Applied Organometallic Chemistry

Two series of diorganotin(IV) complexes with dihalogenobenzohydroxamate ligands were prepared and shown to exhibit in vitro cytotoxic activities towards human leukemic promyelocites HL-60, BGC-823, BEL-7402 and KB cell lines which, in some cases, are identical to, or even higher than, that of cisplatin. The dependence of the cytotoxic activity on some factors was also studied.

Drug-Fe(II) complexes have been synthesized. Structures of the complexes have been investigated using spectroscopic technique. All the complexes exhibit higher antibacterial activity than parental compounds. The absorption titration for sperm herring DNA and gel electrophoresis for pBR322 DNA show interpretative binding and cleavage of DNA with drug-Fe(II) complexes.

The mono-arylpyridyl bromides are very useful key intermediates that can be further functionalized to generate bioactive compounds. It is possible to obtain mono-arylation products of 3,5-dibromopyridine with high preferentiality and high yields by air- and moisture-stable palladacycle (catalyst II) catalyzed Suzuki reaction under the conditions of K₂CO₃–toluene–methanol (4:1, v/v), reflux (75 °C), 5.6 equiv. of 3,5-dibromopyridine with the ratio (mono:bis) ranging from of 99:1 to 90:10. This new method could also be used to easily achieve 3-bromo-5-pyridylpyridine (3j) with pyridylpyridyl bond formation.

The electrochemical incorporation of carbon dioxide into amines catalyzed by electrogenerated Ni complex afforded carbamates in moderate yields under very mild condition (p = 1 atm, room temperature) without any addition of probases. Cyclic voltammetry and mechanistic studies revealed the role of reduced nickel species in the activation of CO₂ and electrogenerated CO as a base in the synthesis of carbamates.

Recycling of the catalyst five times led to a turnover number higher than 500 for this atom-efficient chemical process.

The water soluble Cp and Cp* ruthenium(II) complexes with PTA or mPTA ligands are moderately active in the reduction of CO₂/bicarbonate, the rate of the hydrogenation strongly depends on the pH. The catalytically active species are the [CpRu(H)(PTA)₂] and [Cp*Ru(H)(PTA)₂] hydrides.

The synthesis and characterization of several hexa-coordinated ruthenium(III) Schiff base complexes of the type [RuX(EPh₃)(L)] (X = Cl or Br; E = P or As; L = dianion of the tetradentate Schiff base) are reported. Based on analytical and spectral data, an octahedral geometry has been tentatively proposed for all of these complexes. The new complexes have been subjected to catalytic activity in the reaction of oxidation of alcohols in the presence of N-methylmorpholine-N-oxide.

The direct substitution of alcohols and β-dicarbonyl compounds was catalyzed with FeCl₃ under solvent-free conditions. The catalyst loading could be decreased to 0.01 mol% in high activities.

Nickel(II) complexes bearing β-diketiminate ligands exhibit characteristics of vinyl polymerization of norbornene when activated by MAO.

An easy way of producing three-dimensional metal-organic coordination polymers involving zinc(II) benzene-dicarboxylates is reported. Zinc dicarboxylates obtained from the reaction of zinc oxide with benzene dicarboxylic acids yield after suspension in DMSO and subsequent heating crystalline compounds displaying complex zeotypic structures.

A novel barium(II) coordination polymer, [Ba(4-FBA)₂(4-FBAH)]_n, I, containing neutral and deprotonated 4-formylbenzoic acid ligands has been synthesized. The adjacent barium(II) atoms are bridged by the 4-FBA⁻ ligand into a 2D lamellar structure which exhibits blue fluorescent emission in the solid state at room temperature.

The charge transfer complexes formation of 5,10,15,20-tetra(4-tolyl)porphyrin and Zn-5,10,15,20-tetra(4-tolyl) porphyrin with some aromatic nitro acceptors such as 2,4,6-trinitrophenol (picric acid), 3,5-dinitrosalicylic acid, 3,5-dinitrobenzoic acid and 2,4-dinitrophenol have been studied spectrophotometrically in dichloro- methane, chloroform and carbontetrachloride solutions at different temperatures.

A novel method for the cyanosilylation of various aldehydes using 0.5 mol% SmI₂ under solvent-free conditions is reported. The corresponding cyanosilylethers are obtained in high yields (up to 99%) in relatively short reaction time.