- THE SYNTHESIS AND PROPERTIES OF ANTIMONY-SULPHUR AND ANTIMONY-OXYGEN LIGANDS
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The synthesis and properties of a series of potentially bi-, tri- and tetra-dentate ligands containing various combinations of antimony and sulphur and antimony and oxygen donors, is described.Included are SbPhn(o-C6H4OMe)3-n (n = 0, 1, 2); SbMe2(o-C6H4OMe); SbPhn(o-C6H4SMe3)3-n (n = 0, 1, 2); SbMe2(o-C6H4SMe); MeS(CH2)3SbR2 (R = Me, Ph) and S(CH2CH2CH2SbPh2)2.Attempts to prepare ligands with dimethylene backbones including (R2SbCH2CH2)2S (R = Me, Ph) failed.The ligands were characterised by analysis, 1H NMR and mass spectra, and by the preparation of quaternary derivatives.
- Levason, William,Sheikh, Baharuddin
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- Crown Thioether Chemistry. Synthesis and Structural Investigation of 1,5,9-Trithiacyclododecane (Trithia-12-crown-3) and its Copper(II) Chloride Adduct
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1,5,9-Trithiacyclododecane (L1) (trithia-12-crown-3) adopts a square conformation similar to that of cyclododecane, with one sulphur atom at a corner and two in side positions.Reaction with copper(II) chloride yields an adduct, 1)2Cl2>, that has been characterized by X-ray diffraction.Each copper ion occupies a centre of inversion and has idealized octahedral microsymmetry, with thioether groups at distances of 2.447(1) and 3.050(1) Angstroem.The conformation adopted by the macrocycle is virtually identical to that adopted by the free ligand, which suggests that its conformation is determined by intrinsic factors rather than packing forces.
- Rawle, Simon C.,Admans, Gary A.,Cooper, Stephen R.
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- Intramolecular sulfur-assisted NaBH4 reduction of esters synthesis of 5-oxo-ETE and 5-oxo-12-HETE
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Ester groups are reduced very efficiently in sulfur-containing molecules situated at close proximity to the ester group. We have used this procedure to regioselectively, efficiently and in high yield reduce an ester group in the presence of another ester group further removed from the sulfur atom. (C) 2000 Elsevier Science Ltd.
- Khanapure, Subhash P.,Saha, Goutam,Sivendran, Sashikala,Powell, William S.,Rokach, Joshua
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- Platinum(II) complexes of the tridentate thioether ligands RS(CH2)3S(CH2)3SR (R = Et, iPr, Ph). Structures of [PtCl(iPrS(CH2)3S(CH2)3SiPr)][BF4], [Ptl(PhS(CH2)3S(CH2)2SPh)][BF4], and
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The tridentate thioether ligands RS(CH2)3S(CH2)3SR (L1, R = Et; L2, R = iPr, L3, R = Ph) were synthesized by nucleophilic addition of thiolate, SR-, to the ditosylate TsO(CH2)3S(CH2)3OTs. The complexes [PtX(Ln)][BF4] were prepared by displacement of 1,5-COD from [PtX2(1,5-COD)] (X = Cl, I) in the presence of one equivalent of AgBF4 and one equivalent of thioether ligand. [PtCl(L2)][BF4] crystallized in the monoclinic space group P21/c with a = 10.409(6), b = 14.180(4), c = 13.726(8) angstrom, β = 104.49(4)°, V = 1961(2) angstrom3, and Z = 4. The structure refined to R = 5.62% and Rw = 6.86% for 2121 reflections with F02 > 3σ(F02). [PtI(L3)][BF4 crystallized in the monoclinic space group P2l/n with a = 13.415(4), b = 12.350(5), c = 14.316(5) angstrom, β = 107.48(3)°, V = 2262(1) angstrom3, and Z = 4. The structure refined to R = 4.85% and Rw 6.33% for 2168 reflections with F02 > 3σ(F02). In both compounds, the thioether ligand acts as a tridentate chelator occupying three of the four sites of the square-planar Pt(II) complex. Variable temperature 13C{1H} NMR verified that there are three possible stereoisomers for these complexes resulting from inversion at sulphur: meso-A, meso-B, and racemic. Thermodynamic parameters were calculated for the interconversion among isomers of [PtCl(L2)][BF4] by a full line-shape analysis. Removal of chloride ligand from [PtCl(L2)][BF4] with Ag+ in the presence of PPh3 yielded the phosphine adduct [Pt(PPh3)(L2)][BF4]2, which crystallized in the triclinic space group PI with a = 13.266(3), b = 11.315(2), c = 13.970(2) angstrom, α = 106.04(2)°, β = 84.95(2)°, γ = 86.56(2)°, V = 1999.7(7) angstrom3, and Z = 2. The structure refined to R = 4.22% and Rw = 5.38% for 4493 reflections with F02 > 3σ(F02). Unlike the two halide complex structures, which crystallized in the meso-B form, [Pt(PPh3)(L2)][BF4]2 crystallized in the racemic form.
- Loeb,Mansfield
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p. 1377 - 1390
(2007/10/03)
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- Sulfoboration of Cyclic Ethers - A Preparative Route to Mercaptoalkanols and Bis(hydroxyalkyl) Sulfides
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Bis(1,5-cyclooctanediylboryl) sulfide (1) reacts slowly with the cyclic ethers A-D to give O,S-bis(9-BBN)mercaptoalkanols 2a-d in excellent yields.From oxetane (E) and 1, however, 2e is obtained rapidly, which further reacts with E to yield the bis(9-BBN-oxypropyl) sulfide 3ee. 2a and c react with E to form the mixed thioethers 3ae and 3ce, respectively.The methanolysis of 2a-e leads to the O-(9-BBN)mercaptoalkanols 4a-e.The compounds 2 and 3 react with acetylacetone or with 2-aminoethanol to yield the mercaptoalkanols 7a-c, e and the bis(hydroxyalkyl) sulfides 8ae, 8ce and 8ee, resp., in high yields beside the 9-BBN-chelates 5 or 6.Key Words: Ethers, cyclic, cleavage of / Sulfoborations / Mercaptoethanols, 9-BBN derivatives of / Sulfides, bis(hydroxyalkyl), 9-BBN derivatives of
- Koester, Roland,Kucznierz, Ralf
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p. 835 - 842
(2007/10/02)
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- Immersion oil containing aliphatic thio compounds
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Immersion oils containing aliphatic thio compounds are described. The oils have optical properties and are useful in immersion optics such as fluorescence microscopy.
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