Question

CO stretch change if change in the oxidation state of the metal from +2 to 0

Answer 1

CO molecule O atom C atom 2s TT TTy LS 2σ 2s

CEO CEO Ơ bond T back-bond Carbon monoxide bonds to transition metals using "synergistic n back-bonding." The bonding has three components, giving rise to a partial triple bond. A sigma bond arises from overlap of the nonbonding (or weakly anti-bonding) sp-hybridized electron pair on carbon with a blend of d-, s-, and p-orbitals orn the metal. A pair of n bonds arises from overlap of filled d-orbitals on the metal with a pair of T-antibonding orbitals projecting from the carbon atom of the CO. The latter kind of binding requires that the metal have d- electrons, and that the metal is in a relatively low oxidation state (<+2) which makes the back donation process favorable. As electrons from the metal fill the n-antibonding orbital of Co, they weaken the carbon-oxygen bond compared with free carbon monoxide,