Triorgano antimony(V) complexes with internally functionallized oximes:: Synthetic, spectroscopic and structural aspects of [R3Sb(Br)L], [R3Sb(OH)L] and [R3SbL2] crystal and molecular structures of [Me3Sb{ ON=C(Me)C4H3O}2], [Me3Sb{ON=C(Me)C4H3S}2], 2-OC4H3C(Me)=NOH and 2-SC4H3C(Me)=NOH

Triorganoantimony(V) complexes with internally functionallized oximes of the type [R3Sb{ON=C(Me)Ar}(2)] (1) [R = Me, Pr'; Ar = C5H4N. C4H3S, C4H3O] have been prepared by the reaction of R3SbBr2 with the corresponding oximes in 1:2 molar ratio in anhydrous benzene. Treatment of 1 with one equivalent of R3SbX2 afforded a redistribution product [R3Sb(X){ON=C(Me)Ar}] (2) [X = (a):Br, (b):OH]. The species, R3Sb(OH)L, may also be obtained by the controlled hydrolysis of 1 (R = Pr', Ar = C5H4N)All of these complexes have been characterized by elemental analyses, and IR and NMR (H-1 and C-13) spectroscopic studies. Crystal structures of [Me3Sb{ON=C(Me)C4H3O-2}(2)] (3), [Me3Sb{ON=C(Me)C4H3S-2}(2)] (4) 2-OC4H3C(Me)=NOH (5) and 2-SC4H3C(Me)=NOH (6) are reported. The geometry around the antimony atom in 3 and 4 is distorted trigonal bipyramidal with the carbon atoms of the SbMe3 unit in equatorial positions and the two oxygen atoms of the oxime group occupying axial positions (O(1)-Sb-O(2) 171.67(12) in 3 and 169.14(13) in 4). The free oxime is clearly hydrogen bonded (H-N 2.08 Angstrom in 6) to essentially form a dimer. (C) 2002 Elsevier Science B.V. All rights reserved.