Search results for "phosphine"

Inhibitoren der Korrosion (8) Über die Abhängigkeit der Korrosionsinhibierung des Eisens in Salzsäure von der Struktur quartärer Phosphoniumsalze

1971

Bei quartaren Phosphoniumsalzen be-steht zwischen der Inhibitorwirkung im sauren Medium unter Auschlus von Luft und den polarographisch ermittelten Re-duktionspotentialen keine direkte Bezie-hung. Die sterischen Faktoren der nach Aufnahme von zwei Elektronen entste-henden und an der Eisenoberflache fixierten Fragmente sind offenbar fur die Inhibitorwirkung hauptsachlich ver-antwortlich. Bisphoniumsalze mit gesattigten oder ungesattigten Brucken sind unter den oben genannten Bedingungen hervor-ragende Inhibitoren. Am wirksamsten sind Bisphosphoniumsalze mit Ketten von 4 bis 10 Methylengruppen zwischen den Phosphoniumzentren. Der starre p-Phenylenrest ist als Verknupfungs-prinzip weniger geei…

STUDY OF THE INTERNAL DYNAMICS OF NON PLANAR PYRAMIDAL MOLECULES IN VIBRATIONALY VERY EXCITED STATES.

2007

From the U (p+1) formalism, we built a Hamiltonian adapted to the stretching modes of nonplanar XY3 molecules having the C3v group of geometrical invariance. This Hamiltonian is then coupled with two possible Hamiltonians describing the bending modes of these molecular system: a) based on the U (p+1) approach, a bending Hamiltonian is developed and the interaction between the bending and the stretching modes is taking into account through adapted 2:1 resonance coupling operator defined as a Us(4) x Ub(4) enveloping algebra operator ; b) based on the standard normal modes formalism, a bending modes Hamiltonian is expanded and the 2:1 interaction is taken into account as a tensorial product o…

Preparation and reactions of palladium(II) complexes with C2-bonded heteroaromatic ligands trans[PdCl(RN)(PPh3)2] (RN = 2-pyridyl, 2-pirazyl, 2-pyrim…

1986

Abstract The complexes trans -[PdCl(R N )(PPh 3 ) 2 ] (I) [R N = 2-pyridyl (2-Py), 2-pyrazyl (2-pyz), 2-pyrimidyl (2-pym) group] have been prepared in high yield by deprotonation with NEt 3 of the corresponding cationic compounds trans [PdCl(R N H) (PPh 3 ) 2 ] + (R N H = N -protonated C 2 -heteroaromatic ligand) in the presence of an excess of PPh 3 . In chlorinated solvents, complexes I undergo a slow reversible dimerization into the binuclear derivatives [PdCl(μ-R N )(PPh 3 )] 2 (II) (μ-R N = C 2 , N 1 -bridging ligand). From the 31 P NMR spectra in 1,2-dichloroethane the following dissociation constants were obtained: 1.9 mol 1 −1 (R N = 2-py), 5.1 × 10 −2 (2-pym), 6.6 × 10 −3 (2-pyz). …

Palladium-catalyzed formation of secondary and tertiary amines from aryl dihalides with air-stable ferrocenyl tri- and diphosphines: Synthesis and X-…

2014

Abstract Robust, air-stable tridentate and bidentate ferrocenylphosphines 1,2-bis(diphenylphosphino)-1′-(diisopropylphosphino)-4-tert-butylferrocene, L5, and 1,1′-bis(diisopropylphosphino)-3,3′-bis(tert-butyl)ferrocene, L9, combined with 1 mol% of [PdCl(η3-C3H5)]2 led to two new catalytic systems which allow the coupling of aniline derivatives with mono- and dihaloarenes to form functionalized diarylamines and triarylamines. The excellent selectivity of the reactions avoids the deleterious dehalogenation of the substrates and products. The X-ray structure characterization of the related complex [PdCl2(L9)] is reported in which ligand L9 in its meso form is significantly distorted.

Electrochemical and spectroscopic studies of poly(diethoxyphosphoryl)porphyrins

2011

Abstract The synthesis and electrochemical characterization of two related series of porphyrins bearing diethoxyphosphoryl groups are reported. One group of compounds is represented as (T( p -R)PP)M where R = phos = P(O)(OEt) 2 and M = Zn(II) or H 2 while the other is represented as (di( p -R)Pdi(phos)P)M where R = P(O)(OEt) 2 , H or CH 3 and M = Zn(II) or H 2 . Each porphyrin was investigated by electrochemistry and thin-layer spectroelectrochemistry in CH 2 Cl 2 , CDCl 3 , CHCl 3 or PhCN containing tetra- n -butylammonium perchlorate (TBAP) as supporting electrolyte. The highly electron-withdrawing P(O)(OEt) 2 groups lead to easier reductions and harder oxidations than the two comparison …

New heteronuclear gold(I)-platinum(II) complexes with cytotoxic properties: are two metals better than one?

2014

A series of mono- and heterodinuclear gold(I) and platinum(II) complexes with a new bipyridylamine-phosphine ligand have been synthesized and characterized. The X-ray structures of the ligand precursor 4-iodo-N,N-di(pyridin-2-yl)benzamide, and of one gold derivative are reported. All the complexes display antiproliferative properties in vitro in human cancer cells in the range of cisplatin or higher, which appear to correlate with compounds' uptake. Interestingly, studies of the interactions of the compounds with models of DNA indicate different mechanisms of actions with respect to cisplatin. The biological activity study of these complexes provides useful information about the interest of…

P-Chirogenic Triazole-Based Phosphine: Synthesis, Coordination Chemistry, and Asymmetric Catalysis

2020

Nickel-catalyzed carboxylation of aryl zinc reagent with CO2: A theoretical and experimental study

2019

Abstract Two Ni-complexes with 1,1′-bis(diphenylphosphino)ferrocene (dppf) and tricyclohexylphosphine (PCy3) ligands were tested for the Ni-catalyzed cross-coupling of aryl zinc reagent with CO2 to form aryl carboxylic acid. Theoretical study with the aid of density functional theory (DFT) was carried out to understand the detailed reaction mechanism. The reasonable reaction pathway was deduced. The simulation results suggested that the free energy barrier of the rate-limiting step with (dppf)Ni is only 1.64 kcal mol−1 higher than the barrier with (PCy3)2Ni. However, our experiment provided an unexpectedly low yield by using (dppf)Ni complex as the catalyst. Further theoretical study ascrib…

Crystal structure of bis[μ-1,4-bis(diphenylphosphanyl)butane-κ2P:P′]bis[(3,4,7,8-tetramethyl-1,10-phenanthroline-κ2N,N′)copper(I)] bis(hexafluoridoph…

2016

The dication of the title compound, [Cu2(C28H28P2)2(C16H16N2)2](PF6)2·2CH2Cl2, has crystallographically imposed inversion symmetry. The copper(I) cation is coordinated in a distorted tetrahedral geometry by two N atoms of a chelating 3,4,7,8-tetramethyl-1,10-phenanthroline ligand and two P atoms of two bridging 1,4-bis(diphenylphosphanyl)butane ligands, forming a 14-membered ring. An intramolecular π–π interaction stabilizes the conformation of the dication. In the crystal, dications are linked by π–π interactions involving adjacent phenanthroline rings, forming chains running parallel to [111]. Weak C—H...F hydrogen interactions are also observed.

Amine functionalized ZrO2 nanoparticles as biocompatible and luminescent probes for ligand specific cellular imaging

2015

Surface functionalized ZrO2 nanoparticles show strong photoluminescence and are a versatile tool for cellular targeting due to their chemical functionality. They are highly photostable, biocompatible and amenable to coupling with bioligands (e.g. secondary goat anti-rabbit antibody (GAR) and tri-phenyl phosphine (TPP)) via carbodiimide chemistry. Antibody (GAR) functionalized ZrO2 nanoparticles were used to image the nuclear protein Sirt6, whereas triphenyl phosphonium ion (TPP) functionalized ZrO2 nanoparticles specifically targeted the mitochondria. The versatility and easiness of the ZrO2 surface modification opens up new possibilities for designing non-toxic water dispersible and photos…