Synthesis of polyamides by a new direct polycondensation reaction using triphenyl phosphite and lithium chloride

Metal salts such as lithium chloride were found to facilitate significantly the reaction of carboxylic acids and amines promoted by triphenyl phosphite, and the reaction was applied successfully to the direct polycondensation reaction of dicarboxylic acids and diamines and of p-aminobenzoic acid. Among metal salts tested, lithium chloride was most effective to the reaction; the chloride was involved catalytically in the reaction, its addition of about twice equivalent to triphenyl phosphite giving the most favorable results. Triphenyl phosphite was most effective, whereas diphenyl phosphite was less effective, and alkyl esters gave no polymers. The reaction was also markedly affected by solvents, the most favorable results being given in N-methylpyrrolidone (NMP). Various polyamides of high molecular weight were obtained in quantitative yield.     

Reactions of triphenyl phosphite with di- and tribromoacetaldehydes

Conclusions The reaction of triphenyl phosphite and di- and tribromoacetaldehydes proceeds through initial halophilic attack with subsequent formation of triphenyl phosphate and tetraphenylphosphonium bromide.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 7, pp. 1668–1670, July, 1988.     

Reaction of triphenyl phosphite witho-aminophenol

Conclusions The reaction ofo-aminophenol with triphenyl phosphite gave spirophosphorane (III).Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 6, p. 1426, June, 1973.     

ortho-metallation reactions involving some triphenyl phosphite complexes of osmium

Osmium triphenylphosphine complexes, OsH₄(PPh₃)₃, OsH₂ (CO)(PPh₃)₃ and OsHCl(CO)(PPh₃)₃ react with triphenyl phosphite in boiling organic solvents to yield triphenyl phosphite derivatives which subsequently undergo ortho-metallation reactions.     

Flash photolysis study of the reactivity of isomeric forms of arylnitroso oxides toward triphenyl phosphite

The kinetics of the reactions of phenylnitroso oxide and 4-CH₃O-, 4-CH₃-, and 4-Br-phenylnitroso oxides with triphenyl phosphite was studied in acetonitrile, benzene, and hexane by flash photolysis. The reaction occurs only with the trans-isomers of nitroso oxides. The value of the reaction rate constant increases with an increase in the electron-withdrawing power of substituents on the nitroso oxide aromatic ring, with the rate constant being almost the same in benzene and acetonitrile, and increasing by a factor of 2–3 in hexane. The temperature dependence for the decay rate constants of isomeric nitroso oxides in the presence of triphenyl phosphite was studied in acetonitrile.     

Formation of isomeric diphenyl pentaerythrityl diphosphites in transesterification of triphenyl phosphite with pentaerythritol

Conclusions Employing the method of thin-layer chromatography, it was shown that the transesterification of triphenyl phosphite with pentaerythritol gives a mixture of two isomeric diphenyl pentaerythrityl diphosphites, the structure of which was confirmed by synthesis.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 5, pp. 1116–1118, May, 1973.The authors express their gratitude to S. G. Vul'fson and L. N. Surkova for assistance in the work.     

Oxidation of diazo compounds by triphenyl phosphite ozonide. Quenching of singlet oxygen by diazo compounds

The reaction of triphenyl phosphite ozonide with various types of diazo compounds results in their oxidation, which is accomplished by singlet oxygen (¹O₂) evolved during thermal decomposition of the ozonide. A decrease in the ionization potential of the substrate results in an increase in the overall rate constant of quenching of¹O₂. In the case of 9-diazofluorene, the main channel of¹O₂ quenching is physical quenching.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 9, pp. 1567–1571, September, 1994.The work was carried out with the financial support of the Russian Foundation for Basic Research (Project No. 93-03-5231).     

Kinetics of the hydrolysis of tri- and diethyl phosphite

Conclusions We have studied the kinetics of the hydrolysis of triethyl phosphite in water and dilute KOH, and of the hydrolysis of diethyl phosphite in water and dilute HCl. The temperature dependences of the velocity constants have been determined.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 11, pp. 2551–2552, November, 1967.     

17O NMR investigation of phosphite hydrolysis mechanisms

The use of solution 17O NMR spectroscopy in verifying the mechanism of trialkyl phosphite hydrolysis is presented. Trimethyl phosphite was reacted with 17O-labeled H2O at different temperatures and two reactant concentrations, with the reaction being monitored by 17O NMR. Kinetic details elucidated from the NMR spectra are also discussed.     

Mesoporous aluminum phosphite

High surface area pure mesoporous aluminum-phosphorus oxide-based derivatives have been synthesized through an S⁺I⁻ surfactant-assisted cooperative mechanism by means of a one-pot preparative procedure from aqueous solution and starting from aluminum atrane complexes and phosphoric and/or phosphorous acids. A soft chemical extraction procedure allows opening the pore system of the parent as-prepared materials by exchanging the surfactant without mesostructure collapse. The nature of the pore wall can be modulated from mesoporous aluminum phosphate (ALPO) up to total incorporation of phosphite entities (mesoporous aluminum phosphite), which results in a gradual evolution of the acidic properties of the final materials. While phosphate groups in ALPO act as network building blocks (bridging Al atoms), the phosphite entities become basically attached to the pore surface, what gives practically empty channels. The mesoporous nature of the final materials is confirmed by X-ray diffraction (XRD), transmission electron microscopy (TEM) and N₂ adsorption–desorption isotherms. The materials present regular unimodal pore systems whose order decreases as the phosphite content increases. NMR spectroscopic results confirm the incorporation of oxo-phosphorus entities to the framework of these materials and also provide us useful information concerning the mechanism through which they are formed.     

Effect of initiation conditions on the direct polycondensation reaction using triphenyl phosphite and pyridine

In a model reaction of terephthalic acid with aniline by using triphenyl phosphite in a mixed solvent of pyridine and N-methylpyrrolidone (NMP), mono- and dianilides were produced with relative yields varying with the content of pyridine in the solvent. The polycondensation of terephthalic acid with aromatic diamines was found to proceed more favorably via monoamidation, and highmolecular-weight polyterephthalamides were prepared by controlling initiation conditions (selective activation of carboxylic groups), such as initial solvent systems, including the amount and kind of pyridines and initiation temperatures.     

High-molecular-weight poly(amino acid)s by the direct polycondensation reaction promoted by triphenyl phosphite and LiCl in the presence of polyvinylpyrrolidone

Poly(α-amino acid)s of high molecular weight were obtained by the direct polycondensation reaction of α-amino acids in the presence of polyvinylpyrrolidone (PVP) as a matrix of triphenyl phosphite and LiCl in N-methylpyrrolidone (NMP). Molecular weights of the polymer produced were improved by use of an increasing amount of matrix of higher molecular weight. Most favorable results were obtained by the reaction at 80°C for 16 hr at a monomer concentration of 0.33 mole/liter in a NMP solution that contained about 3 wt % LiCl in the presence of an equivalent unit mole of PVP with the molecular weight of 3.6 x 10⁵. The polymer from β-alanine with high molecular weight, which is difficult to obtain by the NCA method, was easily prepared by this process.     

Structure and acid-basic properties of the surface of titanium oxides modified by phosphorus and aluminum and prepared by the alkoxo method. 2. Study of the active surface of titanium oxides

The data of temperature-programmed desorption of ammonia from the surface of oxide systems and IR spectroscopy were used to demonstrate that the strength of the surface acid sites in titanium oxides prepared by the alkoxo method and modified by aluminum decreases with respect to that in nonmodified titanium oxide. Modification of titanium oxide with P³⁺ ions from ethriol phosphite almost completely suppresses the acid properties. Modified oxides are able to chemisorb water. XANES data suggest that modification of titanium oxide with phosphorus ions increases the electron density on the titanium atoms and, correspondingly, the basicity of the materials.     

Wholly aromatic polyamides by the direct polycondensation reaction using triphenyl phosphite in the presence of poly(4-vinylpyridine)

The polycondensation reaction of aromatic dicarboxylic acids and diamines by using triphenyl phosphite were carried out in N-methylpyrrolidone (NMP) in the presence of poly(4-vinylpyridine) (P4VP). The reaction, especially of terephthalic acid (TPA), was markedly facilitated to give the absence of P4VP. The reaction promoted by P4VP was further favored by the addition of various pyridine derivatives; of the pyridines examined, pyridine was most effective, giving the best results at a high level (pyridine/P4VP values up to 26). P4VP of the molecular weight in the range of 1.3 × 10⁴?3.0 × 10⁵ did not affect the viscosity of the resulting polymer. These favorable additive effects of P4VP on the reaction of TPA were not observed in the reactions of isophthalic acid, and m -and p-aminobenzoic acids.     

Orientational correlations in the glacial state of triphenyl phosphite

Spallation neutron and high-energy X-ray diffraction experiments have been performed to investigate the local structure of the glacial and supercooled liquid states in triphenyl phosphite. The observed diffraction patterns have been interpreted using a Reverse Monte Carlo modeling technique. The results show that the glacial state forms unusually weak intermolecular hydrogen bonds between an oxygen atom connected to a phenyl ring and an adjacent phenyl ring aligned in an approximately antiparallel configuration. The structure is very different from the hexagonal crystal which is characterized by two weaker hydrogen bonds between linear arrays of molecules which are offset from each other and packed in a hexamer arrangement.     

Oxidation of 2-trimethylsilyloxy-1,3-dienes with triphenyl phosphite ozonide. A regioselective α′-hydroxylation of α,β-unsaturated ketones

The present work deals with a novel method for the introduction of hydroxyl group to the α′-carbon of α,β-unsaturated ketones using triphenyl phosphite ozonide.     

Ligand exchange reactions with η6-arene-η5-cyclopentadienyliron cations under thermal or photochemical conditions

Reactions of various η⁶-arene-η⁵-cyclopentadienyliron or substituted cyclopentadienyliron cations with trimethyl, triethyl or triphenyl phosphite under either thermal or photochemical conditions all resulted in the replacement of the arene ligand with three phosphite ligands to give η⁵-tris(trimethyl, triethyl or triphenyl phosphite)-η⁵-cyclopentadienyliron or substituted cyclopentadienyliron cations. The yields of the phosphite complexes were higher from photolysis than from the analogous thermolysis. Photolysis of the η⁶-chlorobenzene-η⁵-cyclopentadienyliron cation (IX) carried out in the presence of a more basic or more electron-rich aromatic ligand resulted in the exchange of the chlorobenzene of IX with the more basic arene, thus providing synthetic routes to cyclopentadienyliron complexes that may be difficult to prepare by other means. New complexes synthesized in this way are the η⁶-2-phenylethyl tosylate-η⁵-cyclopentadienyliron cation and the CpFe⁺ complexes of thiophene, 2-methylthiophene, 3-methylthiophene and 2,5-dimethylthiophene.     

The role of organic phosphite primary structure in the overall stabilization performance in polypropylene

The role of the primary P³⁺ functionality in the phosphite overall stabilization performance was re-evaluated. Tris(2,4-di-t-Bu-phenyl)phosphite (P-1) and its oxidation product tris(2,4-di-t-Bu-phenyl)phosphate (P-1_ox) were tested both alone and in the presence of hindered phenol during processing in polypropylene. Efficiencies were quantified using the processing degradation index (PDI). The position of the traditional multiple extrusion curve was determined by a single parameter, describing the degree of polymer degradation. Its reciprocal allowed calculating formulations relative efficiencies. It was shown that oxidation of P³⁺ into P⁵⁺ is responsible for 75 % phosphite stabilization performance, regardless phosphite acts alone or in combination with phenol. If P³⁺ is completely oxidized, stabilizer still works. For the residual performance, the reactions of 2,4-di-t-Bu-phenyl substituents (secondary structure), are responsible. Besides processing, reactions of P³⁺ also contribute to the long-term stability at 150 °C. Once phosphite is oxidized, the secondary structure does not contribute to the long-term stability at all.     

Effects of substituted triphenyl phosphites on the radical polymerization of acrylonitrile

The radical polymerization of acrylonitrile in the presence of nuclear-substituted triphenyl phosphites (p-Cl, H, p-CH₃, p-OCH₃) initiated by α,α′-azobisisobutyronitrile at 50°C was investigated. It was found that the rate of polymerization decreased at low concentrations of phosphite, but after reaching a minimum the rate increased again with further increase in the phosphite concentration in the case of all substituted triphenyl phosphites. Formation of a weak complex between phosphite as donor and acrylonitrile as acceptor was confirmed from the change in chemical shifts of vinyl protons to higher magnetic fields on NMR spectroscopy. From the results of continuous variation method using NMR spectra, the complex was found to be of the 1:1 type. The effects of substituted triphenyl phosphite on the rate of polymerization and the chain-transfer reaction to substituted triphenyl phosphites are discussed on the basis of these results.     

Photopolymerization of acrylonitrile in the presence of substituted triphenyl phosphites

It was found that acrylonitrile was polymerized at 30°C by ultraviolet irradiation in the presence of triphenyl phosphite and its derivatives, namely m-CH₃, p-C₂H₅, and p-CH₃ substituted triphenyl phosphites under conditions where acrylonitrile alone did not polymerize and phosphites did not undergo photolysis. The rate of polymerization in the presence of triphenyl phosphite and tri-p-tolyl phosphite was found to be proportional to the monomer concentration, the phosphite concentration, and the light intensity. From these results, it was thought that a donor–acceptor complex formed between phosphite and acrylonitrile which absorbed light and initiated the radical polymerization. In the photopolymerization of acrylonitrile with substituted triphenyl phosphites, the rate of polymerization increased with an increase in electron-donating ability of substituent. From the plot obtained by use of Hammett's equation (log R_p/R_p0 = ρσ), the ρ value was found to be ?1.0.