Introduction to the series: an editor's foreword (A. Padwa). Preface (G.W. Gokel). Hydrogen binding in biological and artificial molecular recognition (A.D. Hamilton). Synthetic ditopic receptors (I.O. Sutherland). Molecular recognition by macrocycles having a three-dimensionally extended hydrophobic cavity (Y. Murakami et al.). Pre-organization and molecular recognition in the formation and reactions of binuclear metal complexes (A.E. Martell). Index.