Technetium electrochemistry. 2. Electrochemical and spectroelectrochemical studies of the bis(tertiary phosphine) (D) complexes trans-(Tc/sup III/D/sub 2/X/sub 2/)/sup +/ (X = Cl, Br) and (Tc/sub I/D/sub 3/)/sup +/

Journal Article · Tue Apr 24 23:00:00 EST 1984 · Inorg. Chem.; (United States)

DOI:https://doi.org/10.1021/ic00177a020· OSTI ID:6549564

Ichimura, A; Heineman, W R; Vanderheyden, J L; Deutsch, E

The redox chemistry of a series of the well-characterized, robust, cationic technetium complexes trans-(Tc/sup III/D/sup 2/X/sup 2/)/sup +/ and (Tc/sup I/D/sub 3/)/sup +/, where D = 1,2-bis(dimethylphosphino)ethane (dmpe) and 1,2-bis(diethylphosphino)ethane (depe) and X = Cl and Br, has been investigated in nonaqueous media with use of cyclic voltammetry at 25 and -40/sup 0/C, spectroelectrochemistry with a gold-minigrid optically transparent thin-layer electrode, and thin-layer coulometry plus in aqueous media with use of normal pulse voltammetry. The (TcD/sub 2/X/sub 2/)/sup +/ complexes undergo two electrochemical reactions in N,N-dimethylformamide (DMF), 0.5 M in tetraethylammonium perchlorate (TEAP), corresponding to the reduction of Tc(III) to Tc(II) and Tc(II) in water, acetonitrile, propylene carbonate, or DMF. The redox potentials for these Tc(II)/Tc(I) couples in propylene carbonate (0.5 M TEAP) are +0.330 and +0.166 vs. Ag/AgCl for the dmpe and depe complexes, respectively. The Tc(II) complex (Tc(dmpe)/sub 3/)/sup 2 +/ undergoes further, more complicated oxidation reactions in propylene carbonate. In aqueous media the E/sup 0/' value governing the (Tc(dmpe)/sub 3/)/sup 2 +///sup +/ couple is the same as it is in DMF, but the E/sup 0/' values governing the (TcD/sub 2/X/sub 2/)/sup +/0/ couples are markedly shifted to more positive potentials, reflecting the water insolubility of the neutral technetium(II) complexes (TcD/sub 2/X/sub 2/)/sup 0/.

• DOE Contract Number: AC02-80EV10380
• OSTI ID: 6549564
• Journal Information: Inorg. Chem.; (United States), Journal Name: Inorg. Chem.; (United States) Vol. 23:9; ISSN INOCA
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
38 RADIATION CHEMISTRY, RADIOCHEMISTRY, AND NUCLEAR CHEMISTRY
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ALKANES
CHEMISTRY
COMPLEXES
DATA
ELECTROCHEMISTRY
EXPERIMENTAL DATA
HYDROCARBONS
INFORMATION
NUMERICAL DATA
ORGANIC COMPOUNDS
ORGANOMETALLIC COMPOUNDS
TECHNETIUM COMPLEXES
TEMPERATURE EFFECTS
TRANSITION ELEMENT COMPLEXES
VOLTAMETRY