Yu Zhao Xiang, Wang Xiao Ping, Feng Yaoyu
Department of Chemistry, Tongji University, Siping Rd, Shanghai 200092, People's Republic of China.
Acta Crystallogr C. 2004 Apr;60(Pt 4):m194-6. doi: 10.1107/S0108270104005864. Epub 2004 Mar 31.
The intermediate [Cd(4-PTZ)(2)(H(2)O)(4)] [4-PTZ is 5-(4-pyridyl N-oxide)tetrazolate, C(6)H(4)N(5)O], (I), in the synthesis of 4-HPTZ, (II), from the cycloaddition reaction of 4-cyanopyridine N-oxide with NaN(3) in water using CdCl(2) as catalyst, was structurally characterized. The unique Cd atom lies on a twofold axis and the coordination geometry of the Cd atom is that of a slightly distorted octahedron, involving four water molecules and two tetrazolate ligands. The catalytic role of the Cd(2+) ion in the tetrazole generation reaction stems from the formation of (I). In acidic solution, (I) can be disassociated and the free ligand, (II), can be released.
在以CdCl₂为催化剂，4-氰基吡啶N-氧化物与NaN₃在水中发生环加成反应合成4-HPTZ（II）的过程中，中间体[Cd(4-PTZ)₂(H₂O)₄]（I）[4-PTZ为5-(4-吡啶基N-氧化物)四唑化物，C₆H₄N₅O]的结构得到了表征。独特的Cd原子位于二重轴上，Cd原子的配位几何构型为轻微畸变的八面体，涉及四个水分子和两个四唑配体。Cd²⁺离子在四唑生成反应中的催化作用源于（I）的形成。在酸性溶液中，（I）可解离并释放出游离配体（II）。
