Deoxygenation of polynuclear metal-oxo anions: Synthesis, structure, and reactivity of the condensed polyoxoanion [(C{sub 4}H{sub 9}){sub 4}N]{sub 4}(NbW{sub 5}O{sub 18}){sub 2}O
- Columbia Univ., New York, NY (United States)
The deoxygenation of the mixed-metal polyoxoanion [(C{sub 4} H{sub 9}){sub 4}N]{sub 3}NbW{sub 5}O{sub 19} with benzoyl chloride in dichloromethane forms quantitatively the condensed polyoxanion [(C{sub 4}H{sub 9}){sub 4}N]{sub 4}(NbW{sub 5}O{sub 18}){sub 2}O, in which two polyoxoanion fragments are linked together by a Nb-O-Nb oxo bridge. The product is characterized by a strong IR band at 692 cm{sup {minus}1} assigned to a Nb-O-Nb stretch and a broad single {sup 93}Nb NMR resonance at 975 ppm. Partial hydrolysis of [(C{sub 4}H{sub 9}){sub 4}N]{sub 4}(NbW{sub 5}O{sub 18}){sub 2}O to NbW{sub 5}O{sub 19}O{sup 3{minus}} in wet acetonitrile was observed by IR and {sup 17}O NMR spectroscopy. The reaction of [(C{sub 4}H{sub 9}){sub 4}N]{sub 4}(NbW{sub 5}O{sub 18}) (R = methyl, ethyl, isopropyl, cholesteryl, phenyl). The similarity of the IR spectra of these deriviatives suggests that functionalization occurs at the terminal NbO oxygen. A crystallographic study of [(C{sub 4}H{sub 9}){sub 4}N]{sub 4}(NbW{sub 5}O{sub 18}){sub 2}O revealed a crystallographically imposed linear Nb-O-Nb oxo bridge (Nb-O{sub bridge} = 1.887(3) {Angstrom}) and a structure in which the terminal tungsten-oxo bonds on the adjoining polyoxoanion fragments are eclipsed.
- OSTI ID:
- 281131
- Journal Information:
- Inorganic Chemistry, Journal Name: Inorganic Chemistry Journal Issue: 9 Vol. 35; ISSN 0020-1669; ISSN INOCAJ
- Country of Publication:
- United States
- Language:
- English
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