Syntheses, Crystal Structures, Weak Interactions, and Magnetic Properties of Two Tetrachlorocuprate(II) Salts With Substituted Benzyl 4-Dimethylaminopyridinium

Abstract

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 P2₁/n, while 2 crystallizes in the orthorhombic system with space group P2₁2₁2₁. These two salts comprise one [CuCl₄]^2– anion and two cations, and the [CuCl₄]^2– anions exhibit distorted tetrahedral coordination geometry. The C˭H···Cl, C˭H···π hydrogen bonds and π···π 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.

Keywords:

• crystal structure
• magnetic properties
• substituted benzyl-4-dimethylaminopyridinium
• tetrachlorocuprate(II)

Acknowledgments

The authors thank the Science and Technology Project (No. 2008B080701002.2011B080701026) from Guangdong Science and Technology Department and the key Academic Program of the third phase “211 Project” of South China Agricultural University (No. 2009B010100001) for financial support of this work.