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A new ligand, 4-dipropylaminobenzaldehyde thiosemicarbazone (abbreviated as HL), and its complexes [ML.sub.2] (M = Ni, Pd, and Cu) have been synthesized and fully characterized by elemental analyses, ELMS, IR and UV-vis spectroscopy, and photoluminescence measurements. All of the compounds exhibit a blue-green color with dual fluorescence in DMF solution. The quantum yield ratio ([PHI](CT)/[PHI](LE)) decreases in the order Ni[L.sub.2] > HL >Pd[L.sub.2] > Cu[L.sub.2]. The ligand HL crystallizes in the monoclinic system, space group P[2.aub.1]/n, with a = 15.1680, b = 8.5573, and c = 25.3920 [Angstrom], [beta] = 100.3457 [degrees], and V = 3242.2 [[Angstrom].sub.3]. The nickel complex (Ni[L.sub.2]) crystallizes in the triclinic system, space group P1, with a = 8.3093, b = 9.7540. and c = 10.2802 [Angstrom], [alpha] = 101.383[degrees], 13 = 107.693[degrees], [gamma] = 96-703[degrees], and V = 764.12 [[Angstrom].sub.3]. In these complexes, HL has lost a proton from its tautometric thiol form and acts as a single negatively charged bidentate ligand coordinating to the nickel ion via the mercapto sulfur and [beta]-nitrogen atoms. The geometry around Ni(II) is almost square-planar with two equivalent Ni--N and two equivalent Ni--S bonds. The monomeric structure of HL or Ni[L.sub.2] is extended into an infinite two-dimensional network via hydrogen bonds. The two-photon absorption of HL and [ML.sub.2] solutions (in DMF) was measured at 532 nm by the open-aperture Z-scan technique. Key words: crystal structure, metal complex, dual fluorescence, NLO.

Three new carbazole derivatives ( L1- L3) with different functional groups have been synthesized and characterized. L1 and L2 are connected through methylene unit to construct L3 with enhanced molecular distortion configuration. The compounds exhibit dependent aggregation-induced enhanced emission (AIEE) properties and cellar uptake region in HepG2 cells. It is demonstrated that L1 and L2 exhibit modest AIEE properties in THF-HO mixtures, while L3 shows superior AIEE character with 13 times enhancement. This is because of the enhanced molecular distortion configuration of L3 and the related restriction of π-π stacking interactions between adjacent L3 molecules resulted from the introduction of methylene unit. Due to the unique structure of the compounds, the superior fluorescence emission of L1-L3 in aqueous media, further imaging studies demonstrated the suitability of probes L1-L3 for the biological applications in both human liver hepatocellular carcinoma cells (HepG2) and plant tissues of Arabidopsis seedlings. The imidazole unit in L2 leads selective target to lysosome of HepG2 cells through acid-base interactions, while L1 and L3 are inclined to act with endoplasmic reticulum. [ABSTRACT FROM AUTHOR]

Coke deposition is commonly identified as the main cause of deactivation for dehydrogenation (DH) catalysts. The VO x -K 2 O/γ-Al 2 O 3 catalysts for non-oxidative DH of isobutane were studied to better understand the formation and nature of coke. Coke deposition influenced VO x species and acid sites, leading to a deterioration of DH performances. The coke was identified as aliphatic and polyaromatic species. As the DH reaction proceeding, the deposited carbonaceous species progressively transformed from aliphatic into aromatic species, with aromaticity increasing. They continuously shift between metallic VO x species and acid sites. Of note is that the aromatic species eventually condense onto the support resulting in polyaromatic and graphitic carbon mixtures. A possible coke generation process was proposed, which contained consecutive reactions such as cracking, oligomerization, and aromatization. The establishment of the coke formation mechanisms and study of the nature of the deposited coke provide guidance for future DH catalyst optimization while reducing coke formation. [ABSTRACT FROM AUTHOR]

The title novel noncentrosymmetric metal-organic framework, [Zn2Cl4(C17H20N8)] n, was prepared solvothermally using the tetradentate tetrakis[(imidazol-1-yl)methyl]methane (tiym) linker in the presence of zinc nitrate under acidic conditions. The asymmetric unit contains one ZnII cation, two Cl− anions and a quarter of each of two symmetry-independent tiym ligands. Each ZnII cation is four-coordinated by two Cl− anions and two imidazole N atoms from two tiym ligands, forming a distorted tetrahedral coordination geometry. The tetrahedral tetradentate tiym linker has a quaternary C atom located on a crystallographic axis. With its four peripheral imidazole N atoms, the linkers are bridged by four [ZnCl2] subunits to generate a three-dimensional diamond topological framework, which is represented by the Schläfli symbol {66}. To the best of our knowledge, the title compound is the first example of a non-interpenetrating diamond net based on the tiym ligand. [ABSTRACT FROM AUTHOR]

The crystal structure of the tetranuclear organotin compound 1,1,3,3,5,5,7,7-octabutyl-7-(( E)-2-cyano-3-{9-[2-(2-methoxyethoxy)ethyl]-9 H-carbazol-3-yl}prop-2-enoyloxy)-4,8-dimethyl-2,4,6,8-tetroxa-1,3,5,7-tetrastannatricyclo[4.2.0.02,5]oct-3-yl ( E)-2-cyano-3-{9-[2-(2-methoxyethoxy)ethyl]-9 H-carbazol-3-yl}prop-2-enoate, [Sn4(C4H9)8(C21H19N2O4)2(CH3O)2(μ3-O)2], consists of a core of three fused Sn2O2 rings. The central ring consists of two Sn atoms each coordinated by two n-butyl chains, two μ3-bridging O atoms and one μ2-bridging methanolate O atom. The peripheral Sn2O2 rings consist of one of the central ring Sn atoms, and an Sn coordinated by one μ3-bridging O atom, one μ2-bridging methanolate O atom, two n-butyl chains and the carboxylate O atom of a ( E)-2-cyano-3-{9-[2-(2-methoxyethoxy)ethyl]-9 H-carbazol-3-yl}prop-2-enoate ligand ( L). Despite an apparent centrosymmetric nature, the complex does not crystallize about an inversion centre. The structure packs with π-π interactions between carbazole moieties on adjacent molecules. [ABSTRACT FROM AUTHOR]

The tetradentate N2S2 Schiff base ligand 3,3′-[2,2′-(ethyl­ene­di­oxy)di­benzyl­idene]­bis­( S-methyl di­thio­car­ba­zate) (H2 L), prepared by the condensation of S-methyl di­thio­carb­aza­te with 1,4-bis(2-formyl­phenyl)-1,4-dioxa­butane in a 1:2 molar ratio, reacts with nickel acetate to form the title neutral metal complex, [Ni(C20H20N4O2S4)]. The X-ray structure of the complex shows a distorted square-planar geometry around the Ni atom. The monomeric units are weakly associated into dimers via a long Ni⃛S interaction [3.569 (1) Å]. These dimeric units are then linked by C-H⃛S intermolecular contacts to form a polymeric chain along the a axis. [ABSTRACT FROM AUTHOR]

The title compound, [Ni(C21H15N2S2)2], has a novel cis configuration with two fluorene moieties on the same side. The Ni atom is in a square-planar configuration. The molecular packing is stabilized by intramolecular stacking between the fluorene moieties and extensive C-H⃛π interactions. [ABSTRACT FROM AUTHOR]

In the crystal structure of the title compound, C11H16N4OS, the phenyl ring and the thio­semicarbazone moiety from a dihedral angle of 7.7 (1)°. The crystal structure is governed by N-H⃛O and O-H⃛S hydrogen bonds leading to the formation of a two-dimensional network. [ABSTRACT FROM AUTHOR]