6224-65-3Relevant academic research and scientific papers
Mechanism of sulfur transfer from 1,2,4-dithiazolidine-3,5-diones to triphenylphosphines
Ponomarov, Oleksandr,Padelkova, Zdenka,Hanusek, Jiri
supporting information, p. 560 - 564 (2013/07/26)
The mechanism of sulfurization of substituted triphenylphosphines with 4-(3- and 4-substituted)-1,2,4-dithiazolidine-3,5-diones in acetonitrile, dichloromethane, tetrahydrofuran and toluene at 25°C was studied. The reaction pathway involves rate-limiting initial nucleophilic attack of the phosphorus at sulfur followed by fast decomposition of the phosphonium intermediate to the corresponding phosphine sulfide, phenylisocyanate and carbonylsulfide. From the Hammett correlations and from the solvent dependency, it was concluded that the transition-state structure is very polar and resembles the zwitter-ionic intermediate. The extent of P-S bond formation and S-S bond cleavage is very similar in the solvents series, but the latter gradually decreases with the decreasing polarity of the solvent. Copyright 2013 John Wiley & Sons, Ltd. The mechanism of sulfurization of substituted triphenylphosphines with 4-(3- and 4-substituted)-1,2,4-dithiazolidine-3,5- diones in acetonitrile, dichloromethane, tetrahydrofuran and toluene at 25°C was studied. The reaction pathway involves rate-limiting initial nucleophilic attack of the phosphorus at sulfur followed by fast decomposition of the phosphonium intermediate to the corresponding phosphine sulfide, phenylisocyanate and carbonylsulfide. The transition-state structure is very polar and resembles the zwitter-ionic phosphonium intermediate. Copyright
A new series of bis(ene-1,2-dithiolato)tungsten(iv), -(v), -(vi) complexes as reaction centre models of tungsten enzymes: Preparation, crystal structures and spectroscopic properties
Sugimoto, Hideki,Hatakeda, Kohei,Toyota, Kazuo,Tatemoto, Susumu,Kubo, Minoru,Ogura, Takashi,Itoh, Shinobu
supporting information, p. 3059 - 3070 (2013/03/28)
The carbomethoxy substituted dithiolene ligand (LCOOMe) enabled us to develop a series of new bis(ene-1,2-dithiolato)tungsten complexes including WIVO, WIV(OSiBuPh2), W VIO2, WVIO(OSiBuPh2) and W VIO(S) core structures. By using these tungsten complexes, a systematic study of the terminal monodentate ligand effects has been performed on the structural, spectroscopic properties and reactivity. The structure and spectroscopic properties of the tungsten complexes have also been compared to those of the molybdenum complexes coordinated by the same ligand to investigate the effects of the metal ion (W vs. Mo). X-ray crystallographic analyses of the tungsten(iv) complexes have revealed that the tungsten centres adopt a distorted square pyramidal geometry with a dithiolene ligand having an ene-1,2-dithiolate form. On the other hand, the dioxotungsten(vi) complex exhibits an octahedral structure consisting of the bidentate LCOOMe and two oxo groups, in which π-delocalization was observed between the WVIO2 and ene-1,2-dithiolate units. The tungsten(iv) and dioxotungsten(vi) complexes are isostructural with the molybdenum counter parts. DFT calculation study of the WVIO(S) complex has indicated that the WS bond of 2.2 A? is close to the bond length between the tungsten centre and ambiguously assigned terminal monodentate atom in aldehyde oxidoreductase of the tungsten enzyme. Resonance Raman (rR) spectrum of the WVIO(S) complex has shown the two inequivalent LCOOMe ligands with respect to their bonding interactions with the tungsten centre, reproducing the appearance of two ν(CC) stretches in the rR spectrum of aldehyde oxidoreductase. Sulfur atom transfer reaction from the WVIO(S) complex to triphenylphosphines has also been studied kinetically to demonstrate that the tungsten complex has a lower reactivity by about one-order of magnitude, when compared with its molybdenum counterpart.
Mechanism of the sulfurisation of phosphines and phosphites using 3-amino-1,2,4-dithiazole-5-thione (xanthane hydride)
Hanusek, Jiri,Russell, Mark A.,Laws, Andrew P.,Jansa, Petr,Atherton, John H.,Fettes, Kevin,Page, Michael I.
, p. 478 - 484 (2008/03/27)
Contrary to a previous report, the sulfurisation of phosphorus(iii) derivatives by 3-amino-1,2,4-dithiazole-5-thione (xanthane hydride) does not yield carbon disulfide and cyanamide as the additional reaction products. The reaction of xanthane hydride with triphenyl phosphine or trimethyl phosphite yields triphenyl phosphine sulfide or trimethyl thiophosphate, respectively, and thiocarbamoyl isothiocyanate which has been trapped with nucleophiles. The reaction pathway involves initial nucleophilic attack of the phosphorus at sulfur next to the thiocarbonyl group of xanthane hydride followed by decomposition of the phosphonium intermediate formed to products. The Hammett ρ-values for the sulfurisation of substituted triphenyl phosphines and triphenyl phosphites in acetonitrile are ~ -1.0. The entropies of activation are very negative (-114 ± 15 J mol-1 K-1) with little dependence on solvent which is consistent with a bimolecular association step leading to the transition state. The negative values of ΔS ≠ and ρ values indicate that the rate limiting step of the sulfurisation reaction is formation of the phosphonium ion intermediate which has an early transition state with little covalent bond formation. The site of nucleophilic attack has been also confirmed using computational calculations. The Royal Society of Chemistry 2007.
Reactivity of X3P compounds with elemental sulfur, carbon disulfide or both, to yield X3PS, X3RCS2 or X3P.Sn.CS2 adducts
Demarcq, Michel C.
, p. 307 - 320 (2007/10/03)
Kinetic constants k2 have been obtained for the reaction of sulfur with 25 PIII compounds in toluene or hexane. In the series PhnMe3-nP (n = 1-3) or PhnBu3-nP (n = 0-3), log k2 decreases linearly with Σχi (χi=Tolman's electronic parameter of each ligand on P), taken as a gauge for the donor strength of P. Dramatic deviations from additivity are observed for the series PhnP(OEt)3-n, PhnP(OEt)3-n, and BunP(OEt)3-n(n = 0-3); the deviation is smaller for PhnPCl3-n, and even smaller for PhnP(NEt2)3-n . The results are discussed in terms of P-coordination (PIV vs. PV), stability and geometry of the intermediate X3P.S8 or of the transition state leading to this adduct, emphasis being laid on the donor/acceptor character of the P site. A similar dependence on X governs the reactivity of X3P with S8, CS2 or both, to give X3PS, X3P.CS2 (binary red adduct) or X3P.Sn.CS2 (ternary yellow adduct) respectively; an explanation for this parallelism is proposed.
The Kinetics and Mechanism of the Reaction of Tricoordinate Phosphorus Compounds with Diaryl Trisulfides
Hall, C. Dennis,Tweedy, Bruce R.,Kayhanian, Robert,Lloyd, John R.
, p. 775 - 779 (2007/10/02)
Kinetic data and activation parameters are reported for the reaction of a series of tricoordinate phosphorus compounds, , with diaryl trisulfides.The second-order rate coefficients for series of arylphosphines, phosphinites and phosphonites, correlate with the Hammett ? constants of the aryl substituents with ρ values of -1.1, -1.1 and -1.1 respectively and these results are discussed in terms of a biphilic mechanism analogous to that proposed for the reaction of tricoordinate phosphorus with S8.
A convenient alternative to prepare phosphine sulfides
Miranda,Salas,Mondragon,Velasco
, p. 1077 - 1080 (2007/10/02)
An efficient procedure to obtain phosphine sulfides by means of their corresponding phosphines in presence of sodium polisulfide solution, is described. Reaction yields are high and the work-up is very simple.
Kinetics and mechanism of the reaction of trico-ordinate phosphorus ompounds with octasulphur
Lloyd, John R.,Lowther, Nicholas,Zsabo, G.,Hall, C. Dennis
, p. 1813 - 1818 (2007/10/02)
Kinetic data and activation parameters are reported for the reactions of a series of phosphites, arylphosphonites, diarylphosphinites, and triarylphosphines with octasulphur (S8) in toluene as solvent.For the phosphites the data are explained in terms of changes in p-character of the Ione-pair orbital on phosphorus and inductive electron donation by the alkyl groups.The rates of reaction of series of arylphosphonites, diarylphosphonites, and triarylphosphones correlate with the Hammett ? constants to give ? values of -3.0, -3.0, and -2.5, respactively, and the results are discussed in terms of the Reactivity-Selectivity Principle and the biphilic mechanism or insertion of trico-ordinate phosphorus into ?-bonds.
