Acting on long range charge transfer and localization in molecular systems with intense single cycle THz pulses

• Research unit: COST
• Project number: C14.0075

Key words (English)

Electron transfer; azurin; coherent spectroscopy; 2D spectroscopy; THz generation; UV; ultrafast; structural dynamic

Research programs (English)

COST-Action CM1202 - Supramolecular photocatalytic water splitting (PERSPECT-H2O)

Short description (English)

Long range (>2 nm) electron transfer (ET) between protein cofactors, and in general between distant sites, is fundamental to photosynthesis. Thus a full comprehension of fundamental mechanisms of ultrafast charge generation upon optical excitation and its separation by long range ET is crucial to design functional and scalable artificial photosystems and this would ultimately be a major breakthrough in conversion of solar energy into chemical fuels. I propose to study the effect of intense picosecond quasi electrostatic THz fields on the charge dynamics in artificial functional molecular units and paradigmatic proteins (in particular azurin and cytochrome C proteins). In this way we will keep the molecular system itself unchanged, both concerning the molecular Hamiltonian and the interaction with environment, while modifying the intra-molecular Coulomb forces that ultimately drive and stabilize the electron within or through the macromolecule. To visualize these effects I will use advanced UV 2D spectroscopy which allows exploiting chromophores naturally occurring in macromolecules as probes and can report on local fluctuation and intramolecular electronic couplings. This original approach will open the way to a deeper comprehension of the mechanisms underlying charge transfer and localization with the long term prospect to manipulate such a kind of phenomena.

Partners and International Organizations (English)

AT; BE; CY; CZ; DK; FI; FR; DE; EL; IE; IL; IT; NL; PL; PT; RO: ES; SE; TR; UK; MD

Abstract (English)

Long range (>2 nm) electron transfer (ET) between protein cofactors, and in general between distant sites, is fundamental to photosynthesis. Thus a full comprehension of fundamental mechanisms of ultrafast charge generation upon optical excitation and its separation by lang tange ET is crucial to design functional and scalable artificial photosystems and this would ultimately be a major breakthrough in conversion of salat energy into chemical fuels. 1 propose to study the effect of intense picosecond quasi electrostatic THz fields an the charge dynamics in artificial functional molecular units and paradigmatic proteins ( in patticular azurin and cytochrome C proteins). In this way we will keep the molecular System itself unchanged, both concerning the molecular Hamiltonian and the interaction with environment, while modifying the intra-molecular Coulomb forces that ultimately drive and stabitize the electron within ot through the mactomolecule. Ta visualize these effects 1 Witt use advanced UV 2D spectroscopy which allows explolting chromophotes naturalty occurring in macromolecules as ptobes and can report an local fluctuation and intramolecular electronic couplings. This original approacl, will open the way to a deepet comptehension ofthe mechanisms underlying chatge transfer and localization with the lang term prospect to manipulate such a kind of phenomena.

References in databases (English)

Swiss Database: COST-DB of the State Secretariat for Education and Research Hallwylstrasse 4 CH-3003 Berne, Switzerland Tel. [phone] Swiss Project-Number: C14.0075