Applied Organometallic Chemistry

A new ferrocenyl ligand, 1,1′-bis[(1- methyl-5-phenyl-4H-(1,3,4)-thiadiazolo (2,3-c)(1,2,4)triazin-4-one)]ferrocene was prepared from the reaction of 1,1′-diacetylferrocene with 4-amino-2,3-dihydro-6-phenyl-3-thioxo[1,2,4]triazin- 5(4H)one. The ligand, L, forms 1:1 complexes with Mn(II), Fe(III), Co(II), Ni(II), Cu(II) and Zn(II) in good yield. Biological activity of the ligand and its complexes were carried out against Escherichia coli, Staphylococcus aureus, Aspergillus niger, Cladosporium herbirum and Fusarium mo- niliformae. The biological results indicated that the complexes are more active than the ligand.

Eight new water soluble 1,1′-dimethylvanadocene amino acid complexes [(MeCp)₂V(aa)]Cl have been prepared via the reaction of (MeCp)₂VCl₂ (2) with one equivalent of amino acid (aa). Complexes have been characterized by EPR, IR, Raman and X-ray spectroscopy, elemental analysis and mass spectrometry. Prepared compounds embody identical or slightly higher antiproliferative activity then corresponding unsubstituted vanadocene analogues.

Fifteen new ferrocene derivatives containing 1H-1,2,4-triazole moiety were synthesized in various yields by the condensation of ferrocenecarboxaldehyde with 1-aryl-3-(1H-1,2,4-triazo-1-yl)-propen-1-ones in toluene. Their structures have been confirmed by ¹H NMR, IR, MS and elemental analysis. In addition, the crystal structure of 4l was determined. The antifungal and plant growth regulatory activities of the title compounds were discussed.

Ceria–zirconia mixed oxide was successfully synthesized via the sol–gel process at ambient temperature. The most stable cubic phase solid solutions were obtained in the Ce range above 50 mol%. The highest surface area was obtained from the mixed catalyst containing a ceria content of 90 mol% (200 m²/g). Ce₆Zr₄O₂ exhibited the highest activity for the CO oxidation.

The synthesis of ferrocenyl-isoxazole deri-vatives is described. The structure of (η⁵-C₅H₅) Fe(η⁵-C₅H₄)C₃HNOC₆H₄CH₃ has been determined by single-crystal X-ray diffraction method. The electrochemical behaviors of the synthesized ferrocenyl-isoxazole derivatives have been studied.

Three dinuclear copper(I) complexes [Cu₂(µ-X)₂(1,2-(PPh₂)₂-1,2-C₂B₁₀H₁₀)₂](X = Cl,Br,I) with the similar di-µ-X-bridged structure, which contained the closo carborane diphosphine ligand, have been synthesized by the reactions of CuX(X = Cl, Br, I) with 1,2-Bis(diphenylphosphino)-1,2-dicarba-closo-dodecaborane in ethanol. The catalytic property of the complex for X = I was also investigated.

Tetrahedral Pt nanocrystals with sizes of 3–10 nm were obtained in high selectivity by H₂-reduction of aqueous K₂PtCl₆ in the presence of poly(N-vinyl-2-pyrrolidone) (PVP) at moderate PVP:K₂PtCl₆ ratios. The co-existing round/spheroidal crystallites appear smaller than the tetrahedral ones in the systems. Careful examinations of the particle size and shape evolution of the crystallites during the crystal growth suggest that the tetradedral-shaped crystallites share the same type of nuclei with the round ones at the early stage of the crystal formation. Evolution of the tetrahedral shape happens in the later slow crystal growth.

ArF laser irradiation of gaseous methyldisilazanes in excess of Ar affords chemical vapour deposition of solid amorphous nanostructured Si/C/N/H powder containing SiX (XC, H, O, N) bonds. This material heated to 700 °C yields silicon oxycarbonitride, whose structure consists of a network of O- and N-interconnected Si and C atoms.

Heterogeneous palladium catalysts anchored on functionalized silica were prepared by sol-gel methods and their catalytic properties for the oxidative carbonylation of phenol to diphenyl carbonate (DPC) were investigated. The heterogeneous catalyst was more active and stable compared with traditional supported Pd-C catalyst under the same reaction conditions.

Reaction of 2-cycloalkenone and α,β-unsaturated ketone with ammonium cerium(IV) nitrate (CAN), cerium(IV) sulfate (CS)-molecular sieve, or lanthanide triflates in alcohols gave the corresponding 1,1,3-trialkoxy acetal derivatives and β-alkoxyketone in good yields.

The bidentate behaviour of the pyrazoline ligands and distorted trans-octahedral structure around tin(IV) in diorganotin(IV) dipyrazolinates have been suggested. Some diorganotin(IV) dipyrazolinates exhibit higher antibacterial and antifungal effect than free ligand. Molecular structure of diorganotin(IV)3(2′-hydroxyphenyl)-5-(4-X-phenyl) pyrazolinates (where R = Me, Prⁿ and Ph; X = H, CH₃, OCH₃ and Cl).

Lithiation of a series of aryl benzyl ethers has been studied. The formation of ortho, benzylic or dilithiated compounds has been observed depending on the type of substituents or organolithium reagent.

The hydrolytic stability of the sterically protected dichlorosilane (Mes*O)₂SiCl₂ was investigated. The resulting products have been identified by electrospray mass spectrometry and, in the case of (Mes*O)₂Si(OH)₂, the crystal structure could be obtained.

Sn(dmae)₂ (dmaeH = Me₂NCH₂CH₂-OH) is capable of forming 1:1 adducts with unsaturated metal centres such as Cd(acac)₂ and CdI₂, although Sn (dmae)₂Cd(acac)₂ fails to act as single-source precursors for mixed SnCd oxide films. The structure of an hydrolysis product in the synthesis of Sn(dmae)₂, Sn₆O₄(dmae)₄, and that of the related cage Sn₆O₄(OEt)₄, are also reported.

The introduction of the organosilicon substituent into the α-position of an amino group results in cardinal change of the amine reactivity irrespectively of the coordination state of silicon. Amines R₂NCH₂SiX₃ (R = Me, Et, PhCH₂, CH₂SiX₃; SiX₃ = SiMe₃, Si(OEt)₃, Si(OCH₂CH₂)₃N) easily react with AgNO₃, to give the corresponding ammonium salts (R₂NH⁺CH₂SiX₃)NO₃⁻. At the same time, Ag(I) is reduced to Ag(0). The interaction of N-methyl-N,N-bis(silatranylmethyl)amine with AgNO₃ has been investigated by EPR spectroscopy. It was proven that the reaction involved a single electron transfer stage with the formation of cation radical of this amine. A mechanism of the reaction is proposed.

The sequestering capacity of naturally-occurring alginic and fulvic acids towards trimethyltin(IV) cation was calculated by using stability data of complex species formed in aqueous solution at the ionic strength and pH of natural waters. The obtained results, expressed as percentage of TMT complexes formed for different ligand concentrations, show that the sequestering capacity of fulvic acid (FA), similar to that of synthetic polyacrilate(PAA), is higher than that of alginic acid (AA) and much higher than that of low molecular weight carboxylate ligands.