Mononuclear complexes of manganese(II), iron(II), cobalt(II), nickel(II), copper(II), and zinc(II), with 4-amino-3,5-bis(pyridin-2-yl)-1,2,4 triazole and tris(2-aminoethyl) amine: crystal structure of [Ni(tren)(abpt)](NO3)2(H2O)2.25

Complexes of the type M(tren)(abpt)](NO₃)₂(H₂O)_n (1–6) M = Mn^II, Fe^II, Co^II, Cu^II, Zn^II (n = 2), Ni^II (n = 2.25), tren = tris(2-aminoethyl)amine, and abpt = 4-amino-3,5-bis(pyridin-2yl)-1,2,4 triazole] have been prepared. The bonding mode and overall geometry of the complexes have been deduced by elemental analyses, molar conductance values, spectral studies (obtained from FT-IR), ¹H-n.m.r., electronic spectral analyses and magnetic susceptibility measurements. A detailed molecular structure of complex (4) has been determined by single X-ray crystallography.