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DOE OSTI · 3374474

Characterizing Ultrafast Intersystem Crossing Pathways in Molecular Pt Dimers Using Time-Resolved Wide-Angle X-ray Scattering

Mara, Michael W. [Argonne National Laboratory (ANL), Argonne, IL (United States)] (ORCID:0000000337669368)·Leshchev, Denis [Northwestern University, Evanston, IL (United States)] (ORCID:0000000280493671)·Weingartz, Nicholas P. [Northwestern University, Evanston, IL (United States)]·Chan, Arnold M. [Northwestern University, Evanston, IL (United States)] (ORCID:0000000239270636)·Nijhawan, Adam K. [Northwestern University, Evanston, IL (United States)] (ORCID:0000000155271850)·Valentine, Andrew J. S. [University of Washington, Seattle, WA (United States)]·Liu, Xiaolin [University of Washington, Seattle, WA (United States)] (ORCID:000000032157265X)·Kromer, Sarah [North Carolina State University, Raleigh, NC (United States)] (ORCID:000000022430221X)·Hsu, Darren [Northwestern University, Evanston, IL (United States)] (ORCID:0000000203537626)·Kim, Pyosang [Argonne National Laboratory (ANL), Argonne, IL (United States)] (ORCID:0000000212128760)·Biasin, Elisa [SLAC National Accelerator Laboratory (SLAC), Menlo Park, CA (United States); Stanford University, Menlo Park, CA (United States)]·van Driel, Timothy Brandt [SLAC National Accelerator Laboratory (SLAC), Menlo Park, CA (United States); Stanford University, Menlo Park, CA (United States)] (ORCID:0000000340703168)·Castellano, Felix N. [North Carolina State University, Raleigh, NC (United States)] (ORCID:0000000175468618)·Li, Xiaosong [University of Washington, Seattle, WA (United States)] (ORCID:0000000173416240)·Chen, Lin X. [Argonne National Laboratory (ANL), Argonne, IL (United States); Northwestern University, Evanston, IL (United States)] (ORCID:0000000284506687)
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Abstract

Vibronic coupling between transition metal charge transfer states is a potential mechanism for enhancing the intersystem crossing (ISC) rate. Vibronic coupling-driven ISC has been observed in Pt­(II) dimer complexes, where the trajectory across excited-state pathways is tuned by atomic displacements via Pt–Pt stretching vibrations. Time-resolved wide-angle X-ray scattering (TR-WAXS) was utilized to quantify the Pt–Pt contraction following metal–metal-to-ligand charge transfer (MMLCT) excitation in Pt dimers with different bridging ligands. Both complexes exhibit Pt–Pt bond formation with a decrease in Pt–Pt distance of ∼ 0.25 Å and coherent vibrational wavepackets (CVWPs) encoded in the Pt–Pt contraction of both dimers. However, the complexes exhibit different time-dependent evolution of their CVWPs. Analysis of interference patterns between different CVWPs is used to track the trajectory across the excited-state surfaces. Furthermore, this work demonstrates that the interference between CVWPs in ultrafast TR-WAXS encodes indirect information regarding electronic excited-states to reveal the Pt dimer bridge-dependent ISC mechanism.

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Computational chemistryOligomersOscillationPlatinumQuantum mechanics

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Mara, Michael W. [Argonne National Laboratory (ANL), Argonne, IL (United States)] (ORCID:0000000337669368), Leshchev, Denis [Northwestern University, Evanston, IL (United States)] (ORCID:0000000280493671), Weingartz, Nicholas P. [Northwestern University, Evanston, IL (United States)], Chan, Arnold M. [Northwestern University, Evanston, IL (United States)] (ORCID:0000000239270636), Nijhawan, Adam K. [Northwestern University, Evanston, IL (United States)] (ORCID:0000000155271850), Valentine, Andrew J. S. [University of Washington, Seattle, WA (United States)], Liu, Xiaolin [University of Washington, Seattle, WA (United States)] (ORCID:000000032157265X), Kromer, Sarah [North Carolina State University, Raleigh, NC (United States)] (ORCID:000000022430221X), Hsu, Darren [Northwestern University, Evanston, IL (United States)] (ORCID:0000000203537626), Kim, Pyosang [Argonne National Laboratory (ANL), Argonne, IL (United States)] (ORCID:0000000212128760), Biasin, Elisa [SLAC National Accelerator Laboratory (SLAC), Menlo Park, CA (United States); Stanford University, Menlo Park, CA (United States)], van Driel, Timothy Brandt [SLAC National Accelerator Laboratory (SLAC), Menlo Park, CA (United States); Stanford University, Menlo Park, CA (United States)] (ORCID:0000000340703168), Castellano, Felix N. [North Carolina State University, Raleigh, NC (United States)] (ORCID:0000000175468618), Li, Xiaosong [University of Washington, Seattle, WA (United States)] (ORCID:0000000173416240), Chen, Lin X. [Argonne National Laboratory (ANL), Argonne, IL (United States); Northwestern University, Evanston, IL (United States)] (ORCID:0000000284506687). 2025-07-03. Characterizing Ultrafast Intersystem Crossing Pathways in Molecular Pt Dimers Using Time-Resolved Wide-Angle X-ray Scattering. https://doi.org/10.1021/acs.jpclett.5c01245

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