Structural dependences of the η6 complexes of 3-amino-9-ethylcarbazole with chromium tricarbonyl fragment on third-order optical nonlinearities

• 来源期刊: 科学通报（英文版）
• 年，卷（期）: 2008,（10）
• 页码范围: 1473-1478
• 页数: 6页
• 语种: 英文
• DOI: 10.1007/s11434-008-0040-z

摘要

Degenerate four-wave mixing measurements, using the 35 ps pulses at 532 nm, have been employed to investigate the third-order nonlinear optical parameters of two chromium tricarbonyl complexes η6-bonded to 3-amino-9-ethylcarbazole at either the NH2-substituted aryl ring (1) or the unsubstituted ring (2) and their precursor 3-amino-9-ethylcarbazole (AECz). The second-order hyperpolarizability y of the compounds 1 and 2 were found to be 42.9×10-31 and 35.9×10-31 esu, respectively, approximately one order of magnitude greater than AECz. The relation between the molecular structure and second-order hyperpolarizability of the compounds 1 and 2 was explored in detail based on the three-level model and the density functional theory (DFT) calculation. The theoretical results indicate that the spatial distri-bution of electron density has the profound role in the third-order nonlinear optical properties.