Syntheses, crystal structures, and magnetic properties of two novel Ni(mnt) 2-based molecular magnetic materials containing substituted triphenylphosphinium

Abstract

Two novel molecular magnetic materials, [RBzTPP][Ni(mnt) 2] (mnt 2− = maleonitriledithiolate, [RBzTPP] + = 4-R-benzyltriphenylphosphinium; R = CN ( 1), Cl ( 2)) were synthesized and characterized by X-ray diffraction, IR spectroscopy, and magnetic susceptibility measurements. In crystal of 1, the [Ni(mnt) 2] − anions form a dimer via Ni⋯S and π⋯π stacking interactions between Ni(mnt) 2 planes, and the C–H⋯Ni and C–H⋯N H-bonding interactions are found between the [Ni(mnt) 2] − anions and the neighboring [CNBzTPP] + cations. The anions and cations of 2 stack into well-segregated columns in the solid state; and the Ni(III) ions form a 1D alternating chain in a Ni(mnt) 2 column through intermolecular Ni⋯S, or π⋯π interactions with the Ni⋯Ni distances of 3.900, 4.198, and 4.165 Å. Magnetic susceptibility measurements for these complexes in the temperature range 1.8–300 K show that the overall magnetic behavior for 1 and 2 indicates the presence of antiferromagnetic interaction, but 1 exhibits an activated magnetic behavior in the high-temperature (HT) region together with a Curie tail in the low-temperature (LT) region.