Novel Triazole-Bridged Cadmium Coordination Polymers Varying from Zero- to Three-Dimensionality

Cadmium salts with different triazole ligands have led to a series of novel triazole−cadmium compounds varying
from zero- to three-dimensionality. [Cd2(deatrz)2(H2O)Br4] (1) (deatrz = 3,5-diethyl-4-amino-1,2,4-triazole) is a zero-dimensional complex which uses a triazole ligand together with μ-OH2 as bridges to form a 1D chain via hydrogen-bonding contacts. {[Cd3(deatrz)2Cl6(H2O)2]·2H2O}n (2), {[Cd(dmtrz)Cl2]·1.5H2O}n (3) (dmtrz = 3,5-dimethyl-1,2,4-triazole), and {[Cd3(deatrz)4Cl2(SCN)4]·2H2O}n (4) are polymeric 1D chains. 2 and 4 were constructed via trinuclear
cadmium units bridged by triazole ligands and chloride atoms, while 3 consists of μ2-Cl, μ3-Cl, and triazole bridges,
cross-linked by hydrogen bonding to give a 3D framework. {[Cd3(dmatrz)4(SCN)6]}n (5) (dmatrz = 3,5-dimethyl-4-amino-1,2,4-triazole) shows a two-dimensional structure whose fundamental units are trinuclear metal cations
bridged via triazole ligands. The complex {[Cd(dmtrz)(SCN)2]}n (6) is the first three-dimensional example in N1,N2-didentate-bridged triazole−metal compounds. Six complexes exhibit six types of bridging modes of N1,N2-triazole in combination with single-atom bridges. 2, 4, and 5 are the unprecedented examples of polymeric chains
and planes constructed via trinuclear metal ion clusters, whereas 3 is the first example of the μ3-Cl bridging mode
in triazole−metal complexes. We have briefly discussed the variety of dimensionalities based on the tuning of
different organic ligands and anions.