Hydrogen-Bonding in Two Pyridinium Salts of [Mo2O4Cl4(μ2-dmsH)]3−Complex (dmsH− = a Half-Neutralized Form of 2,2-Dimethylsuccinic Acid)

Abstract

Reactions of a mononuclear molybdenum(V) starting material, (PyH)5[MoOCl4(H2O)]3Cl2, with 2,2-dimethylsuccinic acid in the presence of base afforded two products, (PyH)3[Mo2O4Cl4(μ2-dmsH)]·1/2CH3CN (1) and (PyH)4[Mo2O4Cl4(μ2-dmsH)]Cl (2). As revealed by the X-ray structure analysis, the half-neutralized form of the dicarboxylic acid, the dmsH− ion, coordinated to the well-known {Mo2O4}2+ core in the syn-syn bidentate bridging manner. In both compounds, the non-ionized terminus of the ligand, the COOH function, participated in hydrogen-bonding interactions. The incorporation of the chloride counteranion in 2, prevented the formation of the common “carboxylic acid dimer” which was observed for 1. Instead, a hydrogen-bonded linkage of the COOH function with the chloride occurred.

Keywords

• molybdenum
• {Mo2O4}2+ core
• carboxylate complexes
• hydrogen-bonding
• carboxylic acid dimer