Technetium bis(. mu. -oxo) dimers of 1,4,7-triazacyclononane-N,N prime N, double prime -triacetate (TCTA). Synthesis and characterization of (TCTA)Tc(. mu. -O) sub 2 Tc(TCTA) sup n- (n = 2,3) and the crystal structure of Ba sub 2 (TCTA)Tc(. mu. -O) sub 2 Tc(TCTA)(ClO sub 4 )ter dot 9H sub 2 O

Journal Article · Wed Oct 04 00:00:00 EDT 1989 · Inorganic Chemistry; (USA)

DOI:https://doi.org/10.1021/ic00319a014· OSTI ID:7170711

Linder, K E; Dewan, J C; Davison, A ^[1]

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1. Massachusetts Institute of Technology, Cambridge (USA)

The mixed-valence technetium(III/IV) bis({mu}-oxo) dimer ((TCTA)Tc({mu}-O){sub 2}Tc(TCTA)){sup 3{minus}} (1; TCTA = 1,4,7-triazayclononane-N,N{prime},N{double prime}-triacetate) has been prepared as its sodium and barium salts. This complex undergoes a reversible on-electron oxidation with potassium persulfate to form ((TCTA)Tc({mu}-O){sub 2}Tc(TCTA)){sup 2{minus}} (2). Both complexes have been characterized by elemental analysis, infrared, UV/visible, and resonance Raman spectroscopy, and fast atom bombardment mass spectrometry. A crystal structure analysis of the Tc(III/IV) dimeter Ba{sub 2}((TCTA)Tc({mu}O){sub 2}Tc(TCTA))(ClO{sub 4}){center dot}9H{sub 2}O (1c) reveals that the two Tc atoms are linked by a planar Tc({mu}-O){sub 2}Tc ring. One TCTA ligand binds to each Tc through an N{sub 3}O donor set, and one of the acetate groups from each ligand bridges the two metal atoms. Resonance Raman spectra of complexes 1 and 2 were obtained by irradiation at 514.5 nm; strong bands assigned to the four-membered Tc({mu}-O){sub 2}Tc ring and the metal-metal multiple bond were seen. The aqueous electrochemistry of the compounds confirms that they are related by a reversible one-electron wave. The Tc(III/IV) dimer 1 represents the first fully characterized Tc-(amino carboxylate) complex in an oxidation state lower than +4. Evidence for the existence of other Tc(III/IV) bis({mu}-oxo) dimers of this type with amino carboxylate ligands such as EDTA and NTA is presented. 23 refs., 3 figs., 4 tabs.

• OSTI ID: 7170711
• Journal Information: Inorganic Chemistry; (USA), Vol. 28:20; ISSN 0020-1669
• Country of Publication: United States
• Language: English

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37 INORGANIC
ORGANIC
PHYSICAL AND ANALYTICAL CHEMISTRY
ACETATES
SYNTHESIS
BARIUM COMPLEXES
CHLORINE COMPOUNDS
CYCLOALKANES
ORGANIC NITROGEN COMPOUNDS
OXYGEN COMPOUNDS
TECHNETIUM COMPLEXES
CRYSTAL STRUCTURE
EXPERIMENTAL DATA
ALKALINE EARTH METAL COMPLEXES
ALKANES
CARBOXYLIC ACID SALTS
COMPLEXES
DATA
HALOGEN COMPOUNDS
HYDROCARBONS
INFORMATION
NUMERICAL DATA
ORGANIC COMPOUNDS
TRANSITION ELEMENT COMPLEXES
400201* - Chemical & Physicochemical Properties