Question

Describe each highlighted bond in terms of the overlap of atomic orbitals. (a) C=C (b) \(\mathrm{H}-\mathrm{C} \equiv \mathrm{C}-\mathrm{H}\) (c) \(\mathrm{CH}_{2}=\mathrm{C}=\mathrm{CH}_{2}\) (d) C=O (e) O=CO (f) CCO (g) CN (h) COC=O (i) \(\mathrm{H}-\mathrm{O}-\mathrm{N}=\mathrm{O}_{*}^{*+}\)

Short answer

Question: Describe the type of chemical bond and orbital overlap in the following molecules: (a) \(C=C\), (b) \(H-C \equiv C-H\), (c) \(CH_2=C=CH_2\), (d) \(C=O\), (e) \(O=CO\), (f) \(CO\), (g) \(CN\), (h) \(COC=O\), and (i) \(O=NO\).

Step-by-step solution

(a) \(C=C\)

For molecule (a), the bond is a double bond between two carbon atoms. This double bond consists of one sigma bond formed by the overlap of two sp2 hybridized orbitals and one pi bond formed by the overlap of two parallel p orbitals.

(b) \(H-C \equiv C-H\)

In molecule (b), we have a triple bond between two carbon atoms, and each carbon is bonded to a hydrogen atom. The triple bond consists of one sigma bond formed by the overlap of two sp hybridized orbitals and two pi bonds formed by the overlap of parallel p orbitals. The bond between each carbon and hydrogen atom is a single sigma bond formed by the overlap of sp hybridized orbitals in carbon and the 1s atomic orbital of the hydrogen.

(c) \(CH_2=C=CH_2\)

In molecule (c), there is a double bond between two carbon atoms, and each carbon is bonded to two hydrogen atoms. The double bond consists of one sigma bond formed by the overlap of two sp2 hybridized orbitals and one pi bond formed by the overlap of two parallel p orbitals. The bond between each carbon and hydrogen atom is a single sigma bond formed by the overlap of sp2 hybridized orbitals in carbon and the 1s atomic orbital of the hydrogen.

(d) \(C=O\)

In molecule (d), there is a double bond between a carbon and an oxygen atom. The double bond consists of one sigma bond formed by the overlap of one sp2 hybridized orbital from carbon and one sp2 hybridized orbital from oxygen. The pi bond formed by the overlap of two parallel p orbitals.

(e) \(O=CO\)

In molecule (e), we have a double bond between an oxygen and a carbon atom, and a double bond between the same carbon atom and another oxygen atom. Each double bond is made up of one sigma bond formed by the overlap of sp2 hybridized orbitals and one pi bond formed by the overlap of two parallel p orbitals.

(f) \(CO\)

In molecule (f), there is a single sigma bond between one carbon and one oxygen atom, formed by the overlap of sp3 hybridized orbital in carbon and sp3 hybridized orbital in oxygen.

(g) \(CN\)

In molecule (g), there is triple bond between one carbon and one nitrogen atom. The triple bond consists of one sigma bond formed by the overlap of sp hybridized orbitals and two pi bonds formed by the overlap of parallel p orbitals.

(h) \(COC=O\)

In molecule (h), we have a single sigma bond between two carbon atoms, formed by the overlap of sp3 hybridized orbitals. The carbon atom bonded to an oxygen atom has a double bond formed by one sigma bond (overlap of sp2 hybridized orbitals) and one pi bond formed by the overlap of parallel p orbitals.

(i) \(O=NO\)

In molecule (i), there is double bond between one oxygen atom and one nitrogen atom. The double bond consists of one sigma bond formed by the overlap of sp2 hybridized orbitals and one pi bond formed by the overlap of parallel p orbitals.