The aim of the present book is mainly to develop a series of hemi-calix[4]naphthalene like molecular systems based on 1,1'-methylene-bis(2-naphthol) (mbn) or 1,1'-thio-bis(2-naphthol)(tbn) conjugates possessing a variety of binding sites and study their binding and/or receptor properties and also to synthesize their metal ion complexes. Further, then focus of this thesis is to develop sophisticated metalloenzyme models particularly for catecholase activity using Cu2+ complexes. Thus all the studies reported in this book are concerned with the hemi- calix[4]naphthalene like molecular systems.