On the alkylation of tributylphosphinecobaloxime_s by alkyl chlorides

Abstract

The variation in the rate constants (<em>k</em>) for the alkylation of tributylphosphinecobaloxime, by some alkyl chlorides (RCI) is explained in terms of the equation: log<em>k</em>=&rho; (&sigma;*-V) +logk₀'where &sigma;* is Taft's polar substituent constant for an alkyl group R, V a dummy variabie defined to have zero vaiue for the R groups having (&sigma;* &lt; 0.405 and non-zero values otherwise, r the regression coefficient and the subscript 0 refers to the situation where (s* - V)=0. An analysis of the nature of V reveals the ambivaient nature of (&sigma;* operative in the alkyiation reaction - the factor which favours the reaction also acts against it.