Alkylation of (As, Sb, Bi)Cl 3 : formation of [(As, Sb, Bi)RCl 2 ], (E)-[BiR(CH 2 CHC)(SiMe 3 )(C 5 H 4 N-2)] and 2-CH(SiMe 3 ) 2 C 5 H 4 N-5-R [R = C(SiMe 3 ) 2 C 5 H 4 N-2]

Monomeric alkyldichloro-antimony(III) and –bismuth(III) compounds [MRCl2], R = C(SiMe3)2C5H4N-2′, and the thermally unstable arsenic(III) analogue are accessible from the appropriate group 15 trichloride and LiR in diethyl ether; treating BiCl3 with two and three equivalents of LiR in tetrahydrofuran (THF) yields (E)-[BiR(CH2CHC)(SiMe3)(C5H4N-2)] where the C2 insertion–SiMe3 elimination fragment originates from THF, and the ‘head-to-tail’ alkyl coupled species, 2-CH(SiMe3)2C5H4N-5-R.