Nonradiative inter- and intramolecular energy transfer from the aromatic donor anisole to a synthesized photoswitchable acceptor system

作者：Bardhan Munmun; Bhattacharya Sudeshna; Misra Tapas; Mukhopadhyay Rupa; De Asish; Chowdhury Joydeep; Ganguly Tapan^*

来源：Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy , 2010, 75(2): 647-655.

DOI：10.1016/j.saa.2009.11.034

• Energy transfer
• Photoswitchable system
• Time resolved fluorescence
• Excited conformers
• Multichromophoric system

We report steady state and time resolved fluorescence measurements on acetonitrile (ACN) solutions Received 29 May 2009 of the model compounds, energy donor anisole (A) and a photoswitchable acceptor N,N'-1,2-phenylene di-p-tosylamide (B) and the multichromophore (M) where A and B are connected by a spacer containing both rigid triple (acetylenic) and flexible methylene bonds. Both steady state and time correlated single photon counting measurements demonstrate that though intermolecular energy transfer, of Forster type, between the donor and acceptor moieties occurs with rate 10(8)s(-1) but when these two reacting components are linked by a spacer (multichromophore, M) the observed transfer rate (similar to 10(11) s(-1)) enhances. This seemingly indicates that the imposition of the spacer by inserting a triple bond may facilitate in the propagation of electronic excitation energy through bond. The time resolved fluorescence measurements along with the theoretical predictions using Configuration interaction singles (CIS) method by using 6-31G (d,p) basis set, implemented in the Gaussian package indicate the formations of the two excited conformers of B. The experimental findings made from the steady state and time resolved fluorescence measurements demonstrate that, though two different isomeric species of the acceptor B are formed in the excited singlet states, the prevailing singlet-singlet nonradiative energy transfer route was found from the donor A to the relatively longer-lived isomeric species of B.

• 出版日期2010-2