Chemical physics behind formation of effective and selective non-covalent interaction between fullerenes (C60 and C70) and a designed chiral monoporphyrin in solution

Abstract The present letter extricates the chemical physics behind non-covalent interaction between fullerenes (C 60 and C 70 ) and a designed chiral monoporphyrin molecule ( 1 ) in toluene. Steady state fluorescence studies on complex formation reveal higher binding constant ( K ) for C 70 / 1 complex, i.e., K  = 16,020 dm 3  mol −1 , and very good selectivity of binding, viz., K C70/ 1 / K C60/ 1  ∼ 10.0. Time-resolved fluorescence study elicits role of static quenching mechanism behind photoexcited decay of 1 * in presence of fullerene. Density functional theoretical calculations in vacuo validates the strong complexation between C 70 and 1 and establishes the side-on binding motif of C 70 towards 1 during complexation.