Both chloro and pyridine derivatives of rhenium(I) tricarbonyl complexes coordinated to 2,2'-bipyrazine (bpz) and 5,5'-dimethyl-2,2'-bipyrazine (Mebpz) were synthesized. X-ray structures were obtained for Re(bpz)(CO)₃Cl, Re(Mebpz)(CO)₃Cl, and [Re(bpz)(CO)₃py]PF6. For the chloro derivatives, the axial bond distance between the metal and the ligands, Cl and CO, remained similar, the Re-C bond distance for one of the equatorial CO ligands remained nearly constant; the other decreased about 0.02 Å for the Mebpy derivative; the final Re-N distances increased by nearly 0.02 Å for the Mebpy complexes. Theoretically, the metal-ligand bond distances obtained by Density Functional Theory (DFT) all increased by ~0.02 Å in accord with reported results on other systems. Calculations reveal the ground state (HOMO) resides primarily on the metal and the excited state (LUMO) is located on the diimine ligand. The complexes underwent metal-to-ligand charge transfer in the near ultraviolet and Π → Π* transitions in the uv region. Emission occurred between 600 and 700 nm in solution. The complexes were weak emitters, but gave quantum efficiencies near 0.1 at 77 K.