Premium
Stability of N 4 2− ‐based sandwich‐like energetic complexes [N 4 TiN 4 ] 2− : Effect of spins and counterions
Author(s) -
Jin Lin,
Ding YiHong
Publication year - 2009
Publication title -
journal of computational chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.907
H-Index - 188
eISSN - 1096-987X
pISSN - 0192-8651
DOI - 10.1002/jcc.21153
Subject(s) - tin , counterion , singlet state , spins , chemistry , crystallography , paramagnetism , ion , materials science , computational chemistry , chemical physics , atomic physics , physics , organic chemistry , condensed matter physics , excited state
Design and assembly of new aromatic units has received growing attention due to its fundamental and application interests. Recently, a series of singlet sandwich‐like complexes [N 4 MN 4 ] q (M = Ti, V, Cr, Fe, Co, Ni) based on the energetic all‐nitrogen 6π‐aromatic species N 4 2−have been devised. However, how the electronic spins and counterions influence the kinetic stability of sandwich‐like complexes has been very little understood, though it is very important to assess their potential use. In this article, we report our DFT study on the stability of the charged [N 4 TiN 4 ] 2− and [N 4 TiN 4 TiN 4 ] 2− systems as well as the neutral [N 4 TiN 4 ]Li 2 system in both singlet and triplet electronic states. We found that the ground state structures of di‐deckered [N 4 TiN 4 ] 2− and [N 4 TiN 4 ]Li 2 as well as the tri‐deckered [N 4 TiN 4 TiN 4 ] 2− are all in triplet state, rather than the previously reported singlet ones. Therefore, the N 4 2−and Ti 2+ ‐based sandwich‐like complexes should be in high spins and may have potential use for new paramagnetic materials. Moreover, our calculations indicate that although the counterions can induce the electronic stabilization, they on the other hand can lead to the considerable kinetic destabilization of the N 4 2− ‐based sandwich‐like complexes because the counterions can structurally destroy the perfectness of aromatic N 4 2− . Thus, in study of the sandwich‐like complexes, the effect of counterions cannot be neglected for assessment of the kinetic stability. © 2008 Wiley Periodicals, Inc. J Comput Chem, 2009