5‐Amino‐2‐isopropenyltetrazole and its Cupric Chloride Complex: Synthesis, Structure and Magnetism

Abstract

A new tetrazole ligand, 5-amino-2-isopropenyltetrazole, was prepared by regioselective alkylation of 5-aminotetrazole with allyl bromide in sulfuric acid followed by dehydrobromination of intermediate 5-amino-2-(1-bromopropan-2-yl)tetrazole. 5-Amino-2-isopropenyltetrazole (L) was found to react with copper(II) chloride to generate complex [CuL 2 Cl 2 ] n . The ligand and its complex were characterized by single crystal X-ray and thermal analyses. Complex [CuL 2 Cl 2 ] n presents 1D coordination polymer, formed at the expense of double chlorido bridges between neighbouring octahedral coordinated Cu II cations. Tetrazole ligand acts as monodentate ligand coordinated by Cu II cations via the heteroring N 4 atoms only. Magnetic studies revealed that the copper(II) ions were weakly antiferromagnetically coupled. Natural bond orbital analysis was performed to explain the structural peculiarities of the ligand. Its basicity and the relative stability of the protonated forms were investigated using MO calculations.