Seven new metal–organic frameworks assembled from semi-rigid polycarboxylate and auxiliary N-donor ligands: syntheses, structures and properties

Abstract

Seven new metal–organic frameworks (MOFs), namely, [Zn2(L 1)(H2O)3] n (1), [Zn2(L 1)(dib)(H2O)2] n (2), {[Zn2(L 1)(4,4′-bipy)(H2O)2]·H2O} n (3), [Cd2(L 1)(1,10-phen)] n (4), [Ni2(HL 1)(4,4′-bipy)(μ3-OH)(μ2-H2O)] n (5), {[Co4(L 1)(4,4′-bibp)3]·(4,4′-bibp)3} n (6), and [Co2(L 2)(4,4′-bibp)2(H2O)] n (7), where H4 L 1 and H4 L 2 are semi-rigid 3-(3,5-dicarboxylphenoxy)phthalic acid and 4-(3,5-dicarboxylphenoxy)phthalic acid, respectively, and 4,4′-bipy is 4,4′-bipyridine, dib is 1,4-bis(1H-imidazol-1-yl)benzene, 1,10-phen is 1,10-phenanthroline and 4,4′-bipb is 1,4-bis(pyridin-4-yl)benzene, have been prepared under solvothermal conditions with ZnII, CdII, CoII and NiII ions in the presence of auxiliary N-donor ligands. The crystal structures and photoluminescence and magnetic properties of these compounds have been investigated. Compound 1 displays a 3,4,6-connected two-dimensional (2D) topology with a Schläfli symbol of (42.5)2(43.52.7)(45.56.63)2, and the 2D structure was further assembled to form a three-dimensional (3D) framework by intermolecular O—H...O hydrogen bonds. Compound 2 features a novel 3,3,4-connected structure and the point symbol is (4.102)(4.6.84)(62.8). Compound 3 exhibits a 3,4,6-connected 3-nodal net having a 3,4,6 T53 type topology, with the point symbol (4.62)2(42.64)2(42.68.82.103). Compound 4 shows a 2D→3D supramolecular structure formed by π–π stacking interactions. Compound 5 possesses a 3D framework with a tfz-d net topology. Compounds 6 and 7 are constructed from the same auxiliary ligand and metal salt at the same temperature, but with different main ligands and exhibiting different topologies. Compound 6 presents a 3D 4,6-connected topological network with a Schläfli symbol of (3.44.6)(32.44.56.63), while compound 7 has a 3D topological network with a Schläfli symbol of (412.616). Magnetic analyses indicate that compounds 5 and 7 show weak antiferromagnetic interactions.

Two luminescent film sensors constructed from new lanthanide coordination polymers for ratiometric detection of Zn2+ and NH3 in water and their white emission properties

“…The frontier occupied HOMO and LUMO orbital energies are all negative, demonstrating molecular chemical stability in the ground state. 36,37 For the singlet state, the electronic cloud distribution for the highest occupied molecular orbital (HOMO) is mainly localized over one of the benzyl salicylamide arms, and that for the lowest unoccupied molecular orbital (LUMO) is scattered over the pyridine ring and salicylamide moiety of another benzyl salicylamide arm. In contrast, the electronic cloud distribution of the HOMO for the triplet state is centered on the same salicylamide moiety of the benzyl salicylamide arm as that in the LUMO of the singlet state, and that for the LUMO of the triplet state is concentrated on the pyridine ring.…”

Synthesis and crystal structure of catena-poly[aqua-bis(nitrato-κ 2 O:O′)- (μ 2-((1 H-imidazol-1-yl)methyl)benzene-κ 2 N,N′)-H2O-κ 2O]cadmium(II), C14H16N6O7Cd

“…Coordination polymers (CPs) not only exhibit novel structures and topologies, but also may possess magnetic, optical and catalytic properties, etc. [9][10][11][12][13][14]. Organic ligands are important for constructing CPs, and flexible ligands have different conformations and can be used to construct CPs with different structures.…”

Self-assembling of three rare structurally various homomultinuclear CuII complexes derived from a bis(salamo)-based multioxime ligand

“…The optimization of the free ligand and HOMO-LUMO energy band gap calculation for H 3 L and complexes (1)-(3) were performed by Gaussian09 software (Frisch et al, 2009) at the B3LYP/Gen level. The title complexes were obtained from the X-ray refinement data (cif) (Zhang et al, 2020c).…”

“…In the occupied orbit, the highest energy level orbit is called the HOMO and the lowest energy level orbital in the empty orbit is called the LUMO, which plays an important role in the chemical stability of molecules. HOMO represents the ability to donate electrons and LUMO represents the ability to accept electrons (Zhang et al, 2020c;Liu et al, 2020b). The energy difference between HOMO and LUMO (E LUMO À E HOMO ) is called as the band gap energy (ÁE).…”