Femtosecond Absorption Spectroscopy of Transition Metal Charge‐Transfer Complexes

McCusker, James K.

doi:10.1002/chin.200411224

Cited by 45 publications

(99 citation statements)

References 11 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…29 Following this cascade of events, most excess vibrational energy from the excitation pulse is still contained in the solute when the 3 MLCT state is populated. It is well-known that the vibrational quantum state on a reactant surface can severely influence the ensuing excited state dynamics.…”

Section: Excited State Dynamics Without Ir Excitationmentioning

confidence: 99%

Directing the path of light-induced electron transfer at a molecular fork using vibrational excitation

et al. 2017

View full text Add to dashboard Cite

Ultrafast electron transfer in condensed-phase molecular systems is often strongly coupled to intramolecular vibrations that can promote, suppress and direct electronic processes. Recent experiments exploring this phenomenon proved that light-induced electron transfer can be strongly modulated by vibrational excitation, suggesting a new avenue for active control over molecular function. Here, we achieve the first example of such explicit vibrational control through judicious design of a Pt(II)-acetylide charge-transfer Donor-Bridge-Acceptor-Bridge-Donor "fork" system: asymmetric 13 C isotopic labelling of one of the two -C≡C-bridges makes the two parallel and otherwise identical Donor→Acceptor electron-transfer pathways structurally distinct, enabling independent vibrational perturbation of either. Applying an ultrafast UV pump (excitation)-IR pump (perturbation)-IR probe (monitoring) pulse sequence, we show that the pathway that is vibrationally perturbed during UV-induced electron-transfer is dramatically slowed down compared to its unperturbed counterpart. One can thus choose the dominant electron transfer pathway. The findings deliver a new opportunity for precise perturbative control of electronic energy propagation in molecular devices. Main TextControlling the function of future advanced materials demands a profound understanding of energymatter interactions in molecular systems at the quantum level. 1 There is a growing consensus that energy-and electron-transfer processes occurring far away from equilibrium in condensed-phase systems on femto-to-picosecond timescales do not conform to the Born-Oppenheimer approximation. Indeed, nuclear and electronic wave functions often strongly interact with each other, leading to exotic phenomena whereby vibrational motion can mediate and dictate the rate and efficiency of electronic transitions. [2][3][4][5] With overwhelming evidence that nuclear-electronic (vibronic) interactions play a crucial role in a broad range of systems, including light harvesting and conversion in photosynthetic organisms, 6-11 this phenomenon represents a tremendous opportunity to acquire deeper knowledge and control over the structural traits that govern molecular function and reactivity.Recent efforts led by Rubtsov et al.,12,13 Bakulin et al., 14 and our group 15,16 have shown that one way to experimentally exploit vibronic coupling to modulate molecular function is to introduce targeted vibrational excitation along specific reaction co-ordinates using ultrafast mid-infrared (IR) pulses. This approach enables promoting or suppressing electronic transitions, notably photo-induced electron transfer (ET), an elementary process that pervades the natural world. Although the demonstrated excited state modulations have been remarkably efficient, up to 100% suppression in one case, 15 predictive and directive control of electron transfer in the condensed phase has not been achieved yet.

show abstract

Section: Excited State Dynamics Without Ir Excitationmentioning

confidence: 99%

Directing the path of light-induced electron transfer at a molecular fork using vibrational excitation

et al. 2017

View full text Add to dashboard Cite

show abstract

“…The complexes absorb visible light via a Ru(dp) to imine (p*) metal to ligand charge transfer. Very rapid intersystem crossing follows to populate the 3 MLCT state (Damrauer and McCusker 1999;Yeh et al 2001;McCusker 2003). This state decays via a combination of radiative and non-radiative processes as well as internal conversion to a triplet state believed to be localized on the metal center (a ligand field state, Van Houten and Watts 1976).…”

Section: Introductionmentioning

confidence: 98%

The influence of bridging ligand electronic structure on the photophysical properties of noble metal diimine and triimine light harvesting systems

Wang

Guerzo

Baitalik³

et al. 2006

Photosynth Res

View full text Add to dashboard Cite

This manuscript discusses the photophysical behavior of transition metal complexes of Ru(II) and Os(II) employed in development of light harvesting arrays of chromophores. Particular emphasis is placed on the relationship between the photophysical behavior of complexes having metal-to-ligand charge transfer (MLCT) excited states and the electronic characteristics of bridging ligands used in preparing oligometallic complexes. Examples are presented that discuss intramolecular energy migration in complexes having two distinct MLCT chromophores with bridging ligands that only very weakly couple the two chromophores. In addition, systems having bridging ligands with localized triplet excited states lower in energy than the MLCT state of the metal center to which they are attached are discussed. These systems very often have excited states localized on the bridging ligand with excited state lifetimes on the order of tens of microseconds. Finally, systems having Fe(II) metal centers, with very low energy MLCT states, are discussed. In complexes also containing bridging ligands with low energy triplet states, energy partitioning between the Fe center MLCT state (or Fe localized ligand field states) and the ligand triplet state is observed; the two states relax to the ground state via parallel pathways, but the Fe(II) center does not serve as an absolute excitation energy sink.

show abstract

“…The study of the ultrafast dynamics of transition metal complexes is an active area of research in chemical physics [43][44][45][46][47][48][49][50][51]. Nevertheless, primary photophysical processes are known in detail for only a few types of transition metal complexes.…”

Section: Introductionmentioning

confidence: 99%

Primary reactions in the photochemistry of hexahalide complexes of platinum group metals: A minireview

Glebov

Pozdnyakov

Plyusnin

et al. 2015

Journal of Photochemistry and Photobiology C: Photochemistry Re

View full text Add to dashboard Cite

Femtosecond Absorption Spectroscopy of Transition Metal Charge‐Transfer Complexes

Cited by 45 publications

References 11 publications

Directing the path of light-induced electron transfer at a molecular fork using vibrational excitation

Directing the path of light-induced electron transfer at a molecular fork using vibrational excitation

The influence of bridging ligand electronic structure on the photophysical properties of noble metal diimine and triimine light harvesting systems

Primary reactions in the photochemistry of hexahalide complexes of platinum group metals: A minireview

Contact Info

Product

Resources

About