Adducts of trimethylindium with amine and phosphine ligands; X-ray crystal structure of Me 3In [formula omitted]Me 2, Me 3InN(CH 2CH 2) 3N and Me 3InNHMe(CH 2) 2NHMeInMe 3

Abstract

Treatment of trimethylindium diethyletherate separately with a number of amines and a phosphine has given the products Me 3InL where L  NH(C 6H 11) 2 ( 1), NHCHMe(CH 2) 3C HMe ( 2), NHCMe 2(CH 2) 3C Me 2 ( 3), N(CH 2CH 2) 3CH ( 4), N(CH 2CH 2) 3N ( 5), (CH 2NEt) 3 ( 6) and P(NMe 2) 3 ( 7). The complexes Me 3In-NHMe(CH 2) 2NHMeInMe 3 ( 8) and Me 2InCl[MeNH C(CH) 4N ] ( 9) have also been made by direct reaction of Lewis acid etherate and Lewis base. The X-ray crystal structure of 3 shows a longer InN bond (2.50 Å) than that found in the crystal structure of 8 (2.38 Å); both possess distorted tetrahedral metal environments. The X-ray crystal structure of 5 shows a linear polymer of alternating Me 3In and N(CH 2CH 2) 3N units; the Me 3In unit is planar and the indium is almost perfectly trigonal bipyramidal and the InN bonds are very long (2.62 Å) compared with 3 and 8. Variable temperature 1H NMR studies of 6 show the adduct bond is very labile: rapid exchange between adduct components is occurring even at −70°C.