Chemical evolution of a nitrogenase model. X. Reduction of coordinated cyanide ion in cyano complexes of molybdenum(IV) and their use as catalysts for the reduction of molecular nitrogen and of other substrates
The complex anions [Mo(O)$sub 2$(CN)$sub 4$$]$$sup 4-$ (1), [MO(O)(OH)(CN)$sub 4$$]$$sup 3-$ (2), and [Mo(O)(H$sub 2$O)(CN)$sub 4$$]$$sup 2-$ (3) represent rare examples of defined monomeric complexes of oxomolybdate(IV) and may be regarded as models of substrate-catalyst complexes in the reduction of CN$sup -$ by molybdothiol catalyst systems. The reduction of coordinated CN$sup - $ in 3 to NH$sub 3$, CH$sub 4$, C$sub 2$$H$$sub 6$, and C$sub 2$$H$$sub 4$ was demonstrated with BH$sub 4$$sup -$, S$sub 2$$O$$sub 4$$sup 2-$, and reduced ferredoxin model compounds as reducing agents. Evidence for a significant stimulatory effect of adenosine triphosphate (ATP) was also obtained. The reduction of coordinated CN$sup -$ is inhibited by O$sub 2$, CO, and the known substrates of nitrogenase enzymes. The latter are reduced under the reaction conditions, involving coordinatively unsaturated cyano complexes of oxomolybdate(IV) as the catalysts. The reduction of molecular N$sub 2$ to NH$sub 3$ and traces of N$sub 2$$H$$sub 4$ was also observed and proceeds more efficiently than in the molybdothiol model systems of nitrogenase. ATP causes a significant stimulation of CN$sup -$ reduction in H$sub 2$O, but not in D$sub 2$O. (auth)
- Research Organization:
- Univ. of California, San Diego
- Sponsoring Organization:
- USDOE
- NSA Number:
- NSA-33-014281
- OSTI ID:
- 4130101
- Journal Information:
- J. Am. Chem. Soc., v. 97, no. 24, pp. 7069-7076, Other Information: Orig. Receipt Date: 30-JUN-76
- Country of Publication:
- United States
- Language:
- English
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