41137-16-0Relevant academic research and scientific papers
New square-pyramidal organoantimony(v) compounds; crystal structures of (biphenyl-2,2′-diyl)phenylantimony(v) dibromide, dichloride and diisothiocyanate, Sb(2,2′-C12H8)PhX2 (X = Br, Cl or NCS), and of octahedral SbPh(o-O2C6Cl4)Cl2·OEt 2
Gibbons, Martin N.,Begley, Michael J.,Blake, Alexander J.,Sowerby, D. Bryan
, p. 2419 - 2425 (2007/10/03)
Oxidative addition between (biphenyl-2,2′-diyl)phenylantimony(III), Sb(2,2′-C12H8)Ph 1 and Br2 or SO2Cl2 gave Sb(2,2′-C12H8)PhBr2 2 and Sb(2,2′-C12H8)PhCl2 3, respectively, while the corresponding fluoride Sb(2,2′-C12H8)PhF2 4 and the thiocyanate Sb(2,2′-C12H8)Ph(NCS)2 5 were obtained by metathesis reactions between 3 and KF and KSCN, respectively. Compounds 2 and 3 are isostructural but, in contrast to the closely related SbPh3X2 species, individual molecules have square-pyramidal geometry. Again in contrast to SbPh3X2 compounds, secondary antimony-halogen interactions trans to the apical carbon atom lead to solid-state dimers, implying Lewis acidity at antimony. Antimony in the thiocyanate 5 snowed similar square-pyramidal geometry with N-bonded thiocyanate groups but bridging by one thiocyanate again gives dimers in the solid. Oxidative addition between SbPhCl2 and tetrachloro-ortho-benzoquinone in ether solution gave the tetrachlorocatechol analogue of 3 as a six-co-ordinate ether solvate, SbPh(o-O2C6Cl4)·OEt2 6. If the weak bond to ether is ignored, antimony again has square-pyramidal geometry but formation of the adduct again points to antimony Lewis acidity. A non-solvated substituted catecholate, SbPh(o-O2C6H2But 2-3,5)Cl2 8, was also synthesized but crystals suitable for X-ray diffraction could not be obtained.
Formation and structure of cyclic five-coordinated antimony derivatives. The first square-pyramidal geometry for a bicyclic stiborane
Holmes, Robert R.,Day, Roberta O.,Chandrasekhar,Holmes, Joan M.
, p. 157 - 163 (2008/10/08)
Stiboranes Ph3Sb(O2C6Cl4) (1) and (Cl4C6O2)(C12H 8)SbPh·0.25C6H6·0.25CH 2Cl2 (2) were formed by the oxidative-addition reaction of tetrachloro-o-benzoquinone with the corresponding stibole. Reaction of Ph3SbCl2 with naphthalenediol in the presence of Et3N led to the isolation of the six-coordinated hypervalent anionic stiborane [Ph3Sb(Cl)(O2C10H6)][Et 3NH] (3). The stiboranes 2 and 3 are new compounds with 2 being the first unsaturated bicyclic five-coordinated antimony derivative structurally studied. X-ray analysis revealed a trigonal-bipyramidal structure for 1, a rectangular-pyramidal geometry for 2, and a distorted-octahedral form for 3. The geometries found for 1 and 2 are considered relatively devoid of lattice effects compared to that for the related monohydrate composition [Ph3Sb(O2C6H4)] 2·H2O. The naphthalene derivative 3 contains a long Sb-Cl bond, which provides this derivative with its octahedral character. In the context of these and other examples, it is concluded that five-coordinated antimony exhibits a high degree of molecular nonrigidity and that the normally less stable rectangular pyramid forms, as with other group 4 (14) and 5 (15) elements, whenever two unsaturated five-membered rings are present with like atoms in any one ring directly bonded to the central atom. Stiborane 1 crystallizes in the monoclinic space group P21/n with a = 10.345 (2) A?, b = 10.904 (3) A?, c = 21.178 (3) A?, β = 102.24 (1)°, and Z = 4. 2 crystallizes in the triclinic space group P1 with a = 13.566 (4) A?, b = 13.762 (4) A?, c = 14.086 (3) A?, α = 90.10 (2)°, β = 105.85 (2)°, γ = 107.20 (2)°, and Z = 4. 3 crystallizes in the monoclinic space group C2/c with a = 28.600 (5) A?, b = 12.685 (2) A?, c = 18.515 (4) A?, β = 113.58 (1)°, and Z = 8. The final conventional unweighted agreement factors were 0.039 (1), 0.035 (2), and 0.039 (3).
