Hydrogen-bonded networks from η 5-semiquinone complexes of manganese tricarbonyl

Abstract

The cationic manganese tricarbonyl complexes containing η 6-2-methylhydroquinone ( 2a), η 6-2,3-dimethylhydroquinone ( 3a), η 6-2- t-butylhydroquinone ( 4a), η 6-tetramethylhydroquinone ( 5a) and η 6-4,4′-biphenol ( 6a) are readily deprotonated to the corresponding neutral (η 5-semiquinone)Mn(CO) 3 ( 2b– 6b) and anionic (η 4-quinone)Mn(CO) 3 − ( 2c– 5c) complexes. The X-ray structures of 2b– 6b feature strong intermolecular hydrogen bonding interactions that result in the formation of supramolecular organometallic networks. Significantly, the substitution pattern at the semiquinone ring affects the stereochemistry of the hydrogen bonding interactions. NMR spectra of 2b, 3b and 5b reveal dynamic hydrogen bonding in solution.