Treatment of the coordinatively unsaturated osmium complex Os(SnMe3)Cl(CO)(PPh3)2with sodium dimethyldithiocarbamate gives the coordinatively saturated complex Os(SnMe3)(es/gifchars/eta.gif" BORDER=0 >2-S2CNMe2)(CO)(PPh3)2 (1). Complex 1 reacts with excess SnI4 to give Os(SnMeI2)(es/gifchars/eta.gif" BORDER=0 >2-S2CNMe2)(CO)(PPh3)2 (3) in high yield. A redistribution reaction of 3 with anequimolar amount of 1 provides Os(SnMe2I)(es/gifchars/eta.gif" BORDER=0 >2-S2CNMe2)(CO)(PPh3)2 (2). The last remainingmethyl group bonded to tin in 3 is removed by treatment with a slight excess of I2, givingthe triiodostannyl complex Os(SnI3)(es/gifchars/eta.gif" BORDER=0 >2-S2CNMe2)(CO)(PPh3)2 (4). Both 3 and 4 have beenfurther derivatized by replacement of the halide groups on tin. Treatment of 3 withpyridinium tribromide gives Os(SnMeBr2)(es/gifchars/eta.gif" BORDER=0 >2-S2CNMe2)(CO)(PPh3)2 (5). Treatment of 3 withcatechol provides Os(SnMe[1,2-O2C6H4])(es/gifchars/eta.gif" BORDER=0 >2-S2CNMe2)(CO)(PPh3)2 (6), while the similarreaction with 1,2-ethanedithiol gives Os(SnMe[1,2-S2C2H4])(es/gifchars/eta.gif" BORDER=0 >2-S2CNMe2)(CO)(PPh3)2 (7).Complex 4 undergoes reaction with an excess of KOH to give the trihydroxystannyl complexOs(Sn[OH]3)(es/gifchars/eta.gif" BORDER=0 >2-S2CNMe2)(CO)(PPh3)2 (8). Treatment of 4 with triethanolamine gives Os(Sn[OCH2CH2]3N)(es/gifchars/eta.gif" BORDER=0 >2-S2CNMe2)(CO)(PPh3)2 (9), while reaction with nitrilotriacetic acid givesthe metal-substituted stannatranone Os(Sn[OC(O)CH2]3N)(es/gifchars/eta.gif" BORDER=0 >2-S2CNMe2)(CO)(PPh3)2 (10). Thecrystal structures of 1, 4, 5, 7, and 10 have been determined.