Six low-dimensional silver(I) coordination complexes derived from 2-aminobenzonitrile and carboxylates

Construction of Two Stable Co(II)-Based Hydrogen-Bonded Organic Frameworks as a Luminescent Probe for Recognition of Fe3+ and Cr2O72- in H2O

A pair of cobalt(II)-based hydrogen-bonded organic frameworks (HOFs), [Co(pca)2(bmimb)]n (1) and [Co2(pca)4(bimb)2] (2), where Hpca = p-chlorobenzoic acid, bmimb = 1,3-bis((2-methylimidazol-1-yl)methyl)benzene, and bimb = 1,4-bis(imidazol-1-ylmethyl)benzene were hydrothermally synthesized and characterized through infrared spectroscopy (IR), elemental and thermal analysis (EA), power X-ray diffraction (PXRD), and single-crystal X-ray diffraction (SCXRD) analyses. X-ray diffraction structural analysis revealed that 1 has a one-dimensional (1D) infinite chain network through the deprotonated pca- monodentate chelation and with a μ2-bmimb bridge Co(II) atom, and 2 is a binuclear Co(II) complex construction with a pair of symmetry-related pca- and bimb ligands. For both 1 and 2, each cobalt atom has four coordinated twisted tetrahedral configurations with a N2O2 donor set. Then, 1 and 2 are further extended into three-dimensional (3D) or two-dimensional (2D) hydrogen-bonded organic frameworks through C-H···Cl interactions. Topologically, HOFs 1 and 2 can be simplified as a 4-connected qtz topology with a Schläfli symbol {64·82} and a 4-connected sql topology with a Schläfli symbol {44·62}, respectively. The fluorescent sensing application of 1 was investigated; 1 exhibits high sensitivity recognition for Fe3+ (Ksv: 10970 M-1 and detection limit: 19 μM) and Cr2O72- (Ksv: 12960 M-1 and detection limit: 20 μM). This work provides a feasible detection platform of HOFs for highly sensitive discrimination of Fe3+ and Cr2O72- in aqueous media.

A one-dimensional silver(I) coordination polymer based on an asymmetric flexible N-donor carboxylate ligand: catena-poly[(μ3-4-{[(1-phenyl-1H-tetrazol-5-yl)sulfanyl]methyl}benzoato-κ(3)O:O':N(4))silver(I)]

The title compound, [Ag(C15H11N4O2S)]n, was synthesized by the reaction of 4-{[(1-phenyl-1H-tetrazol-5-yl)sulfanyl]methyl}benzoic acid (Hptmba) with silver nitrate and triethylamine at room temperature. The asymmetric unit contains one crystallographically independent Ag(I) cation and one ptmba(-) ligand. Each Ag(I) cation is tricoordinated by two carboxylate O atoms and one tetrazole N atom from three different ptmba(-) ligands, displaying a distorted T-shaped geometry. Three Ag(I) cations are linked by tris-monodentate bridging ptmba(-) ligands to form a one-dimensional double chain along the c axis, which is further consolidated by an intrachain π-π contact with an offset face-to-face distance of 4.176 (3) Å between the centroids of two adjacent aromatic rings in neighbouring benzoate groups. The one-dimensional chains are linked into a three-dimensional supramolecular framework by additional π-π interchain interactions, viz. of 3.753 (3) Å between two phenyl substituents of the tetrazole rings and of 4.326 (2) Å between a benzoate ring and a tetrazole ring. Thermogravimetric analysis and the fluorescence spectrum of the title compound reveal its good thermal stability and a strong green luminescence at room temperature.