Enthalpy of formation of triphenylphosphine sulfide

The first measurements of the enthalpies of combustion, sublimation, and fusion of an organo-phosphorus sulfide, triphenylphosphine sulfide, are reported: _c H _m ^o (C₁₈H₁₅PS, cr)=–(10752.58 ±2.90), _sub H _m ^o (C₁₈H₁₅PS, 403 K)=(136.80±6.09), and _fus H _m ^o (C₁₈H₁₅PS, T_m=435.92 K) =(30.53±0.21) kJ·mol^–1. Correction of the phase change enthalpies toT=298.15K and p^o =0.1 MPa results in the standard phase change enthalpy values of _sub H _m ^o (298.15 K)=(142.8 ±6.8) and _fus H _m ^o (298.15 K)=(19.28±0.21) kj·mol^–1. Accordingly, the enthalpies of formation of solid, liquid, and gaseous triphenylphosphine sulfide are derived: _f H _m ^o (C₁₈H₁₅PS, cr) =(63.20±2.56), _fH _m ^o (C₁₈H₁₅PS, l)=(82.48±2.57), and _fH _m ^o (C₁₈H₁₅PS, g)=(206.0±7.3) kJ·mol^–1. From these ancillary data, the P=S double-bond enthalpy is 394 kJ-mol^–1 and in good agreement with earlier reaction calorimetry results. These phosphorus sulfide values are compared with those for the arsenic sulfides. Plausibility arguments are given for our results.     

The extraction of HCl by TDPO in benzene

The results of the extraction of HCl by TDPO in benzene and the co-extraction of water are discussed. From the infrared spectra of normal (HCl-H₂O) and deuterated (DCl-D₂O) systems it may be concluded that TDPO·HCl·H₂O is formed in the organic phase on extraction from aqueous solutions with c_HCl≤5M, and TDPO·HCl with c_HCl>5M. Compounds such as TDPO·2HCl are found in the organic phase if there is an excess of HCl in the organic phase. From cryoscopic and viscosity measurements of the organic phase, conclusions can be made about the presence of polymeric compounds in this phase.     

A cyclic hexamer of silver trifluoroacetate supported by four triphenylphosphine sulfide template molecules

Crystallization of silver trifluoroacetate from chloroform solutions containing triphenylphosphine sulfide affords a trigonal and a monoclinic form of a 6:4 complex {[CF3C(O)OAg]6(Ph3PS)4} of C2 symmetry with different amounts of chloroform in the crystals. With the Ph3PS components as template molecules, the CF3C(O)OAg units are assembled to form a 6-membered metallacycle codetermined by metallophilic bonding and enclosed by a 24-membered ring [AgOCO]6. A complex of the type [LAgOC(O)CF3]2, with L representing the isocyanide ligand pTolSO2CH2NC, has been shown to have a conventional bicyclic structure with three-coordinate silver atoms engaged in transannular metallophilic interactions.     

Synergic extraction of dioxouranium(VI) with di (2-ethylhexyl) dithiophosphoric acid and triphenylphosphine oxide in benzene

Synergic extraction of dioxouranium (VI) from aqueous solutions with di (2-pethylhexyl) di thi ophosphoric acid (HEhdtp) and triphenylphosphine oxide (TPPO) in benzene has been investigated. Slope analysis of the extraction results indicates the composition of mixed species formed in the organic phase as UO₂ (Ehdtp)₂TPPO. The extraction constant and formation constant of the mixed species has been calculated.     

Temperature dependence of benzene hydrogenation over sulfide catalysts

Non-Arrhenius temperature dependence of benzene hydrogenation was found for sulfide alumina-supported (Ni,Mo) and (Ni,W) catalysts under unsteady-state reaction conditions. It was shown that THE observed decrease in the catalyst activity at high temperature cannot be explained by the increasing role of the reverse reaction. The activity decrease was supposed to result from the catalyst reduction with the reaction mixture.     

Palladium extraction by amines from nitrate medium in the presence of chloride ions

The extraction of palladium has been studied in amine-solvent-HNO₃–HCl systems. It has been found that palladium is extracted in the forms Am₂PdCl₄ and Am₂Pd₂Cl₆ simultaneously /Am=ammonium cation/.     

Palladium extraction by a cyanex 301-based binary extractant from chloride solutions

We studied the extraction of chloropalladium complexes by solutions of trioctylmethylammonium di(2,4,4-trimethylpentyl)dithiophosphinate in toluene over a wide range of aqueous acidities. Distribution factors and spectroscopic studies of extraction products showed that (R₄N)[Pd₂Cl₄A] complexes are formed in the organic phase during extraction under near-saturation conditions. As the concentration of the binary extractant or dialkyldithiophosphinic acid increases, palladium di(2,4,4-trimethylpentyl)dithiophosphinate is formed in the organic phase.     

Palladium extraction from nitrate solutions by tertiary amines and quaternary ammonium salts

The mechanism of palladium extraction by trilaurylamine and trilaurylmethylammonium nitrate from nitric acid solutions was studied. The composition of the extracted compounds was determined by the Job method as well as by organic phase saturation. Both reagents were found to extract palladium as Am₂Pd/NO₃/₄ /Am=ammonium cation/.     

Hydrogenation of benzene on sulfide catalysts in the presence of thiophene

The principles of benzene hydrogenation have been studied with sulfide catalysts NI/MS₂, Ni/SiO₂, M/SiO₂ and (Ni, M)/SiO₂ (M=Mo, W) obtained via metal complex precursors or by impregnation. In bimetallic catalysts active sites of benzene hydrogenation are formed upon reduction of the active component for thiophene hydrogenolysis.

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Ni/MS₂, Ni/SiO₂, M/SiO₂, (Ni,M)/SiO₂, M=Mo W, , . , .

     

Kinetic studies and mechanism of triiron dodecacarbonyl reactions : I. Nucleophilic substitution in triiron dodecacarbonyl by triphenylphosphine in benzene

The kinetics of the reaction of triiron dodecacarbonyl with triphenylphosphine has been studied at various temperatures and different concentrations. It is a first order reaction with respect to Fe₃(CO)₁₂. P(C₆H₅)₃ reacts with Fe₃(CO)₁₂ according to the expression K_obsd = K[Fe₃(CO)₁₂] + K[P(C₆H₅)₃]/ [Fe₃(CO)₁₂]. Up to a certain ratio of P(C₆H₅)₃ to Fe₃(CO)₁₂ (approx. 10/1), after which K_obsd deviates from the above expression. K_obsd also depends upon the concentrations of both the reactants. An induction period is always observed which decreases with increase in temperature. Thermodynamic parameters for the reaction have also been calculated.     

Mixed ligand extraction of cobalt(II) by thenoyltrifluoroacetone and triphenylphosphine or triphenylarsine oxides in chloroform

Extraction of Co(II) from perchlorate aqueous media by mixtures of thenoyltrifluoroacetone and triphenylarsine oxide or triphenylphosphine oxide in chloroform has been studied. It is found that the presence of these oxides enhances the extraction of Co(II). Synergic factors and formation constants were calculated and interpreted in the light of the electron donating properties of these oxides.     

The role of octanol in the extraction of hydrochloric acid by trilaurylamine dissolved in benzene

The extraction of hydrochloric acid by trilaurylamine (TLA) dissolved in benzene was studied in the presence and in absence of n-octanol. The extraction of HCl was found to be enhanced by the addition of octanoi to the organic phase. In order to explain this effect by means of the law of mass action, the systems TLA-HCL-benzene and n-octanol-HCl-benzene as well as TLA-octanol-benzene were also studied. It was found that TLA reacts with octanol to form a complex, TLAROH, while the octanol itself associates in benzene to form dimers and tetramers, although it does not extract HCl alone from the dilute solutions used in the present study. The enhancement of the extraction of HCl by TLA upon the addition of n-octanol could be described by the formation of the species TLA·ROH·HCl and its stability constant was determined.     

Reaction of 4-(N,N-Dimethylaminophenyl)magnesium Bromide with Palladium Tetrakis(triphenylphosphine)

The influence of reaction conditions on catalyzed by Pd(PPh₃)₄ cross-coupling of 4-N,N-dimethylaminophenylmagnesium bromide with 4-bromobenzonitrile in tetrahydrofuran was investigated. The yield of the product of the catalytic process, 4-N,N-dimethylamino-4'-cyanobiphenyl, and of the main product of noncatalytic process, 4-N,N-dimethylaminophenyl 4'-bromophenyl ketone, is mainly governed by the order of introduction of reagents and catalyst into the reaction zone. Experimental observations and analysis of side products suggested conclusions on the processes resulting in deactivation of the catalyst.     

Oxidation of dienes by triphenylphosphine peroxopalladium

Thermal reaction of 1,3-diphenylisobenzofuran and tetramethylcyclopentadienone with PdLO₂ complex (L = PPh₃) gives compounds identical to those produced by singlet molecular oxygen. Photochemical reaction of 1,9-diphenylanthracene with PdLO₂ or PdL₃ in the presence of oxygen gives the 9,10-endoperoxide adduct.