Polyoxoanions as soluble metal oxide analogs. Synthesis and characterization of the polyoxoanion-supported iridium(I) complex (1,5-COD)Ir[center dot]SiW[sub 9]Nb[sub 3]O[sub 40][sup 6[minus]]
- Univ. of Oregon, Eugene, OR (United States)
The synthesis and characterization of (Bu[sub 4]N)[sub 4][(1,5-COD)Ir[center dot]SiW[sub 9]Nb[sub 3]O[sub 40]], a Keggin polyoxoanion-supported Ir(1,5-COD)[sup +] complex, is reported (1,5-COD = 1,5-cyclooctadiene). The complex was characterized by means of an element analysis (all elements), ultracentrifugation solution molecular-weight measurements, and [sup 1]H, [sup 13]C, and [sup 183]W NMR and IR spectroscopies in both weakly coordinating the strongly coordinating solvents. The solvent-dependent NMR results demonstrate that, in weakly coordinating solvents, a C[sub s] symmetry complex obtains. On the basis of literature precedent, two most plausible, slightly different C[sub s] symmetry structures are proposed, one involving Ir(1,5-COD)[sup +] bonding to two ONbW bridging oxygens and one OW[sub 2] bridging oxygen and another involving the same two ONbW bridging oxygens but then one ONb terminal oxygen. The significance of this work is 3-fold: It describes the first Keggin-type polyoxoanion-supported Ir(1,5-COD)[sup +] complex; it describes the first Keggin anion-supported complex that also serves as an effective catalyst precursor; and it sets the stage for the first detailed comparison of the catalytic properties of two different polyoxoanion-supported catalysts of any type, namely the present Keggin anion-based complex (Bu[sub 4]N)[sub 4]Na[sub 2][(1,5-COD)Ir[center dot]SiW[sub 9]Nb[sub 3]O[sub 40]] and the Wells-Dawson anion-based complex (Bu[sub 4]N)[sub 5]Na[sub 3][(1,5-COD)Ir[center dot]P[sub 2]W[sub 15]Nb[sub 3]O[sub 62]] the authors reported previously.
- OSTI ID:
- 5110009
- Journal Information:
- Inorganic Chemistry; (United States), Journal Name: Inorganic Chemistry; (United States) Vol. 32:26; ISSN 0020-1669; ISSN INOCAJ
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
400201* -- Chemical & Physicochemical Properties
ABSORPTION SPECTROSCOPY
CARBON 13
CARBON ISOTOPES
CATALYST SUPPORTS
CATALYSTS
CHALCOGENIDES
CHEMICAL COMPOSITION
CHEMICAL PREPARATION
COMPLEXES
EVEN-ODD NUCLEI
HEAVY NUCLEI
IRIDIUM COMPLEXES
ISOMERIC TRANSITION ISOTOPES
ISOTOPES
LIGHT NUCLEI
MAGNETIC RESONANCE
NIOBIUM COMPOUNDS
NUCLEAR MAGNETIC RESONANCE
NUCLEI
OXIDES
OXYGEN COMPOUNDS
RADIOISOTOPES
REFRACTORY METAL COMPOUNDS
RESONANCE
SECONDS LIVING RADIOISOTOPES
SILICON COMPOUNDS
SPECTROSCOPY
STABLE ISOTOPES
STRUCTURAL CHEMICAL ANALYSIS
SYNTHESIS
TRANSITION ELEMENT COMPLEXES
TRANSITION ELEMENT COMPOUNDS
TUNGSTEN 183
TUNGSTEN COMPOUNDS
TUNGSTEN ISOTOPES