Ab initio <scp>MO</scp> Calculations of benzene + TCNE and naphthalene + TCNE complexes with <scp>STO</scp>‐3G π‐split basis set

Abstract

Abstract Ab initio SCF MO calculations have been carried out on benzene + TCNE (tetracyanoethylene) and naphthalene + TCNE complexes with the STO ‐3G, STO ‐3G π‐split ( STO ‐3G for π orbitals and a split basis for π orbitals), and 4–31G basis sets. The interaction energy, gross charges, dipole moment, and the electron density in the middle plane of the complexes have also been evaluated. The STO ‐3G π‐split basis set is appropriate for the calculation of large π–π stacking complexes from two points of view, production of reliable results and ease of computations. The approximation scheme based on the semiorthogonalized orgitals is revealed to be very efficient to save CPU time and storage in such calculations. The stable conformation and the charge‐transfer interaction of the two complexes are discussed on the basis of the calculated quantities.