Coherent ring-current migration of Mg-phthalocyanine probed by time-resolved X-ray circular dichroism. Issue 35 (19th August 2022)

• Record Type: Journal Article
• Authors: Sun, Shichao; Yong, Haiwang; Chen, Feng; Mukamel, Shaul
• Is Part Of: Chemical science. Volume 13:Issue 35(2022)
• Page Start: 10327
• Page End: 10335
• Publication Date: 2022-08-19
• Subjects: Chemistry -- Periodicals; 540.5
• DOI: 10.1039/d2sc02768b
• Languages: English
• ISSNs: 2041-6520

Abstract

Abstract : The coherent ring current of Mg-phthalocyanine are created by a broad band UV-visible pump pulse and migrate into different regions within the molecule. This coherent ring current dynamics is probed by time-resolved X-ray circular dichroism. Abstract : The coherent ring current of Mg-phthalocyanine created by a broad band UV-visible pump pulse shows variation with time, where the ring currents at the corner benzene rings, around the Mg cation and on the outer ring oscillate with different time periods and the current density migrates among these regions. The 7 pairs of E u degenerate excited states populated upon photoexcitation, generate 21 distinct coherent ring currents. We further calculate the time-resolved X-ray circular dichroism (TRXCD) spectrum of the coherences contributing to the ring current obtained by an attosecond X-ray probe pulse resonant with the nitrogen K-edge. A frequency domain TRXCD signal obtained by a Fourier transform of the signal with respect to the pump-probe delay time clearly separates the currents induced by different state pairs.