3820-68-6Relevant academic research and scientific papers
Electronic Structure and 31P NMR Chemical Shift of Substituted Triaryl, Diaryl Methyl and Dimethyl Aryl Phosphates - a Semi-empirical Molecular Orbital Approach
Silva, J. F. Cajaiba da,Pedrosa, M. S.,Nakayama, H. T.,Neto, C. Costa
, p. 97 - 106 (2007/10/03)
The 31P NMR chemical shift of triaryl phosphate, diaryl methyl phosphate and dimethyl aryl phosphate series was determined.The δ31P values exhibit an increasing downfield trend when aryl substituents are exchanged for alkyl groups and δ31P values show an increasing upfield trend as the electron withdrawing ability of the substituent in the aromatic ring is increased.Semi-empirical calculations showed an increasing positive charge on phosphorus atom and an increasing phosphoryl bond order when δ31P values go upfield.These results are in good agreement with the effect of "back bonding" from the phosphoryl oxygen to the phosphorus atom. - Keywords: 31P NMR chemical shifts; structural effects; molecular orbitals; triaryl phosphates; diaryl alkyl phosphates; dialkyl aryl phosphates
"One-pot" Synthesis of Triaryl Phosphates a Reaction Calorimetry Approach
Silva, J. F. Cajaiba da,Nakayama, H. T.,Neto, C. Costa
, p. 71 - 82 (2007/10/03)
Triaryl phosphates were obtained in yields ranging from 85-96percent in a "one-pot" synthesis via an alkaline route: an ethanolic solution of sodium hydroxide was added to a solution of substituted phenol in toluene.The mixture was distilled until all ethanol was removed.Phosphorus oxychloride was then added and the toluene was distilled.The triaryl phosphates were characterized by NMR (1H and 31P), MS and FTIR.The heat capacity (Cp), the total heat transfer coefficient (U) and the reaction enthalpy (ΔH) were determined for the synthesis of tris(4-chloro-3-methylphenyl), tris(p-cresyl), tris(o-methoxyphenyl) and tris(p-nitrophenyl) phosphates. - Keywords: Phosphate; NMR spectra; heat capacity; phosphorus oxychloride
SYNTHESIS OF TRIARYL PHOSPHATES CATALYZED BY POLYETHYLENE GLYCOLS IN A TWO-PHASE SYSTEM: PHASE TRANSFER CATALYSIS
Krishnakumar, V. K.
, p. 189 - 196 (2007/10/02)
The synthesis of triaryl phosphates has been accomplished, at room temperature, in nearly quantitative yields in a two-phase system with poly(ethylene glycol) as a phase transfer catalyst.
