BARC/PUB/2013/0470

 
 

Spectroscopic and theoretical insights on effective and selective non-covalent binding between fullerenes (C60 and C70) and a designed diporphyrin in solution

 
     
 
Author(s)

Mukherjee, S.; Bauri, A. K.; Bhattacharya, S.
(BOD)

Source

Spectrochimica Acta-A, 2013. Vol. 115: pp. 835-839

ABSTRACT

The present work reports the photophysical insights behind effective non-covalent interaction between a designed diporphyrin (1) and fullerenes C60 and C70 in toluene. Ground state electronic interaction between fullerenes and 1 is evidenced from UV–Vis measurements in which it is observed that the intensity of the Soret absorption band of 1 is decreased considerably in presence of both C60 and C70. Steady state fluorescence studies reveal efficient quenching of the fluorescence intensity of 1 in presence of fullerenes. Evaluation of binding constants for the fullerene/1 systems evoke that 1 may be employed as an efficient molecular tweezers for C70 in toluene as selectivity in binding is determined to be ˜9.4. Time resolved emission studies establish relatively long-lived charge separated state for the C70/1 system in comparison to C60/1. Molecular mechanics calculations by force field method in vacuo interpret well regarding stability difference between C60 and C70 complexes of 1 and give formidable support in favor of side-on orientation motif of C70 towards the plane of 1 during non-covalent complexation process.

 
 
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