HOMOLEPTIC ORGANOMETALLIC COMPOUNDS OF HEAVY PNICOGENS. CRYSTAL AND MOLECULAR STRUCTURE OF [2-(iP2NCH2)C6H4]3M (M = Sb, Bi)

Two new homoleptic triorganopnicogen(III) species, [2-((Pr2NCH2)-Pr-i)C6H4](3)M [M = Sb (2), Bi (3)] were obtained by reacting [2-((Pr2NCH2)-Pr-i)C6H4]MgBr (prepared in situ from [2-((Pr2NCH2)-Pr-i)C6H4]Br (1) and Mg filings] with MCl3. The compounds were characterized by multinuclear NMR solution studies and the crystal and molecular structure of 2 and 3 was established by single-crystal X-ray difft action. The NMR data are consistent with one type of organic group attached to the metal atom in 2 and 3. The main difference between the molecules of the organometallic species is observed in the solid state. While for the antimony(III) compound all pendant arms are twisted to push the nitrogen atoms far from the metal centre, in the bismuth(III) derivative weak intramolecular N -> Bi interactions are established for all three nitrogen atoms, thus increasing the coordination number from three to six in a distorted octahedral (C,N)(3)Bi core.