Syntheses, Crystal Structures, Weak Interactions, and Magnetic Properties of Two Bis(maleonitriledithiolate)copper(II) Salts with Substituted Benzyl 1-Methylimidazolium

In two new bis(maleonitriledithiolate)copper(II) salts, [Bz-1-MeIm](2)[Cu(mnt)(2)] (1) and [4-NO(2)Bz-1-MeIm](2)[Cu(mnt)(2)] (2) ([Bz-1-MeIm](+) = Bz-1-MeMz = 1-methyl-3-benzylimidazolium; [4-NO(2)Bz-1-MeIm](+) = 1-methyl-3-(4'-nitrobenzyl)imidazolium), 1 crystallizes in the triclinic system with space group P-1, whereas 2 crystallizes in the monoclinic system with space group P2(1)/c. The cations and anions stack alternately into a column by pi center dot center dot center dot pi and C-H center dot center dot center dot pi interactions, and the C-H center dot center dot center dot N and C-H center dot center dot center dot O hydrogen bonds consolidate the crystal packing and give further rise to a 3D network structure. Magnetic susceptibility measurements show that 1 displays strong antiferromagnetic interaction with theta = -255.98 K, whereas 2 shows weak ferromagnetic coupling with theta = 0.527 K.