39181-26-5Relevant articles and documents
Dissolution behaviour and activation of selenium in phosphonium based ionic liquids
Zhang, Tao,Schwedtmann, Kai,Weigand, Jan J.,Doert, Thomas,Ruck, Michael
, p. 7588 - 7591 (2017/07/12)
The dissolution behaviour of grey selenium in phosphonium based ionic liquids (ILs) has been investigated for the first time by 31P and 77Se nuclear magnetic resonance (NMR) experiments. The investigations evidence the formation of trialkylphosphane selenides which can serve as a selenium reservoir in the subsequent formation of metal selenides.
Mechanistic study of precursor evolution in colloidal group II-VI semiconductor nanocrystal synthesis
Liu, Haitao,Owen, Jonathan S.,Alivisatos, A. Paul
, p. 305 - 312 (2008/04/18)
The molecular mechanism of precursor evolution in the synthesis of colloidal group II-VI semiconductor nanocrystals was studied using 1H, 13C, and 31P NMR spectroscopy and mass spectrometry. Tri-n-butylphosphine chalcogenides (TBPE; E = S, Se, Te) react with an oleic acid complex of cadmium or zinc (M-OA; M = Zn, Cd) in a noncoordinating solvent (octadecene (ODE), n-nonane-d20, or n-decane-d22), affording ME nanocrystals, tri-n-butylphosphine oxide (TBPO), and oleic acid anhydride ((OA)2O). Likewise, the reaction between trialkylphosphine selenide and cadmium n-octadecylphosphonic acid complex (Cd-ODPA) in tri-n-octylphosphine oxide (TOPO) produces CdSe nanocrystals, trialkylphosphine oxide, and anhydrides of n-octadecylphosphonic acid. The disappearance of tri-n-octylphosphine selenide in the presence of Cd-OA and Cd-ODPA can be fit to a single-exponential decay (kobs = (1.30 ± 0.08) × 10-3 s-1, Cd-ODPA, 260 °C, and kobs = (1.51 ± 0.04) × 10-3 s-1, Cd-OA, 117 °C). The reaction approaches completion at 70-80% conversion of TOPSe under anhydrous conditions and 100% conversion in the presence of added water. Activation parameters for the reaction between TBPSe and Cd-OA in n-nonane-d20 were determined from the temperature dependence of the TBPSe decay over the range of 358-400 K (ΔH? = 62.0 ± 2.8 kJ·mol-1, ΔS? = -145 ± 8 J·mol-1·K-1). A reaction mechanism is proposed where trialkylphsophine chalcogenides deoxygenate the oleic acid or phosphonic acid surfactant to generate trialkylphosphine oxide and oleic or phosphonic acid anhydride products. Results from kinetics experiments suggest that cleavage of the phosphorus chalcogenide double bond (TOP=E) proceeds by the nucleophilic attack of phosphonate or oleate on a (TOP=E)-M complex, generating the initial M-E bond.
Palladium-catalyzed activation of E-E and C-E bonds in diaryl dichalcogenides (E = S, Se) under microwave irradiation conditions
Ananikov,Orlov,Beletskaya
, p. 576 - 587 (2007/10/03)
The first example of palladium-catalyzed stereoselective addition of diphenyl disulfide and diphenyl diselenide to the triple bond of terminal alkynes under microwave irradiation conditions is described. It was found that both the element-element (E-E) and carbon-element bonds can be activated in the catalytic system studied. The products of both reactions were isolated in quantitative yields. According to quantum-chemical calculations, the reaction mechanism involves the oxidative addition of the E-E bond to Pd0. Depending on the microwave power and reaction conditions, the next stage is either the reaction with alkyne or the carbon-element bond activation. The product of the oxidative addition of Ph2Se2 to Pd 0, namely, dinuclear complex [Pd2(SePh) 4(PPh3 2], was detected by 31P{ 1H}NMR spectroscopy directly in the Ph2Se 2/PPh3 melt formed under microwave irradiation conditions.
