The photostimulated reactions of ButHgCl with 1 ,I -diarylethylenes yield differen! products for the aryl groups C6H5, p-02NC6H4, or p-MeOC& reflecting the donor or acceptor properties of ButCB2C(Ar)p. ... We have studied the products formed by trapping t-butyl radicals in the photostimulated reactions of diarylethylenes (1a-c) with BufHgCl. Photolysis in Me2S0 of ButHgC1 and (la) formed (3a)' and (4a)* in an approximately 1: 1 ratio 1). BY gc.-mass spectrometry a small amount ...