Cu(μ-MeCO2)2(4-Bzpy)]2 (4-Bzpy = 4-benzylpyridine): Study of the intermolecular C[sbnd]H⋯O hydrogen bonds at two temperatures

Abstract

[Cu(μ-MeCO2)2(4-Bzpy)]2 (4-Bzpy = 4-benzylpyridine) has been synthesized by reaction of [Cu(μ-MeCO2)2(H2O)]2 with 4-Bzpy in methanol at room temperature. The compound was characterized by Elemental Analysis, ATR-FTIR and X-ray Powder Diffraction. The molecular structure was determined by single crystal X-ray diffraction analysis at 100 K and 303 K. The compound consists of binuclear units where both Cu(II) atoms are linked by four syn-syn carboxylate bridges, showing a paddle-wheel unit. The role of CH⋯O hydrogen bonds in the establishment of its supramolecular network is discussed, comparing the resulting structural parameters at the two different temperatures. Finally, the thermal variation of XpT for compound 1 has also been studied, suggesting an antiferromagnetic Cu⋯Cu interaction (J = −311 cm−1), which agrees with the presence of four μ-κO-κO′ carboxylates bridging the metallic centers in the binuclear complex.