New nickel(II) and copper(II) complexes with 1-tert-butyl-1H- and 1,5-diaminotetrazoles

[Display omitted] •M(II) complexes with 1-tBu-tetrazole (L1) and 1,5-diaminotetrazole (L2) are studied.•Crystal structures are determined for Cu(L1)Br2 and Cu(L2)2(C2N3)2 complexes.•The structure of Cu(L1)Br2 is formed by [Cu(L1)(μ2-Br)4] fragments.•The compound Cu(L2)2(C2N3) represents a layered polymer.•Cu(II) complexes reveal the presence of exchange interactions between spins of Cu(II) ions. Novel nickel(II) and copper(II) coordination compounds with 1-tert-butyl-1H-tetrazole (L1) and 1,5-diaminotetrazole (L2) having compositions of Ni(L1)Cl2·H2O, Ni(L1)2Br2·2H2O, Cu(L1)Cl2, Cu(L1)Br2, Ni(L2)2(C2N3)2, Cu(L2)2(C2N3)2 were synthesized. The compounds were studied using the methods of infrared and diffuse reflectance spectroscopy, single-crystal and powder X-ray diffraction, static magnetic susceptibility. Crystal structures have been determined for Cu(L1)Br2 and Cu(L2)2(C2N3)2 complexes. Magnetic susceptibility measurements of Cu(II) and Ni(II) based complexes have revealed a wide spectrum of low-temperature magnetic states ranging from paramagnets composed of virtually isolated single magnetic ions or ferromagnetic chains to a weak ferromagnet with a remarkably strong magnetocrystalline anisotropy.