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Reactivity, structure and electrospray mass spectrometry of pentafluoro- and pentachloro-phenoxy-substituted cyclotriphosphazenes

Abstract
The reaction of N3P3Cl6 with the sodium salts of pentachloro- and pentafluorophenol, has been investigated. In contrast to the non-geminal substitution typified by other RO− nucleophiles, the regiochemistry of the reaction of C6X5O− (X=Cl and F) with N3P3Cl6 is dominated by geminal substitution. The reaction of C6Cl5O− with N3P3Cl6 in refluxing tetrahydrofuran yielded gem-N3P3Cl2(OC6Cl5)4 (1) as the major product. The fully substituted derivative N3P3(OC6Cl5)6 (2) was attained in low yield from reaction in refluxing diglyme. In contrast, the reaction of C6F5O− with N3P3Cl6 in refluxing tetrahydrofuran yielded the fully substituted product N3P3(OC6F5)6 (3) after approximately 4 h. 31P NMR spectral results suggest the C6F5O− ion may be attacking in a 'random' fashion at low degrees of substitution, which is largely replaced by an electronic geminal-directing effect at tetrasubstitution. Single crystal X-ray crystallographic analyses have been carried out on compounds 1 and 3. Electrospray mass spectrometry has been evaluated as a general technique for characterizing cyclotriphosphazenes, N3P3R6. If R=OEt or OPh, good positive ion spectra are observed but, in contrast, if R is more strongly electron withdrawing (Cl, C6Cl5O or C6F5O) negative ion spectra are obtained.
Type
Journal Article
Type of thesis
Series
Citation
Depree, C.V., Ainscough, E.W., Brodie, A.M., Burrell, A.K., Lensink, C. & Nicholson, B.K. (2000). Reactivity, structure and electrospray mass spectrometry of pentafluoro- and pentachloro-phenoxy substituted cyclotriphosphazenes. Polyhedron, 19(18-19), 2101-2110.
Date
2000-09-01
Publisher
Degree
Supervisors
Rights
This article is published in the journal Polyhedron, (c) 2000 Elsevier Science Ltd.