A convenient new synthetic route to metallo-1,2-enedithiolates was applied to the synthesis of (dppe)M{S2C2-(heterocycle)(H)}; dppe 1,2-bis(diphenyldiphosphino)ethane, hi Ni, Pd, and Pt, and heterocycle = 2-quinoxaline, 2-, 3-, and 4-pyridine, and 2-pyrazine. These complexes were prepared from the corresponding bis(hydrosulfido) complexes (dppe)M(SH)(2) and the alpha-bromo ketones, heterocycle-C(O)CH2Br. Zn the solid state, (dppe)Ni{S2C2(2-pyrazine)(H)} is a slightly distorted square plane with a planar five-membered metallo-1,2-enedithiolate ring. The metallo-l,2-dithiolate is approximate to 6 degrees from being coplanar with the pyrazine ring, These complexes all have a UV-visible band assignable to an intraligand transition (ILCT) that is best described as a 1,2-enedithiolate pi-->heterocycle pi* charge transfer transition. The energy of the ILCT transition tracks with the reduction potential of the appended aromatic heterocycle. The pK(a) of the protonated complexes is 1-3 units higher than that of the parent heterocycle, independent of the metal, and consistent with resonance stabilization of the protonated heterocycle by the 1,2-enedithiolate ligand.