Hydrothermal and structural chemistry of the zinc(II)- and cadmium(II)-1,2,4-triazolate systems

Hydrothermal reactions of 1,2,4-triazole with zinc and cadmium salts have yielded 10 structurally unique materials of the M(II)/trz/Xn- system, with M(II)) = Zn and Cd and Xn- = F-, Cl-, Br-, I-, OH-, NO3-, and SO42- (trz = 1,2,4-triazolate). Of the zinc-containing phases, [Zn(trz)(2)] (1), [Zn-2(trz)center dot 3H(2)O (3 center dot H2O), and [Zn-2(trz)(SO4)- (OH)] (4) are three-dimensional, while [Zn(trz)Br] (2) is two-dimensional. All six cadmium phases, [Cd-3(trz)(3)F-2- (H2O)]center dot 2.75H(2)O (5 center dot 2.75H(2)O), [Cd-2(trz)(2)Cl-2(H2O)] (6), [Cd-3(trz)(3)Br-3] (7), [Cd-2(trz)(3)I] (8), [Cd-3(trz)(5)(NO3)(H2O)]center dot H2O (9 center dot H2O), and [Cd-8(trz)(4)(OH)(2)(SO4)(5)(H2O)] (10), are three-dimensional. In all cases, the anionic components Xn- participate in the framework connectivity as bridging ligands. The structural diversity of these materials is reflected in the variety of coordination polyhedra displayed by the metal sites: tetrahedral; trigonal bipyramidal; octahedral. Structures 3, 5, and 7 - 9 exhibit two distinct polyhedral building blocks. The materials are also characterized by a range of substructural components, including trinuclear and tetranuclear clusters, adamantoid cages, chains, layers, and complex frameworks.