Analysis of the distance dependence and magnitude of the .pi.+,.pi.- and .pi.+*,.pi.-* splittings in a series of diethynyl[n]staffanes: an ab initio molecular orbital study

Abstract

Through-bond orbital interactions between the π orbitals and between the π * orbitals of the first five members of the series of α,ω-diethynyloligo[1.1.1]propellanes, or α,ω-diethynyl[n]staffanes, 4(1)-4(5), have been investigated using ab initio MO theory. The π + ,π - and π + * ,π - * splittings of 4(1)-4(5) were obtained in the Koopmans'theorem approximation, using the STO-3G, 3-21G, and 6-31G * basis sets