2 Comprehensive Electrochemistry of Tc …
27
• Potentials of technetium redox couples are shifted usually by 0.2–0.3 V toward
more positive values as compared with the respective rhenium analogs. Not all
redox systems known for Re are observed for Tc and vice versa.
• The tendency to dimerization or polymerization of Tc(IV) makes it similar to
Mo(IV) and Ru(IV).
• Voltammetric curves of metallic technetium do not reveal the electrical double
layer charging region, which makes technetium similar not only to rhenium but
also to, e.g., ruthenium.
• Transport properties (e.g., diffusion coefficients, conductance) of technetium ionic
forms are very similar to their rhenium analogs. They are practically the same for
low concentrations of the ions (~mmol dm
−3 ).
• Influence of the electrode material on electroreduction of MO
−
4 ions is observed
for the manganese group elements (Mn, Tc, Re).
• Ionic forms of Re(VI) or Tc(VI) are unstable both in aqueous and nonaqueous
solutions.
• Re(V) and Tc(V) forms are stabilized in concentrated acid solutions.
References
Ardon M, Pernick A (1974) The binuclear molybdenum(III)-aquo ion. Inorg Chem 13(9):2275–
2277
Astheimer L, Schwochau K (1976) Electrochemical reduction of MnO
−
4 , ReO
−
4 and TcO
−
4 in organic
solvents. Preparation of tetraoxomanganate(VI), -technetate(VI) and -rhenate(VI). J Inorg Nucl
Chem 38:1131–1134
Atlas of Eh-pH diagrams. Intercomparison of thermodynamic databases. (2005) Geological Survey
of Japan Open File Report No. 419. National Institute of Advanced Industrial Science and
Technology, pp 251–253
Bard AJ, Parsons R, Jordan J (eds) (1985) Standard potentials in aqueous solution. IUPAC, Marcel
Dekker, pp 421, 450, 480
Baumann A, Yalçýnta¸ t E, Gaona X et al (2018) Thermodynamic description of Tc(IV) solubility and
carbonate complexation in alkaline NaHCO 3 –Na 2 CO 3 –NaCl systems. Dalton Trans 47:4377–
4392
Boyd GE (1978) Osmotic and activity coefficients of aqueous HTcO 4 and HReO 4 solutions at 25
°C. Inor Chem 17(7):1808–1810
Cartledge GH (1971) Free energies of formation of hydrous oxides of technetium in its lower
valencies. J Electrochem Soc 118(2):231–236
Chatterjee S, Hall GB, Johnson IE et al (2018) Surprising formation of quasi-stable Tc(VI) in high
ionic strength alkaline media. Inorg Chem Front 5(9):2081–2091
Chotkowski M, Czerwi´ nski A (2012) Electrochemical and spectroelectrochemical studies of
pertechnetate electroreduction in acidic media. Electrochim Acta 76:165–173
Chotkowski M, Rogulski Z, Czerwi´ nski A (2011) Spectroelectrochemical investigation of MnO 2
electro-generation and electro-reduction in acidic media. J Electroanal Chem 651:237–242
Cordoba de Torresi SI, Gorenstein A (1992) Electrochromic behavior of manganese dioxide films
in slightly alkaline solutions. Electrochim Acta 37:2015–2019
Crompton TR, Crompton TPJ (2000) Battery reference book, 3rd ed, Chapters 6, 9, 10, 21, 25, 39.
Newnes
Czerwi´ nski A, Rogulski Z (2005) Patent RP–185542, Primary zinc-manganese cell (in polish)
27
• Potentials of technetium redox couples are shifted usually by 0.2–0.3 V toward
more positive values as compared with the respective rhenium analogs. Not all
redox systems known for Re are observed for Tc and vice versa.
• The tendency to dimerization or polymerization of Tc(IV) makes it similar to
Mo(IV) and Ru(IV).
• Voltammetric curves of metallic technetium do not reveal the electrical double
layer charging region, which makes technetium similar not only to rhenium but
also to, e.g., ruthenium.
• Transport properties (e.g., diffusion coefficients, conductance) of technetium ionic
forms are very similar to their rhenium analogs. They are practically the same for
low concentrations of the ions (~mmol dm
−3 ).
• Influence of the electrode material on electroreduction of MO
−
4 ions is observed
for the manganese group elements (Mn, Tc, Re).
• Ionic forms of Re(VI) or Tc(VI) are unstable both in aqueous and nonaqueous
solutions.
• Re(V) and Tc(V) forms are stabilized in concentrated acid solutions.
References
Ardon M, Pernick A (1974) The binuclear molybdenum(III)-aquo ion. Inorg Chem 13(9):2275–
2277
Astheimer L, Schwochau K (1976) Electrochemical reduction of MnO
−
4 , ReO
−
4 and TcO
−
4 in organic
solvents. Preparation of tetraoxomanganate(VI), -technetate(VI) and -rhenate(VI). J Inorg Nucl
Chem 38:1131–1134
Atlas of Eh-pH diagrams. Intercomparison of thermodynamic databases. (2005) Geological Survey
of Japan Open File Report No. 419. National Institute of Advanced Industrial Science and
Technology, pp 251–253
Bard AJ, Parsons R, Jordan J (eds) (1985) Standard potentials in aqueous solution. IUPAC, Marcel
Dekker, pp 421, 450, 480
Baumann A, Yalçýnta¸ t E, Gaona X et al (2018) Thermodynamic description of Tc(IV) solubility and
carbonate complexation in alkaline NaHCO 3 –Na 2 CO 3 –NaCl systems. Dalton Trans 47:4377–
4392
Boyd GE (1978) Osmotic and activity coefficients of aqueous HTcO 4 and HReO 4 solutions at 25
°C. Inor Chem 17(7):1808–1810
Cartledge GH (1971) Free energies of formation of hydrous oxides of technetium in its lower
valencies. J Electrochem Soc 118(2):231–236
Chatterjee S, Hall GB, Johnson IE et al (2018) Surprising formation of quasi-stable Tc(VI) in high
ionic strength alkaline media. Inorg Chem Front 5(9):2081–2091
Chotkowski M, Czerwi´ nski A (2012) Electrochemical and spectroelectrochemical studies of
pertechnetate electroreduction in acidic media. Electrochim Acta 76:165–173
Chotkowski M, Rogulski Z, Czerwi´ nski A (2011) Spectroelectrochemical investigation of MnO 2
electro-generation and electro-reduction in acidic media. J Electroanal Chem 651:237–242
Cordoba de Torresi SI, Gorenstein A (1992) Electrochromic behavior of manganese dioxide films
in slightly alkaline solutions. Electrochim Acta 37:2015–2019
Crompton TR, Crompton TPJ (2000) Battery reference book, 3rd ed, Chapters 6, 9, 10, 21, 25, 39.
Newnes
Czerwi´ nski A, Rogulski Z (2005) Patent RP–185542, Primary zinc-manganese cell (in polish)