Xiao-Hong Zhu

Syntheses, structures, and properties of a series of new assembled metal complexes with 4-(benzimidazol-1-ylmethyl)benzoate

A series of complexes based on 4-(benzimidazol-1-ylmethyl)benzoic acid (HL), [Co(L)2]·H2O (1), [Zn(L)2]·H2O (2), [Mn(L)2(phen)]·H2O (3), and [Mn2(L)2(phen)4]·2ClO4 (4) [phen = 1,10-phenanthroline], were synthesized under hydrothermal conditions and characterized by single-crystal and powder X-ray diffractions, IR, elemental, and thermogravimetric analyzes. HL features O-donor carboxylate and flexible N-donor benzimidazol-1-ylmethyl groups, allowing varied coordination and conformations. Complex 1 exhibits a uninodal 4-connected 2-D network structure with (44.62) topology. Complex 2 has a similar 2-D architecture to 1. Complex 3 consists of 2-D networks, displaying a uninodal 4-connected 2-D network with (44.62) topology. Complex 4 shows a dinuclear structure, which can be further linked to form a 2-D layer through interactions. The results imply that metal centers, auxiliary ligand, and counter anions subtly infiuence the structure of resultant complexes. In addition, the fluorescence of 2 and magnetism of 4 have been examined.

Synthesis, structure, and properties of a coordination polymer based on N- and O-donors

A ternary coordination polymer, [Cd(L)(pbda)0.5] n [HL = 3,5-bis(2-pyridylmethyl)aminobenzoic acid, pbda = dianion of 1,4-benzenedicarboxylic acid], has been synthesized and characterized by elemental analysis, FT-IR spectroscopy, powder X-ray diffraction, thermogravimetric analysis, and single-crystal X-ray diffraction analysis. The single-crystal X-ray crystallography reveals that the complex is a 2-D wave-like network. The cadmium has an unsymmetrical seven-coordinate [CdN2O5] geometry, coordinated by two nitrogens and five oxygens from L− and pbda. Hydrogen bonds between the uncoordinated (2-pyridylmethyl)amino groups from adjacent layers form dimers across the inversion center, superposing different layers to construct a 3-D framework. To the best of our knowledge, [Cd(L)(pbda)0.5] n represents the first example of a complex containing 3,5-bis(2-pyridylmethyl)aminobenzoate.

Two cobalt(II) complexes with 5-(1H-benzotriazol-1-ylmethyl)isophthalate: synthesis, structural characterization and magnetism

Co(II) salts react with 5-(1H-benzotriazol-1-ylmethyl)isophthalic acid (H2L) under hydrothermal conditions to yield [Co(L)(py)(H2O)] (1) and [Co(L)] (2) [py = pyridine], which have been characterized by single crystal and powder X-ray diffractions, Infrared, elemental and thermogravimetric analysis. The two complexes have structures dependent on the different experimental conditions. As a result, 1 has a 1-D ladder structure, which can be further linked to build a 3-D framework through hydrogen bonding and π–π interactions; 2 is a binodal (3,6)-connected 2-D kgd network with (43)2(46.66.83) topology. Synthetic strategies on coordination modes of ligand and structures of resultant complexes are discussed. Magnetism of 2 was investigated.

Cd(II) complexes from imidazole substitute isophthalate ligand: syntheses, structural characterization, and fluorescence property

The hydrothermal reaction of Cd(II) salt with 5-[(2-methyl-1H-imidazol-1-yl)methyl]isophthalic acid (H2L) leads to the formation of a new complex [Cd(L)(H2O)] (1). While in the presence of 2,2′-bipyridine (bpy) and 1,10-phenanthroline (phen) as auxiliary ligands, complexes [Cd(L)(bpy)]∙H2O (2) and [Cd(L)(phen)]∙2H2O (3) were obtained. Complexes 1–3 have been characterized by single crystal and powder X-ray diffractions, IR, and elemental and thermogravimetric analyzes. As a result, complex 1 exhibits twofold interpenetrated 3-D (10,3)-a architecture, 2 displays chain structure, and 3 shows uninodal 3-connected hcb network with (63) topology. The impact of auxiliary ligands on the structures of resultant complexes is discussed. Moreover, luminescence property of 1–3 was investigated.

Synthesis, characterization, and crystal structures of two coordination polymers from 3,5-bis(pyridin-4-ylmethyl) aminobenzoic acid

Aqueous medium reactions of transition metal salts with HL under hydrothermal conditions at 90°C led to two new coordination polymers, [M(L)2(H2O)2] · H2O [M = Co(1) and Mn(2); HL = 3,5-bis(pyridin-4-ylmethyl)aminobenzoic acid]. HL contains both flexible N-donor groups [(pyridin-4-ylmethyl)amino] and carboxylate. The flexibility of (pyridin-4-ylmethyl)amino endows HL the ability to adopt varied conformations and coordination modes. Due to the presence of nitrogen and oxygen of HL and water in the reaction system, hydrogen-bonding interactions are available to assemble donor and acceptor building blocks. The two complexes are structurally similar to L− doubly interconnecting M(II) to form 1-D chains. The extension of the 1-D chain through hydrogen-bonding forms fascinating 3-D supramolecular frameworks. FT-IR spectroscopy and thermal stability have been studied. The two compounds represent the first complexes containing 3,5-bis(pyridin-4-ylmethyl)amino benzoate.

Co(II) and Cd(II) coordination polymers from a semirigid N- and O-mixed donor-containing ligand: Synthesis, characterization, and property

Co(II) and Cd(II) salts react with 3,5-bis(benzimidazol-1-ylmethyl)benzoic acid (HL) under hydrothermal conditions to yield two new complexes, [Co(L)(Cl)]n (1) and {[Cd(L)2]·2.5H2O}n (2), which have been characterized by single-crystal and powder X-ray diffractions, IR, element, and thermogravimetric analysis. Complexes 1 and 2 exhibit structural diversity dependent on different metal salts; 1 has 2-D undulating sheet-like structure with (63) hcb topology and 2 is a 3-D 2-nodal (3,6)-connected flu framework with ()2() topology. Luminescence of 2 was investigated.

Cd(II) complexes based on a tricarboxylate: synthesis, structural characterization and properties

Reactions of cadmium(II) with 5-(4-carboxybenzylamino)isophthalic acid (H3L) in the presence of 2-(pyridin-2-yl)-1H-benzo[d]imidazole (pybim) and 2,2′-bipyridine (bpy) by hydrothermal method lead to two complexes, [Cd(HL)(pybim)]·H2O (1) and [Cd2(L)(HCOO)(bpy)2(H2O)]·H2O (2). Complexes 1 and 2 have been characterized by single-crystal and powder X-ray diffraction, Infrared spectra, and elemental and thermogravimetric analyses. 1 has a double-chain structure while 2 consists of uninodal 3-connected 2-D hcb networks with (63) topology. Luminescence and sorption properties of 1 and 2 were also investigated.

Cu(II) and Zn(II) Complexes with an N- and O-Donor Ligand: Structural Characterization, Jahn-Teller Effect and Fluorescence

Cu(II) and Zn(II) salts react with 5-(1H-benzotriazol-1-ylmethyl)isophthalic acid (H2L) under hydrothermal conditions to yield two new complexes [Cu(L)(DMF)(H2O)] (1) and [Zn(L)] (2) [DMF=N,N-dimethylformamide], which have been characterized by single-crystal and powder X-ray diffraction, IR, elemental and thermogravimetric analyses. As a result, 1 shows a chain structure, further linked together by hydrogen bonding and π-π interactions to give rise to a 3D supramolecular framework. Complex 2 is a binodal (3,6)-connected 2D kgd network with (43)2(46.66.83) topology. The influential factors of synthetic strategies on coordination modes of the ligand and structures of the resulting complexes are embodied in the study. Significantly, 1 has structural features consistent with the Jahn-Teller effect. Furthermore, the fluorescence properties of 2 were preliminarily investigated. Graphical Abstract Cu(II) and Zn(II) Complexes with an N- and O-Donor Ligand: Structural Characterization, Jahn-Teller Effect and Fluorescence

A Zn(II) complex from an imidazolyl-thiophene ligand: synthesis, structural characterization, and fluorescence

Abstract The hydrothermal reaction of ZnSO4 with 2,5-di(1H-imidazol-4-yl)thiophene (L) at 100°C yields a new complex [Zn(L)(SO4)]n (1). Complex 1 has been characterized by single-crystal X-ray diffraction, IR spectroscopy, and elemental and thermogravimetric analyses. It crystallizes in the monoclinic system, space group P21/c with Z=4, and shows a (44.62) network structure. Complex 1 shows fluorescence. Single crystals of L·2H2O were accidentally obtained in hydrothermal reaction attempts of L with MnCl2 at 120°C.

A Co(II) complex from a pyridylamide ligand: synthesis and structural characterization

Abstract The hydrothermal reaction of N3,N5-di(pyridin-4-yl)pyridine-3,5-dicarboxamide (L) with Co(NO3)2·6H2O and ErCl3·6H2O yields a new complex, {[Co(L)2(NO3)1.15(Cl)0.85]·4DMF}n (1). Complex 1 has been characterized by single-crystal and powder X-ray diffraction, IR, and elemental and thermogravimetric analysis. It crystallizes in the orthorhombic space group Fddd and shows a chain structure.