STUDY ON THE THROUGH-SPACE AND THROUGH-BOND INTERACTIONS IN TRICYCLO 4,2,2,2 DODECADIENE-1. 5

Thrtough-space interactions of π orbiatl andσ orbital in molecule tricyclo 4,2,2,2,dodecadiene -1.5 werestudied by means of DV-Xa SVF method using a modelmolecule that consist of two ethylenes with interdeck distanceD.The results show the through-space interactions of the titlemolecule decrease with the increasing of D,the through-spaceinteractions of π orbital are larger than that of σ orbital.Fur-thermore,through-bond interactions of the π orbtial and σ or-bital were analyzed basing on the calculations of the electronicstructure of the title molecule.Both through-space andthrough-bond interactions are large and the net interactionsare small.The calculated ionization potential energies of thetitle molecule which were obtained by transition-state proce-dure are in good agreement with the PE spectroscopy.