The crystal structure of the title compound N,N-bisphenyl-3,6-diethyl-1,4- dihydro-s-tetrazine-1,4-dicarbonamide (C20H22N6O2, Mr = 378.44) has been prepared and determi- ned by single-crystal X-ray diffraction. The crystal is of orthorhombic, space group Pbca with a = 16.287(2), b = 11.347(4), c = 20.975(4) ? V = 3876.4(16) ?, Z = 8, Dc = 1.297 g/cm3, F(000) = 1600, m = 0.088 mm-1, MoKa radiation (l = 0.71073 ?. The structure was refined to R = 0.0337 and wR = 0.1038 for 1952 observed reflections with I > 2s(I). X-ray diffraction analysis reveals that two amide groups are located at the 1 and 4 positions, and the tetrazine ring itself shows a boat conformation.
The title compound bis[-chloro-(o-chloro-benzylidene) hydrazine] (C14H8Cl4N2, Mr = 346.02) has been prepared, and its crystal structure was determined by single-crystal X-ray diffraction. The crystal is of monoclinic, space group P21/n with a = 10.777(2), b = 6.456(2), c = 10.988(3) , b = 90.48(2), V = 764.5(3) 3, Z = 2, Dc = 1.503 g/cm3, F(000) = 348 and ?MoK? = 0.763 mm-1 (l = 0.71073 ?. The structure was refined to R = 0.0793 and wR = 0.2398 for 1694 observed reflections with I > 2s(I). The results of crystal structure determination show that both C(7) and C(7)a are of sp2 hybridization and there exists electronic conjugation in the aza-diene of -C=NN=C.
The reaction of 3,6-di-(3-methyl-pyridin-2-yl)-s-tetrazine (DMPTZ, II) with CeIII salt [Ce(NO3)3·6H2O] generates a new ligand, N-(3-methyl-pyridin-2-yl)-formimidoyl-(3-methyl- pyridin-2-yl) hydrazone (L), and forms a new complex: a mononuclear complex [Ce(L)(NO3)2 (H2O)3]·NO3 (III). Crystal data for III: space group P-1, with a = 0.7133(4) nm, b = 1.1139(2) nm, c = 1.4572(3) nm, a = 102.13(2)? b = 99.81(3)? g = 91.10(3)? Z = 2, V = 1113.6(7) nm3, m = 2.123 mm-1 and F(000) = 630. L acts as a tri-dentate chelating ligand in III. There are 10 coor-dination sites around Ce3+ of III, which are respectively occupied by seven oxygen atoms (four from two nitrate anions and three from three H2O molecules) and three nitrogen atoms (all from L). The cerium atom and three chelating nitrogen atoms are coplanar. The mechanism of the metal assisted decomposition is discussed briefly.
JIANG Yinzhi1,2 & HU Weixiao1 1. Department of Pharmaceutical Science, Zhejiang University of Technology, Hangzhou 310032, China
