D. Bryan Sowerby

The preparation of phenyl substituted antimony(III) and antimony(V) chlorides and bromides

Abstract In the absence of solvent, the redistribution of 2 1 and 1 2 molar mixtures of Ph 3 Sb and SbX 3 , where X = Cl or Br, is rapid giving quantitative yields of Ph 2 SbX and PhSbX 2 , respectively.

Antimony(III) diorganophosphoro- and diorganophospinodithioates: Crystal structure of Sb[S2P(OR)2]3 (R = Me and i-Pr)

Abstract Several antimony(III) tris(dialkylphosphorodithioates) Sb[S 2 P(OR) 2 ] 3 (R = Me, Et, i-Pr, n-Bu, i-Bu and sec-Bu) and tris(diorganophosphinodithioates Sb(S 2 PR 2 ) 3 (R = Me, Et and Ph) have been prepared by reactions between antimony trichloride and respectively the ammonium and sodium salts of the corresponding acid. The compounds were characterised by infrared and 1 H NMR spectroscopy and the structures of two phosphorodithioates (R = Me and i-Pr) have been determined by X-ray diffraction. Each antimony atom is surrounded by six sulphur atoms from three anisobidentate phosphorodithioate ligands with three atoms at 2.528 and three at 3.010 A. The overall arrangement is distorted octahedral and although this geometry is consistent with stereochemical activity of the 5s electrons at antimony, it cannot be interpreted as direct proof.

Phenylantimony(III) diorganophosphorodithioates: the crystal structure of diphenylantimony(III) di-isopropylphosphorodithioate, Ph2SbS2P(OiPr)2; unusual polymerisation through semibonding

Abstract The diphenylantimony(III)phosphorodithioates, Ph 2 SbS 2 P(OR) 2 where R = Me, Et, i Pr and Ph, have been prepared and the methyl and isopropyl derivatives obtained as crystalline solids. The compounds have been characterised by infrared and NMR spectroscopy. An X-ray structural determination for the isopropyl compound shows the presence of two independent molecules in the asymmetric unit, with similar but not identical molecular parameters. The ligand in each molecule is strongly bonded to antimony by one sulphur atom (SbS 2.54 A), but there are two weaker SbS contacts ( ca. 3.2 and 3.8 A) making the ligand effectively tridentate. These interactions generate infinite chains in the solid state, providing an example of a new dithiophosphate structure.

Phenylchloroantimon(III)ates; their preparations, and the crystal structures of Me4N[PhSbCl3], [Hpy]2[PhSbCl4], and Me4N[Ph2SbCl2]

Phenylantimony dichloride reacts with ionic chlorides such as Me4NCl or HpyCl to give salts of both the [PhSbCl3]− and [PhSbCl4]2− anions, whereas the related diphenylantimony chloride will accept only one chloride ion to give [Ph2SbCl2]− salts. Under similar conditions, no anionic products are formed from Ph3Sb. These results can be rationalised if chloride ion addition takes place trans to antimonychlorine bonds in the starting material and the negative charge is delocalised via three-centre bonding in the resulting ClSb⋯Cl− system. Structures have been determined by single crystal X-ray diffraction for Me4N[PhSbCl3] (a 9.214(5), b 11.499(5), c 16.179(6) A, β 121.65(5)°, space group P21/c), [Hpy]2[PhSbCl4] (a 8.549(5), b 8.899(5), c 14.509(6) A, α 100.16(5), β 90.09(4), γ 114.69(5)°, space group P1) and Me4N[Ph2SbCl2] (a 12.255(5), b 11.078(5), c 14.200(6) A, β 112.28(5)°, space group P21/n). Me4N[PhSbCl3] contains a centrosymmetric, double chlorine-bridged dimeric anion, while the anions in both the [PhSbCl4]− and [Ph2SbCl2]− salts are monomeric. Antimonychlorine bond distances are discussed in terms of the delocalisation picture mentioned above.

Strukturen von [Me4Sb]2[MeSbI4]MeSbI2, und [Me4Sb]I. Darstellung von Me3Sb · MeSbI2 und farbwechsel bei Me4Sb2 · Me2SbBr

Abstract The crystal structures of the complex [Me 4 Sb] 2 [MeSbI 4 ] ( 1 ) and its precursors MeSbI 2 ( 2 ) and [Me 4 Sb]I ( 3 ) are reported. In 1 there are tetrahedral cations and square pyramidal anions with Sb-I distances of 290–320 pm. The structure of 2 contains MeSbI 2 molecules. They associate via iodine bridges to form linear chains with alternating short and long Sb-I distances. The coordination around antimony is distorted tetragonal pyramidal. The tetrahedral coordination of the ions in 3 results in the formation of a wurtzite type structure with antimony-iodine distances of 406 and 435 pm. The novel adducts Me 3 Sb·Me 2 SbI 2 ( 4 ) and Me 2 SbSbMe 2 ·Me 2 SbBr ( 5 ) are formed by reaction of the components. They decompose easily with formation of antimony(V) compounds. Crystals of 5 are yellow but become reversibly black on cooling.

Reactions of [SbR3X2]2O with carboxylates and the crystal structures of [SbPh3(O2CCF3)2]2O and [SbMe3(O2CCH3)2]2O

Abstract Reactions of [SbPh3Br]2O and [SbMe3Cl]2O with a number of carboxylates lead to halogen substitution and formation of either [SbR3(O2CR′)]2O or SbR3(O2CR′)2. X-ray structures for two of the products, [SbPh3(O2CCF3)]2O and [SbMe3(O2CCH3)]2O, show that the carboxylates are unidentate. From NMR spectroscopy, the oxygen bridged compounds are hydrolysed by adventitious water giving SbR3(O2CR′)OH in solution but when R=phenyl the original compounds can be recovered on crystallisation.

Preparation and crystal structures of five organoantimony halides; (p-tolyl)antimony(III) dichloride and dibromide, diphenylantimony(III) bromide, 2′-diyl)antimony(III) chloride and bis-(2′-chlorobiphenyl-2-yl)antimony(V) trichloride

Crystal structures are reported for four organoantimony(III) halides, i.e. (p-tolyl)antimony dichloride (1) and dibromide (2), diphenylantimony bromide (3), (biphenyl-2,2′-diyl) antimony chloride (4) and a new antimony(V) compound, bis(2′-chlorobiphenyl-2-yl)antimony(V) trichloride (5), obtained by oxidising (4) with an excess of chlorine. The two tolyl compounds (1) and (2), which are isostructural and also isostructural with the corresponding phenyl derivatives, contain pyramidal CSbX2 units. These are interlinked by (a) two weak intermolecular Sb ⋯ halogen interactions (mean 3.54 and 3.69 A for the chloride and bromide, respectively), raising the antimony coordination number to five giving infinite chains, and (b) weak contacts between antimony and three of the carbon atoms of a symmetry-related tolyl group (mean 3.41 and 3.42 A for the chloride and bromide, respectively). There are no intermolecular Sb ⋯ Br contacts in 3 but two Sb ⋯ C interactions (mean 3.64 A) interconnect the pyramidal monomers. Such Sb ⋯ C interactions (mean 3.43 A) are also present in the biphenylyl derivative 4, in which the CSbC angle in the pyramidal monomer is constrained to 81.0° by the short bite of the biphenylyl group. Loose dimers are formed in the solid state by Sb ⋯ Cl contacts at 3.71 A. In contrast to the chlorine bridged dimeric structure of Ph2SbCI3, compound 5 is a distorted trigonal bipyramidal monomer in the solid state, providing the first example of an antimony(V) compound with chlorine atoms in both axial and equatorial sites. As expected, distances to the two axial chlorines are substantially longer (2.420(3), 2.421(3) A) than that to the equatorial atom (2.280(3) A). The greatest distortion is shown by the equatorial CSbC angle, which is increased to 137.1°, probably as a consequence of the steric requirements of the bulky chlorobiphenylyl groups.

Diphenylantimony(III) diphenylphosphinate and diphenylmonothiophosphinate: synthesis, spectra and crystal structure

Infrared data suggest that in diphenylantimony(III) diphenylphosphinate and diphenylthiophosphinate, Ph2Sb[OP(X)Ph2], where X = O (1 or S (2), the ligands are symmetrically bonded, either as chelating or bridging groups, and the presence of the latter has been confirmed by X-ray diffraction. Ph2SbO2PPh2 (1) is orthorhombic, space group P212121, with a 9.185(4), b 11.075(4), c 21.099(7) A and Z 4. Ph2SbOSPPh2 (2) is monoclinic, space group P21/n with, a 9.842(4), b 10.561(4), c 21.182(7) A, β 93.19(4)° and Z 4. In both compounds diphenylantimony(III) groups are linked into chains by bridging phosphinate or thiophosphinate groups and antimony achieves pseudotrigonal bipyramidal coordination with the two phenyl groups in equatorial positions. The axial positions are occupied by oxygen and sulphur atoms of the ligands. The independent SbO and PO bond lengths in 1 are very similar (2.23, 2.29 and 1.49, 1.51 A), while in 2 the PO and PS distances, 1.503 and 2.010 A respectively, also point to symmetrical coordination. Stereochemical activity of the lone pair is considered.

Dichlorodiphenylantimony(V) derivatives of oxo-and thioimidodiphosphinic acids, containing novel inorganic SbO2 P2N and SbOSP2 N rings: crystal and molecular structures of Ph2SbCl2[(OPPh2)(XPPh2)N] (X = O, S)

Abstract Ph 2 SbCl 2 [(OPPh 2 )(XPR 2 )N](X = O, S; R = Me, Ph) were prepared by metathesis reactions between Ph 2 SbCl 3 and an alkali metal salt of the corresponding imidodiphosphinic acid. All new compounds were characterized by IR, multinuclear NMR and mass spectrometry. The molecular structures of Ph 2 SbCl 2 [(OPPh 2 ) 2 N] ( 1 ) and Ph 2 SbCl 2 [(OPPh 2 )(SPPh 2 )N] ( 2 ) were determined by X-ray diffractometry. In both compounds the imidodiphosphinato ligand is coordinated through both chalcogen atoms to antimony (Sb-O(l) 2.128(3), Sb-O(2) 2.112(3) in ( 1 ), and Sb-O(1) 2.113(3), Sb-S(l) 2.614(2) A in ( 2 )), leading to novel, non-planar inorganic SbO 2 P 2 N and SbOSP 2 N rings respectively. In both cases the coordination geometry around the metal atom is slightly distorted octahedral, with the phenyl groups in axial positions (C(1)-Sb-C(7) 173.5(2) and 176.8(2)° in ( 1 ) and ( 2 ) respectively).

Oxidation of (AsPh2)2E(E=O or S); supramolecular hydrogen-bonded self-assembly of an unusual tetranuclear adduct and crystal structure of [AsPh2(O)OH · AsPh2(S)OH]2

Abstract Oxidation of (AsPh 2 ) 2 E(E = O or S) with tert-butyl hydroperoxide and sulfur in the ratios 1:1 and 1:2 has been investigated in an attempt to produce compounds of the type AsPh 2 (E)−E−AsPh 2 and [AsPh 2 (E)] 2 E. Although it has been possible to isolate all four compounds of the type AsPh 2 (E)−E-AsPh 2 , where E = O or S, the dioxidation produces are less stable and recrystallisation of the products from oxidation of (AsPh 2 ) 2 O with sulfur and (AsPh 2 ) 2 S with tert-butyl hydroperoxide leads to a mixed arsinic acid-monothioarsonic acid [AsPh 2 (O)OH · AsPh 2 (S)OH] 2 . This compound has an unusual tetranuclear structure, arising from simultaneous intermolecular hydrogen bond formation between the OH groups of the constituent acids and the oxygen of a centrosymmetrically related diphenylarsinic acid molecule.