Executive Summary : | Triplet spin states are incredibly powerful tools to develop next-generation materials. Spin statistics provide the fundamental idea to utilize the triplet spin state in the development of quantum sensing, quantum entangled state, high energy materials, 3D printing, and challenging bond activation reaction, to name just a few. The creation of a triplet spin state involves the ‘Jablonski’ based ‘photophysical process’ within the materials. Hence, upon engineering the molecular energy level of a molecule, two triplet spin states can be brought under the ‘diffusion’ range and create the high energy upconverted fluorescence photon upon triplet-triplet diffusion-based photo-physics. Interestingly, in this project, we are aiming to create the high energy fluorescence photon at the UV range (UVA-UVC) with the expense of the two triplet spin states of annihilator molecule utilizing the basic ‘Jablonski’ based triplet-triplet annihilation (TTA) process. It should be noted, ultraviolet (UV) light (λ less than400 nm) plays a pivotal role in numerous photochemical applications especially hydrogen generation, photopolymerization, and bond activation reactions. However, the proportion of UV light in the solar spectrum is as low as only 5%, and hence, a tremendous amount of effort has already been devoted to generating effective UV light. In particular, the current technology for the artificial generation of UVB and UVC light is inefficient, environmentally unfriendly, and highly energy intensive. Notably, as an alternative route for generating UV light, TTA photon upconversion (UC) from visible light (λ higher than 400 nm) to UV light (λ lower than 400 nm) has recently received widespread attention, owing to its ability to achieve high UC quantum yields at the low excitation light intensities, particularly at solar irradiance level. In this project, our specific aim is to find out the easiest and most concrete process to establish a way to create the high energy fluorescence photon specifically at the range of UVA, UVB, and UVC region and utilizing that output high energy UV photon into clean hydrogen production, 3D printing based on upconverted UV light and challenging bond activation reactions (keto-compound as a model), which are not possible at normal reaction conditions. In a nutshell, successful achievement of high-energy UV photons at the UVA-UVC range will surely open new application opportunities like high energy consuming catalysis reactions, solvent excitation, and synthetic UV photochemistry to name just a few, which will be under the radar of our future research directions. |