Understanding the Two-Photon Absorption Spectrum of PE2 Platinum Acetylide Complex
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- 作者：Marcelo G. Vivas ; Leonardo De Boni ; Thomas M. Cooper ; Cleber R. Mendonca
- 刊名：Journal of Physical Chemistry A
- 出版年：2014
- 出版时间：July 31, 2014
- 年：2014
- 卷：118
- 期：30
- 页码：5608-5613
- 全文大小：315K
- ISSN：1520-5215
文摘
Herein, we report on the two-absorption cross-section spectrum of trans-Pt(PBu3)2 (C鈮鈥擟6H4鈥擟鈮鈥擟6H5)2 (PE2) platinum acetylide complex employing the femtosecond wavelength-tunable Z-scan technique. The PE2 complex can be visualized as two branches containing two phenylacetylene units, each one linked by a platinum center, completely transparent in the visible region. Because of this structure, large delocalization of 蟺-electrons allied to the strong intramolecular interaction between the branches is expected. The 2PA absorption spectrum was measured using the femtosecond wavelength-tunable Z-scan technique with low repetition rate (1 kHz), in order to obtain the 2PA spectrum without excited-state contributions. Our results reveal that PE2 in dichloromethane solution presents two 2PA allowed bands located at 570 and 710 nm, with cross section of about 320 and 45 GM, respectively. The first one is related to the strong intramolecular interaction between the molecule鈥檚 branches due to the presence of platinum atom, while the second one is associated with the breaking of symmetry of the chromophore in solution due, most probably to a large twisting angle of the ligand鈥檚 phenyl rings relative to the Pt core.