Syntheses, one-dimensional chain structures and magnetic properties for two molecular metals of bis(maleonitriledithiolate)nickel(III) anion and disubstituted benzyl triphenylphosphonium

Two molecular metals, [2F4BrBzTPP][Ni(mnt)2]·H2O (1) and [2Br4FBzTPP][Ni(mnt)2] (2) ([2F4BrBzTPP]+ = 1-(2′-fluoro-4′-bromobenzyltriphenylphosphonium, [2Br4FBzTPP]+ = 1-(2′-bromo-4′-fluorobenzyltriphenylphosphonium, mnt2− = maleonitriledithiolate), have been synthesized and structurally characterized by single crystal X-ray diffraction. Compound 1 crystallizes in the triclinic space group P−1, while 2 does in the monoclinic space group P21/c. The Ni(III) ions from [Ni(mnt)2]− anion of 1 form a 1D non-uniform chain through Ni⋯S, Ni⋯Ni and π⋯π interactions with the Ni⋯Ni distances of 3.443, 3.935 and 3.968 Å, as well as CH⋯F, CH⋯N, CH⋯π, and π⋯π weak interactions exist in 1. The anions and cations in 2 stack into segregated structure, and the anions give rise to a 1D uniform column with a Ni⋯Ni distance of 4.148 Å. Magnetic measurements have shown that 1 exhibits a characteristic of spin-gap (Δ/kb = 267.5 K) around 86 K, while 2 shows an antiferromagnetic coupling feature with J = −15.4 cm−1 upon the temperature is lowed.