Photoinduced Charge Transfer and Bimetallic Bond Dissociation of a Bi–W Complex in Solution

Abstract

Organometallic complexes including metal carbonyls have been widely utilized in academic and industrial settings for purposes ranging from teaching basic catalytic reactions to developing state-of-the-art electronic circuits. Characterization of these materials can be obtained via steady-state measurements; however, the intermediate photochemical events remain unclear, hindering effective and rational molecular engineering methods for new materials. We employed femtosecond transient absorption (fs-TA) and ground-state femtosecond stimulated Raman spectroscopy (FSRS) on triphenylbismuth–tungsten pentacarbonyl complex, a solution precursor for bimetallic oxide thin films. Upon 280 nm excitation into a charge-transfer band, an ultrafast bimetallic bond dissociation occurs within ∼140 fs. The subpicosecond nondiffusive solvation events are followed by ∼10 ps (15 ps) methanol (ethanol) complexation of the nascent tungsten pentacarbonyl intermediate, which mainly undergoes vibrational relaxation after crossing into a hot ground state. The trans ligand to axial CO is revealed to play a key role in the electronic and vibrational structure and dynamics of the complex. These findings could power rational design of bimetallic and functional solution precursors for the light-driven nanopatterning of thin films.

Segmented Ag–Au–Ag Heterojunction Nanorods: Pressure-Assisted Aqueous-Phase Synthesis and Engineered Femtosecond-to-Nanosecond Dynamics

“…Transient absorption spectroscopy can effectively explore photogenerated electronic kinetic parameters through monitoring real-time changing process of nanocrystal absorption after illumination, − which may be an effective means for segmented metal/metal HJNRs to examine the SPR modes, hot electron lifetimes, and thermal dissipation rates of its internal photogenerated electrons. The electron–phonon (e-ph) scattering process is an extremely important part of electronic dynamics of metal NPs, , the e-ph scattering time of which associates with excitation power and surface characteristic, surrounding medium, size, and shape of metal NPs. − Moreover, the synergistic effects between different components, contact interfaces, and heterojunction contents of segmented metal/metal HJNRs are perhaps expected to have unique e-ph scattering behavior, which is rarely studied to date.…”

Excited‐State Dynamics of a meta‐Dimethylamino Locked GFP Chromophore as a Fluorescence Turn‐on Water Sensor†

“…5c, d and 6b, c) substantiate the major role played by electronic effects instead of a functional group twisting after photoexcitation. Furthermore, the clearly narrower ESA band observed for L-NMe 2 -LpHBDI in toluene (Figure S5e) is in accord with its reduced conformational inhomogeneity (66,67) due to the locked P-ring substituents of the solute (versus the -NMe 2 group unlocked m-NMe 2 -LpHBDI, Figure S5c) as well as the non-H-bonding solvent (versus the polar protic MeOH, Fig. 6c).…”

Time-Resolved Ultraviolet–Infrared Experiments Suggest Fe–Cu Dinuclear Arene Borylation Catalyst Can Be Photoactivated

“…14 For example, for (CO) 5 M−M(CO) 5 type species there can be competition between metal−metal bond homolysis, dissociation of CO, and nondissociative relaxation, 21 and these routes are generally heavily influenced by excitation wavelength. 22 While we cannot completely rule out that a minor amount of Cp 2 Fe 2 (CO) 4 is formed under UV light exposure due to Fe−Cu metal fragmentation, 23 this is less likely since this compound is present prior to photolysis. Additionally, we do not see new CpFe(CO) 2 absorbances in time-resolved data (see below).…”