Popis: |
To be planar or to be twisted at the bridge junctions in biphenyls or biaryl types of molecular systems depends on two conflicting forces: (1) steric repulsions (destabilizations) and (2) conjugation assisted electron delocalizations (resonance stabilizations). This work reports an unfamiliar kind of behaviour shown by metamers of a zwitterionic biphenyl type of system, where the Reichardt's metamer was found to be in an usual twisted conformation (delicate balance of conflicting forces), but the Brooker's metamer was found to be in a fully planar conformation. Interestingly, at the ωB97xD/aug-cc-pVDZ level, energetically (Δ |