DFT study on the second‐order nonlinear optical property of 12‐vertex close‐carborane derivatives

Density functional theory (DFT) BHandHLYP method based on the 6‐31G(d) level was employed to optimize the structures of 12‐vertex substituted carboranes. The finite field (FF) method was adopted to study their second‐order nonlinear optical coefficients. Moreover, the electron spectra of systems were analyzed. The results show carboranes with alkali‐metal substituted have considerably large first hyperpolarizability (β_tot) values which is 2–3 order of magnitude larger than that of unsubstituted carborane (14.5 a.u). For halogen and organic group substituted systems, however, the β_tot values are only enhanced by one order of magnitude. The β values of carboranes obviously enhance after alkali‐metal substitution. This study may evoke the possibility to explore a new thriving area, i.e., alkali‐metal substituted carboranes for NLO application. © 2010 Wiley Periodicals, Inc. Int J Quantum Chem, 2011