The metal coordination polymer of hypocrellin A bearing tryptamine motif (M-DTrpHA) can include fullerene via a two-point interaction, involving pi-pi stacking and electron donor-acceptor interaction. The 1:1 host-guest system M-DTrpHA/fullerene exhibits a moderate association constant K-a (6.62 x 10(4) to 6.46 x 10(5) M-1). Both of the metal ions in M-DTrpHA and the substituents connected to the fullerene core play important roles in stabilizing the M-DTrpHA/fullerene complex. Transient absorption spectral and NIR absorption spectral results demonstrate that, in the M-DTrpHA/fullerene system, efficient photoinduced electron transfer from the tryptamine group in M-DTrpHA to fullerene may occur, resulting in a long-lived fullerene anion radical. The observed order of quantum yield (Phi(T)(ET)) and rate constants (K-ET(T)) for electron transfer via C-3(60)* is Y3+-DTrpHA > La3+-DTrpHA > DTrpHA, consistent with their binding ability to C-60. The nanostructure of M-DTrpHA is rearranged to form an interpenetrating network after interaction with fullerene.