“…The FL lifetime of free PT was described by three discrete exponential components corresponding to 1.2 (τ 1 , 23%), 8.5 (τ 2 , 37%), and 48 ns (τ 3 , 40%). τ 1 and τ 2 were much shorter than the FL lifetimes of nonsubstituted pyrene (40–65 ns), possibly due to the structural complexity of PT. − As mentioned above, free PT can form dimeric structures held together by H bonds, with such molecular interactions probably contributing to the reduced lifetime. The addition of C 60 to PT significantly shortened the fluorescence lifetime of the latter, with the corresponding decay curves described by lifetimes of 0.38 (τ 1 , 47%), 3.47 (τ 2 , 34%), and 18.17 ns (τ 3 , 19%) for Mix-2 and 0.12 (τ 1 , 85%), 2.09 (τ 2 , 9%), and 10.41 ns (τ 3 , 6%) for Mix-1.…”