Tetrabutylphosphonium phosphonium

Phosphonium salts are readily prepared by the reaction of tertiary phosphines with alkyl or henzylic haHdes, eg, the reaction of tributylphosphine [998-40-3] with 1-chlorobutane [109-69-3] to produce tetrabutylphosphonium chloride [2304-30-5]. 

Kinetics are slow and many hours are requited for a 95% conversion of the reactants. In the case of the subject compound, there is evidence that the reaction is autocatalytic but only when approximately 30% conversion to the product has occurred (19). Reaction kinetics are heavily dependent on the species of halogen ia the alkyl haHde and decrease ia the order I >Br >C1. Tetrabutylphosphonium chloride exhibits a high solubiHty ia a variety of solvents, for example, >80% ia water, >70% ia 2-propanol, and >50% ia toluene at 25°C. Its analogues show similar properties. One of the latest appHcations for this phosphonium salt is the manufacture of readily dyeable polyester yams (20,21). 

In addition to tetrabutylphosphonium chloride, typical phosphonium salts that can be produced include tetraoctylphosphonium bromide [23906-97-0], tetrabutylphosphonium acetate [17786-43-5] (monoacetic acid), and tetrabutylphosphonium bromide [3115-68-2]. Inmost cases, these compounds can be prepared with alternative counterions. 

Reactions conducted in molten quaternary phosphonium salts require no other solvent (199). This material serves as both promoter and reaction medium. Care must be exercised in choosing the salt in such a reaction, since any decomposition could lead to products such as trialkylphosphines and alkyl halides which are expected to be deleterious to catalyst performance. Tetrabutylphosphonium bromide is reported to provide a stable catalyst medium which can be recycled (199, 200), but other related salts show evidence of thermal decomposition during catalytic reactions. Experiments in tetrabutylphosphonium acetate, for example, are found to produce large amounts of methyl and ethylene glycol acetate esters (199). 

Even if anionic chaotropes are the most popular neoteric IPRs, polarizable cations such as sulfonium and phosphonium reagents showed single selectivity toward polarizable anions their behavior was rationalized on the basis of their chaotropicity. Probe anion retention generally increases in the order of tributylsulfonium < tetrabutylammonium < tetrabutylphosphonium. Interestingly, retention was found to be influenced by the kosmotropic/chaotropic character of both the IPR and the probe anion [93] and this confirms the peculiarities of hydrophobic ion-pairing. Quaternary phosphonium salts provided increased selectivity compared to ammonium in the IPC of heavy metal complexes of unithiol [112]. 

Because of the wide range of alkyl substituents and anions, phosphonium salts can be very hydrophilic or hydrophobic this in turn determines the miscibility of various solvents as outlined in Table 2. At the one extreme are salts such as the tetrabutylphosphonium halides which are hygroscopic solids which will form 80-85% aqueous solutions and which are very insoluble in nonpolar solvents such as hexane. At the other end of the scale are such salts as trihexyl(tetradecyl)phospho-nium bistriflamide and hexafluorophosphate which are very hydrophobic and are totally miscible with nonpolar solvents. 

Phosphonium, tetrabutyl-, bromide. See Tetrabutylphosphonium bromide Phosphonium, tetrabutyl-, chloride. See Tetrabutylphosphonium chloride Phosphonium, tetrakis (hydroxymethyl)-, sulfate (2 1). See Tetrakis (hydroxymethyl) phosphonium sulfate... 

Uses Phase transfer catalyst, polymerization catalyst, chemical intermediate Manuf./Distrib. Cytec Ind. http //www.cytec.com Tetrabutylphosphonium bromide CAS 3115-68-2 EINECS/ELINCS 221-487-8 Synonyms Phosphonium, tetrabutyl-, bromide Tetra-N-butylphosphonium bromide Empirical CieHseBrP Formula (n-C4Hg)4PBr... 

Tetra-N-butylphosphonium bromide. See Tetrabutylphosphonium bromide Tetrabutylphosphonium chloride CAS 2304-30-5 EINECS/ELINCS 218-964-8 Synonyms Phosphonium, tetrabutyl-, chloride Empirical CisHseCIP Formula (n-C4Hg)4PCI... 

Benzyl trimethyl ammonium hydroxide Cetrimonium bromide Dimethyl diallyl ammonium chloride Laurtrimonium bromide Laurtrimonium chloride Methyl tributyl ammonium chloride Tetrabutyl ammonium bromide Tetrabutyl ammonium chloride Tetrabutyl ammonium fluoride Tetra-n-butyl ammonium hydrogen sulfate Tetra-n-butyl ammonium hydroxide Tetrabutyl ammonium iodide Tetrabutylphosphonium acetate, monoacetic acid Tetrabutylphosphonium bromide Tetrabutylphosphonium chloride Tetraethylammonium bromide Tetraethylammonium hydroxide Tetrakis (hydroxymethyl) phosphonium chloride Tetramethylammonium bromide Tetramethylammonium chloride Tetramethylammonium hydroxide Tetramethyl ammonium iodide Tetraphenyl phosphonium bromide Tetrapropyl ammonium bromide Tetrapropyl ammonium iodide Tributylamine Tributyl phosphine Tributyl (tetradecyl) phosphonium chloride Trioctyl (octadecyl) phosphonium iodide catalyst, phase-transfer Tetraethylammonium chloride Tetraoctylphosphonium bromide Tri-n-butyl methyl ammonium chloride Tri methyl phenyl ammonium hydroxide catalyst, phenolics Triethylamine... 

The preparation of ethylene glycol directly from synthesis gas via homogeneous rhodium (14-20), ruthenium (21-26), and cobalt (27-30) catalysis has generally been limited by the high pressures necessary to effect reaction and the modest turnover frequencies. We have demonstrated the preparation of ethylene glycol and its monoalkyl ether derivatives from CO/H2 (eq. 1) using ruthenium or a Ru-Rh catalyst combination dispersed in a low-melting quaternary phosphonium or ammonium salt such as tetrabutylphosphonium bromide. Monohydric alkanols are the major by-products data in Table 1 illustrate typical preparations. The important features of this catalysis are ... 

Kirk [52] described the use of tetrabutylphosphonium hydroxide, which brings about rapid rearrangement and polymerization of siloxanes at temperatures up to 100 C. After the polymerization is completed, the phosphonium catalyst is decomposed by heating the polymer above 130°C, as shown in Eq. (20). 

Phosphonium salts also increase the conversion and molecular weight in nylon 4 polymerization. This is shown in Table VI for tetrabutylphosphonium bromide. 

Tetrabutylphosphonium and triphenylchlorophosphonium chlorides were reported to act as catalysts for the addition of diethylzinc to aldehydes (aromatic, heteroaromatic or aliphatic) and the dehydration of aromatic and aliphatic aldoximes to nitriles, respectively. Catalysis was so efficient that both types of reactions occurred at room temperature, even with phosphonium salts in pol)Tner-bonded form. 

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