
%0 Journal Article
%A Fayyaz, MU 
%A Grant, MW 
%T The Lewis-acidity of square-planar nickel(II) complexes. II. A kinetic investigation of the addition of substituted phenanthrolines to Bis(O,O-diethylphosphorodithioato-S,S')nickel(II), Bis(O-ethylxanthato)nickel(II) and Bis(4-mercaptopent-3-en-2-onato)nickel(II) in toluene
%J Australian Journal of Chemistry
%D 1977/02/01
%V 30
%N 2
%P 285-292
%K 
%R https://doi.org/10.1071/CH9770285
%U https://www.publish.csiro.au/paper/CH9770285 
%X The rates of the addition reaction between substituted phenanthrolines and the square-planar nickel complexes bis(O,O-diethyl phosphorodithioato-S,S')nickel(II), Ni(dtp)2, bis(O-ethylxanthato)-nickel(II), Ni(xan)2, and bis(4-mercaptopent-3-en-2-onato)nickel(II), Ni(sacac)2, have been measured in toluene by the stopped-flow technique. For Ni(xan)2, the second-order rate constants, kf, are in the range (1- 8)&#215;105 l. mol-1 s-1, &#916;Hf&#8225; is 16±2 kJ mol-1 and there is a significant substituent effect. For Ni(dtp)2, kf is (1-3)&#215;104 l. mol-1 s-1, &#916;Hf&#8225; is 24±2 kJmol-1 and there is a minor substituent effect. For Ni(sacac)2, kf is about 5&#8225;102 l. mol-1 s-1, &#916;Hf&#8225; is 50 kJ mol-1 and there is no substituent effect. The results are discussed in terms of the relative importance of Ni-N bond formation and displacement of the in-plane ligands in the transition state. 
