Synthesis and crystal structure of a Mn-based coordination complex as precursor for the synthesis of Mn2O3

Syntheses, structures and properties of two one-dimensional coordination polymers constructed by phenol-sulfonate ligands and rare earth metal ions

Two new isomorphic and heterogeneous coordination polymers (CPs), namely {[RE (L) (H2O) 2] · (Hbipy) · H2O} n (RE = Yb(1), Y(2), Na2H2L = 4,5-dihydroxy-1,3-benzenedisulfonic acid disodium salt, bipy = 2,2′-bipyridine) have been synthesized by hydrothermal methods and structurally characterized by elemental analyses, power X-ray diffraction (PXRD) and single crystal X-ray diffraction. Compounds 1 and 2 feature one-dimensional (1D) wavy ladder-like chain structures, which are further connected by hydrogen bonds from water molecules to result in two-dimensional (2D) layered structures. The 1H-protonated bipy molecules act as uncoordinated cations, leading to valences of zero in compounds 1 and 2. Compounds 1 and 2 emit luminescence at 382 nm and 372 nm in the ultraviolet regions, respectively. The luminescent emissions originate from the typical ligand-centered (n–π* and π–π*) transitions. In addition, compound 1 has characteristic near-infrared emission of ytterbium ion at 964 nm.

Three New Metal Complexes with Imidazole-Containing Tripodal Ligands as Fluorophores for Nitroaromatics- and Ion-Selective Sensing

Three new metal-organic complexes [Cd(TIPA)(suc)0.5(NO3)·1/2H2O]n (1), [Ni(TIPA)(tda)0.5(H2O)·1/4H2O]n (2) and [Cd(TIPA)(tda)0.5·11/2H2O] (3) were synthesized via rigid tripodal ligand tris(4-(1H-imidazol-1-yl)phenyl)amine (TIPA) and three dicarboxylic acids; either succinic acid (H2suc) or 2,5-thiophenedicarboxylic acid (H2tda). Crystallographic data for 1 - 3 reveal three-dimensional (3D) networks and channels in the structures. The structure of 2 is unique featuring an interpenetrating 2D network, 2D + 2D → 3D, with the two associated 2D networks existing in two opposite spiral channels. TGA plots exhibit a loss of mass corresponding to the loss of the solvated water molecules in the 100 - 200 °C temperature region and begin to lose additional fragments only at T > 300 °C revealing the robust nature of the 3D framework in the complexes. The metal-organic frameworks (MOFs) are screened for their potential application in the detection and removal of environmentally hazardous industrial pollutants. Fluorescence emission spectra for 1 and 2 show that the two MOFs are capable of sensing nitrobenzene (NB), with the nickel complex 2 exhibiting significantly higher sensing ability. Powder XRD data measured for 1 and 2 and those of NB-treated 1 and 2 show significant differences in their patterns, providing further support for the strong interaction between the MOF complexes and NB. The fluorescence emission observed for 1 is more effectively quenched by the presence of Fe3+ than the series of 17 other metal ions investigated. Complex 3 possesses some ability to adsorb inorganic pollutants.