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

Abstract

The present paper reports the role of silver nanoparticles, i.e., AgNp (having diameter ∼5–15nm), 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=18,800dm3mol−1) and C70-1 systems (KC70-1=27,300dm3mol−1) in presence of AgNp, i.e., KC60-1-AgNp=3700dm3mol−1 and KC70-1-AgNp=1600dm3mol−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., ∼39nm, compared to C60-1-AgNp, e.g., ∼22nm. 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.