Syntheses, Structures, Photoluminescence, and Theoretical Studies of d¹⁰ Metal Complexes of 2,2‘-Dihydroxy-[1,1‘]binaphthalenyl-3,3‘-dicarboxylate

Abstract

The free solvated ligand, H(2)bna.CH(3)OH.H(2)O (1), and its dimeric complex, [Cd(2)(bna)(2)(H(2)O)(6)] (2) (bna = 2,2'-dihydroxy-[1,1']-binaphthalene-3,3'-dicarboxylate), were obtained by evaporation of the solutions, while two new d(10) metal-hydroxy cluster-based coordination polymers, namely [Cd(8)(OH)(4)(H(2)O)(10)(bna)(6)].17H(2)O (3) and [Hpy](2)[Zn(4)(OH)(2)(H(2)O)(2)(bna)(4)].2H(2)O.2CH(3)CN (4), were obtained by a hydrothermal route. All the compounds have been characterized by X-ray crystallography and photoluminescence measurements. Compound 1 consists of a three-dimensional, hydrogen-bonded supramolecular array, 2 exhibits a dimeric molecule featuring a square motif organized by two Cd(II) atoms and two bna ligands each at the corner, and 3 contains unprecedented [Cd(8)(micro(3)-OH)(2)(micro-OH)(2)(micro-H(2)O)(2)](12+) octanuclear metallacrown cores which are interlinked through bna to afford a two-dimensional structure, while 4 features layers with butterfly-shaped [Zn(4)(micro(3)-OH)(2)](6+) clusters. All the complexes display photoluminescent properties in the blue/green range. The manifestation of photoluminescence, as probed by molecular orbital calculations performed on the complexes and also on hypothetical multinuclear complexes, is attributed to a ligand-to-metal charge-transfer mechanism. In addition to presenting a new approach for the study of the photoluminescent properties of metal-cluster-based coordination polymers by using simple model compounds, the study also reveals the dominant role of the structure of the ligand over that of the d(10) metal-hydroxy (or oxy) cluster and the presence of the cluster significantly increasing the emission lifetime.

Crystal structure of 2,2'-[1,2-diethanediyl-bis(thio)]bis(1,3,4-thiadiazole) copper(II) diperchlorate, [Cu(C6H6N4S4)4][ClO4]2

“…In constructing metal-organic frameworks, flexible ligands are usually selected because the flexibility and conformation restrainability offers the new possibilities for the arrangement of diverse frameworks [1][2][3]. Meanwhile, thiadiazoles have attracted increasing attention because of their potential applications in pharmaceutical, agricultural, industrial, coordination and polymer chemistry [4][5][6].…”

Crystal structure of catena-bis[2,2'-(1,3-propanedithio)- bis(1,3,4-thiadiazole)]bis(2,4,6-trinitrophenolate)copper(II), Cu(C7H8N4S4)2(C6H2N3O7)2

“…In recent years, the rational design of coordination polymers based on multitopic or flexible bridging ligands as linkers and metal centers as connectors represents one of the most rapidly developing fields owingtotheir potentialasfunctional materials in,e.g., electronic,magnetic, optical, catalytic applications [1][2][3]. In particular,t he uses of flexible ligands in such studies have attractedremarkableattention becausethe flexibilityand conformation restrainability of such ligands offer the possibility for the construction of diverse frameworks.…”

Crystal structure of tris{2,2′-[1,2-[methylenebis(thio)]-bis[1,3,4-thiadiazole]]}copper(II) tetranitrate — acetonitrile (1:1), Cu2(C5H4N4S4)3(NO3)4 · CH3CN

“…In recent years, the rational design of coordination polymers based on multi-topic or flexible bridging ligands as linkers and metal centers as connectors represents one of the most rapidly developing fields owing to their potential as functional materials in electronic, magnetic, optical, catalytic applications [1][2][3]. In particular, the use of flexible ligands in such studies have attracted remarkable attention because the flexibility and conformation restrainability of such ligands offer the possibility for the construction of diverse frameworks.…”