Two New bis(maleonitriledithiolate)nickelate Anion Salts with Substituted Chlorobenzylpiperidinium Counterion: Syntheses, Crystal Structures, and Magnetic Properties

Abstract

Two new salts [4-ClBzPid]2[Ni(mnt)2](1) and [4-ClBzPid][Ni(mnt)2](2)([4-ClBzPid]+ = 1-(4′-chlorobenzyl)-piperidinium and mnt2− = maleonitriledithiolate) were synthesized and characterized by elemental analyses, IR, UV-Vis, ESI-MS, single crystal X-ray diffraction, and magnetic measurements. The [Ni(mnt)2]2− anions of 1 form a one-dimensional side-by-side structure via N···N short interaction, whereas the [Ni(mnt)2]− anions in 2 form a one-dimensional face-to-face column through short inter-molecular Ni···Ni, Ni···S, and S···S interactions in which the Ni(III) ions form a nonuniform magnetic chain with the Ni···Ni distances of 3.676 Å and 4.357 Å. Furthermore, the [4-ClBzPid]+ cations in 1 stack into 1D columns via C–H···Cl and Cl···Cl interactions, while the cations (C) and [Ni(mnt)2]− anions (A) of 2 stack into a 1D column with a A-CC-A-CC-A sequence by N···π and N–H···N weak interactions. Some other weak interactions including C–H···N and C–H···Ni hydrogen bonds result in the forming of a 3D network. Magnetic susceptibility measurements in the temperature range 2 to 300 K show that two salts exhibit diamagnetic behavior.