Ultrafast structural dynamics of UV photoexcited cis , cis -1,3-cyclooctadiene observed with time-resolved electron diffraction.

Autor: Muvva SB; Department of Physics and Astronomy, University of Nebraska-Lincoln, Lincoln, Nebraska, USA. bhavya.m@huskers.unl.edu., Liu Y; SLAC National Accelerator Laboratory, Menlo Park, California, USA.; Department of Physics and Astronomy, Stony Brook University, Stony Brook, New York, USA., Chakraborty P; Department of Chemistry, Temple University, Philadelphia, Pennsylvania, USA.; School of Chemistry, Pharmacy and Pharmacology, University of East Anglia, Norwich NR4 7TJ, UK., Nunes JPF; Department of Physics and Astronomy, University of Nebraska-Lincoln, Lincoln, Nebraska, USA. bhavya.m@huskers.unl.edu., Attar AR; SLAC National Accelerator Laboratory, Menlo Park, California, USA., Bhattacharyya S; J.R. Macdonald Laboratory, Department of Physics, Kansas State University, Manhattan, Kansas, USA., Borne K; J.R. Macdonald Laboratory, Department of Physics, Kansas State University, Manhattan, Kansas, USA., Champenois EG; SLAC National Accelerator Laboratory, Menlo Park, California, USA., Goff N; Department of Chemistry, Brown University, Providence, Rhode Island, USA., Hegazy K; SLAC National Accelerator Laboratory, Menlo Park, California, USA.; Department of Physics, Stanford University, Stanford, USA., Hoffmann MC; SLAC National Accelerator Laboratory, Menlo Park, California, USA., Ji F; SLAC National Accelerator Laboratory, Menlo Park, California, USA., Lin MF; SLAC National Accelerator Laboratory, Menlo Park, California, USA., Luo D; SLAC National Accelerator Laboratory, Menlo Park, California, USA., Ma L; Department of Chemistry, Brown University, Providence, Rhode Island, USA., Odate A; Department of Chemistry, Brown University, Providence, Rhode Island, USA., Pathak S; J.R. Macdonald Laboratory, Department of Physics, Kansas State University, Manhattan, Kansas, USA., Rolles D; J.R. Macdonald Laboratory, Department of Physics, Kansas State University, Manhattan, Kansas, USA., Rudenko A; J.R. Macdonald Laboratory, Department of Physics, Kansas State University, Manhattan, Kansas, USA., Saha SK; Department of Physics and Astronomy, University of Nebraska-Lincoln, Lincoln, Nebraska, USA. bhavya.m@huskers.unl.edu., Shen X; SLAC National Accelerator Laboratory, Menlo Park, California, USA., Wang X; SLAC National Accelerator Laboratory, Menlo Park, California, USA., Ware MR; SLAC National Accelerator Laboratory, Menlo Park, California, USA., Weathersby S; SLAC National Accelerator Laboratory, Menlo Park, California, USA., Weber PM; Department of Chemistry, Brown University, Providence, Rhode Island, USA., Wilkin KJ; Department of Physics and Astronomy, University of Nebraska-Lincoln, Lincoln, Nebraska, USA. bhavya.m@huskers.unl.edu., Wolf TJA; SLAC National Accelerator Laboratory, Menlo Park, California, USA., Xiong Y; Department of Physics and Astronomy, University of Nebraska-Lincoln, Lincoln, Nebraska, USA. bhavya.m@huskers.unl.edu., Xu X; Department of Chemistry, Brown University, Providence, Rhode Island, USA., Yang J; SLAC National Accelerator Laboratory, Menlo Park, California, USA., Matsika S; Department of Chemistry, Temple University, Philadelphia, Pennsylvania, USA., Weinacht T; Department of Physics and Astronomy, Stony Brook University, Stony Brook, New York, USA., Centurion M; Department of Physics and Astronomy, University of Nebraska-Lincoln, Lincoln, Nebraska, USA. bhavya.m@huskers.unl.edu.
Jazyk: angličtina
Zdroj: Physical chemistry chemical physics : PCCP [Phys Chem Chem Phys] 2024 Dec 09. Date of Electronic Publication: 2024 Dec 09.
DOI: 10.1039/d4cp02785j
Abstrakt: Conjugated diene molecules are highly reactive upon photoexcitation and can relax through multiple reaction channels that depend on the position of the double bonds and the degree of molecular rigidity. Understanding the photoinduced dynamics of these molecules is crucial for establishing general rules governing the relaxation and product formation. Here, we investigate the femtosecond time-resolved photoinduced excited-state structural dynamics of cis , cis -1,3-cyclooctadiene, a large-flexible cyclic conjugated diene molecule, upon excitation with 200 nm using mega-electron-volt ultrafast electron diffraction and trajectory surface hopping dynamics simulations. We tracked the photoinduced structural changes from the Franck-Condon region through the conical intersection seam to the ground state. Our findings revealed a novel primary reaction coordinate involving ring distortion, where the ring stretches along one axis and compresses along the perpendicular axis. The nuclear wavepacket remains compact along this reaction coordinate until it reaches the conical intersection seam, and it rapidly spreads as it approaches the ground state, where multiple products are formed.
Databáze: MEDLINE