The PLS reactivity can be determined by the topology of the lowest-triplet potential energy surface. Around the FC region, the triplet-state has the character of the 3 MLCT, and it changes to the 3 MC state as the Re-CO bond is elongated, bent and contracted. The PLS reaction proceeds via axial CO ligand (R1) selectively as equatorial CO ligands (R2 and R3) have a much higher energy barrier to dissociate than that of the axial CO. Contrary to common belief, the axial Re-CO bond is first elongated to reach 3 TS state then the bond bents and contracted to reach a 3 MC state. After reaching 3 MC1 the bond further elongates and bent via IC to reach a dissociative 3 MC state i.e., 3 MC5. Furthermore, we also observed the formation of a singlet-adduct via minimum energy crossing point region. Finally, the stable photoproduct [Re(CO)2(CH3CN)(Pyta)(TPP))] + is formed via the formation of singlet penta coordinated complex. This work paves the way to improve the modeling strategies for designing novel PhotoCORMs, which consequently, opens new perspectives towards efficient bactericidal materials, potentially usable for fighting AMR.