Artificial light-harvesting systems in aqueous media which mimic nature are of significant importance; however, they often restrained by the solubility and undesired aggregation-caused quenching effect hydrophobic chromophores. Here, we report a generalized strategy toward construction efficient artificial based on supramolecular peptide nanotubes water. By molecularly aligning chromophores along slipped manner, an system with two-step sequential Förster resonance energy transfer process is...

Materials with electrically tunable optical properties offer a wide range of opportunities for photonic applications. The the single-walled carbon nanotubes (SWCNTs) can be significantly altered in near-infrared region by means electrochemical doping. states' filling, which is responsible absorption suppression under doping, also alters nonlinear response material. Here, first time we report that doping tailor SWCNT films and demonstrate its application to control pulsed fiber laser...

The relationship between exposure to ultraviolet (UV) radiation and skin cancer urges the need for extra photoprotection, which is presently provided by widespread commercially available sunscreen lotions. Apart from having a large absorption cross section in UVA UVB regions of electromagnetic spectrum, chemical absorbers these photoprotective products should also be able dissipate excess energy safe way, i.e. without releasing photoproducts or inducing any further, harmful, photochemistry....

Methyl-E-4-methoxycinnamate (E-MMC) is a model chromophore of the commonly used commercial sunscreen agent, 2-ethylhexyl-E-4-methoxycinnamate (E-EHMC). In an effort to garner molecular-level understanding photoprotection mechanisms in operation with E-EHMC, we have time-resolved pump-probe spectroscopy explore E-MMC's and E-EHMC's excited state dynamics upon UV-B photoexcitation S1 (11ππ*) both gas- solution-phase. gas-phase, our studies suggest that are driven by non-radiative decay from...

Heterostructures built from 2D, atomically thin crystals are bound by the van der Waals force and exhibit unique optoelectronic properties. Here, we report structure, composition properties of 1D heterostructures comprising carbon nanotubes wrapped boron nitride molybdenum disulfide (MoS2). The high quality composite was directly made evident on atomic scale transmission electron microscopy, macroscopic a study heterostructure's equilibrium ultrafast optoelectronics. Ultrafast pump–probe...

A strong negative photoconductivity was identified in thin film networks of single-walled carbon nanotubes using optical pump, THz probe spectroscopy. The films were controllably doped, either adsorption doping with different p-type dopant concentrations or ambipolar an ionic gate. While enhanced the conductivity and increased momentum scattering rate, interband photoexcitation lowered spectral weight reduced rate. This observed for all levels, regardless chemical potential, decayed within a...

Abstract Strong intertube excitonic coupling is demonstrated in 1D van der Waals heterostructures by examining the ultrafast response of radial C/BN/MoS 2 core/shell/skin nanotubes to femtosecond infrared light pulses. Remarkably, excitation excitons semiconducting carbon (CNTs) creates a prominent visible range from MoS skin, even with photons at energies well below bandgap . Via classical analogies and quantum model light–matter interaction these findings are assigned correlations....

Photoprotection from harmful ultraviolet (UV) radiation exposure is a key problem in modern society. Mycosporine-like amino acids found fungi, cyanobacteria, macroalgae, phytoplankton, and animals are already presenting promising form of natural photoprotection sunscreen formulations. Using time-resolved transient electronic absorption spectroscopy guided by complementary ab initio calculations, we help to unravel how the core structures these molecules perform under UV irradiation. Through...

Ultrafast time-resolved ion yield (TR-IY) and velocity map imaging spectroscopies are employed to reveal the relaxation dynamics after photoexcitation in ethyl 4-hydroxy-3-methoxycinnamate (ethyl ferulate, EF), an active ingredient commercially available sunscreens. In keeping with a bottom-up strategy, building blocks of EF, 2-methoxy-4-vinylphenol (MVP) 4-hydroxy-3-methoxycinnamyl alcohol (coniferyl alcohol, ConA), were also studied assist our understanding EF as we build up molecular...

We present, for the first time, rotationally resolved photoelectron images resulting from ionization of a polyatomic molecule. Photoelectron angular distributions pertaining to formation individual rotational levels $\mathrm{NH}_{3}{}^{+}$ have been extracted and analyzed enable complete determination radial dipole matrix elements relative phases that describe dynamics. This leads deduction significantly different dynamics those in previous studies which lacked either information or resolution.

The photoinduced dynamics of the lignin building blocks syringol, guaiacol, and phenol were studied using time-resolved ion yield spectroscopy velocity map imaging. Following irradiation syringol guaiacol with a broad-band femtosecond ultraviolet laser pulse, coherent superposition out-of-plane OH torsion and/or OMe torsion/flapping motions is created in first excited (1)ππ* (S1) state, resulting vibrational wavepacket, which probed by virtue dramatic nonplanar → planar geometry change upon...

The ultrafast excited state dynamics of the sunscreen ingredient menthyl anthranilate (MenA) and its precursor methyl (MA) were studied in vacuum (using time-resolved ion yield spectroscopy) solution transient electronic absorption spectroscopy). MenA MA both show long-lived dynamics, with observation a kinetic isotope effect suggesting that hydrogen motion acts as rate determining process overall decay. Complementary computational studies exploring intuitive decay pathways revealed bound S1...

Abstract The plant sunscreen derivative methyl sinapate is studied in the gas‐ and solution‐phase as an important step understanding structure‐dynamics‐function relationship of sunscreens such sinapoyl malate. Results from gas‐phase experiments suggest a three deactivation process after photoexcitation. Photoexcitation to S 1 state results internal vibrational energy redistribution within 3 ps. Intersystem crossing then occurs 30 ps between T latter persists outside our probe window ( ns)....

Continuous advancements in biophysics and medicine at the molecular level make requirements to image structure–function processes living cells ever more acute. While fluorophores such as green fluorescent protein have proven instrumental toward efforts, advent of nondiffraction limited microscopy limits utility tags. Monoaminomaleimides are small, single molecule that been shown possess stark variations their emission spectra different solvent environments, making them a potentially powerful...

The electron-phonon interaction controls the intrinsic mobility of charges in metal halide perovskites, and determines rate at which carriers lose energy. Here, carrier cooling dynamics were directly examined using a combination ultrafast transient absorption spectroscopy optical pump, THz probe spectroscopy, perovskites with different lead tin content, for range densities. Significantly, ``hot phonon bottleneck'' regime, where LO bath keeps warm, was found to be similar cold carriers. A...

A spectroelectrochemical set-up using a boron doped diamond mesh electrode is presented; from ultrafast photodynamics to steady-state, the photochemistry and photophysics of redox active species their reactive intermediates can be investigated.

By using high-resolution photoelectron velocity map imaging and a pump–probe ionization scheme we are able to demonstrate that angular distributions from ammonia depend sensitively on the neutral rotational level is ionized, of ion formed. We use this sensitivity fully determine photoionization dynamics giving rise observed branching ratios. In addition, observe dependence initially prepared alignment, by varying relative polarizations pump probe. This can be used corroborate determined...

Eumelanin is a naturally synthesized ultraviolet light absorbing biomolecule, possessing both photoprotective and phototoxic properties. We infer insight into these properties of eumelanin using bottom-up approach, by investigating an motif eumelanin, 4-tert-butylcatechol. Utilizing combination femtosecond transient electronic absorption spectroscopy time-resolved velocity map ion imaging, our results suggest environmental-dependent relaxation pathway, following irradiation at 267 nm to...

The dynamics of photoexcited 2,4-dimethylpyrrole (DMP) were studied using time-resolved velocity map imaging spectroscopy over a range photoexcitation wavelengths (276–238 nm). Two dominant H atom elimination channels inferred from the total kinetic energy release spectra, one which occurs with time constant ∼120 fs producing atoms high energies centered around 5000–7000 cm–1 and second channel ∼3.5 ps low 2500–3000 cm–1. first these is attributed to direct excitation ground electronic state...

The dynamic increase in terahertz photoconductivity resulting from energetic intraband relaxation was used to track the formation of highly mobile charges thin films tin iodide perovskite Cs1–xRbxSnI3, with x = 0 and 0.1. Energy times were found be around 500 fs, comparable those prototypical inorganic semiconductor GaAs. At low excess energies, efficient energy lowest conduction valence bands Cs1–xRbxSnI3 can understood within context Fröhlich electron–phonon interaction, a strong coupling...

Nonribosomal peptides are a structurally diverse and bioactive class of natural products constructed by multidomain enzymatic assembly lines known as nonribosomal peptide synthetases (NRPSs). While the core catalytic domains even entire protein subunits NRPSs have been elucidated, little biophysical work has reported on docking that promote interactions—and thus transfer biosynthetic intermediates—between subunits. In present study, we closely examine COM mediate COMmunication between donor...

The ability to probe energy flow in molecules, following the absorption of ultraviolet light, is crucial unraveling photophysical phenomena. Here we excite a coherent superposition vibrational states first excited electronic state (${\mathit{S}}_{1}$) catechol, resulting wave packet. observed quantum beats, assigned superpositions low-frequency, and strongly mixed, O--H torsional mode ${\ensuremath{\tau}}_{2}$, elegantly demonstrate how changes geometry upon photoionization from ${S}_{1}$...