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Papers by Alexander Lumpov
Radiochemistry, 2009
ABSTRACT The kinetics of decarbonylation of pentacarbonyltechnetium halides TcX(CO)5 (X = Cl, Br,... more ABSTRACT The kinetics of decarbonylation of pentacarbonyltechnetium halides TcX(CO)5 (X = Cl, Br, I) in CCl4 solution with the formation of dimers [TcX(CO)4]2 and of CO substitution in TcBr(CO)5 by the solvent molecule in CH3CN solution with the formation of the complex TcBr(CO)3(CH3CN)2 was studied. In all the systems, the reaction is first-order with respect to the starting compound. It was concluded that the limiting step of the reaction is dissociation into the intermediate complex TcX(CO)4 and CO molecule. The rate constants and activation energies of the reactions were determined.
Radiochemistry, 2009
ABSTRACT The crystal and molecular structures of [TcCl(CO)5] and [TcBr(CO)5] were determined. The... more ABSTRACT The crystal and molecular structures of [TcCl(CO)5] and [TcBr(CO)5] were determined. The compounds crystallize in the rhombic system, space group Pnma; a = 11.6757(18) and 11.9564(18) Å, b = 11.7365(14) and 11.7250(18) Å, c = 6.0407(7) and 6.2020(15) Å, V = 827.77(19) and 869.5(3) Å3, respectively; Z = 4. The structural data for pentacarbonyl halides were compared in the series Mn-Tc-Re and Cl-Br-I. Quantum-chemical calculations of the compounds [TcX(CO)5] (X = F, Cl, Br, I) and of the anion [TcCl3(CO)3]2− were made. A correlation between the geometry, electronic structure, and reactivity of the complexes is considered.
Radiochemistry, 2011
Hexacarbonyltechnetium(I) cation undergoes rapid hydrolysis in aqueous solutions at pH ≥ 7 with t... more Hexacarbonyltechnetium(I) cation undergoes rapid hydrolysis in aqueous solutions at pH ≥ 7 with the formation of an unidentified carbonyl compound or mixture of compounds in the form of a pale yellow precipitate. Two crystalline fractions were isolated in the course of vacuum sublimation of the precipitate and were identified by single crystal X-ray diffraction as Tc2(CO)10 and Tc3H3(CO)12. The crystal
Journal of Organometallic Chemistry, 2012
ABSTRACT Technetium hexacarbonyl perchlorate was prepared in CH2Cl2 in a reasonable yield. Reacti... more ABSTRACT Technetium hexacarbonyl perchlorate was prepared in CH2Cl2 in a reasonable yield. Reaction of this complex with acetonitrile was studied. The only reaction product was [Tc(CO)3(MeCN)3]ClO4. The crystal structure of [Tc(CO)3(MeCN)3]ClO4 was determined by single crystal X-ray diffraction. The kinetics of thermal decarbonylation of [Tc(CO)6]+ in acetonitrile was studied by IR spectroscopy. The rate constants and the activation energy of this reaction were determined. The rate constant is lower by more than an order of magnitude than that of [TcBr(CO)5]. The causes of increased stability of [Tc(CO)6]+ were analyzed by DFT calculations.
Inorganic Chemistry, 2011
ABSTRACT Technetium(I) tetracarbonyl complexes with diethyldithiocarbamate and methylxanthate lig... more ABSTRACT Technetium(I) tetracarbonyl complexes with diethyldithiocarbamate and methylxanthate ligands [TcL(CO)(4)] (L = S(2)CNEt(2) and S(2)COMe) were prepared. Conditions required for the formation of these complexes were found. The crystal and molecular structure of the xanthate complex was determined by single-crystal X-ray diffraction. [Tc(S(2)CNEt(2))(CO)(4)] undergoes decarbonylation both in solution and in the course of vacuum sublimation with the formation of a dimer [Tc(S(2)CNEt(2))(CO)(3)](2) whose structure was determined by single-crystal X-ray diffraction. In donor solvents, [Tc(S(2)CNEt(2))(CO)(4)] and [Tc(S(2)COMe)(CO)(4)] undergo decarbonylation with the formation of tricarbonyl solvates [TcL(CO)(3)(Sol)]. The crystal structure of the pyridine solvate [Tc(S(2)CNEt(2))(CO)(3)(py)], chosen as an example, was determined by single-crystal X-ray diffraction. The possibility of using bidentate S-donor acidic ligands for tethering the tetracarbonyltechnetium fragment to biomolecules was examined.
Acta Crystallographica Section E Structure Reports Online, 2008
Key indicators: single-crystal X-ray study; T = 293 K; mean (O-C) = 0.004 Å; disorder in main res... more Key indicators: single-crystal X-ray study; T = 293 K; mean (O-C) = 0.004 Å; disorder in main residue; R factor = 0.031; wR factor = 0.068; data-to-parameter ratio = 15.2.
Chemometrics and Intelligent Laboratory Systems, 2015
Restoring important process information from complex optical spectra with MCR-ALS: Case study of ... more Restoring important process information from complex optical spectra with MCR-ALS: Case study of actinides reduction in spent nuclear fuel reprocessing, Chemometrics and Intelligent Laboratory Systems (2015),
Inorganic Chemistry, 2014
Technetium(I) and rhenium(I) pentacarbonyl complexes with ethyl 2-isocyanoacetate and methyl 11-i... more Technetium(I) and rhenium(I) pentacarbonyl complexes with ethyl 2-isocyanoacetate and methyl 11-isocyanoundecanoate, [M(CO)5(CNCH2COOEt)]ClO4 (M = Tc (1) and Re (2)) and [M(CO)5(CN(CH2)10COOMe)]ClO4 (M = Tc (3) and Re (4)), were prepared and characterized by IR, (1)H NMR, and (13)C{(1)H} NMR spectroscopy. The crystal structures of 1 and 2 were determined using single-crystal X-ray diffraction. The kinetics of thermal decarbonylation of technetium complexes 1 and 3 in ethylene glycol was studied by IR spectroscopy. The rate constants and activation parameters of this reaction were determined and compared with those for [Tc(CO)6](+). It was found that rhenium complexes 2 and 4 were stable with respect to thermal decarbonylation. Histidine challenge reaction of complexes 1 and 2 in phosphate buffer was examined by IR spectroscopy. In the presence of histidine, the rhenium pentacarbonyl isocyanide complex partially decomposes to form an unidentified yellow precipitate. Technetium analogue 1 is more stable under these conditions.
SAE International Journal of Materials and Manufacturing, 2013
SAE International Journal of Materials and Manufacturing, 2014
Radiochimica Acta, 2012
ABSTRACT UV-Vis spectroscopic measurements were performed in model mixtures simulating solutions ... more ABSTRACT UV-Vis spectroscopic measurements were performed in model mixtures simulating solutions obtained in the course of PUREX spent nuclear fuel reprocessing. Mixtures contained constant concentrations of nitric acid and uranium with varied content of neptunium and plutonium. Spectral data were processed with classical chemometric technique - PLS regression. This approach has shown significant improvement in analytical precision of actinides determination compared to standard univariate data processing. The combination of spectroscopic measurements with chemometric data processing shows good promise for the development of on-line spectroscopic techniques for SNF reprocessing monitoring.
Radiochimica Acta, 2013
ABSTRACT Optical spectroscopic measurements in the UV-Vis and ER ranges were performed in model s... more ABSTRACT Optical spectroscopic measurements in the UV-Vis and ER ranges were performed in model solutions of aqueous and organic phases of the PUREX process for spent nuclear fuel (SNF) reprocessing. Chemometric processing of the spectral data with PLS (partial least squares) regression allowed simultaneous quantification of several key components (uranium, neptunium, plutonium, nitric acid) in these mixtures in an effective and elegant way. The content of all key components was quantitively determined with mean relative errors not exceeding 10%. It was shown that the employment of the whole spectra or their certain continuous regions for a PLS calibration enables to decrease the analytical errors compared to the use of a single wavelength in an ordinary least squares approach. The results of this research imply that the development of on-line techniques for SNF reprocessing monitoring is fully possible and can be based on optical spectroscopy methods combined with multivariate data processing techniques.
The Analyst, 2014
The experimental design of mixtures for multivariate calibration is introduced. The idea of this ... more The experimental design of mixtures for multivariate calibration is introduced. The idea of this design is based on uniform distribution of experimental points in a concentration hypercube. Unlike the already reported uniform designs this one is pretty simple and not computationally demanding. The suggested approach does not employ the concept of fixed "levels" and allows for designs with any number of experimental mixtures and any number of components depending on "time and money" considerations for each particular calibration experiment. The performance of the design is assessed with a UV-Vis spectroscopic experiment for simultaneous quantification of four inorganic components in complex mixtures. The performance of the PLS regression models derived from the design is compared with that of cyclic permutation and Kennard-Stone designs. The suggested approach allows for comparable or higher prediction accuracy with the lower number of experimental points.
Nuclear Medicine and Biology, 2009
Introduction: The use of 99m Tc-macroggregated albumin for lung perfusion imaging is well establi... more Introduction: The use of 99m Tc-macroggregated albumin for lung perfusion imaging is well established in nuclear medicine. However, there have been safety concerns over the use of blood-derived products because of potential contamination by infective agents, for example, Variant Creutzfeldt Jakob Disease. Preliminary work has indicated that Tc(CO) 5 I is primarily taken up in the lungs following intravenous administration. The aim of this study was to evaluate the biodistribution and pharmacokinetics of 99m Tc(CO) 5 I and its potential as a lung perfusion agent. Methods: 99m Tc(CO) 5 I was synthesized by carbonylation of 99m TcO 4− at 160 atm of CO at 170°C in the presence of HI for 40 min. Radiochemical purity was determined by HPLC using 99 Tc(CO) 5 I as a reference. 99m Tc(CO) 5 I was administered by ear-vein injection to three chinchilla rabbits, and dynamic images were acquired using a gamma camera (Siemens E-cam) over 20 min. Imaging studies were also performed with 99m Tc-labeled macroaggregated albumin ( 99m Tc-MAA) and 99m TcO 4− for comparison. 99m Tc(CO) 5 I was administered intravenously to Sprague-Dawley rats, and tissue distribution studies were obtained at 15 min and 1 h postinjection. Comparative studies were performed using 99m Tc-MAA. Results: Radiochemical purity, assessed by HPLC, was 98%. The retention time was similar to that of 99 Tc(CO) 5 I. The dynamic images showed that 70% of 99m Tc(CO) 5 I appeared promptly in the lungs and remained constant for at least 20 min. In contrast, 99m TcO 4− rapidly washed out of the lungs after administration. As expected 99m Tc-MAA showed 90% lung accumulation. The percentage of injected dose per gram of organ ±S.D. at 1 h for 99m Tc(CO) 5 I was as follows: blood, 0.22±0.02; lung, 12.8±2.87; liver, 0.8±0.15; heart, 0.15±0.01; kidney, 0.47 ±0.08. The percentage of injected dose per organ ±S.D. at 1 h was as follows: lung, 22.47±2.31; liver, 10.53±1.8; heart, 0.18±0.01; kidney, 1.2±0.17. Tissue distribution studies with 99m Tc-MAA showed 100% lung uptake. Conclusion: 99m Tc(CO) 5 I was synthesized with a high radiochemical purity and showed a high accumulation in the lungs. Further work on the mechanism and optimization of lung uptake of 99m Tc-pentacarbonyl complexes is warranted.
Journal of Labelled Compounds and Radiopharmaceuticals, 2013
Radiochemistry, 2014
The molar solubilities of Ba, Sr and Pb nitrates in nitric acid as a function of total nitrate co... more The molar solubilities of Ba, Sr and Pb nitrates in nitric acid as a function of total nitrate concentration is presented and described by the mass action law, indicating on formation of the adducts with nitric acid. Precipitates of Ba(NO 3 ) 2 and Sr(NO 3 ) 2 crystallized from nitric acid were studied by ISP OES and IR spectroscopy. The data obtained confirmed formation of metastable adducts with nitric acid. IR and X-ray diffraction studies of the mixed salt systems indicated conversion of the mixed salts into (Ba,Sr)(NO 3 ) 2 solid solution of discrete structure in range of total nitrate ion concentration *6 mol/L.
Radiochemistry, 2009
ABSTRACT The kinetics of decarbonylation of pentacarbonyltechnetium halides TcX(CO)5 (X = Cl, Br,... more ABSTRACT The kinetics of decarbonylation of pentacarbonyltechnetium halides TcX(CO)5 (X = Cl, Br, I) in CCl4 solution with the formation of dimers [TcX(CO)4]2 and of CO substitution in TcBr(CO)5 by the solvent molecule in CH3CN solution with the formation of the complex TcBr(CO)3(CH3CN)2 was studied. In all the systems, the reaction is first-order with respect to the starting compound. It was concluded that the limiting step of the reaction is dissociation into the intermediate complex TcX(CO)4 and CO molecule. The rate constants and activation energies of the reactions were determined.
Radiochemistry, 2009
ABSTRACT The crystal and molecular structures of [TcCl(CO)5] and [TcBr(CO)5] were determined. The... more ABSTRACT The crystal and molecular structures of [TcCl(CO)5] and [TcBr(CO)5] were determined. The compounds crystallize in the rhombic system, space group Pnma; a = 11.6757(18) and 11.9564(18) Å, b = 11.7365(14) and 11.7250(18) Å, c = 6.0407(7) and 6.2020(15) Å, V = 827.77(19) and 869.5(3) Å3, respectively; Z = 4. The structural data for pentacarbonyl halides were compared in the series Mn-Tc-Re and Cl-Br-I. Quantum-chemical calculations of the compounds [TcX(CO)5] (X = F, Cl, Br, I) and of the anion [TcCl3(CO)3]2− were made. A correlation between the geometry, electronic structure, and reactivity of the complexes is considered.
Radiochemistry, 2011
Hexacarbonyltechnetium(I) cation undergoes rapid hydrolysis in aqueous solutions at pH ≥ 7 with t... more Hexacarbonyltechnetium(I) cation undergoes rapid hydrolysis in aqueous solutions at pH ≥ 7 with the formation of an unidentified carbonyl compound or mixture of compounds in the form of a pale yellow precipitate. Two crystalline fractions were isolated in the course of vacuum sublimation of the precipitate and were identified by single crystal X-ray diffraction as Tc2(CO)10 and Tc3H3(CO)12. The crystal
Journal of Organometallic Chemistry, 2012
ABSTRACT Technetium hexacarbonyl perchlorate was prepared in CH2Cl2 in a reasonable yield. Reacti... more ABSTRACT Technetium hexacarbonyl perchlorate was prepared in CH2Cl2 in a reasonable yield. Reaction of this complex with acetonitrile was studied. The only reaction product was [Tc(CO)3(MeCN)3]ClO4. The crystal structure of [Tc(CO)3(MeCN)3]ClO4 was determined by single crystal X-ray diffraction. The kinetics of thermal decarbonylation of [Tc(CO)6]+ in acetonitrile was studied by IR spectroscopy. The rate constants and the activation energy of this reaction were determined. The rate constant is lower by more than an order of magnitude than that of [TcBr(CO)5]. The causes of increased stability of [Tc(CO)6]+ were analyzed by DFT calculations.
Inorganic Chemistry, 2011
ABSTRACT Technetium(I) tetracarbonyl complexes with diethyldithiocarbamate and methylxanthate lig... more ABSTRACT Technetium(I) tetracarbonyl complexes with diethyldithiocarbamate and methylxanthate ligands [TcL(CO)(4)] (L = S(2)CNEt(2) and S(2)COMe) were prepared. Conditions required for the formation of these complexes were found. The crystal and molecular structure of the xanthate complex was determined by single-crystal X-ray diffraction. [Tc(S(2)CNEt(2))(CO)(4)] undergoes decarbonylation both in solution and in the course of vacuum sublimation with the formation of a dimer [Tc(S(2)CNEt(2))(CO)(3)](2) whose structure was determined by single-crystal X-ray diffraction. In donor solvents, [Tc(S(2)CNEt(2))(CO)(4)] and [Tc(S(2)COMe)(CO)(4)] undergo decarbonylation with the formation of tricarbonyl solvates [TcL(CO)(3)(Sol)]. The crystal structure of the pyridine solvate [Tc(S(2)CNEt(2))(CO)(3)(py)], chosen as an example, was determined by single-crystal X-ray diffraction. The possibility of using bidentate S-donor acidic ligands for tethering the tetracarbonyltechnetium fragment to biomolecules was examined.
Acta Crystallographica Section E Structure Reports Online, 2008
Key indicators: single-crystal X-ray study; T = 293 K; mean (O-C) = 0.004 Å; disorder in main res... more Key indicators: single-crystal X-ray study; T = 293 K; mean (O-C) = 0.004 Å; disorder in main residue; R factor = 0.031; wR factor = 0.068; data-to-parameter ratio = 15.2.
Chemometrics and Intelligent Laboratory Systems, 2015
Restoring important process information from complex optical spectra with MCR-ALS: Case study of ... more Restoring important process information from complex optical spectra with MCR-ALS: Case study of actinides reduction in spent nuclear fuel reprocessing, Chemometrics and Intelligent Laboratory Systems (2015),
Inorganic Chemistry, 2014
Technetium(I) and rhenium(I) pentacarbonyl complexes with ethyl 2-isocyanoacetate and methyl 11-i... more Technetium(I) and rhenium(I) pentacarbonyl complexes with ethyl 2-isocyanoacetate and methyl 11-isocyanoundecanoate, [M(CO)5(CNCH2COOEt)]ClO4 (M = Tc (1) and Re (2)) and [M(CO)5(CN(CH2)10COOMe)]ClO4 (M = Tc (3) and Re (4)), were prepared and characterized by IR, (1)H NMR, and (13)C{(1)H} NMR spectroscopy. The crystal structures of 1 and 2 were determined using single-crystal X-ray diffraction. The kinetics of thermal decarbonylation of technetium complexes 1 and 3 in ethylene glycol was studied by IR spectroscopy. The rate constants and activation parameters of this reaction were determined and compared with those for [Tc(CO)6](+). It was found that rhenium complexes 2 and 4 were stable with respect to thermal decarbonylation. Histidine challenge reaction of complexes 1 and 2 in phosphate buffer was examined by IR spectroscopy. In the presence of histidine, the rhenium pentacarbonyl isocyanide complex partially decomposes to form an unidentified yellow precipitate. Technetium analogue 1 is more stable under these conditions.
SAE International Journal of Materials and Manufacturing, 2013
SAE International Journal of Materials and Manufacturing, 2014
Radiochimica Acta, 2012
ABSTRACT UV-Vis spectroscopic measurements were performed in model mixtures simulating solutions ... more ABSTRACT UV-Vis spectroscopic measurements were performed in model mixtures simulating solutions obtained in the course of PUREX spent nuclear fuel reprocessing. Mixtures contained constant concentrations of nitric acid and uranium with varied content of neptunium and plutonium. Spectral data were processed with classical chemometric technique - PLS regression. This approach has shown significant improvement in analytical precision of actinides determination compared to standard univariate data processing. The combination of spectroscopic measurements with chemometric data processing shows good promise for the development of on-line spectroscopic techniques for SNF reprocessing monitoring.
Radiochimica Acta, 2013
ABSTRACT Optical spectroscopic measurements in the UV-Vis and ER ranges were performed in model s... more ABSTRACT Optical spectroscopic measurements in the UV-Vis and ER ranges were performed in model solutions of aqueous and organic phases of the PUREX process for spent nuclear fuel (SNF) reprocessing. Chemometric processing of the spectral data with PLS (partial least squares) regression allowed simultaneous quantification of several key components (uranium, neptunium, plutonium, nitric acid) in these mixtures in an effective and elegant way. The content of all key components was quantitively determined with mean relative errors not exceeding 10%. It was shown that the employment of the whole spectra or their certain continuous regions for a PLS calibration enables to decrease the analytical errors compared to the use of a single wavelength in an ordinary least squares approach. The results of this research imply that the development of on-line techniques for SNF reprocessing monitoring is fully possible and can be based on optical spectroscopy methods combined with multivariate data processing techniques.
The Analyst, 2014
The experimental design of mixtures for multivariate calibration is introduced. The idea of this ... more The experimental design of mixtures for multivariate calibration is introduced. The idea of this design is based on uniform distribution of experimental points in a concentration hypercube. Unlike the already reported uniform designs this one is pretty simple and not computationally demanding. The suggested approach does not employ the concept of fixed "levels" and allows for designs with any number of experimental mixtures and any number of components depending on "time and money" considerations for each particular calibration experiment. The performance of the design is assessed with a UV-Vis spectroscopic experiment for simultaneous quantification of four inorganic components in complex mixtures. The performance of the PLS regression models derived from the design is compared with that of cyclic permutation and Kennard-Stone designs. The suggested approach allows for comparable or higher prediction accuracy with the lower number of experimental points.
Nuclear Medicine and Biology, 2009
Introduction: The use of 99m Tc-macroggregated albumin for lung perfusion imaging is well establi... more Introduction: The use of 99m Tc-macroggregated albumin for lung perfusion imaging is well established in nuclear medicine. However, there have been safety concerns over the use of blood-derived products because of potential contamination by infective agents, for example, Variant Creutzfeldt Jakob Disease. Preliminary work has indicated that Tc(CO) 5 I is primarily taken up in the lungs following intravenous administration. The aim of this study was to evaluate the biodistribution and pharmacokinetics of 99m Tc(CO) 5 I and its potential as a lung perfusion agent. Methods: 99m Tc(CO) 5 I was synthesized by carbonylation of 99m TcO 4− at 160 atm of CO at 170°C in the presence of HI for 40 min. Radiochemical purity was determined by HPLC using 99 Tc(CO) 5 I as a reference. 99m Tc(CO) 5 I was administered by ear-vein injection to three chinchilla rabbits, and dynamic images were acquired using a gamma camera (Siemens E-cam) over 20 min. Imaging studies were also performed with 99m Tc-labeled macroaggregated albumin ( 99m Tc-MAA) and 99m TcO 4− for comparison. 99m Tc(CO) 5 I was administered intravenously to Sprague-Dawley rats, and tissue distribution studies were obtained at 15 min and 1 h postinjection. Comparative studies were performed using 99m Tc-MAA. Results: Radiochemical purity, assessed by HPLC, was 98%. The retention time was similar to that of 99 Tc(CO) 5 I. The dynamic images showed that 70% of 99m Tc(CO) 5 I appeared promptly in the lungs and remained constant for at least 20 min. In contrast, 99m TcO 4− rapidly washed out of the lungs after administration. As expected 99m Tc-MAA showed 90% lung accumulation. The percentage of injected dose per gram of organ ±S.D. at 1 h for 99m Tc(CO) 5 I was as follows: blood, 0.22±0.02; lung, 12.8±2.87; liver, 0.8±0.15; heart, 0.15±0.01; kidney, 0.47 ±0.08. The percentage of injected dose per organ ±S.D. at 1 h was as follows: lung, 22.47±2.31; liver, 10.53±1.8; heart, 0.18±0.01; kidney, 1.2±0.17. Tissue distribution studies with 99m Tc-MAA showed 100% lung uptake. Conclusion: 99m Tc(CO) 5 I was synthesized with a high radiochemical purity and showed a high accumulation in the lungs. Further work on the mechanism and optimization of lung uptake of 99m Tc-pentacarbonyl complexes is warranted.
Journal of Labelled Compounds and Radiopharmaceuticals, 2013
Radiochemistry, 2014
The molar solubilities of Ba, Sr and Pb nitrates in nitric acid as a function of total nitrate co... more The molar solubilities of Ba, Sr and Pb nitrates in nitric acid as a function of total nitrate concentration is presented and described by the mass action law, indicating on formation of the adducts with nitric acid. Precipitates of Ba(NO 3 ) 2 and Sr(NO 3 ) 2 crystallized from nitric acid were studied by ISP OES and IR spectroscopy. The data obtained confirmed formation of metastable adducts with nitric acid. IR and X-ray diffraction studies of the mixed salt systems indicated conversion of the mixed salts into (Ba,Sr)(NO 3 ) 2 solid solution of discrete structure in range of total nitrate ion concentration *6 mol/L.