The reactivity of Me 3SnMn(CO) 5, (CH 2CHCH 2) 3SnMn(CO) 5, Me 3SnFeCp(CO) 2, and Me 2Sn[FeCp(CO) 2] 2 has been investigated with respect to iodine, organomercury chlorides, trialkyl- and triarylchlorosilane, inorganic chlorides (SiCl 4, SnCl 4, TiCl 4, ZnCl 2, HgCl 2) and Mn 2(CO) l0. Iodination proceeded with dominant metal-metal bond cleavage in all solvents used, as was the case in most of the subsequent reactions, with the exception of the triallyltin derivative where carbon—metal bond fission occurred. Me 3SnFeCp(CO) 2 reacted with MeHgCl in a 1 1 ratio in DMSO- d 6 to give initially MeHgFeCp(CO) 2 and Me 3SnCl which subsequently gave Me 4Sn, Me 2Hg, Hg[FeCp(CO) 2] 2 and ClHgFeCp(CO) 2. In contrast with the phenyl analogue, the intermediate MeHgFeCp(CO) 2 was not stable enough to be isolated. Me 2Sn[FeCp(CO) 2] 2 reacted similarly but secondary reactions yielded Me 3SnCl and, using excess MeHgCl, Me 2SnCl 2. Reaction of Me 3SnMn(CO) 5 followed similar patterns but in this instance MeHgMn(CO) 5 appeared much more stable than PhHgMn(CO) 5. Pathways accounting for all the products are discussed. Evidence is also presented for a range of exchange reactions with a variety of inorganic and organometallic chlorides.