E. V. Guseva

Kinetics of homogeneous dehydrogenation of formic acid in the presence of supramolecular rhodium(III) complex with P-functionalized calix[4]resorcine

The kinetics of homogeneous dehydrogenation of formic acid in the presence of supramolecular rhodium(III) complex with P-functionalized calix[4]resorcine were studied in dioxane, tetrahydrofuran, dimethylformamide, and binary formamide-dioxane mixtures (volume ratio 10: 90, 20: 80, 30: 70) over a wide temperature range (40–90°C). The examined Rh(III) complex catalyzed the dehydrogenation process, and its catalytic activity was higher than that observed previously for rhodium complexes with non-macrocyclic phosphorus-containing ligands. The dehydrogenation rate constants were proportional to neither catalyst concentration nor dielectric constant of the medium, which is likely to be related to supramolecular nature of the Rh(III) complex. No micelle formation was observed in the examined systems.

Reaction of rhodium trichloride and dirhodium(II) acetate with trans-4,4′-bis(diethoxyphosphoryl)biphenyl-18-crown-6

The complexation of RhCl3·3H2O and [RH2(CH3COO)4·2H2O] with trans-4,4′-bis (diethoxyphosphoryl)biphenyl-18-crown-6 in various media was studied. In the synthesized compounds the rhodium(III) or dirodium(II) ions form supramolecular ensembles with ligand environment. The compounds were characterized by NMR, IR, Raman, ESR, X-ray electron spectroscopy, conductivity, and the data of elemental and X-ray fluorescence analyses. The predominant role of diethoxyphosphoryl groups at the macrocycle in binding rhodium(III) and dirhodium(II) ions was demonstrated.

Reaction of rhodium trichloride with P-functionalized calix[4]resorcinols in various media

The features of the reaction of rhodium trichloride with calix[4]resorcinols modified with various types of phosphorus-containing groups in ethanol, ethanol-formate medium and acetone under an inert atmosphere were studied. Neutral complexes were isolated in the solid form, the solvent molecules were shown to be actively involved into the formation of the final reaction products. The compounds were characterized by IR, Raman, 31P NMR, ESR, X-ray photoelectron and electronic spectroscopy, and electric conductivity. The composition was confirmed by the data of elemental analysis, X-ray fluorescence analysis, and derivatography. Based on the analysis of the ESR spectrum, the electronic and geometric structures of the paramagnetic product isolated from the acetone medium was determined.

Complexes of dirhodium(II) carboxylates with calix[4]resorcinarenes functionalized at the upper and lower rim of the molecule with P,N-containing Fragments

AbstractThe features of the reaction between dirhodium(II) carboxylate and calix[4]resorcinarenes modified with various type functional groups at the upper and lower rim of the molecule in protic anhydrous solvent (ethanol) under inert atmosphere were investigated. Neutral complex compounds were isolated formed as a result of substitution of a water molecule by the macroligand in the axial position with respect to the R

Complexes of rhodium(III) with N-functionalized calix[4]resorcinolol

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Interaction of rhodium trichloride with N-functionalized calix[4]resorcinol in acetone

Rh bond occurring with the conservation of the latter. The compounds were characterized by 31P NMR, UV, IR, Raman, and ESR spectroscopy. Their composition was confirmed by elemental analysis.

Reaction of rhodium trichloride with oxyethylated calix[4]resorcinarene

Specific features of the reaction of anhydrous PtCl4 with 18-crown-6 in anhydrous solvents with different donor and solvating abilities, such as nitromethane, acetonitrile, and 1,2-dichloroethane, under an inert atmosphere are studied. Ionic platinum complexes with oligoethylene glycols or with crown ethers, formed by macroring opening and/or fragmentation under the action of the acidic agent, were isolated. The 1H NMR, IR, and Raman spectra of the complexes were studied. To assess the coordination mode of the crown ether cleavage product with Pt(IV), quantum-chemical calculations at the density functional theory level were carried out.

Complex Formation of Potassium Hexachloroplatinate with 18-Crown-6 and Dibenzo-18-Crown-6 in Acetonitrile

Singularities of the rhodium trichloride reaction with calix[4]resorcinol functionalized with CH2N· (CH3)2 groups in ethanol on the upper rim of the molecule, and also of calix[4]resorcinol with ethanol solution of rhodium trichloride saturated with nitrogen monoxide were studied. Neutral complex compounds separated in the solid form were characterized by IR spectroscopy, Raman spectroscopy, 1H NMR, ESR, X-ray electron spectroscopy, electronic spectroscopy, and conductometry. Quantum-chemical calculations were performed on the basis of the density functional method in order to determine the geometric structure and energy characteristics of the complex compound and the zwitter-ion form of the ligand.