Mixed donor quinone complexes of nickel, zinc, cobalt, manganese and vanadium

Thesis/Dissertation · Wed Jan 01 04:00:00 EST 1992

OSTI ID:7283766

Scotto, C S

Mixed donor complexes of several first row metals have been prepared and examined for variations in redox properties, charge distribution and stability in comparison with homoleptic metal quinone species. Schiff base condensation between 3,5-di-tert-butylcatechol and ammonia provided the 3,5 di-tert-butyl-1,2-quinone-1-(2-hydroxy-3,5-di-tert-butlyphenyl)imine ligand for known M(QNQ)[sub 2] compounds. X-ray diffraction, cyclic voltammetry and solution susceptibility measurements were employed to compare properties with the pure quinone complexes and, in the case of Mn(QNQ)[sub 2] and CO(QNQ)[sub 2], with mixed ligand pyridyl quinone compounds of the two metals. Synthesis of the V(QNQ)[sub 2] analog was undertaken with partial characterization achieved through EPR, cyclic voltammetry and mass spectrometry. The vanadium chemistry was extended to mixed ligand catecholate complexes of V[sup III] and V[sup IV]. Such species are currently of interest in tunicate vanadium studies and in the catalytic oxygenation of pyrocatechols. Tetrachlorocatecholate analogs of known compounds were prepared and fully characterized. The x-ray structure of V(bipyridyl)(tetrachlorocatecholate)[sub 2] provided an unusual example of trigonal prismataic geometry about the metal center. A proposed intermediate in the synthesis of the target complex anion [V(bipyridyl)(tetrachlorocatecholate)[sub 2]] from V(acac) was isolated and identified as V(acetylacetone) (bipyridyl) (tetrachlorocatecholate). [V(bipyridyl) (tetrachlorocatecholate)[sub 2]] was obtained and characterized by cyclic voltammetry and visible spectroscopy. Reactivity of this species toward bipyridine was tested and the results discussed in relation to to bipyridyl assay for tunicate vanadium.

• Research Organization: Colorado Univ., Boulder, CO (United States)
• OSTI ID: 7283766
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
400201* -- Chemical & Physicochemical Properties
400400 -- Electrochemistry
AROMATICS
CHARGE DISTRIBUTION
CHEMICAL PROPERTIES
CHEMISTRY
COBALT COMPLEXES
COMPLEXES
ELECTROCHEMISTRY
IMINES
MANGANESE COMPLEXES
NICKEL COMPLEXES
ORGANIC COMPOUNDS
ORGANIC NITROGEN COMPOUNDS
ORGANIC OXYGEN COMPOUNDS
ORGANOMETALLIC COMPOUNDS
QUINONES
REDOX POTENTIAL
SCHIFF BASES
STRUCTURAL CHEMICAL ANALYSIS
TRANSITION ELEMENT COMPLEXES
VANADIUM COMPLEXES
ZINC COMPLEXES