Syntheses, crystal structures, weak interactions and magnetic properties of two tetrachlorocuprate(II) salts with substituted benzyl 4-dimethylaminopyridinium

Two new tetrachlorocuprate(II) salts, [BzDMAP](2)[CuCl4](1) and [4FBzDMAP](2)[CuCl4](2) ([BzDMAP](+) = 1-benzyl-4-dimethylaminopyridinium; [4FBzDMAP](+) = 1-(4'-fluorobenzyl)-4-dimethylaminopyridinium), have been prepared and characterized by elemental analysis, IR, MS, single-crystal X-ray diffraction and magnetic susceptibility. Compound 1 crystallizes in the monoclinic system with space group P2(1)/n, while 2 crystallizes in the orthorhombic system with space group P2(1)2(1)2(1). These two salts comprise one [CuCl4](2-) anion and two cations, and the [CuCl4] (2-) anions exhibit distorted tetrahedral coordination geometry. The C-H center dot center dot center dot Cl, C-H center dot center dot center dot pi hydrogen bonds and pi center dot center dot center dot pi stacking interactions in the crystal play important roles in the stacking and stabilization of the two salts, and give rise to a 3D network structure. Magnetic susceptibility measurements in the temperature range of 2-300 K show that both 1 and 2 exhibit a ferromagnetic coupling behavior.