Reactions of alkyltriphenylphosphonium iodides with bismuth triiodide

Abstract

The bismuth complexes [Ph3PCH2С(О)Me]+[BiI4(dmso)2] (1), [Ph3PCH=CHMe]+2[Bi2I8(dmso)2]2 (2), [Ph3PCH2OMe]+4[Bi6I22]4 (3) and [Ph3PCH2C(O)Me]+4[Bi8I28]4 (4) were synthesized by the interaction of alkyltriphenylphosphonium iodides with bismuth triiodide in dimethyl sulfoxide or acetone. The structures of these complexes were established by X-ray diffraction. The P atoms in phosphonium cations 1, 2 and two pairs of crystallographically independent cations of complexes 3, 4 have a distorted tetragonal coordination [CPC 107.36(16)113.04(16), PC 1.787(4)1.800(3) Å in 1, 106.60(14)111.53(16), 1.765(3)1.801(3) Å in 2, 106.21(19)112.11(18), 1.779(4)1.814(4) Å in 3, 105(2)114(3), 1.73(5)1.83(6) Å in 4]. In the octahedral centrosymmetric anions [BiI4(dmso)2] of complex 1, the iodine atoms occupy equatorial positions [BiI 3.0190(3)3.1029(3) Å], and in the axial positions there are dimethyl sulfoxide molecules coordinated to the metal atom by the oxygen atoms [Bi∙∙∙O=SMe2 2.346(2), 2.382(3) Å]. The bismuth atoms in the binuclear centrosymmetric anions of complexes 2 have a slightly distorted octahedral coordination, with the bismuth atoms linked to each other by two bridging iodine atoms [2-I-Bi 3.1679(3) and 3.2576(3) Å (2)], which are coplanar with four terminal iodine atoms (Bi-Iterm 2.9560(3), 2.9797(3) Å (2). The two remaining positions at the bismuth atoms are occupied by an iodine atom [Bi-I 2.9849(3) Å] and an n-ligand molecule (Bi∙∙∙О 2.457(2) Å. The IBiI cis-angles in binuclear anions are 93.531(8) and 95.671(8)°, the IBiI and OBiI trans-angles are 168.815(7), 171.351(8)°. The product of the reaction of methoxymethyltriphenylphosphonium iodide with bismuth iodide in acetone (molar ratio 2:3) is complex 3, consisting of two types of crystallographically independent tetrahedral alkyltriphenylphosphonium cations and the [Bi6I22]4 anions, in which the Bi atoms have octahedral coordination (the IBiI trans-angles are 168.924(8)176.511(8)], the terminal groups of BiI3 are symmetrically located near the tetranuclear skeleton. The distances between the bismuth atoms and the bridging iodine atoms (2.9963.444 Å) are longer than similar terminal bonds (2.8642.884 Å). At the molar ratio of acetonyltriphenylphosphonium iodide and bismuth triiodide of 1:2, a bismuth complex 4 is formed with the octahedral anion [Bi8I28]4, in which the eight-nuclear anions [Bi8I28]4 consist of four pairs of octahedra united along a common face with central hexacoordinated bismuth atoms, and the lengths of the BiI bonds differ significantly. The BiIterm distances vary in the range of 2.860(6)2.919(6) Å, while the bridging iodine atoms are linked to the bismuth atoms by weaker bonds. [2-IBi 3.024(7)3.065(6) Å), [3-IBi 3.137(6)3.374(7) Å]. Complete tables of atomic coordinates, bond lengths and bond angles of nitrates 14 have been deposited at the Cambridge Crystallographic Data Centre (CCDC 2362566 (1), 2362615 (2), 2362596 (3), 2332810 (4); deposit@ccdc.cam.ac.uk; http://www.ccdc.cam.ac.uk).