Diphenylphosphinyl radical

Recent examples of the application of three-dimensional H/13C/Y correlation spectroscopy for the characterisation of polymers included studies of polystyrene samples obtained by diphenylphosphinyl radical initiated polymerisation of styrene (Y = 31P),38,39,86 and the characterisation of Sn-containing polybutadiene that was prepared by anionic polymerisation... 

The diphenylphosphinyl radical has been observed in the photolysis of tetraphenyldiphosphine at low temperature (259,260). 

Fig. 7-7(b) and Fig. 10-7 show the magnetic field dependence of R(,B) =Y(B)/Y(0 T), where Y(B) represents the yield of the escaped diphenylphosphinyl radical (Ph2P ) observed at 330 nm. The MFEs observed for this reaction in some solvents had the following characteristic features which could not be explained by the usual RPM ... 

Fig. 10-11. CIDEP spectrum observed at a delay time of 0.25 ps after laser excitation of a 2-propanol solution of PhsP at room temperature. Stick diagrams a and b indicate the signal positions due to the 2-hydroxy-2-propyl and diphenylphosphinyl radicals, respectively. (Reproduced from Ref. [7] by permission from Elsevier Science B. V.)...

Since the diphenylphosphinyl radical could also be trapped in single-crystal matrices... 

Figure 17, Illustration of the HCP 3D-NMR spectrum of phosphorus-containing chain-end structures formed through styrene polymerization initiated by diphenylphosphinyl radical (Reproducedfrom reference 19. Copyright 2001 American Chemical Society.)...

Heating Me2P-PMe2 to 650°C and F2P-PF2 to 350°C will produce the phosphinyl radicals McjP and F2R respectively. Diphenylphosphinyl radicals, obtainable as a pink-coloured condensate by low-temperature ultra-violet irradiation of tetraphenyldiphosphine, are stable at 77 K. They may be compared with the diphenylamide and triphenylmethyl radicals, which are prepared from tetrap-henylhydrazine and hexaphenylethane, respectively. 

Phosphinyl radicals will often abstract H or some other atom from the reaction solvent. The photolysis of triphenylphosphine in benzene, which leads to the formation of biphenyl, diphenylphos-phine and tetraphenyldiphosphine, is supposedly due to the initial formation of diphenylphosphinyl and phenyl radicals (13.169). These radicals then react according to (13.170)-(13.172). 

The photo-stimulated reaction of IV-cyclopropyl-lV-ethyl-jp-toluenesulfonamide with excess diphenylphosphide ion produces initially the radical anion (59) via an electron-transfer process. This radical anion then fragments to the jp-toluenesulfonyl anion and an aminyl radical. Ring opening of the aminyl radical followed by trapping with 2 equiv. of the diphenylphosphide ion followed by oxidation leads to the observed l,3-bis(diphenylphosphinyl)-l-(lV-ethyl)propylamine (Scheme 41). ... 

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