New mononuclear Cu(II) complexes and 1D chains with 4-amino-4H-1,2,4-triazole.

The crystal structures of two mononuclear Cu(II) NH2trz complexes Cu(NH2trz)4(H2O)2 (I) and Cu(NH2trz)4(H2O)2 (II) as well as two coordination polymers [Cu(μ2-NH2trz)2Cl]Cl∙H2O (III) and [Cu(μ2-NH2trz)2Cl] (SiF6)0.5∙1.5H2O (IV) are presented. Cationic 1D chains with bridging bis-monodentate μ2-coordinated NH2trz and bridging μ2-coordinated chloride ligands are present in III and IV. In these coordination polymers, the Cu(II) ions are strongly antiferromagnetically coupled with J=-128.4 cm(-1) for III and J=-143 cm(-1) for IV (H=-JΣSiSi+1), due to the nature of the bridges between spin centers. Inter-chain interactions present in the crystal structures were taken into consideration, as well as g factors, which were determined experimentally, for the quantitative modeling of their magnetic properties.