Reaction of Os-3(CO)(12) with thionylaniline (PhN=S=O) in refluxing methylcyclohexane produces OS3(CO)(9)(mu(3)-NPh)(mu(3)-S) (1) in good yield. When Os-3(CO)(10)(NCMe)(2) is treated with PhN=S=O at room temperature, compound 1 and Os-3(Co)(9)(mu(3)-eta(2)-(PhN)(2)SO)(mu(3)-S) (2) result. Compound 1 reacts with trimethylamine oxide in the presence of acetonitrile to give Os-3(CO)(8)(NCMe)(mu(3)-NPh)(mu(3)-S) (3). Compounds 1-3 were characterized by mass, IR, and NMR spectroscopies, and their structures were determined by single-crystal X-ray diffraction. Crystal data for 1: monoclinic (C2/c), a = 16.603(7) Angstrom, b = 8.679(4) Angstrom, c = 29.009(6) Angstrom, beta = 102.08 (2)degrees, Z =8, R (R-w) = 0.036 (0.039). Crystal data for 2: triclinic (P (1) over bar), a = 9.723(4) Angstrom, b = 15.704(4) Angstrom, c = 18.455(7) Angstrom, alpha = 113.17(3), beta = 102.48(3)degrees, gamma = 89.97(3)degrees, Z = 4, R (R-w) = 0.030 (0.026). Crystal data for 3: monoclinic (P2(1)/n), a = 18.792(3) Angstrom, b = 8.856(3) Angstrom, c = 26.210(9) Angstrom, beta = 93.72(2)degrees, Z = 8, R (R-w) = 0.066 (0.063).