The kinetics of copper(II)-promoted
solvolyses of bis(N,N- dibutyldithiocarbamato)nickel(II)
in dimethyl sulphoxide (dmso), N,N- dimethylacetamide
(dma), acetone, and chloroform, and bis(N,N- dicyclohexyldithiocarbamato)nickel(II) in dmso and dma have been examined.
Although the reaction stoichiometry differs in chloroform compared with the
other solvents, in all media the two-term rate law
����������������� -d[Ni(dtc)2]/dt = (k1+k2[Cu2+])[Ni(dtc)2]
is obeyed. However, in the
absence of added sodium and nickel ions, experiments in dmso
at low [Cu2+]O, indicate a negligible contribution from
the k1 path. Results are discussed in the light of a mechanism involving
primary dissociative (k1) and associative (k2) steps.
Although the ratios k2/k1 indicate overall importance for the
associative pathways of reaction in the low dielectric media cf. dmso and dma, the k1
term also appears as a significant contributor to the reaction of the dibutyldithiocarbamate complex in the former solvents.
Confined Water’s Dielectric Constant Reduction Is Due to the Surrounding Low Dielectric Media and Not to Interfacial Molecular Ordering