ELECTRON-STRUCTURE OF NON-TRANSITION ELEM ENT COMPOUNDS

The results of quantum-chemical calculations of the electron structure of non-transition element complexes are reviewed. Their X-ray emissio n and X-ray photoelectron spectra are analysed. General principles of the electron structure of such complexes are established. It is shown that the effective participation of partially or completely occupied v alence np(m)-orbitals of the central atom A of AL(k) complexes in the formation of delocalised MOs, the negligibly small contribution of vac ant And-orbitals to the bonds with ligands, the valence inertness or r ather low contribution of occupied Ans(2)-orbitals (except for 2s(2)-A O) to the valence MOs, and the initiation of the multiple bonds (in th e electron structure of complexes) due to covalent or hypervalent pi-i nteractions involving only 2p (but not 3p, 4p, etc) atomic orbitals ar e the most significant factors influencing the electronic structure of non-transition element compounds. The concept of d-orbitals and hyper valence bonds is critisised.