chloropyrazole

The spectral kinetic characteristics of the triplet states of 1-(4-nitrophenyl)-3-methylpyrazole (1) and 1-ethyl-3-(4-nitrophenyl)-5-chloropyrazole (2) were studied by the laser nanosecond photolysis technique in different solvents. The triplet lifetimes (τ_T) of molecules 1 and 2 were found to depend strongly on the solvent nature. An increase in τ_T by approximately two orders of magnitude on going from nonpolar and polar aprotic solvents (τ_T ≤ 15 ns) to aqueous-acetonitrile solutions (τ_T = 1100 ns for a volume acetonitrile to water ratio of 1 : 3) was analyzed, taking into account the influence of the medium on the relative contribution of the n,π*- and π,π*-configurations to the lowest triplet state. __________ Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 5, pp. 1115–1119, May, 2005.     

Crystal and molecular structure of 1-(iodmethyl)- and 1-(iodpropyl)silatranes

The crystal and molecular structures of 1-(iodmethyl)silatrane and 1-(iodpropyl)silatrane are determined by X-ray diffraction. The effect of the iodine heteroatom upon silatrane moieties of the molecules through oneand three-carbon chains is studied based on the geometric characteristics of the molecules and the analysis of their packings.