Ligand dehydrogenation in ruthenium trinitrogen complexes: synthesis, structure and chirality of the cations [Ru(LH_4)(L)]~(2+) [LH_4 = 2,6-bis(pyrrolidin-2-yl)pyridine]

摘要

Reaction of 2,6-bis(pyrrolidin-2-yl)pyridine (LH_4) with RuCl_3 (centre dot) 3H_2O in refluxing methanol/water mixtures gives rise to the formation of the octahedral complexes [Ru(LH_4)(L)]~(2+), in which one of the two trihapto ligands has been dehydrogenated as 2,6-bis(3,4-dihydro-2H-pyrrol-5-yl)pyridine (L), even if LH_4 was present in excess. With the three stereoisomers of LH_4, the complexes [Ru(R,S-LH_4)(L)]~(2+) (meso), [Ru(R,R-LH_4)(L)]~(2+) and [Ru(S,S-LH_4)(L)]~(2+) have been isolated as the perchlorate salts and characterized by X-ray structure analysis and by CD spectra.