Patterns of hydrogen bonding in crystals of molybdenum carbonyl complexes

The solid-state structures of complexes of the type [HO–(N∩N′)]Mo(CO)3L (L = CO, THF, PPh3, CNtBu, CNCy) have been determined by X-ray crystallography. Two major types of multiple intermolecular hydrogen-bonding patterns involving the OH group and CH moieties as hydrogen donors and carbonyl groups and solvent molecules as hydrogen acceptors have been found and interpreted in terms of hydrogen bond strength, steric availability and dense packings. Discrimination between the two hydrogen-bonding patterns is also possible on the basis of unit cell dimensions and IR spectroscopy. DFT calculations support the interpretations.