Metal-metal multiply-bonded complexes of technetium. 2. Preparation and characterization of the fully solvated ditechnetium cation [Tc{sub 2}(CH{sub 3}CN){sub 10}]{sup 4+}

Journal Article · Wed Mar 29 04:00:00 EST 1995 · Inorganic Chemistry

DOI:https://doi.org/10.1021/ic00111a040· OSTI ID:401819

Bryan, J C ^[1]; Cotton, A; Daniels, L M ^[2]

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1. Los Alamos National Lab., NM (United States)
2. Texas A & M Univ., College Station (United States); and others

Acidification of Tc{sub 2}Cl{sub 4}(PR{sub 3}){sub 4} with HBF{sub 4}{center_dot}Et{sub 2}O in a mixture of acetonitrile and methylene chloride results in the formation of the metal-metal triply-bonded solvated complex [Tc{sub 2}(CH{sub 3}CN){sub 10}][BF{sub 4}]{sub 4} (1) in 80% yield. This compound may also be prepared through reduction of [Bu{sub 4}N]{sub 2}[TcCl{sub 6}] with either Bu{sub 3}SnH or finely divided Zn followed by treatment with HBF{sub 4}{center_dot}Et{sub 2}O, but in lower yields (approximately 50%). The quadruply bonded species Tc{sub 2}Cl{sub 8}{sup 2{minus}} also reacts with HBF{sub 4}{center_dot}Et{sub 2}O in a mixture of acetonitrile and diethyl ether under mild heating to produce small amounts of blue [Tc{sub 2}(CH{sub 3}CN){sub 10}][BF{sub 4}]{sub 4} (yield 14%). In addition to the formation of 1, yellow crystals that proved to be the mononuclear Tc(III) species [TcCl{sub 2}(CH{sub 3}CN){sub 4}][BF{sub 4}] (2) were isolated in 34% yield from the reaction solution. The dinuclear cation [Tc{sub 2}(CH{sub 3}CN){sub 10}]{sup 4+} was crystallized as the mixed [Tc{sub 2}(CH{sub 3}CN){sub 8}(CF{sub 3}-SO{sub 3}){sub 2}](BF{sub 4}){sub 2}{center_dot}CH{sub 3}CN (1a{center_dot}CH{sub 3}CN) by addition of 8 equivs of Tl(CF{sub 3}SO{sub 3}) to a CH{sub 3}CN solution of 1 followed by slow diffusion of a mixture of Et{sub 2}O and hexanes. Compound 1a{center_dot}CH{sub 3}CN crystallized in the tetragonal space group P4{sub 1}2{sub 1}2. Single crystal X-ray analysis of [TcCl{sub 2}(CH{sub 3}CN){sub 4}][BF{sub 4}] revealed a trans disposition of chloride ligands with approximate D{sub 4h} symmetry about the Tc atom. Nitrile complexes 1 and 2 have been fully characterized by a variety of physical and spectroscopic techniques including {sup 1}H NMR, UV-vis and IR spectroscopies and cyclic voltammetry.

• Sponsoring Organization: USDOE
• OSTI ID: 401819
• Journal Information: Inorganic Chemistry, Journal Name: Inorganic Chemistry Journal Issue: 7 Vol. 34; ISSN 0020-1669; ISSN INOCAJ
• Country of Publication: United States
• Language: English

Related Subjects

40 CHEMISTRY
ABSORPTION SPECTROSCOPY
ACETONITRILE
CATIONS
CHEMICAL PREPARATION
CHEMICAL REACTION YIELD
CRYSTAL STRUCTURE
NUCLEAR MAGNETIC RESONANCE
ORTHORHOMBIC LATTICES
TECHNETIUM COMPLEXES
TETRAGONAL LATTICES
VOLTAMETRY