Authors:Kseniya V. Zherikova, Ludmila N. Zelenina, Natalia B. Morozova, and Tamara P. Chusova
,5-dimethyl-2,4-hexanedione (Ru(ptac) 3 —were published by us [ 4 , 17 – 19 ].
To continue the systematic investigation we studied the vaporization processes for ruthenium(III) 1,1,1,6,6,6-hexafluoro-2,4-pentanedionate (Ru(hfac) 3 ) and the thermal
Authors:N. Morozova, K. Zherikova, P. Semyannikov, S. Trubin, and I. Igumenov
Complexes of ruthenium(III) with the following beta-diketones: 2,4-pentanedione (Ru(acac)3), 1,1,1-trifluoro-2,4-pentanedione (Ru(tfac)3), 2,2,6,6-tetramethyl-3,5-heptanedione (Ru(thd)3), 2,2,6,6–tetramethyl-4-fluoro-3,5-heptanedione (Ru(tfhd)3) and 1,1,1-trifluoro-5,5-dimethyl-2,4-hexanedione (Ru(ptac)3) were synthesized and identified by means of mass spectrometry. By effusion Knudsen method with mass spectrometric registration
of gas phase composition the temperature dependencies of saturated vapor pressure were measured for ruthenium(III) compounds
and the thermodynamic characteristics of vaporization processes enthalpy ΔHT* and entropy
Authors:Riya Sailani, Mridula Sharma, Deepmala Pareek, C. L. Khandelwal, and P. D. Sharma
-point. Since ruthenium(III) chloride as a catalyst has been variously reported in redox systems, our aim is to delineate the role of ruthenium(III) chloride in reactions of peroxomonosulfate which is yet to be established. Second, aspartic acid was chosen owing
Authors:S. Sysoev, T. Cheremisina, L. Zelenina, S. Tkachev, K. Zherikova, N. Morozova, and N. Kuratieva
The comprehensive analysis of volatile β-diketonate compound—ruthenium(III) trifruoroacetylacetonate (Ru(tfac)3)—was carried out. By means of flow method in quasi-equilibrium conditions and static method the temperature dependencies
of saturated vapor pressure have been measured over solid and liquid cis- and trans-modifications of Ru(tfac)3 and isomer mixture. The thermodynamic characteristics of sublimation, evaporation, melting, and phase conversion have been
calculated for structural isomers. Also by differential-scanning calorimetry the temperature meanings and the thermodynamic
characteristics of melting have been determined for individual isomers of Ru(tfac)3 and their mixtures. By XRD the structures for cis- and trans-modifications have been determined. Both structures consist of neutral molecules arranged in pseudo layers.
Authors:K. Byadagi, D. Naik, A. Savanur, S. Nandibewoor, and S. Chimatadar
Oxidation of thiamine hydrochloride (vitamin B1) by cerium(IV) mediated by micro amounts (10−6 mol dm−3) of ruthenium(III) in aqueous perchloric acid medium has been studied spectrophotometrically at 25 °C and I = 1.10 mol dm−3. The reaction is first order in both cerium(IV) and ruthenium(III) concentrations. The order with respect to vitamin B1 concentration varies from first order to zero order as the vitamin B1 concentration increases. An increase in perchloric acid concentratrion decreases the reaction rate. The active species of
oxidant and catalyst are [Ce(OH)3+] and [Ru(H2O)6]3+. A possible mechanism is proposed and reaction constants involved have been determined. The activation parameters for the
slow step of the mechanism are determined.
Authors:A. F. Bykov, N. B. Morozova, I. K. Igumenov, and S. V. Sysoev
By means of a tensimetric flow method and a static method with a silica-membrane zero gauge, the dependence of vapour pressure on temperature was obtained for tris(2,4-pentanedionato)ruthenium(III), Ru(aa)3, and tris(1,1,1-trifluoropentane-2,4-dionato)ruthenium(III), Ru(tfa)3. The thermodynamic characteristics of vaporization and sublimation of these complexes were determined. The processes of thermal decomposition of the vapour of the compounds in vacuum, hydrogen and oxygen were investigated by using mass spectrometry in the temperature range 170–550‡C for Ru(aa)3 and 150–620‡C for Ru(tfa)3. The threshold temperatures of the stability of the vapour of the complexes and the rate constants of the thermolysis processes were determined. The main gaseous products of the thermal decomposition and the dependences of their composition on the presence of hydrogen and oxygen were established.
The kinetics of ruthenium (III)-catalyzed oxidative cleavage of phenylpropanolamine (2-amino-1-phenyl-propan-1-ol) (PPA) with
N-bromosuccinimide (NBS) in HCl medium has been investigated at 308 K. The oxidation reaction follows the rate law, d[NBS]/dt = k[NBS][PPA][Ru(III)]a[H+]−b, where a and b are less than unity. The stoichiometry of the reaction has been found to be 1:1, and benzaldehyde and acetaldehyde
were identified as the oxidation products of PPA. The activation parameters have been evaluated from the Arrhenius plot. NBS
itself has been postulated as the reactive oxidizing species. The observed results have been explained by plausible mechanisms
and the related rate law has been deduced.
Authors:P. Ruikar, M. Nagar, M. Subramanian, K. Gupta, N. Varadarajan, and R. Singh
The extraction of plutonium(IV), uranium(VI), zirconium(IV), europium(III) and ruthenium(III) with -pre-irradiated n-dodecane solutions of methylbutyl substituted hexanamide (MBHA), octanamide (MBOA) and decanamide (MBDA) from 3.5M HNO3 has been studied as a function of absorbed dose up to 184×104 Gray. The distribution ratios (Kd) of uranium(VI) decreased gradually up to a dose of 50×104 Gray and became almost constant thereafter, while ruthenium(III) and europium(III) were not extracted in the entire dose range studied. The Kd values of Pu(IV) decreased gradually up to 10×104 Gray, for MBOA, and 30×104 Gray for MBHA and MBDA and then increased up to a dose of 72×104 Gray, indicating the synergistic effect of radiolytic products at higher doses. The extraction of zirconium(IV) was found to increase gradually up to 72×104 Gray. However, the steep fall in Kd values of plutonium(IV), zirconium(IV) beyond a dose of 72×104 Gray was atrributed to third phase formation. The radiolytic degradation of amides was monitored by quantitative IR spectroscopy and was found to follow the order MBOA>MBDA>MBHA at 184×104 Gray having the amines and carboxylic acids as the main radiolytic products.
Authors:Mihaela Badea, Rodica Olar, Dana Marinescu, Valentina Uivarosi, and Daniela Iacob
A series of new complexes with mixed ligands of the type RuL2(DMSO)mCl3·nH2O ((1) L: norfloxacin (nf), m = 1, n = 1; (2) L: ciprofloxacin (cp), m = 2, n = 2; (3) L: ofloxacin (of), m = 1, n = 1; (4) L: enrofloxacin (enro), m = 0.5, n = 4; DMSO: dimethylsulfoxide) were synthesised and characterised by chemical analysis and IR data. In all complexes both
fluoroquinolone derivative and DMSO act as unidentate. The thermal behaviour steps were investigated in synthetic air flow.
The thermal transformations are complex processes according to TG and DTG curves including dehydration, quinolone derivative
and DMSO degradation respectively. The final product of decomposition is ruthenium (IV) oxide.