Inhibition in binding between fullerene and bisporphyrin in presence of silver nanoparticles: A new physicochemical insight into fullerene–bisporphyrin complexation in solution

The present paper reports non-covalent interaction between fullerenes (C60 and C70) and a designed bisporphyrin (1) in p-xylene in absence and presence of silver nanoparticles (AgNp) having diameter ∼5–15 nm. Both UV–vis and fluorescence experiments reveal reduction in the average binding constant (Kav) value for C60-1 (KC60-1 = 27,980 dm3 mol−1) and C70-1 systems (KC70-1 = 115,020 dm3 mol−1) in presence of AgNp, i.e., KC60-1-AgNp = 22,465 dm3 mol−1 and KC70-1-AgNp = 30,830 dm3 mol−1. Dynamic light scattering experiment gives clear indication regarding formation of larger aggregates as a result of electrostatic attraction between porphyrin-based supramolecule and AgNp in solution. Scanning electron microscope measurement reveals formation of molecular cluster comprising C70-1-AgNp composite.

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► Fullerene–bisporphyrin complexation is examined in presence of silver nanoparticles.
► Silver nanoparticles (AgNp) inhibits binding between fullerene and bisporphyrin (1).
► Fluorescence studies elicit quenching of 1 in presence of fullerene–AgNp mixture.
► DLS study reveals larger size particles of AgNp in presence of C70-1 complex.
► SEM measurements establish that nanoparticles are dispersed randomly.