MOLECULAR-STRUCTURE AND ELECTRONIC-PROPERTIES OF A 1-SULFONYLINDOLIZINE DERIVATIVE, 2-ISOPROPYL-1-METHYLSULFONYLINDOLIZINE

For the title compound, C12H15NO2S, both the crystallographic data and theoretical results (ab initio molecular-orbital calculations) indica te a stabilization of the symmetrical conformation of the sulfone grou p with respect to the indolizinic bicycle. The crystal packing and the topology of the frontier orbitals clearly suggest a charge-transfer p rocess from the five-membered ring towards the six-membered ring of th e indolizine for two adjacent molecules.