Synthesis, characterization and molecular recognition of meso-Tetrakis(o-BocGlyamidophenyl)porphyrinatozinc

meso-Tetrakis (o-BocGlyamido) porphyrin [H2T (o-BocGly) APP),1] and its zin c complex [ZnT(o-BocGly)APP, 2] were synthesized and characterized. By mean s of spectrophotometer technique, the equilibrium constants of the axial co ordination reaction were measured between complex 2 and a series of imidazo les, molecular recognition of imidazoles by the receptor porphyrin 2 was st udied. The results show that the equilibrium constants decrease in the orde rs of K(Im)>K(2-CH(3)Im)>K(EMIm)>K(2-HOCH(2)Im) and K (Im) > K(N-CH(3)Im)>K (GMZ), suggesting that the steric effect was the key factor, the data of st eric effect were calculated, the thermodynamic parameters Delta(r)G(m)(diam eter), Delta(r)H(m)(diameter) and Delta(r)S(m)(diameter) were investigated by van't Hoff's equation, the phenomenon of enthalpy-entropy compensation w as the observed in the coordination process.