Tris phosphine selenide

Electron donors which interact at only one end of the X2 or XY molecule form simple adducts (Fig. 1, mode A), often referred to as a spoke structure. The diiodine complex of tris(diethylamino)phosphine selenide (PAQKIB) [ 135] shown in Fig. 2a is an excellent example of this mode, as the Se- I distance at one end of the I2 molecule is 2.715 A, while at the other end there are no close contacts with any other atom. 

Reactants HPS = tri(n-butyl)phosphine selenide BPT = tri(n-butyl)phosphine teluride NTA = nitrilotriacetate complex ion SeCN = sellenocy-anide SOS = selenosulfite STS = sodium thiosulfate TeCN = tellurocyanide TEMS = trifluoromethane sulfanate TSS = triphenylstibine sulfide. 

In physical and theoretical methods there has been a notable increase in the use of recently developed techniques - most of which have trendy acronyms. Thus DRAMA P NMR has been used to determine internuclear P-P distance in a phosphine sulfide 4,8-residue substituted decapeptide, and XANES has been applied to structural studies of phosphine selenides. In the mass spectral field MALDI-TOF has been found to be better than FAB for the determination of the mass spectra of nucleotide triphosphates, LA-FTICR has been used to study tris(cyanoethyl)phosphine and metaphosphates have been detected for the first time by laser photoionisation MS. ERMS was shown to be a powerful technique for the analysis of structurally similar organophosphate insecticides (OPs) and trace quantities of OPs can be determined by Cl using water as the ionising agent. 

Structural and Physical Aspects. - The stability of the various conformers of the phosphines oxides (269)- 211) has received theoretical consideration. A new triclinic polymorph of triphenylphosphine sulfide has been structurally characterised, together with a related triclinic polymorph of triphenylphos-phine. Two reports of the solid state crystal structure of the phenolic phosphine oxide (272) have appeared. A crystallographic study has confirmed that the product of electrochemical oxidation of o-diphenylphosphinoben-zenethiol is the disulfide-bridged bis(phosphine oxide) (273). Solid-state structural studies of the dioxides (274), the (i )-(-I-)-isomer of (275), 1-hexynyl(diphenyl)phosphine oxide,tribenzylphosphine oxide, and tris(t-butyl)phosphine selenide," have also been reported. 

A detailed study of I iSe and 3lp nuclear spin relaxation in tri(tertbutyI)phosphine selenide has been reported 6 and the kinetics and mechanism of formation of tetracoordinate P(V) sulphides from the reaction of tricoordinate phosphorus compounds with diaryl trisulphides have been investigated.1 ... 

PbSe nanorods were synthesized by the reaction of Pb-oleate with tris(diethylamino)-phosphine selenide. The amount of water present in the reaction, either added intentionally or present as a contaminate, had a dramatic effect on both the PbSe nanorod morphology and yield. The precursors were carefully dried and water was intentionally added which had an effect on the nanorod aspect ratio which was controlled from 1.1 to 10 and the yield from 1 to 14% by varying the water concentration from 0 to 204 mM as shown in Fig. 13. 

Several triarylphosphine oxides and related compounds have been reported. The tri-o-tolylphosphine, phosphine oxide, and phosphine selenide structures have been determined in order to study the rotational isomerism of the P-C(aryl) bonds. The geometry at the phosphorus is normal, with P-C... 

C6Hi8N3Pf Tris(dimethylamido)phosphite (gas-ed), 38B, 1068 CgHi8N3PSe, Tris(dimethylamino)phosphine selenide, 45B, 735 C6H18N3P3, Hexamethylcyclotriphosphazene, 43B, 845 C6Hi8Ne02P2f Tris(dimethylhydrazino)bis(phosphineoxide), 38B, 655 CsHi, Tetra-P-oxo-closo-tetraphosphorus hexakis(methylimide), 44B, 603... 

Cl5H25N2O2P, cis-2-Oxo-2-dimethylamino-3-phenyl-5-t-butyl-1,3,2-oxazaphosphorinane, 45B, 737 CisHaoNaP, Tris(piperidino)phosphine, 44B, 616 CigHaoNjPSe, Tris(piperidino)phosphine selenide, 45B, 735 ClsHgFgOsP, 2-Phenoxy-2,2-o-phenylenedioxy-4,5-bis(trifluoromethyl)-... 

Koh and co-workers have used tris(diethylamino)phosphine selenide (TDPSe) as a new source for selenium instead of the commonly used TOPSe for the synthesis of PbSe nanorods (NRs) by colloidal method (Fig. 9). The new phosphine selenide precursor (TDPSe) in tris(diethylamino)phos-phine (TDP) was rapidly injected to a mixture of PbO, OA in ODE at 170 °C to produce monodisperse single-crystalline PbSe NRs of ca. 4nm diameter with length of ca. 40 nm. The growth mechanism of the NRs was possibly by oriented attachment in addition to the Ostwald ripening process. These NRs showed absorption and emission peaks at 1360 and 1440 nm compared to the spherical PbSe NCs absorption and emission at 1375 and 1420nm respectively. The QY of the NRs was found to be 15 % which is close to the reported QY (20-40 %) of spherical PbSe NCs and notably high. 

As mentioned earlier, by using the dipole moment method and different quantum-chemical methods, the conformational analyses of 6rs(2-phe-nylalkyl)phosphine selenides, and of l,3,2-dioxaphospholan-2-yl 2,2,2-trifluoroacetate (7) and 4,5-benzo-l,3,2-dioxaphosphol-2-yl 2,2,2-tri-fluoroacetate (8) were carried out. The experimental dipole moments... 

A"-Ray structure determinations (see Chapter 11 for details) have been reported for triphenylphosphine oxide, tri-o-tolylphosphine oxide, sulphide, and selenide, and for cw-2,2,3,4,4-pentamethyl-l-phenylphos-phetan-1-oxide (5). Electron spectroscopic studies of phosphorus oxychloride and thiophosphoryl chloride in the gaseous state, and n.m.r., i.r., and u.v. spectra of phosphine sulphides have appeared. Dipole moments have been used to define the stereochemistry of 2-cyanoethylphosphine oxides, such as (6), which is shown in its preferred conformation. 

Restricted rotation has been observed in tris-o-tolylphosphine sulphide and selenide (39). The spectrum of the selenide shows two methyl environments in the ratio 2 1 at 30 °C but the methyl signals of the sulphide resolved to this pattern only upon cooling the sample. The corresponding oxide and the parent phosphine showed only one methyl environment down to — 60 °C. Y-Ray diffraction of the selenide showed that the methyl group on one aryl group is directly behind the phosphorus atom in the crystal, as shown in (39). 

J. K. Lorenz, A. B. Ellis, Surfactant-Semi-conductor Interfaces Perturbation of the Photoluminescence of Bulk Cadmium Selenide by Adsorption of Tri-n-octyl phosphine Oxide as a Probe of Solution Aggregation with Relevance to Nanocrystal Stabilization, J. Am. Chem. Soc. 1998, 120, 10970-10975. 

Although both CdSe and CdS can be deposited in nanocrystaUine form by this nonaqueous deposition, the essentially total insolubility of Te in DMSO prevents the use of the method for deposition of nanocrystalline tellurides (a small amount ofTe can be codissolved with Se and mixed selenide-tellurides with small amounts of Te can be deposited see following section). However, a related method to deposit CdTe has been described by Cocivera and associates [23, 24]. They reacted elemental Te with tri-n-butyl phosphine (TBP), which reacts with Te to form TBP telluride. This compound, together with a Cd salt dissolved in propylene carbonate, allowed cathodic electrodeposition of CdTe. The as-deposited films were reported to be X-ray amorphous, a fact that suggested that they might in fact be nanocrystalline [26]. (Cd,Hg)Te films grown by the same... 

Bis (trimethylsilyl) selenide s. under BuLi Tris( trimethylsilyl) phosphine... 

Second, among the newer methods developed to effect the elimination to produce the least substituted alkene is one that involves converting the alcohol to a selenium derivative. In this procedure, a primary alcohol is treated with o-nitrophenyl sele-nocyanate in a suitable solvent such as (THF, oxacyclopentane) in the presence of a phosphine (such as tri-n-butylphosphine [(CH3CH2CH2CH2)3P]) to produce the primary alkyl selenide (Scheme 8.74). Then, in a second step, the primary alkyl o-nitrophenyl selenide is oxidized with hydrogen peroxide to yield the corresponding selenoxide, which readily undergoes elimination to the alkene. Scheme 8.74 shows the application of the sequence of reactions described above to cyclohexylmethanol and the resulting formation of the exo-methylenecyclohexane. 

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