DER EINFLUSS VON WECHSELWIRKUNGEN DURCH DEN RAUM UND UEBER BINDUNGEN AUF DIE WALSH-ORBITALE VON SPIROCYCLOPROPYLVERBINDUNGEN

Article abstract of DOI:10.1016/0040-4020(80)85046-0

The PE spectra of spiro- and dispirocyclopropyl derivatives of cyclobutane are investigated, and an assignment of the PE bands based on MINDO/3- and 4-31G calculations is proposed.The influence of the ?_CH2 orbitals of the cyclobutane ring is discussed by means of a LCBO model: in the case of the 1,3-derivative through-bond interactions cause an inversion of the natural order of the orbitals, whereas through-space interactions reduce the conjugative splitting of the Walsh orbitals in the 1,2-derivative.The proposed model naturally explains also the various splittings of the Walsh orbitals in rotanes.