Electron and energy transfer mechanisms are key elements in the study of natural and artificial photosynthesis. As we attempt to mimic natural systems, the immense, complex nature of these processes becomes evident. Early indications suggest that the engine to natural photosynthesis is an elaborate array of processes based upon electronic energy transfer in a supramolecular system. To understand energy transfer mechanisms in supramolecular systems, we have developed smaller, simpler donor-acceptor complexes. The basis for these chromophores is Ru(II) metal centers connected by bis-bidentate bridging ligands. These complexes were developed to study the nature of energy transfer in transition metal complexes The syntheses of these bridging ligands are covered in Chapter 2. Diimine bridging ligands were developed to study the distance dependance of energy transfer. By synthesizing bridging ligands of various lengths, the donor-acceptor distance separation was modified. Diimine bridging ligands offer many desirable structural, redox, and photophysical properties. The use of bis-bipyridines linked by phenylene groups afforded such desirable characteristics. Four ligands were prepared: (1) 1,4-bis(2,2$\sp\prime$-bipyrid-4yl)-benzene (bpb) (2) 4,4$\sp\prime$-bis(2,2$\sp\prime$-bipyrid-4yl)-biphenyl (bppb) (3) 4,4$\sp{\prime\prime\prime}$-bis-(2,2$\sp \prime$-bipyrid-4yl)-p-terphenyl (bpppb) (4) 4,4$\sp{\prime\prime}$-bis(2,2$\sp \prime$-bipyrid-4yl)-p-quarterphenyl (bppppb). Each phenylene ring adds 4.1A($\pm$0.1A) to the distance between the donor and acceptor. These bridging ligands were prepared using the Krohnke and Suzuki reactions in good yields The ligands were coordinated to synthesize the donor-acceptor chromophores with Ru(II) metal centers. The transition metal complex synthesis is covered in Chapter 3. The synthesis of these complexes allowed for the study of the distance dependence of energy transfer. Because electronic energy transfer and dipole-dipole energy transfer mechanisms have different distance dependence relationships, we can conclude from the experimental data that these donor-acceptor complexes follow the electronic exchange energy transfer mechanism Chapter 4 covers the synthesis and photophysical studies for Ru(II) metal complexes with coordinating ligands with phosphonic acid functional groups. These complexes were developed for use as sensitizers for semiconductors. Photophysical studies confirmed that these chromophores are extremely stable in the oxidized form and thus have great potential as one electron donor to the conductance band of semiconductors The work in this dissertation hoped to answer some fundamental questions about energy transfer mechanism in transition metal donor-acceptor complexes. The results suggest that these transition metal complexes are excellent models for the development of artificial photosynthesis