Zn^II Coordination Poylmers Based on 2,3,6,7-Anthracenetetracarboxylic Acid: Synthesis, Structures, and Luminescence Properties

Abstract

In our efforts to investigate polydentate ligands bearing bulky backbones, we used a bulky ligand, 2,3,6,7-anthracenetetracarboxylic acid (H 4 ata), to react with Zn II ions under different conditions, yielding four new coordination polymers, {[Zn(ata) 0.5 (DMF)(H 2 O)] 3 DMF 3 H 2 O} n (1), {[Zn(ata) 0.5 (4,4 0 -bipy) 0.5 (DMF)] 3 DMF} n (2), {[Zn(ata) 0.5 (azpy) 0.5 (DMF)] 3 DMF} n (3), and {[Zn(ata) 0.5 (4,4 0 -bipy)(DMAC)] 3 (DMA) 0.5 } n (4) (DMF = N,N-dimethylformamide, 4,4 0 -bipy = 4,4 0 -bipyridine, azpy=4,4 0 -azopyridine, DMAC=N,N-dimethylacetamide, DMA=dimethylamine), which were characterized by IR and single crystal X-ray diffraction. Complex 1 forms a two-dimensional (2D) network with (4,4) topology assembled by ata 4-ligands and Zn II ions. Complexes 2 and 3 are three-dimensional (3D) frameworks with {8 3 } 2 {8 5 ;10} topology containing infinite 2D networks pillared by 4,4 0 -bipy and azpy, respectively. Complex 4 takes a 2D structure with (4,4) net containing infinite onedimensional chains constructed by Zn II ions with 4,4 0 -bipy and ata 4-ligands. These results show that the reaction of 2,3,6,7-anthracenetetracarboxylic acid with Zn II in DMF tends to yield a layer structure which could be pillared by bipyridine-like ligands into 3D frameworks, and the final structure of the coordination polymer is greatly influenced by the solvent. Furthermore, the luminescence properties of 1-4 were studied in the solid state at room temperature.

Crystal structure of diaquabis[(4,4′-azopyridine)(hydrogen 2,3- naphthalenedicarboxylato)]zinc(II), Zn(H2O)2(C10N4H8)2(C12H7O4)2

“…As for 2,3-naphthalenedicarboxylate (L 2-), we found that only one mononuclear Cu II complex [Cu(trpy)(L) (H 2O)] (trpy =2 ,2':6'2''-terpyridine) has been obtained and reported to date [8]. In addition, the skillful introduction of 4,4'-bipyridyl-like linear bridging molecules into the reaction systems involving various carboxylic acids, as an auxiliary ligand, usually may generate some interesting coordination architectures [9,10]. The title crystal structure consists of the mononuclear molecules.…”

Crystal structure of triaqua(4,4′-azopyridine-κ2N,N′)(2,3- naphthalenedicarboxylato)cobalt(II) monohydrate, Co(H2O)3(C12O4H6)(C10N4H8) · H2O

“…In many of these investigating the linear N,N'-donor spacers such as 4,4'-bipyridine ligand and its analogues were used [9,10]. 4,4'-azopyridine (azpy) ligand, the more extended ligand compared with 4,4'-bipyridine, is an ideal connector between metal atoms for the propagation of coordination networks due to its bidentate character [11,12]. The title crystal structure consists of 1D Co(L)(azpy)(H 2 O) 3 chains.…”

Crystal Structure and Luminescent Properties of Diverse Cadmium(II) Coordination Polymers Based on A Semirigid Multicarboxylate Ligand

“…Excitation at 360 nm leads to an intense blue fluorescent emission band at 434 nm for 1, which can be assigned to a mixture of characters of intraland π to π* transition, namely, ligand-to-ligand charge transition (LLCT). [40,41] Similar to 1, compounds 2 and 3 also exhibit strong blue fluorescent emission bands with excitation wavelength at 350 and 324 nm, respectively. However, the emission spectrum of complex 4 contains a strong peak at 384 nm and a weak shoulder peak at 526 nm, respectively, which probably originate from the intraligand (π-π*) fluorescent emission of both H 3 L and phen ligands.…”