Synthesis, Crystal Structure, and Luminescence of Zn/Cd Coordination Polymers with a New Fuctionalized Terpyridyl Carboxylate Ligand

Abstract

Eight new coordination polymers, [Zn(L)Cl] n (1), [Zn 2 (L) under hydrothermal conditions and characterized by elemental analysis, IR, and single crystal X-ray diffraction. Complexes 1, 2, and 7 display a two-dimensional (2D) layer structure. Complex 3 presents a complicated 2D layer structure with paddle-wheel units, which exhibits an interesting (3,4,6)-connected 3-nodal new topological net with the point symbol of (3Complex 4 is a 2-nodal (3,5)-connected 2D bilayer structure with the gek1 topological net and the point symbol of (3•4•5)(3 2 •4•5•6 2 •7 4 ). Complex 5 shows a self-penetrating three-dimensional (3D) framework based on pentanuclear clusters, which features an intriguing (3,3,4,4,12)-connected 5-nodal new topological net with the point symbol of (4•6 2 ) 2 (4 2 •6 4 ) 4 (4 3 ) 2 (4 8 •6 34 •8 22 •10 2 ). Complex 6 features a 2-fold interpenetrating (3,4)-connected 3D framework with the ins topological net and the point symbol of (6 3 )(6 5 •8). Complex 8 is a new (4,4,5,6)-connected 3D network built up by a linear Cd 3 (COO) 6 trinuclear cluster with the point symbol of (4 2 •6 3 •8) 2 (4 3 •6 3 ) 2 (4 4 •6 4 •8 2 ) 2 (4 8 •6 6 •8). The diverse structures indicate that rational adjustment of the second ligand, the pH value, and counteranion are good methods to further design metal−organic compounds with new structures and properties. In addition, the thermal stabilities and photoluminescence properties of 1−8 were also studied.

Crystal structure of poly[diaqua-μ5-4-(3,5-dicarboxylato-κ 3 O 1:O 2:O 3-phenoxy)phthalato-κ 3 O 5,O 7:O 8)(μ2-4-(1H-pyrazol-5-yl)pyridine-κ

“…Over the past decades, numerous CPs have been successfully constructed, and crystal engineering has reached a relatively mature level that some CPs with speci c topologies can be designed by the judicious selection of metal ions and organic ligands [4]. However, it still remains a great and long-term challenge to predict exactly the molecular structure and property of coordination polymers because of many subtle factors involved in the formation and crystallization process such as the geometries of the metal ions (node) and ligands (linker), supramolecular interaction, and reaction conditions [5]. One strategy is to perform reactions with mixed-ligands such as polycarboxylate and N-containing ligands in the same system, and a great number of novel intriguing structures are obtained [6][7][8][9], which indicates that the introduction of N-containing auxiliary ligands into a metal-polycarboxylate system often leads to structural diversity and a ords novel frameworks.…”

Syntheses, structures and luminescent properties of four novel Cd/Zn(II) complexes constructed from dicarboxylate and bis(imidazole) co-ligands

“…Upon an excitation band at 330 nm, intense emissions are observed at 424 nm for 1, 424 nm for 2, 440 nm for 3 and 421 nm for 4, respectively. The enhancement of luminescence intensity compared to the free ligand is perhaps a result of the metal-ligand coordination, which effectively increases the rigidity of the ligand and reduces the nonradiative decay of the intraligand (p-p * ) excited state [9,20]. The profile of the emission band of complexes 1-4 is quite similar to that of the free organic ligands, but the emission maxima of all the complexes show slight blue shift in wavelength.…”

“…In recent years, the direct use of two types of organic ligands, such as multicarboxylate and bis(imidazole) ligands, has been found to be an effective method for the synthesis of MCPs, because of their rich coordination modes, including monodentate, bridging and chelating [7,8]. Thereinto, di-and polycarboxylic acids are widely used as bridging ligands to construct coordination frameworks with versatile structures [9]. Meanwhile, the bis(imidazole)propane(bip) bearing alkyl spacers are a good choice of N-donor ligands, in which the flexible nature of spacers allows the ligands to bend and rotate when it coordinates to metal centers [10,11], and this often causes the structural diversity.…”

Two new cobalt(II) coordination polymers based on 4′-(2-carboxyphenyl)-4,2′:6′,4″-terpyridine: Syntheses, structures and magnetic properties

“…And we have already reported eight new Zn/Cd coordination polymers stemming from it, as well as their luminescence and thermal properties [33]. In order to enrich our research system and make the best use of its advantages, Hcptpy is employed continuously to construct MOFs with remarkable structures.…”