HOMO-LUMO: The HOMO-LUMO (Figure ) gap values of -0.02376, -0.02146, and 0.13246 (Figure ) indicate a narrow energy separation between the frontier molecular orbitals of the N-Pt-N phenalene derivative. A reduced gap thus permits effective photoexcitation under low-energy (visible or near-visible) illumination, thereby enabling the promotion of electrons from the HOMO to the LUMO with minimal energy input. The consequence of this property is a direct enhancement of the material's light-harvesting efficiency, a critical factor in the context of photocatalysis. The system's capacity to absorb photons within a broad spectral range is essential for generating photoinduced charge carriers (electrons and holes), which are pivotal drivers of redox reactions in photocatalytic processes.