Investigation of the intermediates in the oxidation of a bulky arylphosphine ligand with ferric chloride

Dunbar, Kim R.; Quillevéré, Anne

doi:10.1016/s0277-5387(00)81763-5

Cited by 20 publications

(11 citation statements)

References 52 publications

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“…We report here the structure determination of tris (2 (Boorman et al, 1981) and KAXQUW (Hagenbach & Abram, 2005)] yields an average AE(C-P-C) value of 333.3 (9) (see Table 2). Obviously more sterically bulky phosphonium salts identified from this search include four exemplars of tris(2,4,6-trimethoxyphenyl)phosphonium salts [refcodes LAFGEE10, WIBJEW and WIBJIA (Dunbar & Quillevere, 1993), and TAJGAM (Dunbar & Pence, 1991)]. These structures show greater variation in pyramidality compared to Ph 3 PH + apparently because the substituents take differing orientations around the P atom, resulting in an average AE(C-P-C) value of 340 3, with a rather large s.u.…”

Section: Resultsmentioning

confidence: 99%

A study of the pyramidality index in tris(2,4,6-triisopropylphenyl)phosphonium perchlorate

Boeré

Zhang

2013

Acta Crystallogr C

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The title compound, C45H70P(+)·ClO4(-) or [Tripp3PH(+)][ClO4(-)], was produced from the perchlorate salt of the corresponding radical cation Tripp3P(·+) through very slow H-atom abstraction reactions in a solution of 1,2-dimethoxyethane (Tripp is 2,4,6-triisopropylphenyl). The H atom on the P atom was located in a difference map and was freely refined with an isotropic displacement consistent with full occupancy [P-H = 1.37 (3) Å]. It is the most sterically congested triarylphosphonium salt yet to be reported and has a `propeller' arrangement of the three Tripp groups around the P atom, with the protonation site located along the molecular threefold axis. There are short contacts between the flanking isopropyl methine H atoms and the P atom [P···H = 1.99 (2)-2.17 (2) Å]. The sum of the angles around the P atom [Σ(C-P-C) = 349.9 (6)°] is a convenient index of pyramidality for tricoordinate centres. This value is significantly larger than in analogous Mes3PH(+) salts (Mes is mesityl or 2,4,6-trimethylphenyl), for which the average of the three reported structures in the literature is Σ(C-P-C) = 345.3 (6)°. For comparison, in the ubiquitous Ph3PH(+) salts, this parameter has a typical average value of only 333.3 (9)°. The value of Σ(C-P-C) in the title compound is midway between that of the neutral phosphane Tripp3P [334.4 (6)°] and the phosphoniumyl radical cation Tripp3P(·+) [359.8 (2)°]. This geometrical feature provides additional support for the assignment as a phosphonium salt.

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Section: Resultsmentioning

confidence: 99%

A study of the pyramidality index in tris(2,4,6-triisopropylphenyl)phosphonium perchlorate

Boeré

Zhang

2013

Acta Crystallogr C

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“…Monodentate ligands such as substituted phosphines or carbenes have frequently been used for the formation of Fe-based catalysts. − The structure of the resulting Fe/ligand complexes ,, is, however, very similar to the systems with the solvent acting as the ligand (see Figure ), , which appears to be the reason why K ATRP of such complexes is close to the one of [FeBr 3 (MMA)] − . Some of these ligands may be preferable in that they improve catalyst robustness , at ppm concentrations and also solubility .…”

Section: Atom Transfer Radical Polymerizationmentioning

confidence: 99%

Detailed Kinetic and Mechanistic Insight into Radical Polymerization by Spectroscopic Techniques

2016

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The in-depth understanding of the kinetics and mechanism of conventional and reversible deactivation radical polymerization (RDRP) strategies requires efficient techniques to attain accurate rate coefficients of the individual reaction steps. Within the recently developed SP-PLP-EPR technique, pulsed-laser polymerization (PLP) induced by a laser single pulse (SP) is carried out in conjunction with highly time-resolved EPR detection of the type and the concentration of radicals. The method provides an unrivaled direct access to the measurement of chain-length-dependent termination and also of propagation rate. Even for systems where as a consequence of transfer reactions different types of radical species with distinctly different properties occur, a full kinetic analysis is within reach. The SP-PLP-EPR technique is also applicable toward the measurement of RDRP-related rate coefficients for reversible addition–fragmentation transfer (RAFT) polymerization, atom transfer radical polymerization (ATRP), and organometallic-mediated radical polymerization (OMRP). Investigations into the latter two polymerization strategies benefit from additionally applying UV/vis/NIR in conjunction with Mössbauer spectroscopy to monitor reactions of the metal catalyst.

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“…18 The phosphine may be partially oxidised during formation of these xerogels, which is possibly catalysed by Fe(III). 19 The partial oxidation was also confirmed by MS. However, the PQO presence in the gels could not be proved due to overlapping.…”

Section: Gelation Studymentioning

confidence: 79%

Metal–organic gels as functionalisable supports for catalysis

Zhang

Wang

et al. 2009

New J. Chem.

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Modification of Fe-tricarboxylate based metal-organic gels yielded tert-butyl substituted or phosphine-functionalised gels in alcohols or DMF, which were prepared from 5-tert-butylisophthalic acid and 5-diphenylphosphanylisophthalic acid, respectively. Owing to their permeability, such phosphine-functionalised metal-organic gels can act as a new type of functionalisable porous scaffold. The phosphorus-containing gel was subsequently functionalised with Pd(II) by immersion in a solution of Pd(COD)Cl 2 (COD = 1,5-cyclooctadiene). The subsequently functionalised Pd(II)-immobilised gel and its xerogel/aerogel showed high activity in the catalysis of Suzuki C-C coupling comparable to unsupported complexes. The gel/xerogels could be reused under ambient atmosphere.

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Investigation of the intermediates in the oxidation of a bulky arylphosphine ligand with ferric chloride

Cited by 20 publications

References 52 publications

A study of the pyramidality index in tris(2,4,6-triisopropylphenyl)phosphonium perchlorate

A study of the pyramidality index in tris(2,4,6-triisopropylphenyl)phosphonium perchlorate

Detailed Kinetic and Mechanistic Insight into Radical Polymerization by Spectroscopic Techniques

Metal–organic gels as functionalisable supports for catalysis

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