The reaction between Os-2(OAC)(4)Cl-2 and Hap (Hap is 2-anilinopyridine) under prolonged refluxing conditions resulted in an Os(III)2 compound, Os-2(ap)(4)Cl-2 (1), that can be crystallized as either the cis-(2,2) isomer from a CH3OH-CH2-Cl-2 solution or the (3,1) isomer from a hexanes-CH2Cl2 solution. Compound 1 undergoes facile reactions with LiC2Y to yield a series Of Os-2(ap)(4)(C2Y)(2) Compounds with Y as Ph (2), ferrocenyl (3), SiMe3 (4), and C2SiMe3 (5). X-ray diffraction study of compound 2 reveals solvent-dependent isomerism similar to that of the parent compound 1. Compound 1 has Os-Os distances of 2.3937(8) and 2.3913(8) angstrom for the cis-(2,2) and (3,1) isomers, respectively, and is paramagnetic (S = 1). Both the ethynyl derivatives 2-4 and butadiynyl derivative 5 are diamagnetic and have Os-Os distances of 2.456(1), 2.471(1), and 2.481(1) angstrom for the cis-(2,2) and (3,1) isomers of 2 and (3,1) isomer of 4, respectively. Compounds 1-5 exhibit multiple one-electron redox couples in their cyclic voltammograms, including a reversible Os-2(8+/7+) couple for 2. Resonance Raman spectra of both compounds 1 and 2 are reported.