A two-dimensional CdII coordination polymer based on naphthalenediimide: synthesis, crystal structure and photochromic properties

Coordination Polymers Based on Highly Emissive Ligands: Synthesis and Functional Properties

Coordination polymers are constructed from metal ions and bridging ligands, linking them into solid-state structures extending in one (1D), two (2D) or three dimensions (3D). Two- and three-dimensional coordination polymers with potential voids are often referred to as metal-organic frameworks (MOFs) or porous coordination polymers. Luminescence is an important property of coordination polymers, often playing a key role in their applications. Photophysical properties of the coordination polymers can be associated with intraligand, metal-centered, guest-centered, metal-to-ligand and ligand-to-metal electron transitions. In recent years, a rapid growth of publications devoted to luminescent or fluorescent coordination polymers can be observed. In this review the use of fluorescent ligands, namely, 4,4'-stilbenedicarboxylic acid, 1,3,4-oxadiazole, thiazole, 2,1,3-benzothiadiazole, terpyridine and carbazole derivatives, naphthalene diimides, 4,4',4''-nitrilotribenzoic acid, ruthenium(II) and iridium(III) complexes, boron-dipyrromethene (BODIPY) derivatives, porphyrins, for the construction of coordination polymers are surveyed. Applications of such coordination polymers based on their photophysical properties will be discussed. The review covers the literature published before April 2020.

Crystal structure of N,N'-bis-[3-(methyl-sulfan-yl)prop-yl]-1,8:4,5-naphthalene-tetra-carb-oxy-lic di-imide

The title compound, C22H22N2O4S2, was synthesized by the reaction of 1,4,5,8-naphthalene-tetra-carb-oxy-lic dianhydride with 3-(methyl-sulfan-yl)propyl-amine. The whole mol-ecule is generated by an inversion operation of the asymmetric unit. This mol-ecule has an anti form with the terminal methyl-thio-propyl groups above and below the aromatic di-imide plane, where four intra-molecular C-H⋯O and C-H⋯S hydrogen bonds are present and the O⋯H⋯S angle is 100.8°. DFT calculations revealed slight differences between the solid state and gas phase structures. In the crystal, C-H⋯O and C-H⋯S hydrogen bonds link the mol-ecules into chains along the [2 direction. adjacent chains are inter-connected by π-π inter-actions, forming a two-dimensional network parallel to the (001) plane. Each two-dimensional layer is further packed in an ABAB sequence along the c-axis direction. Hirshfeld surface analysis shows that van der Waals inter-actions make important contributions to the inter-molecular contacts. The most important contacts found in the Hirshfeld surface analysis are H⋯H (44.2%), H⋯O/O⋯H (18.2%), H⋯C/C⋯H (14.4%), and H⋯S/S⋯H (10.2%).

Different photochromic properties induced by lone pair–π interactions with varying strengths in two stereocontrolled self-assembly isomeric coordination polymers

The different photochromic properties of two naphthalenediimide-based isometric compounds are derived from two lone pair–π interactions with varying strengths.