JEE Advanced2018ChemistryCoordination CompoundsActual
The correct statement(s) regarding the binary transition metal carbonyl compounds is (are) (Atomic numbers: F e = 26 , N i = 28 )
Options
- ATotal number of valence shell electrons at metal center in F e C O 5 o r N i C O 4 is 16
- BThese are predominantly low spin in nature
- CMetal - carbon bond strengthens when the oxidation state of the metal is lowered
- DThe carbonyl C - O bond weakens when the oxidation state of the metal is increased
Correct answer
B. These are predominantly low spin in nature
Step-by-step solution
( A ) F e C O 5 a n d N i C O 4 Complexes have 18- electrons in their valence shell ( B ) Carbonyl complexes are predominantly low spin complexes due to strong ligand field ( C ) As electron density increases on metals (with lowering oxidation state on metals), the extent of synergic bonding increases. Hence M - C bond strength increases ( D ) While positive charge on metals increases and the extent of synergic bond decreases and hence C - O bond becomes stronger.