Themed collection Developments in Ultrafast Spectroscopy
Ultrafast processes: coordination chemistry and quantum theory
The correlation between electronic densities and active molecular vibrations drives the spin–vibronic mechanism of ultrafast decays in coordination chemistry.
Intrachain photophysics of a donor–acceptor copolymer
Ultrafast photophysics in the single chain of a PM6 is studied. The time evolution of locally excited (LE) and charge-transfer (CT)/separated (CS) states depends on the chain length highlighting effects of chain foldings on generating carriers.
Role of conical intersection seam topography in the chemiexcitation of 1,2-dioxetanes
Chemiexcitation of 1,2-dioxetanes is initiated by the cleavage of the O–O bond, then the molecule enters a region where nonadiabatic transitions to excited states are feasible. Does the surface topography explain chemiexcitation yield differences?
Vibrationally resolved absorption spectra and ultrafast exciton dynamics in α-phase and β-phase zinc phthalocyanine aggregates
Vibrationally resolved absorption spectra in α-phase and β-phase zinc phthalocyanine (ZnPc) aggregates.
Circularly polarized light-induced potentials and the demise of excited states
The alignment perpendicular to the field of the molecular axis in dissociative excited states of single electron molecules, prevents quantum control by bond hardening. However, using circularly polarized fields, one can circumvent this problem.
Ultrafast and efficient energy transfer in a one- and two-photon sensitized rhodamine-BODIPY dyad: a perspective for broadly absorbing photocages
A novel tandem design of sensitized BODIPY photolabile protecting groups is presented and characterized by combined spectroscopic and computational studies, paving the way for a new generation of functionalized photoactive compounds.
Electronic relaxation and dissociation dynamics in formaldehyde: pump wavelength dependence
The effect of the incident UV pump wavelength on the subsequent excited state dynamics, electronic relaxation, and ultimate dissociation of formaldehyde is studied using first principles simulation and Coulomb explosion imaging (CEI) experiments.
Modelling quenching mechanisms of disordered molecular systems in the presence of molecular aggregates
A macroscopic model of exciton density decays in disordered molecular systems, including contributions from molecular aggregate quenchers, is proposed. The model can be applied to ultrafast decays of dyes and for global fitting of experimental data.
Effects of Oxygen Vacancy on the Photoexcited Carrier Lifetime in Rutile TiO2
Terahertz pump–probe of liquid water at 12.3 THz
The excitation on the librational band of liquid water at 12.3 THz resonates with the rotationally-damped motion of water molecules.
The states that hide in the shadows: the potential role of conical intersections in the ground state unimolecular decay of a Criegee intermediate
The ground state unimolecular decay of Criegee intermediates may potentially be influenced by conical intersections.
Ultrafast molecular dynamics in ionized 1- and 2-propanol: from simple fragmentation to complex isomerization and roaming mechanisms
Photoexcitation of 1- and 2-propanol initiates a variety of molecular dynamics such as fragmentation, hydrogen migration, and even possible methyl roaming (only in 2-propanol).
Time-resolved relaxation and cage opening in diamondoids following XUV ultrafast ionization
Ultrafast vibrational dynamics induced by XUV excitation was investigated in diamondoids using HHG light source.
Ballistic ΔS = 2 intersystem crossing in a cobalt cubane following ligand-field excitation probed by extreme ultraviolet spectroscopy
Time resolved M2,3-edge XANES spectroscopy of the Co4O4 cubane reveals ultrafast intersystem crossing into a quintet state within 38 fs.
Time- and momentum-resolved image-potential states of 2H-MoS2 surface
Rydberg-like image potential states (IPSs) form special series surface states on metal and semiconducting surfaces.
Femtosecond photodecarbonylation of photo-ODIBO studied by stimulated Raman spectroscopy and density functional theory
Photo-oxa-dibenzocyclooctyne (Photo-ODIBO) undergoes photodecarbonylation under UV excitation to its bright S2 state, forming a highly reactive alkyne, ODIBO.
Understanding the mechanism of plasmon-driven water splitting: hot electron injection and a near field enhancement effect
Both hot electron injection and a near field enhancement effects on water splitting reaction at the nanoscale are investigated by the hybird FDTD/TDDFT approach.
Ultrafast relaxation investigated by photoelectron circular dichroism: an isomeric comparison of camphor and fenchone
We study the isomeric effects using time resolved photoelectron circular dichroism (TR-PECD).
Investigation of nonadiabatic dynamics in the photolysis of methyl nitrate (CH3ONO2) by on-the-fly surface hopping simulation
Photolysis reaction channels of CH3ONO2 are obtained in the nonadiabatic dynamics simulations.
Ultrafast photoelectron spectroscopy of photoexcited aqueous ferrioxalate
The photochemistry of metal–organic compounds in solution is determined by both intra- and inter-molecular relaxation processes after photoexcitation.
Coherent internal conversion from high lying electronic states to S1 in boron-dipyrromethene derivatives
Coherent internal conversion between higher electronic excited states is observed directly by excitation of molecules to Sn (n ≥ 2) state and detection of fluorescence from S1 state by wave-packet-resolved time-resolved fluorescence.
Determining the photostability of avobenzone in sunscreen formulation models using ultrafast spectroscopy
We explore how ultrafast spectroscopy can be utilised to predict the longer-term efficacy of avobenzone in sunscreen formulation models.
Ultrafast photochemistry of a molybdenum carbonyl–nitrosyl complex with a triazacyclononane coligand
The photochemistry of a molybdenum complex bearing both carbonyl and nitrosyl ligands is investigated by ultrafast spectroscopy and quantum-chemical calculations with the goal to elucidate possibilities of photoinduced ligand release.
Exciton delocalization length in chlorosomes investigated by lineshape dynamics of two-dimensional electronic spectra
The spectral and temporal profiles of exciton delocalization length in chlorosomes are determined with two-dimensional electronic spectroscopy.
Toward Å–fs–meV resolution in electron microscopy: systematic simulation of the temporal spread of single-electron packets
Effects of experimental parameters – including laser pulse duration, photon energy, aperture diameter, and cathode size – on single-electron temporal resolution are explored via particle-tracer simulations in ultrafast electron microscopy.
Ellipticity controlled dissociative double ionization of ethane by strong fields
The ellipticity of a laser can control the dissociation pathways of ethane dications produced by strong fields.
Trajectory surface hopping molecular dynamics simulations for retinal protonated Schiff-base photoisomerization
A global-switching trajectory surface hopping method on TDDFT potential energy surfaces has been used to simulate complex conical intersection networks and to predict photoproduct quantum yield distributions for a real RPSB system.
Effects of substituent position on aminobenzoate relaxation pathways in solution
Transient absorption spectroscopy reveals the excited state dynamics of meta- and para-methyl anthranilate in solution. Implicit solvent computational methods insufficiently model these systems's behaviour, implying the need for explicit solvent models.
Ultrafast evolution of the complex dielectric function of monolayer WS2 after photoexcitation
This study provides the basis for the reliable and quantitative comparison of experimentally determined exciton dynamics in TMDCs from independent femtosecond time-resolved optical spectroscopy experiments on different samples and substrates.
Selecting two-photon sequential ionization pathways in H2 through harmonic filtering
A frequency filter enhances ionization–excitation versus excitation–ionization, suppressing channels that prevent the extraction of the dynamical information in an experiment.
An efficient implementation of spin–orbit coupling within the framework of semiempirical orthogonalization-corrected methods for ultrafast intersystem crossing dynamics
We implement spin–orbit coupling (SOC) within the framework of the OMx/CIS method and then incorporate it into Tully's fewest switches surface hopping algorithm to enable excited-state nonadiabatic dynamics simulations.
Ultrafast vibrational wave packet dynamics of the aqueous tyrosyl radical anion induced by photodetachment
Ultrafast vibrational wave packet dynamics of the tyrosyl radical anion provide insight into sub-picosecond structural rearrangements induced by ionizing radiation.
Ultrafast “end-on”-to-“side-on” binding-mode isomerization of an iron–carbon dioxide complex
Femtosecond UV/MIR spectroscopy reveals the binding mode isomerization of an iron–carbon dioxide complex following the impulsive photolysis of iron oxalate precursor.
Interfacial photoinduced carrier dynamics tuned by polymerization of coronene molecules encapsulated in carbon nanotubes: bridging type-I and type-II heterojunctions
Theoretical studies demonstrate that the polymerization degree of molecules encapsulated in carbon nanotubes can be used to tune their interfacial and optoelectrical properties.
About this collection
This collection aims at promoting the ability of attosecond-to-picosecond laser pulses to decipher ultrafast dynamics of charge carriers, atoms and molecules in gas and condensed phases. The scope of this themed collection is designed to disseminate state-of-the-art theoretical and experimental developments, and to demonstrate their potential in the interpretation and prediction of a variety of processes at the physics-chemistry-biology-materials frontiers. By exploring the intimacy of matter, ultrafast spectroscopy not only provides detailed structural understanding but also in-depth knowledge of the processes that control primary functions, either at the atomic and molecular scale or in specific environments. Guest edited by Chantal Daniel (University of Strasbourg, France), Luis Banares (Universidad Complutense de Madrid, Spain), Spiridoula Matsika (Temple University, USA) and Jin Zhao (University of Science and Technology of China, Hefei).