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

Authors：Cai Hua Tang; Qian Ye Long; Pan Yan Hui; Li Man Na; Liu Qian Ting; Ouyang Min Yi; Zhou Jia Rong^*; Yang Le Min; Ni Chun Lin

Source：Synthetic Metals, 2014, 197: 105-111.

DOI：10.1016/j.synthmet.2014.09.010

• Bis(maleonitriledithiolate)nickel(III) anion
• Disubstituted benzyl triphenylphosphonium
• Crystal structures
• One-dimensional chain
• Magnetic properties

Two molecular metals, [2F4BrBzTPP][Ni(mnt)(2)]center dot H2O (1) and [2Br4FBzTPP][Ni(mnt)(2)] (2) ([2F4BrBzTPP](+) = 1-(2'-fluoro-4'-bromobenzyltriphenylphosphonium, [2Br4FBzTPP](+) = 1-(2'-bromo-4'-fluorobenzyltriphenylphosphonium, mnt(2-) = 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 P2(1)/c. The Ni(III) ions from [Ni(mnt)(2)](-) anion of 1 form a 1D non-uniform chain through Ni center dot center dot center dot S, Ni center dot center dot center dot Ni and pi center dot center dot center dot pi interactions with the Ni center dot center dot center dot Ni distances of 3.443, 3.935 and 3.968 angstrom, as well as C-H center dot center dot center dot F, C-H center dot center dot center dot N, C-H center dot center dot center dot pi, and pi center dot center dot center dot pi weak interactions exist in I. The anions and cations in 2 stack into segregated structure, and the anions give rise to a 1D uniform column with a Ni center dot center dot center dot Ni distance of 4.148 angstrom. Magnetic measurements have shown that 1 exhibits a characteristic of spin-gap (Delta/k(b) = 267.5 K) around 86K, while 2 shows an antiferromagnetic coupling feature with J = -15.4 cm(-1) upon the temperature is lowed.

• Institution
  China Agricultural University; South China Agricultural University