Liu Ze-Hua, Duan Chun-Ying, Hu Jun, You Xiao-Zeng
Coordination Chemistry Institute and The State Key Laboratory of Coordination Chemistry, Nanjing University, Nanjing 210093, P. R. China.
Inorg Chem. 1999 Apr 19;38(8):1719-1724. doi: 10.1021/ic9711731.
A cis-configuration bis(4,5-diazafluorene-9-one thiosemicarbazone) palladium trihydrate, which exhibits approximately five times SHG (second harmonic generation) efficiency of urea, has been designed, synthesized, and structurally characterized. The complex, C(24)H(16)N(10)PdS(2).3H(2)O, crystallizes in trigonal space group P3(1) with cell parameters a = 10.749(2) Å, c = 19.872(4) Å, V = 1988.3(6) Å(3), and Z = 3. The coordination geometry about the Pd(II) is surprisingly a cis-configuration square-planar formed by two imino nitrogen atoms N(3) and N(8) and two sulfur atoms S(1) and S(2) from two thiosemicarbazone ligands. Intramolecular contact analyses in the crystals and 1D and 2D (1)H NMR spectra in solution show that the cis-positioning of the two ligands was stabilized by the pi-pi interaction between the two delocalized diazafluorene moieties. Detailed crystal structure analyses demonstrate that both the intermolecular pi-pi stacking between the diazafluorene planes in different molecules and intermolecular hydrogen bonds between the water molecules and the deprotonated ligands might be the factors that influence the molecules to be packed in the acentric space group P3(1). The crystal structure of the free ligand was also reported here for comparison. The ligand, C(12)H(9)N(5)S, crystallizes in orthorhombic space group Pbca with cell parameters a = 8.432(2) Å, b = 15.427(3) Å, c = 17.387(3) Å, V = 2272.7(8) Å(3), and Z= 8. The thiosemaicarbazone moiety adopts an E configuration with N(1) cis to N(3).
一种顺式构型的双（4,5-二氮芴-9-酮缩氨基硫脲）三水合钯，其二阶谐波产生（SHG）效率约为尿素的五倍，已被设计、合成并进行了结构表征。该配合物C(24)H(16)N(10)PdS(2)·3H(2)O以三方晶系P3(1)空间群结晶，晶胞参数a = 10.749(2) Å，c = 19.872(4) Å，V = 1988.3(6) Å(3)，Z = 3。钯（II）周围的配位几何构型令人惊讶地是由来自两个缩氨基硫脲配体的两个亚氨基氮原子N(3)和N(8)以及两个硫原子S(1)和S(2)形成的顺式构型平面正方形。晶体中的分子内接触分析以及溶液中的一维和二维(1)H NMR光谱表明，两个配体的顺式定位通过两个离域二氮芴部分之间的π-π相互作用得以稳定。详细的晶体结构分析表明，不同分子中二氮芴平面之间的分子间π-π堆积以及水分子与去质子化配体之间的分子间氢键可能是影响分子堆积在非中心空间群P3(1)中的因素。本文还报道了游离配体的晶体结构以供比较。该配体C(12)H(9)N(5)S以正交晶系Pbca空间群结晶，晶胞参数a = 8.432(2) Å，b = 15.427(3) Å，c = 17.387(3) Å，V = 2272.7(8) Å(3)，Z = 8。缩氨基硫脲部分采用E构型，N(1)与N(3)顺式。
