Real-Time Tracking of Photoinduced Metal-Metal Bond Formation in a d<SUP>8</SUP>d<SUP>8</SUP> Di-Iridium Complex by Vibrational Coherence and Femtosecond Stimulated Raman Spectroscopy
The result's identifiers
Result code in IS VaVaI
<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F61388955%3A_____%2F25%3A00618281" target="_blank" >RIV/61388955:_____/25:00618281 - isvavai.cz</a>
Result on the web
<a href="https://hdl.handle.net/11104/0365124" target="_blank" >https://hdl.handle.net/11104/0365124</a>
DOI - Digital Object Identifier
<a href="http://dx.doi.org/10.1021/jacs.4c18527" target="_blank" >10.1021/jacs.4c18527</a>
Alternative languages
Result language
angličtina
Original language name
Real-Time Tracking of Photoinduced Metal-Metal Bond Formation in a d<SUP>8</SUP>d<SUP>8</SUP> Di-Iridium Complex by Vibrational Coherence and Femtosecond Stimulated Raman Spectroscopy
Original language description
We report real-time dynamics of photoinduced metal-metal bond formation acquired from ultrafast time-resolved stimulated emission and femtosecond stimulated Raman spectra (FSRS) of [Ir2(2,5-dimethyl-2,5-diisocyanohexane)4]2+ (Ir(TMB)) in the region of low-frequency vibrations. Interpretation was supported by impulsive stimulated Raman experiments and time-dependent density-functional theory (TDDFT) calculations. The Ir-Ir stretching frequency doubled on going from ground to the lowest singlet excited state 1d sigma*p sigma, from 53 to 126 cm-1, demonstrating Ir-Ir bond formation. Spectral evolution during the first 4 ps after excitation showed extremely large-amplitude coherent oscillations of stimulated emission as well as FSRS signal intensities, which occurred with the excited-state Ir-Ir stretching frequency combined with frequencies of several deformation vibrations and the first Ir-Ir overtone. Corresponding vibrations were observed in FSRS directly but most of them vanished in the first 3 ps, indicating that they belonged to transiently populated hot vibrational states. Fourier transforms of intensity oscillations plotted against FSRS frequencies produced two-dimensional (2D-FSRS) maps with diagonal and off-diagonal features due to Franck-Condon-excited and anharmonically coupled vibrations, some of which acquired Raman intensity through coupling with the Ir-Ir stretch. We concluded that optical excitation impulsively shortens the Ir-Ir distance and increases its stretching force constant, assisted by a simultaneously excited network of coupled deformation modes. The electronically/vibrationally excited system then relaxes through periodic strengthening and weakening of the Ir-Ir interaction and changing conformations of the TMB ligand framework, forming a metal-metal bonded 1d sigma*p sigma state after 4-5 ps.
Czech name
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Czech description
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Classification
Type
J<sub>imp</sub> - Article in a specialist periodical, which is included in the Web of Science database
CEP classification
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OECD FORD branch
10403 - Physical chemistry
Result continuities
Project
Result was created during the realization of more than one project. More information in the Projects tab.
Continuities
I - Institucionalni podpora na dlouhodoby koncepcni rozvoj vyzkumne organizace
Others
Publication year
2025
Confidentiality
S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů
Data specific for result type
Name of the periodical
Journal of the American Chemical Society
ISSN
0002-7863
e-ISSN
1520-5126
Volume of the periodical
147
Issue of the periodical within the volume
11
Country of publishing house
US - UNITED STATES
Number of pages
15
Pages from-to
9810-9824
UT code for WoS article
001438807000001
EID of the result in the Scopus database
2-s2.0-86000670136