Syntheses, Crystal Structures and Antibacterial Properties of Bis(1-benzyl-4′-R-pyridinium)tetrabromocuprate(II) [R = NH₂ or N(CH₃)₂]

Abstract

Two tetrabromocuprate(II) salts with benzyl substituted pyridinium, [Bz-4-NH₂Py]₂[CuBr₄] (1) and [Bz-4-N(CH₃)₂Py]₂- [CuBr₄] (2) ([Bz-4-NH₂Py]⁺ = (1-benzyl-4′-aminopyridinium), [Bz-4-N(CH₃)₂Py]⁺ = 1-benzyl-4′-dimethylaminopyridinium) were crystallized from methanol and diluted in HBr solution. Compound 1 crystallizes in the orthorhombic Pna2₁, with 2 in the monoclinic P2₁/n. Two salts are composed of one tetrahedral [CuBr₄]²⁻ anion and two tortuous [Bz-4-NH₂Py]⁺/[Bz-4-N(CH₃)₂Py]⁺ cations. The [CuBr₄]²⁻ anions in 1 form a linear chain, while the combination of C-H···π, C-H···Br, C-H···N weak hydrogen bonds and π···π interactions results in the forming of a 3D network structure of 1 and 2. The two salts show good antibacterial activities for E. coli and S. aureus.

Keywords:

• antibacterial activities
• benzyl substituted pyridinium
• crystal structures
• tetrabromocuprate(II)
• weak interactions

Acknowledgments

This work has been partially supported by the Science and Technology Project (No. 2010B080701002, 2011B080701026) from the Guangdong Science and Technology Department and the key Academic Program of the 3rd phase “211 Project” of South China Agricultural University (No. 2009B010100001).