[trans-5, 15-Bis (2, 7-dihydroxy-1-naphthyl)-2, 3, 7, 8, 12, 13, 17, 18-octaethylporphyrinato] zinc (II)(1), a trifunctionalized porphyrin host, was prepared as a receptor for amino acid derivatives, particularly those having a hydrogen-bonding site in the side chain. The free energy changes for the binding of Leu-OMe, Asp-OMe, and Glu-OMe to 1 were-5.8 kcal/mol,- 6.6 kcal/mol, and-5.9 kcal/mol, showing a selectivity for Asp-OMe. 1H NMR titration ...