c Rationalize the interring dihedral angle of strans 22bipyr

c) Rationalize the inter-ring dihedral angle of s-trans 2,2\'-bipyridine in comparison to the other biaryl species discussed in part b). Explain what additional factor(s) may exert a major effect on the structure of this anomalous biaryl species. (4 pts)

Solution

Dear student,

The dihedral angle between the rings of biphenyl is determined to be 32 ± 2° in the molten and solution states.The inter-ring dihedral angle of biphenyl is influenced by the steric bulk of the groups in the ortho positions.s-trans face a twist in angle due to non planar configuration

Additional factors contributing are :

1) Pi conjugation

2) Steric influence

3) Relative steric size of the groups or lone pairs at ortho position

Regards