Unsymmetrical Calixcrowns Incorporating Hard and Soft Loops as a New Scaffold for Multinuclear Endo/Exocyclic Complexation and Networking

Unsymmerical calix[4]crowns containing [(O₄S)(O₅)] (L¹) and [(O₄S₂)(O₅)] (L²) as crown loops were employed as new scaffolds both for complexation studies and for network formation. Reactions of L¹ and L² with KI in the presence of CuI afforded a copper(I) iodide cluster linked 1D-type endocyclic dipotassium(I) complex [K₂(L¹)(Cu₇I₉)]_n (1) and a copper(I) iodide cluster linked 1D-type endocyclic monopotassium(I) complex [KL²(μ₂-Cu₃I₄)]_n (2), respectively. By comparison, the reaction of L² with KPF₆ in the presence of CuI and HgI₂ afforded the 1-D endocyclic potassium(I) complex [K(L²)(CuHgI₄)]_n (3), linked with a CuHgI₄ cluster unit. The formation of homo- and heterodinuclear complexes in solution was also confirmed by comparative NMR studies.