Phosphine Selenides Research Articles

Phenylamino (diphenyl)phosphine selenide: supramolecular aggregation via weak N-H…Se, C-H…π and π…π interactions

Phenylamino (diphenyl)phosphine selenide 1 was synthesized and analyzed by X-ray. The analysis revealed a deformation of the phosphorus tetrahedron, the planar geometry around the nitrogen atom, and the torsion angle Se1-P1-N1-C11, corresponding to a synclinal conformation (-46.7(4)). It has been postulated that the conformation of 1 is stabilized by short intramolecular

A Facile Atom-Economic Synthesis of Imidazoles with Chalcogenophosphoryl Substituents via Free-Radical Addition of Secondary Phosphine Chalcogenides to 1-Vinylimidazoles

Secondary phosphine sulfides and selenides react with 1-vinylimidazoles under radical initiation conditions to give the corresponding anti-Markovnikov adducts in up to 98% yields.

Synthesis of tris(organylthioethyl)phosphines and their derivatives on the basis of the reaction of phosphine with vinyl sulfides

Phosphine generated from the red phosphorus in the system KOH-H2O-toluene adds regio- and chemoselectively to vinyl sulfides under radical initiation conditions with the formation of tris(2-organylthioethyl)phosphines, which are easily oxidized by elemental sulfur and selenium to the corresponding phosphine sulfides and phosphine selenides in 54–78% yield. The obtained adducts are split when treated with sodium amide in THF to give trivinylphosphine and trivinylphosphine chalcogenides.

Quantum-chemical calculations of NMR chemical shifts of organic molecules: II. Influence of medium, relativistic effects, and vibrational corrections on phosphorus magnetic shielding constants in the simplest phosphines and phosphine chalcogenides

The influence of solvent nature, relativistic effects, and vibrational corrections on the accuracy of calculation of 31P chemical shifts of the simplest phosphines, phosphine oxides, phosphine sulfides, and phosphine selenides was studied. Consideration of the above factors at the stage of both geometry optimization and calculation of magnetic shielding constants was found to appreciably improve the accuracy of calculation of 31P NMR chemical shifts in the series of phosphines and phosphine chalcogenides.

A simple one-pot synthesis of phosphinoselenoic amides and diamides from secondary phosphine selenides and amines using Et3N-CCl4

The multi-component reaction between secondary phosphine selenides and amines (primary, secondary, and primary diamines) proceeds using the Et3N-CCl4 system under mild conditions to give phosphinoselenoic amides or diamides in 81–89% isolated yields.

Evaluation of ligand effects in the modified cobalt hydroformylation of 1-octene. Crystal structures of [Co(L)(CO)3]2 (L = PA–C5, PCy3 and PCyp3)

A series of phosphine ligands with different electronic and steric properties were evaluated at fully modified conditions in cobalt catalysed hydroformylation of 1-octene. The steric demand of the ligands was based on the Tolman cone angle model covering a range of 132-175°. The electron donating ability was evaluated through the first order Se-P coupling constants as determined from the corresponding phosphine selenides covering a range of 672-752 Hz. Crystal structures of three phosphine modified cobalt dimers, [Co(CO)(3)(L)](2) (L = PA-C(5), PCy(3) and PCyp(3) with PA-C(5) = 1,3,5,7-tetramethyl-8-pentyl-2,4,6-trioxa-8-phosphatricyclo[3.3.1.1(3,7)]decane), are reported. The Phoban and Lim ligands (Phoban = mixture of 9-phosphabicyclo[3.3.1 and 4.2.1]nonane, Lim = 4,8-dimethyl-2-phosphabicyclo[3.3.1]nonane) resulted in systems about twice as active as most of the other ligands investigated, these ligands have a high Lewis basicity with (1)J(Se-P) values from 684-687 Hz. The linearity of the alcohol product in general decreased for the less electron donating ligands while no clear relationship was evident as a function of steric size. The parallel competing hydrogenation of 1-octene to octane varied from 9-15% for a cone angle range of 132-172°, but a sharp increase of up to 40% was observed for PA-C(5), PCy(3) and PCyp(3), all with cone angles > 169°. The catalytic behaviour provides evidence that is contrary to the dissociative substitution of CO by an alkene as the rate limiting step in all cases. For large symmetrical ligands, such as PA-C(5), PCy(3) and PCyp(3) the rate limiting step may move within the catalytic cycle and may now be situated at the carbonylation step where the chemoselectivity is also determined. The lack of clear correlation between the steric and electronic effect of the ligands and all catalytic parameters may serve as additional proof that the same system, especially in terms of the rate determining step, is not operative in all cases. The Phoban and Lim systems are superior with the highest reactivity and lowest alkene loss through hydrogenation. The unsymmetrical nature of the Phoban and Lim ligands may provide flexibility to adopt geometries inducing both high and low steric crowding, which may be a reason for its beneficial catalytic properties.

Synthesis and structural characterization of novel zinc(II) and cadmium(II) complexes with pyridine-phosphine chalcogenide ligands

New pyridine-phosphine chalcogenide ligands, tris[2-(2-pyridyl)ethyl]phosphine sulfide 1a and tris[2-(2-pyridyl)ethyl]phosphine selenide 1b, react with zinc(II) and cadmium(II) chlorides in EtOH at room temperature to afford complexes of compositions 2ZnCl 2·2L ( 2, L = 1a) and 3CdCl 2·2L ( 3a, b, L = 1a, b) in high yields. The solid-state structure of complexes 2, 3 has been proved by X-ray analysis data. Complex 2 is a centrosymmetric dimer, where two atoms of zinc are bonded by two bridging pyridine-phosphine sulfide ligands through N atoms. Complexes 3a, b exist as polymeric chains with each bridging ligand acting as a chelate N,S- or N,Se-donor to one cadmium(II) center and as a pyridine N-donor to the next cadmium(II) center.

Radical addition of secondary phosphine sulfides and selenides to vinyl tellurides

The regiospecific addition of secondary phosphine sulfide and phosphine selenide to alkyl vinyl tellurides proceeds under radical initiation (AIBN, 65–70°C, 2.5–3.5h) to afford the anti-Markovnikov adducts, (2-alkyltellanylethyl)phosphine chalcogenides, in 86–99% yields.

Synthesis, Characterization, and Crystal Structures of Tris(2-pyridyl)phosphine Sulfide and Selenide

We report the synthesis and structural determinations of tris(2-pyridyl)phosphine sulfide and selenide, which were prepared by the reaction of 2-lithiopyridine with phosphorus trichloride at –100°C, and treatment of resulted (2-pyridyl)phosphine with elemental sulfur or selenium in hot toluene. These compounds were characterized by elemental analysis, melting point determination, mass spectroscopy, IR, 1H, and 31P NMR spectroscopies. Furthermore, the molecular structures of tris(2-pyridyl)phosphine sulfide and selenide were determined by single crystal X-ray analysis and compared with the structures of tris(2-pyridyl)phosphine and tris(2-pyridyl)phosphine oxide. Supplemental materials are available for this article. Go to the publisher's online edition of Phosphorus, Sulfur, and Silicon and the Related Elements to view the free supplemental file.

Synthesis of aurocyanide and auricyanide complexes of phosphines, phosphine sulfides and phosphine selenides, and their characterization by IR, far-IR, UV solution, and solid-state NMR spectroscopic methods

A series of aurocyanide and auricyanide complexes of phosphines, phosphine sulfides, and phosphine selenides were synthesized. These new complexes have the general formula [L n Au(CN) m ], where L could be Cy3P, (2-CN-Et)3P, Me3PS, Et3PS, Ph3PS, Me3PSe, or Ph3PSe. Auricyanide was reacted with L at 1 : 2 ratio. Products were characterized using elemental analysis, melting point, UV, IR, far-IR solution, and solid-state NMR spectroscopy. Phosphine ligands cause gold(III) reduction to gold(I); less redox tendency was found for phosphine sulfides and phosphine selenides. Tri-coordinate complexes [L2AuCN] were produced from phosphine ligands with gold-tetracyanide. IR and UV spectroscopic methods were used to identify gold oxidation state in the synthesized complexes.

Electrochemistry of 1,1′-Bis(2,4-dialkylphosphetanyl)ferrocene and 1,1′-Bis(2,5-dialkylphospholanyl)ferrocene Ligands: Free Phosphines, Metal Complexes, and Chalcogenides

The oxidative electrochemistries of a series of chiral bisphosphinoferrocene ligands, 1,1'-bis(2,4-dialkylphosphetanyl)ferrocene (FerroTANE) and 1,1'-bis(2,5-dialkylphospholanyl)ferrocene (FerroLANE), were examined. The reversibility of the oxidation is sensitive to the steric bulk of the alkyl groups. New transition metal compounds and phosphine chalcogenides of these ligands were prepared and characterized. X-ray crystal structures of 10 of these compounds are reported. The percent buried volume (%V(bur)) is a recently developed measurement based on crystallographic data that examines the steric bulk of N-heterocyclic carbene and phosphine ligands. The %V(bur) for the FerroTANE and FerroLANE structures with methyl or ethyl substituents suggests these ligands are similar in steric properties to 1,1'-bis(diphenylphosphino)ferrocene (dppf). In addition the %V(bur) has been found to correlate well with the Tolman cone angle for phosphine chalcogenides. The oxidative electrochemistries of the transition metal complexes occur at more positive potentials than the free ligands. While a similar positive shift is seen for the oxidative electrochemistries of the phosphine chalcogenides, the oxidation of the phosphine selenides does not occur at the iron center, but rather oxidation occurs at the selenium atoms.

Mysteries of TOPSe Revealed: Insights into Quantum Dot Nucleation

We have investigated the reaction mechanism responsible for QD nucleation using optical absorption and nuclear magnetic resonance spectroscopies. For typical II-VI and IV-VI quantum dot (QD) syntheses, pure tertiary phosphine selenide sources (e.g., trioctylphosphine selenide (TOPSe)) were surprisingly found to be unreactive with metal carboxylates and incapable of yielding QDs. Rather, small quantities of secondary phosphines, which are impurities in tertiary phosphines, are entirely responsible for the nucleation of QDs; their low concentrations account for poor synthetic conversion yields. QD yields increase to nearly quantitative levels when replacing TOPSe with a stoiciometric amount of a secondary phosphine chalcogenide such as diphenylphosphine selenide. Based on our observations, we have proposed potential monomer identities, reaction pathways, and transition states and believe this mechanism to be universal to all II-VI and IV-VI QDs synthesized using phosphine based methods.

Atom-economic synthesis of ammonium diselenophosphinates from secondary phosphine selenides, elemental selenium, and ammonia

Atom-economic synthesis of ammonium diselenophosphinates from secondary phosphine selenides, elemental selenium, and ammonia

Chlorination of secondary phosphine selenides with the system CCl4/NEt3

Selenophosphoryl chlorides R2P(Se)Cl are highly reactive selenophosphorylating reagents widely used in the synthesis of organoelement compounds [1–5]. They readily react with alkylmagnesium halides [1], al-cohols [2], amines [3] and other compounds [4, 5] to form tertiary phosphine selenides as well as esters, amides, and salts of selenophosphinic acids: ligands for the design of single-source precursors of nanomaterials [6, 7], efficient iniferters [8], prospective extragents of the rare-earth elements [9] and coordination media for synthesis of semiconducting nanomaterials [10].

Synthesis of Monodisperse PbSe Nanorods: A Case for Oriented Attachment

Monodisperse, high-quality, single-crystal PbSe nanorods were synthesized in a catalyst-free, one-pot reaction using a new phosphine selenide precursor. PbSe nanorods were assembled to provide liquid-crystalline alignment or vertical alignment under controlled evaporation conditions. The growth of nanorods was monitored by TEM and absorption spectroscopy, indicating that oriented attachment could be involved to provide anisotropic PbSe nanostructures. In-plane XRD showed an enhanced (200) peak for PbSe nanorods, indicating the preferred alignment of nanorods on the substrates and their growth along the <100> direction. Absorption and emission spectra, along with lifetime measurements, show the differences between nanoscale PbSe spheres and rods.

Synthesis of vinylphosphine oxides: vinyl selenides as vinylating agents

2-(Alkylselanyl)ethyl(diorgano)phosphine selenides readily accessible from secondary phosphine selenides and alkyl vinyl selenides react with aqueous solution of hydrogen peroxide to form vinylphosphine oxides in high yields.

Cycloaurated triphenylphosphine-sulfide and -selenide

The first examples of cycloaurated phosphine sulfides and triphenylphosphine selenide have been synthesised; these complexes are fairly rare examples of gold(iii) complexes with potentially reducing sulfur- and selenium-donor ligands. The cycloaurated complex (AuCl(2)(2-C(6)H(4)P(S)Ph(2)) was synthesised in good yield by transmetallation of the organomercury precursor Hg(2-C(6)H(4)P(S)Ph(2))(2) with Me(4)N[AuCl(4)]. A route to the chloro-mercury analogue ClHg(2-C(6)H(4)P(S)Ph(2)) was developed by reaction of the cyclomanganated triphenylphosphine sulfide (CO)(4)Mn(2-C(6)H(4)P(S)Ph(2)) with HgCl(2); this mercury substrate was also used in the synthesis of AuCl(2)(2-C(6)H(4)P(S)Ph(2)). The cycloaurated triphenylphosphine selenide complex AuCl(2)(2-C(6)H(4)P(Se)Ph(2)) was synthesised by an analogous methodology using the new phosphine selenide Hg(2-C(6)H(4)P(Se)Ph(2))(2) [prepared from Hg(2-C(6)H(4)PPh(2))(2) and elemental Se under sonication]. The phosphonamidic analogue AuCl(2)(2-C(6)H(4)P(S)(NEt(2))(2)) has also been synthesised from PhP(S)(NEt(2))(2)via lithiation and mercuration. X-Ray crystal structures of several compounds are reported, and show the presence of puckered ring systems.

One-Pot Reaction of Secondary Phosphine Selenides with Selenium and Nitrogen Bases: A Novel Synthesis of Diorganodiselenophosphinates

A three-component reaction of secondary phosphine selenides­ R2P(Se)H [R = PhCH2CH2, PhCH(Me)CH2, 4-t-BuC6H4CH2CH2, (2-methyl-5-pyridyl)CH2CH2, Ph], elemental selenium, and primary, secondary, and tertiary amines and diamines proceeds under mild conditions (25-85 ˚C, 1-90 min) in tetrahydrofuran-ethanol as medium to give previously unknown mono-, di-, and triorganoammonium salts of diorganodiselenophosphinates in high yields (up to 99%).

A Simple Atom-Economic Synthesis of Functional Tertiary Phosphine Chalcogenides Bearing Furan or Tetrahydrofuran Rings

The first examples of hydrophosphorylation reactions of vinyl ethers of a series offurans are reported. Regiospecific addition of secondary phosphines, phosphine sulfides, or phosphine selenides to 2-[(vinyloxy)methyl]furan, 2-[1-(vinyloxy)butan-2-yl]furan, or 2-[(vinyloxy)methyl]tetrahydrofuran proceeds under UV irradiation to give the corresponding anti-Markovnikov adducts in 72-99% yield.

Reactivities of Secondary Phosphine Selenides Cp(CO)2FeP(Se)(OR)2: Formation of a Diiodine Charge Transfer Adduct and Se-Methylation

The organoiron-substituted phosphine selenides Cp(CO)2FeP(Se)(OR)2 (R = iPr (1a), nPr (1b), Et (1c)) were synthesized. The metalloligands, capable of reacting as nucleophiles toward Me3OBF4, formed Se-methylated products (2a−c). Upon reaction with diiodine, they formed spokelike charge-transfer adducts (3a−c). Among them 1b, 2b, and 3a were structurally authenticated, and 3a was the first structurally characterized, charge-transfer spoke adduct of a secondary phosphine selenide with diiodine.