Synthesis and structure of reaction products of 2,2’-bipyridyl with antimony trichloride

Adducts have been obtained from antimony trichloride and 2,2'-bipyridyl in acetonitrile: [C10H9N2]2+[OSb2Cl6]2- (1) и [C10H9N2]+ {[(C10H8N2)SbCl3]2[Cl]}- (2). The compounds have been identified by IR spectroscopy and X-ray diffraction analysis. According to the X-ray diffraction data, the pale green crystals 1 consist of two types of bipyridyl cations and binuclear anions [OSb2Cl6]2-, in which two SbCl3 fragments are linked through an oxygen atom and two bridged chlorine atoms. The coordination polyhedron of the antimony atom is a square pyramid with two terminal (Sb-Clterm 2.418(5)-2.497(4) Å) and two bridged chlorine atoms (Sb-Clbr 3.044(4)-2.849(5) Å) at the base and the oxygen atom at the fifth vertex (Sb-O 1.95(1) and 1.93(9) Å). The Sb-O-Sb group has been curved (119.3(5)o) so that the antimony atoms approach each other at a distance of 3.348(2) Å, which is greater than the sum of the covalent radii of these atoms (2.08 Å), but less than the sum of their van der Waals radii (4.4 Å). The antimony atom shifts from the equatorial plane [Cl4] towards the carbon atom by 0.254 Å. Along with the main product of the reaction, there are minor amounts of yellow-orange crystals 2, consisting of two types of bipyridyl cations and binuclear chlorine-containing anions {[(C10H8N2)SbCl3]2[Cl]}-, in which two antimony-containing fragments (distorted octahedron) (C10H8N2)SbCl3 are linked by a chlorine bridging atom (Sb-Clbr 2.59(8) Å). The bridging chlorine atom occupies the sixth vertex of the octahedron (Sb×××Cl 3.13(1) Å), the opposite vertex is occupied by one of the nitrogen atoms of the bipyridyl ligand, the second nitrogen atom (Sb-N 2.22(9) Å) of which lies in the equatorial plane with three chlorine atoms (Sb-Cl 2.58(1), 2.61(1), 2.56(1) Å). Complete tables of atom coordinates, bond lengths and valence angles are deposited at the Cambridge Crystallographic Data Center ((№ 2041289; deposit@ccdc.cam.ac.uk or http://www.ccdc.cam.ac.uk/data_request/cif).