NEW CONFIGURATIONALLY STABLE CHIRAL BUILDING-BLOCKS FOR POLYNUCLEAR COORDINATION-COMPOUNDS - RU(CHIRAGEN[X])CL-2

The two enantiomers (Delta and Lambda) of Ru(chiragen[X])Cl-2, where ' 'chiragen'' is a tetradentate ligand with a chiral bridging unit betwe en two bipyridine moieties, have been prepared in high yields. X is m- xylyl (m-xyl); other bridging groups (e.g., -(CH2)(5)- or -(CH2)(6)-) behave similarly. This complex can be used as an enantiomerically pure building block for the synthesis of stereochemically well defined pol ynuclear species. As an example, all three isomers (Delta Delta, Lambd a Lambda, and Delta Lambda) of iragen[m-xyl])Ru(bpym)Ru(chiragen[m-xyl ])](PF6)(4) were prepared and fully characterized by NMR and various o ther spectroscopic methods.