Synthesis and reactivity of transition metal complexes containing halogenated boryl ligands

The synthesis and characterization of iron and manganese complexes containing the tetrachlorocatecholboryl (BO2C6Cl4) ligand are reported. Crystallographic study of the methylcyclopentadienyl derivative (η5-C5H4Me)Fe(CO)2BO2C6Cl4 allows comparison of structure and bonding with related complexes of the type (η5-C5R5)Fe(CO)2B(OR)2 and reveals that the relative orientation of (η5-C5H4Me)Fe(CO)2 and BO2C6Cl4 moieties is influenced by intramolecular CH⋯O hydrogen bonding. Additionally, an alternative route to catecholboryl complexes from dilithiocatechol is reported.