Inhibition in binding between fullerene and a bisporphyrin in presence of silver nanoparticles in solution: UV–Vis, DLS, SEM and TEM studies

•Fullerene–bisporphyrin complexation is examined in presence of silver nanoparticles.•Silver nanoparticles (AgNp) inhibits binding between fullerene and bisporphyrin (1).•DLS study reveals considerable increase in particle size of AuNp after complexation.•SEM measurements establish formation of nanoaggregate in case of C70-1-AuNp system.•TEM envisages formation of fibrous structure for fullerene-1-AuNp systems.

The present paper reports the role of silver nanoparticles, i.e., AgNp (having diameter ∼5–15 nm), in non-covalent interaction between fullerenes (C60 and C70) and a designed bisporphyrin (1) in toluene. UV–Vis measurement reveals reduction in binding constant (K) values for both C60-1 (KC60-1 = 18,800 dm3 mol−1) and C70-1 systems (KC70-1 = 27,300 dm3 mol−1) in presence of AgNp, i.e., KC60-1-AgNp = 3700 dm3 mol−1 and KC70-1-AgNp = 1600 dm3 mol−1 for C60-1-AgNp and C70-1-AgNp nanocomposite, respectively. Dynamic light scattering study reveals considerable increase in the particle size of C70-1-AgNp nanocomposite, i.e., ∼39 nm, compared to C60-1-AgNp, e.g., ∼22 nm. Scanning electron microscope measurement reveals that the well arranged and composed structure of uncomplexed 1 is perturbed very much in presence of both C60 and C70, and it ultimately results into formation of nanoaggregate in case of C70-1-AgNp system. Transmission electron microscope study envisages formation of fibrous structure in presence of C60 and C70.

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