Organometallic Compound Identification
An organometallic compound is defined as a compound containing at least one chemical bond between a carbon atom of an organic molecule and a metal atom.
Analysis of Options
We need to identify which of the given options is a well-known, naturally occurring organometallic compound.
- Vitamin $B_{12}$ coenzyme: This molecule, also known as cobalamin, contains a cobalt atom directly bonded to a carbon atom of the 5'-deoxyadenosyl group. This direct metal-carbon bond satisfies the definition of an organometallic compound. Cobalt is the metal.
- Chlorophyll: This molecule contains a magnesium (Mg) atom at its center, coordinated by nitrogen atoms within the porphyrin ring. The magnesium is bonded to nitrogen, not directly to carbon in the typical organometallic sense.
- Cytochrome P-450: This is a heme protein containing an iron (Fe) atom coordinated within a porphyrin ring. Similar to chlorophyll, the iron is bonded to nitrogen atoms, not directly to carbon.
- Myoglobin: This protein also contains an iron (Fe) atom complexed within a heme group, where the iron is bonded to nitrogen atoms.
Conclusion
Based on the definition, Vitamin $B_{12}$ coenzyme is the clear example of a naturally occurring organometallic compound among the choices because it features a specific metal-carbon bond (Co-C).
The other options (chlorophyll, cytochrome P-450, myoglobin) are metallo-organic compounds or metal complexes but lack the defining direct carbon-metal bond characteristic of organometallic compounds.
Important Questions from Bioinorganic Chemistry
Consider the following transformation reactions in the context of co - enzyme B12
A. 1, 2 - Carbon shift
B. Hydration of CO2
C. Benzene to phenol
D. Dimethyl sulfide to dimethyl sulfoxide
The correct statement(s) for co - enzyme B12 is / are
During the binding of O2 to myoglobin (consider 'heme' in xy-plane), the molecular orbital of O2 and atomic orbital of Fe involved in the formation of the σ-bond is
In the catalytic cycle of Cytochrome P450, the generation of [(porphyrin)+•FeIV(O)] from [(porphyrin)FeIII(OOH)] involves
Match List I with List II
List I
List II
Metalloprotein
Metal
A.
carboxypeptidase A
I.
Mn
B.
oxygen-evolving complex
II.
Fe
C.
hemerythrin
III.
Ni
D.
coenzyme F-430
IV.
Zn
Choose the correct answer from the options given below:
In solution, Vaska's complex is known to bind O2 reversibly. In the product, oxidation state of the metal ion center coordination geometry and mode of binding of O2, respectively are
