Diphenyl Chlorophosphate Research Articles

Synthesis and photoluminescence properties of novel polyarylates bearing pendent naphthylamine chromophores

A new series of blue photoluminescent aromatic polyesters (polyarylates) were synthesized from 1-[ N, N-di(4-carboxyphenyl)amino]naphthalene with various bisphenols by the diphenylchlorophosphate (DPCP) activated direct polycondensation in a medium of pyridine and lithium chloride. The synthesis, basic characterizations, photoluminescence and electrochemical properties of this series of novel polyarylates bearing pendent naphthylamine chromophores were investigated. All polymers not only had good solubility in many polar aprotic solvents and excellent thin-film-forming ability, but also exhibited high T g values, good thermal stability and lower highest occupied molecular orbital (HOMO) level. Thus, these naphthylamine-containing polyarylates may be widely applied in P-LED as hole-transporting layer and blue light-emitting materials due to their proper HOMO level, excellent thermal stability and fluorescence quantum efficiency.

Kinetics and Mechanism of the Aminolysis of Diphenyl Phosphinic Chloride with Anilines

The aminolyses of diphenyl phosphinic chloride (1) with substituted anilines in acetonitrile at 55.0 oC are investigated kinetically. Large Hammett ρ X (ρnuc = ?4.78) and Bronsted β X (βnuc = 1.69) values suggest extensive bond formation in the transition state. The primary normal kinetic isotope effects (kH/kD = 1.42-1.82) involving deuterated aniline (XC6H4ND2) nucleophiles indicate that hydrogen bonding results in partial deprotonation of the aniline nucleophile in the rate-limiting step. The faster rate of diphenyl phosphinic chloride (1) than diphenyl chlorophosphate (2) is rationalized by the large proportion of a frontside attack in the reaction of 1. These results are consistent with a concerted mechanism involving a partial frontside nucleophilic attack through a hydrogen-bonded, four-center type transition state.

Dechlorination of diphenyl chlorophosphate with tin and sodium 3,6-di- tert-butyl- ortho-semiquinones

Dechlorination reactions of diphenyl chlorophosphate (PhO) 2P(O)Cl with 3,6-di- tert-butyl- ortho-semiquinone complexes of triphenyl tin, SQSn(Ph) 3 and sodium, SQNa have been investigated by electron spin resonance (ESR) both in solutions at 300 K and in solid phase at 77 K using mechanochemical activation. Paramagnetic 3,6-di- tert-butyl- ortho-semiquinone ligand (SQ) was used as spin probe to monitor changes in the Sn coordination sphere during the dechlorination reaction of (PhO) 2P(O)Cl and consecutive formation of tin chloride derivatives SQSnCl(Ph) 2, SQSnCl 2Ph, and SQSnCl 3. Their structure was revealed based on the analysis of hyperfine interaction constants due to 1H nuclei in the 4,5-positions of the aromatic ring of the SQ ligand, hyperfine interaction constants due to 35Cl and 37Cl nuclei of chlorine atoms in the Sn coordination sphere, and hyperfine interaction constants due to 117Sn and 119Sn nuclei of the central metal ion. Interaction of SQSnCl 3 with (PhO) 2P(O)Cl leads to the formation of a meta-stable radical–anion complex [SQSnCl 4] − P +(O)(OPh) 2, which transforms to SQSnCl 3⋯P(O)R 3, a stable adduct of SQSnCl 3 with dechlorinated phosphate of a general formula P(O)R 3. Analysis of solution dechlorination reaction products suggests the formation of diphenyl-phosphoryl radical (PhO) 2P (O), which was not observed in solutions. Dechlorination of (PhO) 2P(O)Cl with sodium 3,6-di- tert-butyl- ortho-semiquinone SQNa can proceed in solid phase in liquid nitrogen at 77 K via mechanochemical activation using a ball mill. ESR analysis of the cryo-mechanochemical reaction showed the formation of the adduct of (PhO) 2P (O) radical with 3,6-di- tert-butyl- ortho-quinone.

Synthesis and photophysical properties of novel organo-soluble polyarylates bearing triphenylamine moieties

Two series of new blue photoluminescent aromatic polyesters (polyarylates) were synthesized from 4,4′-dicarboxytriphenylamine and 4,4′-dicarboxy-4″-methyltriphenylamine with various bisphenols by the diphenylchlorophosphate (DPCP) activated direct polycondensation in a medium of pyridine and lithium chloride. These polymers were amorphous and readily soluble in various common organic solvents including DMAc, THF, and chloroform, and could be cast from their chloroform solutions into transparent films due to their excellent solubility. These polyarylates exhibited moderately high T g values (186–264 °C) and thermal stability. In THF solution, these triphenylamine-containing polyarylates showed UV-Vis absorption bands at 359–365 nm and photoluminescence peaks around 427–451 nm in the blue region.

A Simple, General and Improved Procedure for Phosphorylation of Alcohols Catalyzed by Indium(III) Chloride.

AbstractFor Abstract see ChemInform Abstract in Full Text.

Structural Requirements of Dolichyl Phosphate as an Apoptosis Inducer

Physiologically active dolichyl phosphate (dol-P) is known to induce apoptosis in human promonoblastic leukemia cells U937 and rat glioma C6 cells. The study on the relation between chemical structure and apoptosis-inducing ability of dol-P indicated that phosphate head group is one of the essential structures. This study investigated the significance of phosphate group by using two structurally related compounds, dolichyl sulfate (dol-S) and dolichyl diphenylphosphate (dol-DPP). Dol-S prepared from dolichol and N, N-dimethyl formamide sulfur trioxide complex, maintains a charge but lacks a phosphate group. Dol-DPP, prepared from dolichol and diphenyl chlorophosphate, retains a phosphate group but has no charge. Human promonoblastic leukemia cells U937 were subjected to the two dol-P analogues, and apoptosis-inducing ability was determined by studies on cell viability, cell morphology, DNA fragmentation, and activations of caspase-3 and 8. Dol-S induced apoptosis but dol-DPP did not. Moreover, dol-S was found to mediate apoptosis at only one-twentieth of the concentration of dol-P. These findings indicated that in dol-P-induced apoptosis, the charged group rather than the phosphate group was the required key structure for apoptosis induction.

Synergistic effect of a phosphorus–nitrogen flame retardant on engineering plastics

AbstractThe novel flame retardant tris(3,5‐dimethyl‐4‐diphenyl phenoxy phosphate)isocyanurate (TDPI) was synthesized from the reaction of diphenyl chlorophosphate and tris(3,5‐dimethyl‐4‐hydroxybenzyl)isocyanurate. The compound was characterized with Fourier transform infrared spectroscopy, elemental analysis, mass spectrometry, 1H‐NMR, and 31P‐NMR. Furthermore, blends of the flame retardant with engineering plastics in various weight ratios were made, and their thermal stability and flame retardancy were determined by thermogravimetric analysis (TGA), UL‐94 vertical testing, and limiting oxygen index (LOI) measurements. The phosphorus–nitrogen synergistic effect on flame retardancy was compared with the effects of commonly used tetraphenyl resorcinol diphosphate and tetrabromobisphenol A. TGA indicated that the TDPI/engineering plastics systems were stable up to 397–503°C at a 5% weight loss in a nitrogen atmosphere with a relatively high char yield (21.0–42.1% at 700°C) and that they a achieved UL‐94 V‐0 rating (with a low flame‐retardant content: P, 0.76 wt %, and N, 0.34 wt %). No fume and toxic gas emissions were observed during the burning test for this system. The LOI values were 31.6–42.2. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 92: 410–417, 2004

Reactivity of Cage-Like Amines toward p-Toluenesulfonyl Chloride and Diphenyl Chlorophosphate in Acetonitrile

The nucleophilic reactivity of amines of the norbornane, norbornene, and adamantane series toward ptoluenesulfonyl chloride and diphenyl chlorophosphate in acetonitrile at 25°C is determined mainly by the steric factor. Parameters characterizing spatial accessibility of the reaction center in the amine molecule have been determined. Cage-like substituents show no appreciable effect on the amine reactivity, as compared to common alkyl groups.

Synthesis and characterization of organosoluble poly(arylate‐imide)s prepared from direct polycondensation of bis(trimellitimide)‐diacids and various bisphenols

AbstractThree diimide‐diacids, 2,2‐bis[4‐(4‐trimellitimidophenoxy)phenyl]hexafluoropropane (I‐A), 2,2‐bis[4‐(4‐trimellitimidophenoxy)phenyl]propane (I‐B), and 5,5′‐bis[4‐ (4‐trimellitimidophenoxy)phenyl]hexahydro‐4,7‐methanoindan (I‐C), were prepared by the azeotropic condensation of trimellitic anhydride with three analogous diamines. Three series of alternating aromatic poly(arylate‐imide)s, having inherent viscosities of 0.41–0.82 dL/g, were synthesized from these diimide‐diacids (I‐A, I‐B, and I‐C) with various bisphenols by direct polycondensation using diphenyl chlorophosphate and pyridine as condensing agents. All of the polymers were readily soluble in a variety of organic solvents such as N‐methyl‐2‐pyrrolidone, N,N‐dimethylacetamide, and even in the less polar tetrahydrofuran. These polymers could be cast into transparent and tough films, which had strength at break values ranging from 73 to 98 MPa, elongation at break from 6 to 11%, and initial modulus from 1.6 to 2.2 GPa. The softening temperatures of the polymers were recorded at 145–248°C. They had 10% weight loss at a temperature above 450°C and left 35–51% residue even at 800°C in nitrogen. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 89: 3818–3825, 2003

Morphology of Poly(p-oxybenzoyl) Crystals Prepared by Direct Polycondensation of p-Hydroxybenzoic Acid with Diphenyl Chlorophosphate

We have studied the morphology of poly( p-oxybenzoyl) (POB) crystals prepared by the direct polycondensation of p-hydroxybenzoic acid (HBA) using diphenyl chlorophosphate (DPCP) in the presence of N,N-dimethylformamide. Lozenge-shaped sheaf-like POB crystals were obtained of which the longer diagonal was 16.0-16.5 μm. Favorable polymerization conditions to prepare the crystal exhibiting clear crystal characteristic were the molar ratio of DPCP to HBA of 1.5, the molar ratio of DMF to HBA of 2.6 and the polymerization concentration of 3.0%. The crystals were comprised of low molecular weight polymer of which the degree of polymerization (DPn) was 14 and possessed extremely high crystallinity. The formation mechanism of the crystals was considered by the polymerization time dependences of morphology, yield, density, DPn, crystallite size, and lattice constant as follows. When the DPn of the oligomers exceeded a critical value of about 3, they were precipitated to form the hexagonal lamellae. The lamellae grew very quickly to sheaf-like lozenge-shaped crystal through the screw dislocation with the continuous precipitation of the oligomer from the solution. Finally, further polymerization and the reorganization of polymer chains occurred in the precipitated crystals.

A simple, general and improved procedure for phosphorylation of alcohols catalyzed by indium( III) chloride

A general and efficient procedure has been developed for the preparation of dialkyl phosphate esters by indium(III) chloride catalyzed phosphoryl transfer from diethyl and diphenyl chlorophosphate to a variety of alcoholsand phenols in THF in presence of triethylamine.

Preparation of the thermotropic copoly(amide ester) ofp-aminobenzoic acid andm-hydroxybenzoic acid with diphenyl chlorophosphate/pyridine

A thermotropic copoly(amide ester) exhibiting a nematic mesophase within the range of 240–360 °C was prepared by the solution copolycondensation of p-aminobenzoic acid (40–70 mol %) and m-hydroxybenzoic acid with diphenyl chlorophosphate in pyridine in the presence of LiCl. For control of the sequence distribution of p-aminobenzoic acid, the amount of LiCl and the dropwise addition of the phosphate were examined. The transition temperatures (from a solid phase to a nematic mesophase) of the resultant copolymers were affected by the period of addition and the amounts of the aminobenzoic acid and LiCl and were investigated in terms of the distributions of the monomers determined by 1H NMR. © 2002 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 40: 1775–1780, 2002

Phenylphosphonic Acid Functionalized Poly[aryloxyphosphazenes

A method for the synthesis of phenylphosphonic acid functionalized poly[aryloxyphosphazenes] is described. Diphenyl chlorophosphate was used as the phosphonating agent and was allowed to react with lithio-functionalized aryloxyphosphazenes, followed by treatment with aqueous sodium hydroxide. Subsequent acidification with aqueous hydrochloric acid yielded phenylphosphonic acid functionalized poly[aryloxyphosphazenes]. These polymers are candidates for use as proton-conducting membranes in fuel cells.

Comparison of Carboxamides Reactivity with Respect to Benzoyl Chloride and Diphenyl Chlorophosphate in Acetonitrile

For amides belonging to series RCONH2 (I), RCONHMe (II), RCONHPh (III), and RCONMe2 (IV) rate constants k1 (l mol-1 s-1) were determined (in acetonitrile at 25°C) specifying the nucleophilic reactivity of the oxygen atom in amides toward benzoyl chloride and diphenyl chlorophosphate. The lack of substrate selectivity in the reactions in question was established. For equal values of inductive constants σ* of the R substituents the reactivity sequence of amides with respect to both substrates is the same (I >> IV > II, and III > II), and it does not follow the corresponding sequence of basicities. A conclusion was drawn that both groups of reactions proceed through cyclic transition states resembling reagents: six-membered with amides I and III, and five-membered with amides II and IV.

Synthesis of P 1-Citronellyl-P 2-α- d-pyranosyl pyrophosphates as potential substrates for the E. coli undecaprenyl-pyrophosphoryl- N-acetylglucoseaminyl transferase MurG

P 1-Citronellyl-P 2-α- d-pyranosyl pyrophosphates containing α- d- N-acetylglucoseaminyl, α- d-glucosyl, and α- d- N-acetylmuramyl carbohydrates were synthesized and used in substrate specificity studies of the Escherichia coli MurG enzyme. Oxalyl chloride activation of citronellyl phosphate for coupling to α- d-pyranose-1-phosphates resulted in markedly improved yields over traditional Khorana–Moffatt and diphenyl chlorophosphate activation strategies.

Promoted random orientation of the phenyl substituent of phenylhydroquinone-terephthalic acid polyesters prepared with a diphenyl chlorophosphate/pyridine condensing agent

The reaction of sterically hindered hydroxyl groups at the 2-position of methylhydroquinone and phenylhydroquinone (PhHQ) to form esters was largely promoted by their slow addition to benzoic acid activated by diphenyl chlorophosphate in pyridine. A modification of this reaction was applied to the preparation of thermotropic terephthalic acid/PhHQ and 2,5-dichloroterephthalic acid/PhHQ polymers with randomly oriented phenyl substituents, and the properties of the polymers were studied in terms of their transition temperatures, which were determined by differential scanning calorimetry and microscopic observation. The melting points were lowered by about 30–50 °C by the dropwise addition of PhHQ over 10–30 min. The molecular structures of the 2,5-dichloroterephthalic acid/PhHQ polymers were studied by 13C NMR. © 2001 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 39: 1726–1732, 2001

Synthesis and properties of new organo-soluble and strictly alternating aromatic poly(ester-imide)s from 3,3-bis[4-(trimellitimidophenoxy)phenyl]phthalide and bisphenols

A series of new strictly alternating aromatic poly(ester-imide)s having inherent viscosities of 0.20–0.98 dL/g was synthesized by the diphenylchlorophosphate (DPCP) activated direct polycondensation of the preformed imide ring-containing diacid, 3,3-bis[4-(trimellitimidophenoxy)phenyl]phthalide (I), with various bisphenols in a medium consisting of pyridine and lithium chloride. The diimide–diacid I was prepared from the condensation of 3,3-bis[4-(4-aminophenoxy)phenyl]phthalide and trimellitic anhydride. Most of the resulting polymers showed an amorphous nature and were readily soluble in a variety of organic solvents such as N-methyl-2-pyrrolidone (NMP) and N,N-dimethylacetamide (DMAc). Transparent and flexible films of these polymers could be cast from their DMAc solutions. The cast films had tensile strengths ranging 66–105 MPa, elongations at break from 7–10%, and initial moduli from 1.9–2.4 GPa. The glass-transition temperatures of these polymers were recorded between 208–275 °C. All polymers showed no significant weight loss below 400 °C in the air or in nitrogen, and the decomposition temperatures at 10% weight loss all occurred above 460 °C. © 2000 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 38: 1090–1099, 2000

Synthesis, characterization, and hydrolytic degradation of copolyesters of 3-(4-hydroxyphenyl) propionic acid andp-hydroxybenzoic acid, vanilic acid, or syringic acid

A series of copolyesters were prepared by a direct polycondensation of 3-(4-hydroxyphenyl) propionic acid and p-hydroxybenzoic acid (HBA), vanilic acid (VA), or syringic acid (SGA) of different composition in pyridine using diphenyl chlorophosphate and lithium bromide as condensing agents. The effects of methoxy substitution in the benzene ring and copolymer composition on the synthesis and thermal properties as well as hydrolytic degradation were examined. The methoxy substitution increased a glass transition temperature and a solubility, while it decreased a crystallinity and a thermal stability. The HBA series copolyesters showed a homogenous nematic phase, while the VA and SGA series copolyestes neither revealed an anisotropic melt nor formed a mobile melt below around 350°C. The hydrolytic degradation of melt-pressed films was performed in a 5% sodium hydroxide aqueous solution at 40°C to test a biodegradability of the copolyesters. HBA-50 and HBA-30 exhibited the much higher degradation rate than HBA-70, showing that the aliphatic ester linkage was more degradable than aromatic one. The degradation rates of VA-50 and SGA-50 were remarkably slower than that of HBA-50 due to the steric hindrance of the methoxy group in the ortho position. © 2000 John Wiley & Sons, Inc. J Appl Polym Sci 78: 2474–2481, 2000

Polymerization of 5-aza-1-oxa-cycloundecan-4,11-dione; a mechanistic study

N-(3-Hydroxypropionyl)-ε-aminocaproic acid lactone [c(3HP-εAC), 1] was polymerized in dimethylformamide solution with dibutyldimethoxytin as initiator at 100°C. A strictly alternating poly-(amide-ester), poly(3-hydroxypropionate-alt-ε-aminocaproate), was obtained, a semicrystalline polymer with a melting point of 145.9°C. The polymerization was found to proceed via a tin alcoholate active species as was deduced from 1H NMR endgroup analysis of the polymer quenched with water. In addition, the active chain ends were quenched with diphenyl chlorophosphate and analyzed by means of 31P NMR spectroscopy; a diphenylalkyl phosphate was identified, proving the alcoholate active site. The polymerization follows a pseudo-first order rate law only at low conversions. However, a linear dependence of the number-average molecular weight on conversion was found, proving that transfer reactions play a minor part throughout the polymerization process. A mechanism for the initiation and propagation is proposed.

Preparation and properties of polyesteramide-graft-poly(2,6-dimethyl-1,4-phenylene oxide) copolymers

New tailor-made polyesteramide-graft-poly(2,6-dimethyl-1,4-phenylene oxide)(PPO) copolymers were prepared by direct polycondensation from a dicarboxy-terminated PPO macromonomer, aromatic dicarboxylic acids, diphenols, eicosanedioic acid and tolylene-2,4-diamine at definite mole ratios in pyridine including lithium chloride in the presence of diphenyl chlorophosphate as a condensation reagent and characterized by FTIR spectra, 1H and 13C NMR spectra and elemental analyses. Most of them were soluble in chloroform at room temperature in spite of the presence of amide linkage in the backbones. Differential scanning calorimetry measurements and optical texture observations by polarizing microscope described that only the graft copolymers containing a biphenyl unit show thermotropic nematic phases. Thermogravimetry-differential thermal analysis measurements showed that the copolymers are thermostable up to 290–300°C.