ORGN 616 |
| Photochromic properties of the diarylethene two diarylethene derivatives 1 and 2 were investigated under one- and two-photon excitation. The peculiarities of the steady-state excitation anisotropy and the quantum-chemical calculations (AM1, ZINDO/S) of (1) revealed a nature of the broad absorption spectrum of the open-form of 1, as a strongly overlapped mixture of the several electronic transitions. The quantum yields of cyclization and cycloreversion reactions of 1 and 2 were obtained in the broad spectral range, and photochemical stability of 1 was determined for different excitation wavelengths. Two-photon absorption (2PA) spectrum of the open-form of 1 with maximum cross-section 80 GM at 337 nm was obtained by up-converted fluorescence method. 2PA cross-section of the open form of 2 at 260 nm was 88 GM at 260 nm and of the close form of 2 at 680 (153 GM) and 750 (145 GM) were determined. The evidences of two-photon induced cyclization reaction of 1 and 2 were shown under picosecond excitation, and corresponding reaction quantum yield was estimated. |
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Materials, Devices, and Switches
8:00 AM-12:00 PM, Thursday, 30 March 2006 Georgia World Congress Center -- Georgia Ballroom 2, Oral
Division of Organic Chemistry |