Question

butadiene (C4H10), the coefficients for the linear combination of atomic orbitals for the two lowest energy π-MOs are:

Normalised Coefficients MO

                            Atom 1                 Atom 2                 Atom 3                 Atom 4

Wavefunction 2: +0.6015               +0.3717               –0.3717                –0.6015
Wavefunction1 : +0.3717               +0.6015                +0.6015                +0.3717

(i) Predict the coefficients at each atom for the two highest energy π-MOs (wavefunctions 3 & 4). Justify your solution using diagrams.

(ii) Calculate the total π-electron densities on atoms 1, 2, 3 and 4.

(iii) Calculate the total p-bond order between atoms 1-2, 2-3 and 3-4.

(iv) Estimate the total σ- and π-bond orders between atoms 1-2, 2-3 and 3-4.

(v) How does (iv) relate to the traditional representation of butadiene with a double-single-double bond structure.

Answer 1