Coordinative Versatility of Guanazole [3,5-Diamino-1,2,4-triazole]: Synthesis, Crystal Structure, EPR, and Magnetic Properties of a Dinuclear and a Linear Trinuclear Copper(II) Complex Containing Small Bridges and Triazole Ligands

New complexes with guanazole (3,5‐diamino‐1,2,4‐triazole = Hdatrz), [Cu2(Hdatrz)2(μ‐OH2)(H2O)4(SO4)](SO4)·3.5H2O (1) and [Cu3(Hdatrz)4(μ‐Cl)2(H2O)4(SO4)2]·11.4H2O (2), have been prepared and structurally characterized. Complex 1 is a noncentrosymmetric dinuclear compound in which the copper(II) ions are bridged by two triazole ligands and one μ‐OH2 molecule, with a Cu(1)···Cu(2) distance of 3.4945(8) Å. The chromophores are Cu(1)N2O2O′ (square pyramidal), and Cu(2)N2O2O′O″ (octahedral). Complex 2 has a linear trinuclear copper(II) structure, with two crystallographically independent copper(II) atoms. Neighboring copper(II) ions are linked by two triazole ligands and one slightly asymmetric chlorido bridge. The intratrimeric Cu(1)···Cu(2) distance is 3.5602 (4) Å. Cu(2), the central copper, is coordinated to N4Cl2 (octahedral) while Cu(1), the terminal copper, is coordinated to N2O2ClO′ (also octahedral). Magnetic susceptibility measurements (2–300 K) are in accordance with the dinuclear (1) and trinuclear (2) nature of these compounds. The best‐fit parameters, obtained with the Hamiltonian H =–JΣi