Real-Time Tracking of Photoinduced Metal–Metal Bond Formation in a d8d8 Di-Iridium Complex by Vibrational Coherence and Femtosecond Stimulated Raman Spectroscopy

Result code in IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F10974938%3A_____%2F25%3A25_88_15" target="_blank" >RIV/10974938:_____/25:25_88_15 - isvavai.cz</a>

Alternative codes found

RIV/00216208:11320/25:10511040 RIV/60461373:22310/25:43931457

Result on the web

<a href="https://doi.org/10.1021/jacs.4c18527" target="_blank" >https://doi.org/10.1021/jacs.4c18527</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1021/jacs.4c18527" target="_blank" >10.1021/jacs.4c18527</a>

Result language

angličtina

Original language name

Real-Time Tracking of Photoinduced Metal–Metal Bond Formation in a d8d8 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

—

Czech description

—

Type

J_imp - Article in a specialist periodical, which is included in the Web of Science database

CEP classification

—

OECD FORD branch

10301 - Atomic, molecular and chemical physics (physics of atoms and molecules including collision, interaction with radiation, magnetic resonances, Mössbauer effect)

Project

<a href="/en/project/GA21-05180S" target="_blank" >GA21-05180S: Driving Charge Transport in Chromophore-Protein Complexes through Tryptophan Pathways</a><br>

Continuities

P - Projekt vyzkumu a vyvoje financovany z verejnych zdroju (s odkazem do CEP)

Publication year

2025

Confidentiality

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

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