Coordination-cyclodimeric array containing both channels and cages: photoluminescence recognition of diiodomethane

Abstract

Self-assembly of a series of ZnX₂ (X⁻ = Cl⁻, Br⁻, and I⁻) with 2,3-bis(4′-nicotinamidephenoxy)naphthalene (L) as a new hemi-circular bidentate ligand yields systematic 46-membered metallacyclodimeric species of [ZnX₂L]₂. These metallacyclodimers constitute, via inter-digitated π⋯π interactions, a characteristically staggered molecular array containing both channels and cages. The slightly different features between the channel and cage have been investigated by ¹H NMR and TGA. The crystals with such vacant volumes effectively stabilize the unstable CH₂I₂ molecule and are monitored by UV spectroscopy. Furthermore, the photoluminescence intensity via the chromophore naphthyl moiety of [ZnCl₂L]₂ gradually decreases with the addition of CH₂I₂.