Exchange and condensation of chloro and methoxyl groups between monomethylphosphino and methyl-substituted silyl or germyl moieties

Abstract

The room-temperature reaction between CH 3PCl 2 and (CH 3) x M(OCH 3) 4−x, where M = Si with x = 2 or 3, or M = Ge with x = 2, exhibits rapid exchange of chloro methoxyl groups between the starting compounds followed by condensation of the phosphorus moieties to give CH 3(O)P ▪ units connected by PP bonds in the resulting oligomers. When CH 3P(OCH 3) 2 is reacted with (CH 3) xitxSiCl 4− x for x = 2 or 3, there is no rapid exchange of chloro and methoxyl groups between the reagents but instead the major observed reaction is a slower condensation of the phosphorus moieties, a process which is necessarily accompanied by a transfer of methoxyl groups from the phosphino to the silyl moiety. In the case of CH 3P(OCH 3) 2 plus (CH 3) 2GeCl 2, there is essentially no reaction in 2 weeks at room temperature except for a slow rearrangement of the phosphorus compound to (CH 3) 2P(O)OCH 3.