p-tert-Butylcalix[4]arene Calix^t-Bu(OH)₄ and its much less exploited sulfur containing variants, namely p-tert-butylthiacalix[4]arene S₄Calix^t-Bu(OH)₄ and p-tert-butylmercaptothiacalix[4]arene, S₄Calix^t-Bu(SH)₄, react with low-valent electron-rich metal precursors to yield mono- and bi-metallic complexes with potential application as models for active sites of heterogeneous catalysts. Reactivity studies of the metal complexes, together with analogues derived from related non-macrocyclic bis-aryloxide ligand frameworks, will be discussed.  For example, Calix^t-Bu(OH)₄ reacts with Mo(PMe₃)₆ and W(PMe₃)₄(CH₂PMe₂)H to give complexes which exhibit unprecedented use of the C-H bond of the calixarene methylene unit as a binding functionality, via either an agostic interaction or via oxidative addition and formation of an alkyl hydride.