The chloromethylation of poly(methylsilane) is readily achieved using
chloromethyl methyl ether in a tin(IV) chloride-catalysed reaction in
chloroform solution at 0 degrees C. A convenient, less hazardous react
ion, in which chloromethyl methyl ether is prepared in situ, is also r
eported. The accompanying variations of the polymer molecular-weight p
arameters are recorded for chloromethylations extending to 95% of the
substituent phenyl groups, and discussed in terms of chain scissions a
rising at isolated siloxane linkages formed adventitiously during the
isolation of the parent polymer.