2-Dimensional Phase-sensitive ULtrafast SpEctroScopy: unravelling photo-induced reactions by multi-dimensional Raman

Descripción del proyecto

Innovadora configuración Raman para espectroscopia avanzada

Las reacciones fotoinducidas abarcan una amplia gama de fenómenos, como la conversión de energía en las proteínas, el fotodaño por irradiación ultravioleta en la piel y la relajación de portadores en dispositivos optoelectrónicos. Sin embargo, estos y otros procesos cruciales suelen quedar ocultos por las limitaciones de nuestros equipos y tecnología. El equipo del proyecto 2D-PULSES, financiado por el Consejo Europeo de Investigación, tiene por objeto desarrollar una innovadora configuración Raman bidimensional de resonancia visible-ultravioleta, utilizando tecnologías de detección sensibles a las fases para estudiar procesos químicos, biológicos y físicos. Este avanzado sistema Raman, que incorpora un enfoque multidimensional, permitirá una investigación crítica y proporcionará conocimientos sobre la femtoquímica y la femtofísica y sus movimientos nucleares sinérgicos.

Objetivo

We propose the construction and development of a visible/ultraviolet (UV) two-dimensional resonance Raman (2DR) setup with phase-sensitive detection to tackle ultrafast Chemical, Physical and Biological processes. Light-induced reactions cover a broad range of phenomena, from screening of photo-damage in skin upon UV irradiation to carrier relaxation in opto-electronic devices and energy conversion in proteins. Their lowest hierarchical level lies in the interplay of nuclear motion and normal mode couplings, such as funnelling the absorbed energy to the solvent via molecular oscillations in nucleobases, electron-phonon/phonon-phonon couplings in graphene, vibrational cooling in hemeproteins. Nature has intricately coupled vibrational degrees of freedom to facilitate light-energy conversion into synergistic nuclear motions, ruling femtochemistry and femtophysics. Conventional spectroscopic methods project structural information along specific normal coordinates, providing limited insights into these coupled motions. 2DR combines the structural sensitivity inherent to the Raman process with a multi-dimensional scheme, yielding frequency correlation spectra that encode information on the vibronic mode couplings across the entire vibrational manifold. Critically, the development of 2DR and its application to light-driven processes has been hindered by technical and conceptual hurdles. Among them: 1) 2DR realizations have been confined to restricted visible regions, while most biomolecules require spectral tunability and/or UV excitations; 2) vibrational signatures recorded by 2DR can be assigned both to vibrational (anharmonic) mode couplings as well as to (harmonic) high-order Raman transitions. The set up of the proposed novel 2DR approach will circumvent these limitations, establishing an interdisciplinary research team toiling over unsolved problems in which the ultrafast and multidimensional facets play a key role.