Photophysical Properties of Diphenylacetylene and Diphenylbutadiyne Derivatives in Solution Phase |
| The results of this paper were initially presented at The Jabłoński Centennial Conference on Luminescence and Photophysics, July 23-27, 1998, Toruń, Poland |
| Y. Hirataa, T. Okadaa,b and T. Nomotoc aDepartment of Chemistry, Graduate School of Engineering Science, Osaka University, Toyonaka 560-8531, Japan bResearch Center for Materials Science at Extreme Conditions, Osaka University, Toyonaka 560-8531, Japan cDepartment of Chemistry, Faculty of Education, Mie University, Tsu 514-0008, Japan |
| Received: July 23, 1998 |
| Full Text PDF |
| By using the femtosecond and picosecond transient absorption measurement techniques, we have investigated diphenylacetylene, diphenylbutadiyne, and their methoxy and cyano derivatives in the solution phase. Both the rapid S2 → S1 internal conversion in the subpicosecond time scale and the triplet formation in the tens of picosecond region were observed for diphenylbutadiyne and its methoxy derivatives, while the dynamic behavior of dimethoxy-diphenylacetylene was quite similar to that of diphenyl acetylene. The level inversion of the lowest excited singlet states of dicyano-diphenylbutadiyne was observed. The thermally activated S2 ← S1 internal conversion was not negligible and the sum of the rate constants of S2 → S1 and S2 ← S1 internal conversions was estimated to be about 5 × 1011 s-1 at room temperature. |
| DOI: 10.12693/APhysPolA.94.627 PACS numbers: 31.70.Hq, 78.47.+p |