Search results for "phosphine"

Reactivity of bimetallic dibridged complexes Cp2Ta(H)(μ-H)(μ-PMe2)M′(CO)4 (M′ = Cr, Mo, W) toward two-electron donor ligands L (L = PR3, Me2P(CH2)nPM…

1998

Abstract The reaction of the heterobimetallic phosphido- and hydrido-bridged complexes Cp 2 TaH(μ-H)(μ-PMe 2 )M′(CO) 4 (M′ = Cr, Mo, W) ( 1–3 ) with phosphines (L = PPh 2 Me, PMe 2 Ph) or diphosphines (L = dmpm, dmpe) leads to Cp 2 Ta(H) 2 (μ-PMe 2 )M′(CO) 4 (L) ( 1a, 1b, c, d-3b, c, d ) with L regiospecifically coordinated to M′. Except for L = PPh 2 Me, the reaction is stereospecific, since a cis arrangement (with respect to the PMe 2 bridge) on the M′ site is obtained. The new compounds Cp 2 Ta(H) 2 (μ-PMe 2 )M′ (CO) 4 (Me 2 P(CH 2 ) 2 PMe 2 ) (M′ = Mo, W) are able to bind [Cr(CO) 5 ] fragments affording the linear trinuclear chain compounds Cp 2 Ta(H) 2 (μ-PMe 2 )M′(CO) 4 (Me 2 P(CH 5 )…

New 1,1′- or 1,2- or 1,3-bis(diphenylphosphino)ferrocenes

2000

The syntheses of ferrocenyl phosphines with bulky substituents are reported using the reaction between FeCl2 and the suitably substituted cyclopentadienyl salts, LiC5H3-1,3-(PPh2)2, LiC5H3-1-PPh2-3- t Bu, LiC5H2-1,2-(PPh2)2-4- t Bu. This strategy leads to bi-, tri- and tetraphosphines, which cannot be obtained by the other access paths used to prepare substituted ferrocenes. [C5H3-1,3(PPh2)2](C5H5)Fe, [C5H3-1-PPh2-3- t Bu]2Fe racemic and meso and [C5H2-1,2-(PPh2)2-4- t Bu](C5H5)Fe have been characterized by single-crystal X-ray diffraction studies. © 2000 Elsevier Science S.A. All rights reserved.

(Cycloheptadienyl)diphenylphosphine: A Versatile Hybrid Ligand

2012

(3,5-Cycloheptadienyl)diphenylphosphine is easily synthesized from the reaction of diphenylphosphine with 1,3,5-cycloheptatriene. This new phosphine-diene has been coordinated as a monodentate P ligand with Pt, Pd, Au, Ni, and Ru; as a bidentate (P, olefin) ligand with Pt and Pd; and as a tridentate (P, diene) ligand with Rh. Fluxional properties of several complexes have been studied via NMR experiments and theoretical consideration.

P-Chirogenic Secondary Phosphine Oxides: New Stereoselective Synthesis and Applications

2015

Preparation and study of silver maleonitriledithiolate complexes

1985

Abstract This paper reports the reaction of Ag2(mnt) and [(NEt4)Ag(mnt)] (mnt2− = maleonitriledithiolate) with PPh3 and 1,2-bis(diphenylphosph

Die Stereochemie der Spaltung chiraler acyclischer quartärer Phosphoniumsalze zu tertiären Phosphinoxiden mit Alkalialkoholat

1975

Die beobachtete Brutto-Stereochemie der Spaltung chiraler acyclischer quartarer Phosphoniumsalze 1–5 zu tertiaren Phosphinoxiden 6–10 mittels Natriumathylat ist — mit einer Ausnahme — prinzipiell die gleiche wie bei der Spaltung der betreffenden Salze mit Natrium-hydroxid. Die Stereoselektivitat ist dagegen bei der Spaltung mit Alkoholat meist deutlich geringer als bei der Reaktion mit Natriumhydroxid. Stereochemistry of the Alkali Alcoholate-induced Fission of Chiral Acyclic Quaternary Phosphonium Salts to Tertiary Phosphine Oxides The stereochemical course of the sodium ethanolate-induced fission of chiral acyclic quaternary phosphonium salts 1–5 to tertiary phosphine oxides 6–10 is (with…

New CpCrCl2(PR3) complexes: physical properties and reduction chemistry

1998

Abstract Compounds CpCrCl2L ( L = PMe 2 Ph , 1 , PMePh 2 , 2 ; PPh 3 , 3 ) have been prepared. Their magnetic moment is in accord with the presence of three unpaired electron and a variable temperature 1H NMR investigation of 1 shows Curie-Weiss behavior. The 1H NMR, EPR and UV-visible spectra are in agreement with those of other previously reported compounds of the same family. An electrochemical investigation shows the accessibility of an irreversible reduction process. A parallel sodium reduction investigation of complexes CpCrCl2L (L = PMe3 and η1-dppe) suggests tjat the reduction process is followed by immediate chloride loss, and then by a ligand redistribution process to afford chrom…

Au70S20(PPh3)12: an intermediate sized metalloid gold cluster stabilized by the Au4S4 ring motif and Au-PPh3 groups

2018

Reducing (Ph3P)AuSC(SiMe3)3 with L-Selectride® gives the medium-sized metalloid gold cluster Au70S20(PPh3)12. Computational studies show that the phosphine bound Au-atoms not only stabilize the electronic structure of Au70S20(PPh3)12, but also behave as electron acceptors leading to auride-like gold atoms on the exterior.

[1,2,3]Triazolo[1,5-a]pyridyl phosphines reflecting the influence of phosphorus lone pair orientation on spectroscopic properties

2010

A series of new triazolopyridine-based phosphines has been prepared. These compounds revealed unexpected spectroscopic patterns. In particular, the NMR spectra are highly dependent on the relative conformational preference of the phosphine substituent at C7. Here, we report on their complete NMR analysis, X-ray structures and DFT calculations that confirm the particular arrangement of the phosphorus lone pair orbital related to the substituent pattern of the chosen phosphine.

Fast preparation and gas-chromatographic separation of lanthanide and actinide hexafluoroacetylacetonates

1986

A fast method for the separation of lanthanide elements by gas chromatography of their hexafluoroacetylacetonates is described. Individual lanthanides can be isolated within a few minutes, and the whole group can be separated in less than 10 min. The hexafluoroacetylacetonates are applied in form of mixed complexes with tri-n-butyl phosphate or trioctylphosphine oxide prepared by fast extraction into quasi-solid solvents. The applicability of this method for the separation of trivalent actinide elements is shown, including the fast preparation of thin counting samples.