Effect of meso-phenyl substitution in tetrabenzoporphin on rate of its coordination by metal acetates in pyridine

The kinetics of coordination of tetraphenyltetrabenzoporphin (TPTBP) by Co-, Cu-, Zn-, Cd acetates in pyridine is studied and its kinetic activation parameters are calculated. It is shown that meso-phenyl substitution in a tetrabenzoporphin molecule results in variation of the kinetic coordination parameters: rate of coordination with Cu, Zn and Cd is higher as compared with the unsubstituted tetrabenzoporphin (for Zn and Cd - by an order). Activation energies of the formation of MTPTBP complexes (M=Cu, Zn, Cd) have mean values while activation entropies are substantially negative