Zinc(ΙΙ) complexes with 5,6-dihydro-1,4-dithiin-2,3-dicarboxylic anhydrate and different N-donors: syntheses, crystal structures, and emission properties

Abstract

Two new ZnII complexes, {[Zn(L)(phen)(H2O)] · H2O}∞ (1) and {[Zn(L)(4bpy)(H2O)] · H2O}∞ (2) (L = 5,6-dihydro-1,4-dithiin-2,3-dicarboxylate, phen = 1,10-phenanthroline, and 4bpy = 4,4′-bipyridine), have been prepared by in situ reaction of Zn(ClO4)2 · 6H2O with 5,6-dihydro-1,4-dithiin-2,3-dicarboxylic anhydrate in the presence of lithium hydroxide, together with incorporating chelating phen or bridging 4bpy as co-ligands. Their structures were determined by single-crystal X-ray diffraction. Complex 1 takes a 1-D helical structure that is further assembled into a 2-D network by O–H ··· O, C–H ··· O hydrogen bonds, and weak S ··· S interactions, and then an overall 3-D supramolecular framework was formed by π ··· π stacking interactions. Complex 2 possesses a 2-D (4,4)-layered structure. The structural difference between 1 and 2 can be attributed to the different N-donor auxiliary co-ligands. Both 1 and 2 are photoluminescent materials whose emission properties are closely related to their intrinsic structure.