Studies in Cyclophosphazenes. Part 9. Influence of the Steric Requirements of the Amino-substituents on the Rates of Amination of 2-Amino-2,4,4,6,6-pentachlorocyclotri(λ5-phosphazenes)

DOI: 10.1039/DT9810000107

Source and publish data:

Journal of the Chemical Society, Dalton Transactions p. 107 - 110 (1981)

Update date:2022-08-24

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Authors:

Goldschmidt, Jacob M.E.

Licht, Eliahu

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Article abstract of DOI:10.1039/DT9810000107

Measurements of the rates of amination of a number of aminopentachlorotriphosphazenes, N3P3Cl5(NRR') (R = n-Bu, R' = H; R = R'=n-Bu; R = i-Pr, R' = H; RR' = C5H10), with dimethylamine to give non-geminal disubstituted products have been made at two temperatures in tetrahydrofuran with the aim of elucidating the steric effects of the amino-substituents in these reactions.The values of the rate constants and of the activation parameters determined showed that steric effects are only very small.To resolve the conflict between these findings and others in literature in which appreciable steric influences were observed, the division of these amination reactions into three classes, each of which is affected by stric factors in its own way, is proposed.This enables much of the kinetic and preparative data on steric effects in these reactions to be rationalised in the framework of one general hypothesis.