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

Kód výsledku v 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>

Výsledek na webu

<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>

Jazyk výsledku

angličtina

Název v původním jazyce

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

Popis výsledku v původním jazyce

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.

Název v anglickém jazyce

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

Popis výsledku anglicky

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.

Druh

J_imp - Článek v periodiku v databázi Web of Science

CEP obor

—

OECD FORD obor

10403 - Physical chemistry

Projekt

Výsledek vznikl pri realizaci vícero projektů. Více informací v záložce Projekty.

Návaznosti

I - Institucionalni podpora na dlouhodoby koncepcni rozvoj vyzkumne organizace

Rok uplatnění

2025

Kód důvěrnosti údajů

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů

Název periodika

Journal of the American Chemical Society

ISSN

0002-7863

e-ISSN

1520-5126

Svazek periodika

147

Číslo periodika v rámci svazku

11

Stát vydavatele periodika

US - Spojené státy americké

Počet stran výsledku

15

Strana od-do

9810-9824

Kód UT WoS článku

001438807000001

EID výsledku v databázi Scopus

2-s2.0-86000670136