Host–Guest Chemistry of 1D Suprachannels and Dihalomethane Molecules: Metallacyclodimeric Ensembles Consisting of Zinc(II)-2,7-bis(nicotinoyloxy)naphthalene Complexes

Abstract

Self-assembly of ZnX₂ (X = Cl, Br, and I) with 2,7-bis­(nicotinoyl­oxy)­naphthalene (L) as a hemicircular bidentate ligand containing a chromophore moiety yields a systematic metallacyclodimeric unit, [ZnX₂(L)]₂. These basic skeletons constitute, via interdigitated π···π interactions, a unique columnar ensemble forming a suprachannel. This can then be employed as an unusual “diiodomethane within the suprachannel” host–guest system, CH₂I₂@​[ZnX₂(L)]₂. Specifically, the suprachannel significantly stabilizes the CH₂I₂ molecules in the order [ZnI₂(L)]₂ > [ZnBr₂(L)]₂ > [ZnCl₂(L)]₂. This suprachannel has significant halogen effects on the photoluminescence (PL), thermal properties, and host–guest inclusion