REACTIONS OF ORGANOTIN COMPOUNDS: I. THE STABILITY OF DIMETHYLTIN DIHYDRIDE, AND ADDITIONS TO SOME FLUORO-OLEFINS

Abstract

The effect of heat and ultraviolet irradiation on dimethyltin dihydride is reported. At 120°, the major decomposition products are (CH3)3SnH, Sn, and H2, with a small amount of (CH3)6Sn2. At 130° under ultraviolet light, decomposition is much more rapid giving (CH3)3SnH, Sn, and H2, and an appreciable quantity of (CH3) 4Sn. If the dihydride is maintained under these conditions for a longer period (40 hours), (CH3)6Sn2 is formed in place of (CH3)3SnH, and other products are (CH3)4Sn, Sn, and H2. Negligible decomposition occurs at 25° even under irradiation.The ready addition of C2F4 to (CH3)2SnH2 gives the first reported mono-addition product of an organotin dihydride, (CH3)2SnH(C2F4H), as well as (CH3)2Sn(C2F4H)2. Physical and chemical properties of these compounds are described. The additions of (CH3)2SnH2 to CF2CFH, CF2CH2, and CF2CFBr are reported and the results interpreted in terms of the formation of unstable mono-addition products, (CH3)2SnH(C2FnXmHp). Surprisingly, these species decompose through the exchange of halogen and hydrogen between (CH3)2SnH2 and the olefin. Thus, usual products from the reaction of (CH3)2SnH2 with CF2CFBr are (CH3)2SnBr2 and CF2CFH, with some (CH3)3SnBr.