Four new Niii antiferromagnetic complexes with azido bridges

Abstract

Four new nickel(II) compound with formulas trans-catena-[Ni(N-Pren)₂(μ_1,3-N₃)](ClO₄) (1), trans-catena-[Ni(N,N-Me₂en)₂(μ_1,3-N₃)](PF₆) (2), trans-catena-[Ni(N,N′-Pren)₂(μ_1,3-N₃)](PF₆) (3) and [Ni(N-Metn)₂(μ_1,3-N₃)]₂(ClO₄)₂ (4) (N-Pren = N-propylethylenediamine, N,N-Me₂en = N,N-dimethylethylenediamine, N,N′-Pren = N,N′-dipropylethylenediamine and N-Metn = N-methylpropanediamine) were synthesized and characterised. A single-crystal structure analysis revealed that compounds (1), (2) and (3) consist of a single end-to-end azido bridged nickel(II) chains in trans position, whereas compound (4) is a dinuclear Ni^II complex with double end-to-end azido bridges between the two nickel(II) centres. From the magnetic point of view, compounds (1) and (2) are uniform antiferromagnetic one-dimensional chains with only one value of J and g. Compound (3) shows two kinds of Ni^II in the structure, but all the azido bridges are equivalent, which generates only one value for the superexchange J but two values for g. Compound (4) shows moderate antiferromagnetic coupling. The best fit parameters obtained for all the compounds are in agreement with the structural parameters and compares well with other similar compounds reported in the literature.