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A demonstration that the diastereomer ratio for Ln(super III) DTPA derivatives remains constant throughout the lanthanide series, in contrast to Ln(super III) EPTPA derivatives, where it varies as a function of the cation size with a maximum for the middle lanthanides is presented. An HPLC analysis showed that the diastereomer ratio for Ln(super III) DTPA derivatives remains constant throughout the lanthanide series.

The synthesis of binuclear Ru(II)-Rh(III) complexes of general formula, (ttpy)Ru-tpy-(ph)n-tpy-Rh(ttpy)5+, where n = 0-2; ttpy = 4'-p-tolyl-2,2':6,2'-terpyridine, is described. The complex is characterized by rigid bridging ligand structures and variable metal-metal distances. The photoinduced electron and energy transfer between Ru(II) and Rh(III) molecular components were examined. The results showed that the energy transfer from excited Ru(II) to Rh(III) occurred for all complexes at both 77 and 150 K.

Phenylene spacers connect the Ru(tpy)(sub 2)(super 2+) complex, where tpy is 2,2':6', 2'-terpyridine, and Os(tpy)(sub 2)(super 2+) binding blocks to produce rigid rod-like Ru(II)/Os(II) terpyridine-type complexes. The two building units exhibit slightly different absorption spectra in the dinuclear compounds. Electrochemical measurements of redox potentials reveal metal-metal and ligand-ligand interactions. Time-resolved luminescence spectroscopic analysis of energy transfer reactions shows that electron exchange through the phenylene linker facilitates energy transfer from the Ru-unit to the Os-unit.

The energy transfer in a rodlike dinuclear complex, (ttp)Ru(tpy-ph-bco-ph-tpy)Os(ttp)4+ (RuOs) was found to be unaffected both by temperature and state of the solvent. In this species, the coordination environment of both metals is composed of tpy-type tridentate ligands and the spacer is a ph-bco-ph fragment. The complex has a rigid, linear geometry and the metal-to-metal distance is fixed at 2.4 nm.