Kekulé di-radical (KDR) with two radical centers of independent spins has a low-spin ground state (singlet S0 with antiparallel spins), and interestingly high-spin triplets (T1) can be thermally activated and populated at high temperature to advance the room-temperature spin-active properties of KDR materials. Hence, it is important to microscopically study the electronic structures of S0 and T1 of KDRs. We plan to use photo-pump muon-probe muSR to learn photo induced effect on muSR spectra at...