Combined DFT and NBO study on the electronic basis of Si...N-beta-donor bond.

Two groups of isoelectronic molecules with different SiXN (X=C, N, O ) units are analyzed by a combined DFT and NBO study to investigate the electronic basis of Si...N-beta-donor bond. The influence of various energy components on the formation of Si...N-beta-donor bond is explored. The importance of the electron delocalization from the lone pair of nitrogen atom into the acceptor-orbitals connected with Si atom is elicited by our calculations. The electron delocalization from the lone pair of nitrogen atom into the antibonding orbital of Si-X bond is quite different among the isoelectronic molecules with various types of SiXN units.