On the Synthesis and Reactivity of Tris (tetrachloropyridyl) Antimony (III) and Antimony (V) Compounds

Abstract

Halogens (X= Cl, Br), Interhalogens and halo-pseudohalogen IX (X = Cl,Br,N3,NCO), freshly generated pseudohalogen (SCN)2 interpseudohalogen XCN (X = Br, I), XSCN (X = Cl, Br) & elemental sulphur to give oxidative addition products (C5Cl4N)3SbX2, (C5Cl4N)3SbIX, (C5Cl4N)3Sb(SCN)2, (C5Cl4N)3SbXSCN, and (C5Cl4N)3SbCNX. (C5Cl4N)3SbS may also be prepared by the reaction of(C5Cl4N)3SbX2¬ with H2S. Products with BrSCN and ClSCN are not stable and rearrange to give (C5Cl4N) 3¬Sb (SCN) 2 and (C5Cl4N)3SbX2, (C5Cl4N)3¬SbIX undergoes metathetical reactions with metallic salt (MY) to give (C5Cl4N)3¬SbY2 and (C5Cl4N)3¬SbIY derivatives respectively (where Y = SCN, NCO, N3, OCOR, HNR2). Reductive cleavage reaction of (C5Cl4N)3SbS with Ar6Pb2 gives (C5Cl4N)3¬Sb and the corresponding (Ph3Sn)2S but treatment of (C5Cl4N)3¬SbX2(X=NCO,Cl) with Ar6Pb2 gave Ar4Pb and Ar2PbX2 together with (C5Cl4N)3Sb.Treatment of (C5Cl4N)3SbCl2 with aqueous NaN3give the binuclear oxo-bridge compounds [(C5Cl4N)3Sb-O- Sb(C5Cl4N)3](N3)2. (C5Cl4N)3SbX2, (X=SCN, NCO) and (C5Cl4N)3SbIX (X=N3, NCS, NCO) are also accessible by displacements reaction of (C5Cl4N)3SbX2¬ and (C5Cl4N)3SbIX, respectively with the corresponding metallic salt. Similarily, 1:2 molar reactions of (C5Cl4N)3SbX2 with the sodium salts of amide, oxime and carboxylate moieties, NaY (Y=OCOMe2, ONCMePh, NCO(CH2)CO, OOCC6H4NH2, OOCC6H4Cl-o and OOCC6H4NO2-m) yielded disubstituded products.The interaction of (C5Cl4N)3SbCl2 and bis(tributyltin)sulphides proceeds with anionic exchange to form (C5Cl4N)3¬SbS and Bu3SnCl. The newely synthesized compounds have been formulated and characterized on the basis of elemental analysis, molar conductances, molecular weights, solid state IR, and 1H, 13C NMR and UV spectral data. The physico-chemical data are consistent with five co-ordinate antimony compounds.