Saroj Barik | Searcharxiv

arXiv2024

Photo-induced molecular growth of benzonitrile in the gas phase

Due to the absorption of high energetic ultraviolet (UV) photons by the surface layers of the cold molecular clouds, only low energetic photons are able to penetrate into the inner regions of these clouds. This leads to lower photo-ionization yield of molecules of higher ionization potential in these environments. However, here we have experimentally shown the ionization of Benzonitrile molecule using 266nm (4.66eV) photons. The low intensity and unfocused laser irradiation of benzonitrile molecules results extensive fragmentation. Moreover, the ion-neutral reactions among the cationic fragments and neutral fragments shows promising molecular mass growth.

physics.chem-ph↗

arXiv2023

Collective Energy Transfer to a Spectator Atom via Multi-Center Intermolecular Coulombic Decay

Molecular mechanisms that enable collective and upconverted energy transfer from multiple photoacceptors to a non-absorbing spectator reaction center are highly desirable for efficient light-energy utilization. Here, we show that intermolecular Coulombic decay (ICD), a nonlocal energy relaxation channel in photoexcited molecules, offers an avenue for such a novel energy transfer mechanism. On irradiation of pyridine-argon gas mixture at 266 nm and at low laser intensities, we observed a surprisingly dominant formation of argon cations. Measurements of the laser power dependence, together with systematic studies of Ar$^+$ yield versus laser intensity and molecular density, reveal that ICD mediates the collective funneling of excitation energy from multiple photoexcited pyridine molecules to a non-photoabsorbing argon atom, leading to its ionization. The density of the reaction center offers an efficient handle to optimize this collective energy transfer. This mechanism opens new avenues in light harvesting design and may help explain the remarkable resistance of biomolecules to photodamage.

physics.chem-ph↗