Comparative study of the catalytic performance of physically mixed and sequentially utilized γ-alumina and zeolite in methanol-to-propylene reactions.

This study aimed to investigate the catalytic performance of H-ZSM-5 zeolite compared with physically mixed and sequentially used synthesized γ-alumina and zeolite in the methanol-to-propylene (MTP) reaction. A facile, green and cost-effective method was first applied to prepare a mesoporous γ-AlO support using a combination of sol-gel and hydrothermal methods via a few consecutive steps. This process was carried out using aluminium nitrate and polyethylene glycol with different molecular weights as non-ionic surfactants.

Ladder-like heteropolynuclear assemblies cyanido bridges and platinum(II)-thallium(I) bonds: structural and photophysical properties.

We describe the mononuclear anionic cyanido-pentafluorophenyl complexes, (NBu)[Pt(C^N)(CF)(CN)] [C^N = 7,8-benzoquinolate (bzq) 1, 2-(2,4-difluorophenyl)pyridinate (dfppy) 2] and the heteropolynuclear derivatives [{Pt(C^N)(CF)(CN)}Tl] (C^N = bzq 3, dfppy 4). These complexes were synthesized a two-step modular synthesis by reaction of the corresponding potassium salts K[Pt(C^N)(CF)(CN)], prepared from [Pt(C^N)(CF)(DMSO)] and KCN in acetone/HO, with TlPF. The structures of {[Pt(bzq)(CF)(CN)Tl]·THF} (3·THF) and [{Pt(dfppy)(CF)(CN)}Tl]·dioxane [4]4·dioxane, determined by X-ray crystallography, confirm the presence of Pt(II)-Tl(I) bonds [2.

Synthesis, characterization, and methanol steam reforming performance of Cu/perovskite-structured catalysts.

In the present work, Cu/perovskite-type structures of the general formula Cu/Ca(ZrTi)O (x = 1, 0.8, 0.6) were synthesized via sol-gel process and afterwards using wetness impregnation method to prepare copper-based catalysts.

Luminescent Anionic Cyclometalated Organoplatinum (II) Complexes with Terminal and Bridging Cyanide Ligand: Structural and Photophysical Properties.

We present the synthesis and characterization of two series of mononuclear heteroleptic anionic cycloplatinated(II) complexes featuring terminal cyanide ligand Q[Pt(C^N)(-MeCH)(CN)] [C^N = benzoquinolate (bzq), Q = K and NBu ; 2-phenylpyridinate (ppy), Q = K and NBu and 2-(2,4- difluorophenyl)pyridinate (dfppy), Q = K and NBu ] and a series of symmetrical binuclear complexes (NBu)[Pt(C^N)(-MeCH)(μ-CN)] (C^N = bzq , ppy , dfppy ). Compounds , , and - were further determined by single-crystal X-ray diffraction. There are no apparent intermolecular Pt···Pt interactions owing to the presence of bulky NBu counterion.

A novel mechanism of heme degradation to biliverdin studied by QM/MM and QM calculations.

Heme degradation by heme oxygenase enzymes is important for maintaining iron homeostasis and prevention of oxidative stress. Previous studies have reported that heme degradation proceeds through three consecutive steps of O2 activation: the regiospecific self-hydroxylation of heme, the conversion of hydroxyheme to verdoheme and CO, and the cleavage of the verdoheme macrocycle to release biliverdin and free ferrous iron. Our results indicate that in the second step of heme degradation, not only verdoheme is generated but ring opening and biliverdin production also occur.

QM/MM Study of the Conversion of Oxophlorin into Verdoheme by Heme Oxygenase.

Heme oxygenase is an enzyme that degrades heme, thereby recycling iron in most organisms, including humans. Pervious density functional theory (DFT) calculations have suggested that iron(III) hydroxyheme, an intermediate generated in the first step of heme degradation by heme oxygenase, is converted to iron(III) superoxo oxophlorin in the presence of dioxygen. In this article, we have studied the detailed mechanism of conversion of iron(III) superoxo oxophlorin to verdoheme by using combined quantum mechanics and molecular mechanics (QM/MM) calculations.

Interrelationship between TiO nanoparticle size and kind/size of dyes in the mechanism and conversion efficiency of dye sensitized solar cells.

In order to provide a comprehensive investigation of TiO nanoparticle size in relation with different dye types in DSSCs, three sizes of TiO nanoparticles and two different dye types including a porphyrin dye (T2) and a ruthenium dye (N3) were synthesized. Steady state current-voltage (J-V) characteristics were investigated for the fabricated DSSCs and the results demonstrated that the optimum TiO nanoparticle size changed with the dye type. The obtained J-V data were interpreted by cyclic voltammetry, UV-visible absorption spectroscopy, BET measurement, DFT calculation, IPCE measurement and impedance spectroscopy.

Density functional theory studies on the conversion of hydroxyheme to iron-verdoheme in the presence of dioxygen.

Detailed insight into the second step of heme degradation by heme oxygenase, oxophlorin to verdoheme and biliverdin, is presented. Density functional theory methods are reported for the conversion of oxophlorin to verdoheme. Since it is currently unclear whether dioxygen binding to iron oxophlorin is followed by a reduction or not, in this work we have focused on the difference in reactivity between [(Im)(O˙)Fe(PO˙)] (PO˙ is the oxophlorin dianion radical) and [(Im)(O˙)Fe(PO)] (PO is the oxophlorin trianion).

A Novel Platinum-based Compound with Preferential Cytotoxic Activity against a Panel of Cancer Cell Lines.

Purpose: Cisplatin as a platinum (Pt)-based chemotherapeutic compound is commonly applied for the treatment of several types of cancer. Nonetheless, drug resistance and severe adverse effects have been observed upon using cisplatin. Here, we have explored the cytotoxicity of novel Pt-based compounds on several cancer cell lines.

A Novel Platinum-based Compound with Preferential Cytotoxic Activity against a Panel of Cancer Cell Lines.

Purpose: Cisplatin as a platinum (Pt)-based chemotherapeutic compound is commonly applied for the treatment of several types of cancer. Nonetheless, drug resistance and severe adverse effects have been observed upon using cisplatin. Here, we have explored the cytotoxicity of novel Pt-based compounds on several cancer cell lines.

Chameleonic nature of hydroxyheme in heme oxygenase and its reactivity: a density functional theory study.

Iron hydroxyheme is an intermediate in heme degradation that binds to HO-1 in a five-coordinated fashion wherein the fifth ligand is His25. The structure and reactivity of hydroxyheme have been investigated using the B3LYP*, OPBE, and CASSCF methods with the 6-31+G* and 6-311+G** basis sets. Hydroxyheme [(Im)Fe(II)(POH)] (POH is the hydroxyporphyrin) is readily oxidized to oxophlorin [(Im)Fe(III)(PO)] (PO is the oxophlorin trianion) in the protein heme oxygenase.

The influence of steric effects on intramolecular secondary bonding interactions; cytotoxicity in gold(III) bithiazole complexes.

The reaction of two sterically different bithiazole ligands with gold(III) was investigated. Our results show that, depending on the ligand used, different coordination geometries around the gold(III) center were achieved. Where sterically unhindered 4bt ligand was used, regular square-planar compound [Au(4bt)Cl2][AuCl4] (1) is isolated, while in the case of sterically hindered dm4bt ligand, the interplay between the steric effect and the intramolecular secondary bonding interaction leads to the formation of disordered square-pyramidal geometry in [Au(dm4bt)Cl3] (2).

Structure and redox behavior of iron oxophlorin and role of electron transfer in the heme degradation process.

Iron-oxophlorin is an intermediate in heme degradation, and the metal oxidation number can alter spin, electron distribution, and the reactivity of the metal and the oxophlorin ring. The role of electron transfer in the structure and reactivity of [(Py)(2)Fe(III)(PO)] (PO is the oxophlorin trianion) in different redox states has been investigated using the B3LYP and OPBE methods with the 6-31+G* and 6-311+G** basis sets. A computation study has shown that [(py)(2) Fe(III)(PO)] loses one electron from its a(2u) orbital.

2,9-Dimethyl-1,10-phenanthrolin-1-ium tetra-chloridoferrate(III) methanol monosolvate.

In the title compound, (C₁₄H₁₃N₂)[FeCl₄]·CH₃OH, the 2,9-dimethyl-1,10-phenanthrolin-1-ium cation, FeCl₄ ⁻ anion and methanol solvent mol-ecule lie on a twofold rotation axis. Due to symmetry, the H atom on the N atom of the cation is half-occupied. In the anion, the Fe(III) atom has a tetra-hedral geometry.

Bis(ethyl-enediamine-κ(2)N,N')bis-(methanol-κO)copper(II) benzene-1,4-dicarboxyl-ate methanol disolvate.

In the cation of the title compound, [Cu(C(2)H(8)N(2))(2)(CH(3)OH)(2)](C(8)H(4)O(4))·2CH(3)OH, the Cu(II) atom lies on an inversion centre. The four N atoms of two ethyl-enediamine ligands around the Cu(II) atom form the equatorial plane, while two methanol O atoms in the axial positions complete a Jahn-Teller distorted octa-hedral coordination. The benzene-1,4-dicarboxyl-ate anion is centrosymmetric.

Effect of axial ligand on the electronic configuration, spin states, and reactivity of iron oxophlorin.

Iron-oxophlorin is an intermediate in heme degradation, and the nature of the axial ligand can alter the spin, electron distribution, and reactivity of the metal and the oxophlorin ring. The structure and reactivity of iron-oxophlorin in the presence of imidazole, pyridine, and t-butyl isocyanide as axial ligands was investigated using the B3LYP and OPBE methods with the 6-31+G* and 6-311+G** basis sets. OPBE/6-311+G** has shown that the doublet state of [(Py)(2)Fe(III)(PO)] (where pyridines are in perpendicular planes and PO is the oxophlorin trianion) is 3.

Solution and solid state characterization of oxo-centered trinuclear iron(III) acetate complexes [Fe3(μ3-O)(μ-OAc)6(L)3]+.

[Fe(3)(μ(3)-O)(μ-OAc)(6)(py)(3)][FeBr(4)](2)[py·H], complex (1), (OAc is acetate) was prepared from the reaction of FeBr(3) with pyridine in 1.2 molar aqueous HBr and 2.4 molar aqueous CH(3)COOH.

(4,5-Diaza-fluoren-9-one-κN,N')bis-(thio-cyanato-κS)mercury(II).

In the title compound, [Hg(NCS)(2)(C(11)H(6)N(2)O)], the Hg(II) atom, lying on a twofold rotation axis, is four-coordinated in a distorted tetra-hedral geometry by an N,N'-bidentate diaza-fluoren-9-one ligand and two thio-cyanate anions. In the crystal, inter-molecular C-H⋯N and C-H⋯O hydrogen bonds are effective in the stabilization of the structure.

Synthesis, characterization, mechanochromism and photochromism of [Fe(dm4bt)3][FeCl4]2 and [Fe(dm4bt)3][FeBr4]2, along with the investigation of steric influence on spin state.

The complexes [Fe(dm4bt)(3)][FeCl(4)](2) (1) and [Fe(dm4bt)(3)][FeBr(4)](2) (2) were prepared from the reaction of 2,2'-dimethyl-4,4'-bithiazole (dm4bt) with FeCl(3)·6H(2)O and FeBr(3), respectively, in methanol. Both complexes were characterized by IR, UV-Vis and (1)H NMR spectroscopy and their structures were studied by single-crystal diffraction. The methylated bithiazole led to high spin Fe(II) centers in the octahedral cation part of complexes 1 and 2 with Fe-N distance of 2.

Tris(4,4'-bi-1,3-thia-zole-κN,N')iron(II) tetra-bromidoferrate(III) bromide.

In the [Fe(4,4'-bit)(3)](2+) (4,4'-bit is 4,4'-bi-1,3-thia-zole) cation of the title compound, [Fe(C(6)H(4)N(2)S(2))(3)][FeBr(4)]Br, the Fe(II) atom (3 symmetry) is six-coordinated in a distorted octa-hedral geometry by six N atoms from three 4,4'-bit ligands. In the [FeBr(4)](-) anion, the Fe(III) atom (3 symmetry) is four-coordinated in a distorted tetra-hedral geometry. In the crystal, inter-molecular C-H⋯Br hydrogen bonds and Br⋯π inter-actions [Br⋯centroid distances = 3.

Manganese substituted Compound I of cytochrome P450 biomimetics: a comparative reactivity study of Mn(V)-oxo versus Mn(IV)-oxo species.

Manganese-oxo porphyrins have been well studied as biomimetic models of cytochromes P450 and are known to be able to catalyze substrate hydroxylation reactions. Recent experimental studies [J.Y.

Anion-directed self-assembly in coordination networks: architectural control via cooperative noncovalent interactions.

The self-assembly of a new flexible tritopic pyrazine-pyridine ligand (pz-3-py) with HgX(2) (X = Cl, Br) was investigated. The results show that coordinated chloride and bromide anions play different roles, and two architecturally different coordination polymers were obtained with the anions used. Where X = Cl, in [Hg(μ(3)-pz-3-py)Cl(2)](n) (1), the 2D network is isolated, while for X = Br, in [Hg(μ-pz-3-py)Br(2)](n) (2), a 1D zigzag chain is constructed.

Theoretical investigation of the ring opening process of verdoheme to biliverdin in the presence of dioxygen.

The conversion of ferrous verdoheme to ferric biliverdin in the presence of O(2) was investigated using the B3LYP method. Both 6-31G and 6-31G (d) basis sets were employed for geometry optimization calculation as well as energy stabilization estimation. Three possible pathways for the conversion of iron verdoheme to iron biliverdin were considered.

Di-μ-iodido-bis{[hydroxy(methoxy)bis(2-pyridyl)methane-κN,O,N']iodidocadmium(II)}.

In the centrosymmetric dinuclear title compound, [Cd(2)I(4)(C(12)H(12)N(2)O(2))(2)], two μ-I atoms bridge two Cd(II) atoms and each Cd(II) atom is also bonded to a terminal I atom and a hy-droxy-meth-oxy-bis-(2-pyrid-yl)methane ligand, which functions in an N,O,N'-tridentate mode, resulting in a distorted octa-hedral coordination environment. Inter-molecular O-H⋯I hydrogen bonds and π-π stacking inter-actions between the pyridine rings [centroid-centroid distance = 3.790 (2) Å] are present in the crystal structure.

Dichlorido(6,6'-dimethyl-2,2'-bipyridine-κN,N')cobalt(II).

In the title compound, [CoCl(2)(C(12)H(12)N(2))], the Co(II) atom is four-coordinated in a distorted tetra-hedral geometry by two N atoms from a 6,6'-dimethyl-2,2'-bipyridine ligand and two terminal Cl atoms. Inter-molecular C-H⋯Cl hydrogen bonds and π-π stacking inter-actions between the pyridine rings [centroid-centroid distances = 3.788 (1) and 3.