Using phase transfer catalyst

we have synthesized a kind of novel rigid chiral D threonine tailed zinc porphyrin( D Thr TPPZn). The binding behavior between D Thr TPPZn and amino acid ester was investigated by UV vis spectropic titration method. When L phenylalanine ethyl ester was added to the solution of D Thr TPPZn

the peak of 556 3 nm blue shifted

the maximal blue shift value is about 4 nm

and the absorption increases. The peak of 596 5 nm band is almost unchanged

but its absorption decreases slightly. It seems that the binding mode between D Thr TPPZn and amino acid esters is different from that reported before.