Excess-electron capture and energy transfer to bulk water for aqueous DNA nucleotide.

We performed QM/MM simulations to investigate excess-electron attachment to four aqueous DNA nucleotide anions (dRT). The negative QM/MM vertical electron affinities (-0.86 to -0.

Ultrasensitive Optical Thermometry via Inhibiting the Energy Transfer in Zero-Dimensional Lead-Free Metal Halide Single Crystals.

Self-referencing optical thermometry based on the fluorescence intensity ratio (FIR) have drawn extensive attention as a result of their high sensitivity and non-invasively fast response to temperature. However, it is a great challenge for luminescent materials to achieve simultaneously high absolute and relative temperature sensitivity based on the FIR technique. Herein, we developed a novel optical thermometer by designing hybrid lead-free metal halide (TTPhP)MnCl:Sb (TTPhP = tetraphenylphosphonium cation) single crystals with multimodal photoluminescence (PL).

Organo-Metal Halide Scintillator with Weak Thermal Quenching Up to 200 °C.

The prominent thermal quenching (TQ) effect of organic-inorganic metal halides limits their applications for lighting and imaging. Herein, we report an organo-metal halide scintillator (TTPhP)MnCl (TTPhP = tetraphenylphosphonium cation), which exhibits a weak TQ effect up to 200 °C under ultraviolet-visible light (efficiency loss of 5.5%) and X-ray radiation (efficiency loss of 37%).

Spatial Separation of Photogenerated Charges on Well-Defined Bismuth Vanadate Square Nanocrystals.

Crystal facet engineering has been recognized as a powerful strategy to finely modulate the charge separation behavior in semiconductor photocatalysis; however, disclosing the intrinsic roles that the morphologies and crystal facets play on photogenerated charge separation of semiconductor nanocrystals remains elusive. Herein, exemplified on the typical visible-light-responsive photocatalyst bismuth vanadate (BiVO ), for the first time, the successful fabrication is reported of well-defined BiVO square nanocrystals with precisely controllable (040)/(200) facet proportion, which undergo a dissolution-recrystallization-facet growth process accompanied with tetragonal to monoclinic phase transition. Spatial separation of photogenerated electrons and holes has been evidently demonstrated to take place between (040) and (200) facets of BiVO nanocrystals, on which the charge separation efficiency is verified to definitely depend on the facet proportion of (040)/(200).

A novel aggregation-induced enhanced emission aromatic molecule: 2-aminophenylboronic acid dimer.

Aggregation-induced enhanced emission (AIEE) molecules have significant applications in optoelectronics, biomedical probes and chemical sensors, and large amounts of AIEE molecules have been reported since the concept of AIEE was proposed. Most aromatic AIEE molecules have complex structures consisting of multiple aromatic rings and/or polycyclic skeletons. In this study, we find that 2-aminophenylboronic acid (2-APBA) with a simple structure is highly emissive in the solid state.

A combined experimental and theoretical investigation of the excited-state dynamics of 2,4,6-trinitrotoluene (TNT) in DMSO solvent.

In the present contribution we carried out a TDDFT and femtosecond transient absorption study of the excited state dynamics of TNT in DMSO solvent. Vertical excitation and excited state relaxation were calculated at the SMD/M06-2X/TZVP level of theory. The electron absorption spectrum for the DMSO solvated TNT was calculated and compared with the experimental results.

Controlling Photoluminescence and Photocatalysis Activities in Lead-Free Cs Pt Sn Cl Perovskites via Ion Substitution.

Lead-free halide perovskites have triggered interest in the field of optoelectronics and photocatalysis because of their low toxicity, and tunable optical and charge-carrier properties. From an application point of view, it is desirable to develop stable multifunctional lead-free halide perovskites. We have developed a series of Cs Pt Sn Cl perovskites (0≤x≤1) with high stability, which show switchable photoluminescence and photocatalytic functions by varying the amount of Pt substitution.

A fluorophore's electron-deficiency does matter in designing high-performance near-infrared fluorescent probes.

The applications of most fluorescent probes available for Glutathione -Transferases (GSTs), including which we developed recently based on 1,8-naphthalimide (), are limited by their short emission wavelengths due to insufficient penetration. To realize imaging at a deeper depth, near-infrared (NIR) fluorescent probes are required. Here we report for the first time the designing of NIR fluorescent probes for GSTs by employing the NIR fluorophore which possesses a higher brightness, hydrophilicity and electron-deficiency relative to .

Doped Zero-Dimensional Cesium Zinc Halides for High-Efficiency Blue Light Emission.

All-inorganic zero-dimensional (0D) metal halides have recently received increasing attention due to their excellent photoluminescence (PL) performance and high stability. Herein, we present the successful doping of copper(I) into 0D Cs ZnBr . The incorporating of Cu cations enables the originally weakly luminescent Cs ZnBr to exhibit an efficient blue emission centered at around 465 nm, with a high photoluminescence quantum yield (PLQY) of 65.

Lead-Free Small-Bandgap CsCuSbCl Double Perovskite Nanocrystals.

Lead-free halide double perovskites (DPs) have attracted great attention due to their stability, nontoxicity and good photophysical property. In this work, we report a new, small-bandgap CsCuSbCl DP nanocrystals (NCs) with a bandgap of 1.66 eV, which is the smallest bandgap in reported lead-free three-dimensional DP NCs.

Self-trapped exciton engineering for white-light emission in colloidal lead-free double perovskite nanocrystals.

Intrinsic broadband photoluminescence (PL) of self-trapped excitons (STEs) are systematically studied in lead-free double perovskite nanocrystals (NCs). It is clarified that bandgap (direct/indirect) has important influence on the PL properties of STEs: indirect bandgap NCs exhibit strong exciton-phonon coupling which results in non-radiative STEs, while direct bandgap NCs exhibit moderate exciton-phonon coupling, inducing bright STE PL. Furthermore, by alloying K and Li ions in CsAgInCl NCs, the NCs exhibit broadband white-light emission.

Enhancing Intersystem Crossing to Achieve Thermally Activated Delayed Fluorescence in a Water-Soluble Fluorescein Derivative with a Flexible Propenyl Group.

It is a challenge to rationally design an organic molecule with thermally activated delayed fluorescence (TADF) due to the intrinsically spin-forbidden transition. Meanwhile, those reported TADF organic molecules have difficulty to be directly applied in the field of biological and medical imaging because they usually have no water solubility. Here, a water-soluble TADF organic molecule DCF-BXJ was developed by introducing a flexible propenyl group into the commercial traditional fluorophore DCF (2,7-dichlorofluorescein).

Semi-Quantitatively Designing Two-Photon High-Performance Fluorescent Probes for Glutathione S-Transferases.

Glutathione S-transferases (GSTs), detoxification enzymes that catalyze the addition of glutathione (GSH) to diverse electrophilic molecules, are often overexpressed in various tumor cells. While fluorescent probes for GSTs have often adopted the 2,4-dinitrobenzenesulfonyl (DNs) group as the receptor unit, they usually suffer from considerable background reaction noise with GSH due to excessive electron deficiency. However, weakening this reactivity is generally accompanied by loss of sensitivity for GSTs, and therefore, finely turning down the reactivity while maintaining certain sensitivity is critical for developing a practical probe.

Manganese-Doped, Lead-Free Double Perovskite Nanocrystals for Bright Orange-Red Emission.

Lead-free halide perovskite nanocrystals (NCs) have recently attracted attention due to their nontoxicity and stability as alternatives to lead-based perovskite NCs. Here, we report undoped and manganese-doped all-inorganic, lead-free double perovskite (DP) NCs: CsNaIn Bi Cl (0 < < 1) and CsNaIn Bi Cl:Mn (0 ≤ ≤ 1) NCs. Undoped NCs exhibit blue emission.

All-Inorganic Lead-Free 0D Perovskites by a Doping Strategy to Achieve a PLQY Boost from <2 % to 90 .

Zero-dimensional (0D) lead-free perovskites have unique structures and optoelectronic properties. Undoped and Sb-doped all inorganic, lead-free, 0D perovskite single crystals A InCl (H O) (A=Rb, Cs) are presented that exhibit greatly enhanced yellow emission. To study the effect of coordination H O, Sb-doped A InCl (A=Rb, Cs) are also synthesized and further studied.

Change of Initial Yield of a Hydrated Electron with Uridine Monophosphate Concentration Is Related to the Excitation Photon Energy in Transient Absorption Spectroscopy.

The initial yield of a hydrated electron (e) in a solution under laser pulse irradiation was investigated by pump-probe transient absorption spectroscopy. The initial quantum yield of e varies with the concentration of uridine monophosphate (UMP). The variation of the concentration of e is often used to study the prehydrated electron (e) and e attachment to UMP.

Carrier Multiplication and Hot-Carrier Cooling Dynamics in Quantum-Confined CsPbI Perovskite Nanocrystals.

Carrier multiplication (CM) is an effective mechanism that makes it possible to use hot carriers (HCs) to bypass the Shockley-Queisser limit for solar-cell efficiency. In this paper, we present a detailed study of both CM and HC cooling dynamics in quantum-confined CsPbI perovskite nanocrystals (NCs), using femtosecond transient absorption spectroscopy. Our results show that barrierless CM, with an efficiency exceeding 90%, can be achieved in strongly confined NCs on a time scale of ≪200 fs.

Lead-Free Sodium-Indium Double Perovskite Nanocrystals through Doping Silver Cations for Bright Yellow Emission.

Lead-free halide perovskite nanocrystals (NCs) have drawn wide attention for solving the problem of lead perovskites toxicity and instability. Herein, we synthesize the direct band gap double perovskites undoped and Ag-doped Cs NaInCl NCs by variable temperature hot injection. The Cs NaInCl NCs have little photoluminescence because of dark self-trapped excitons (STEs).

Colloidal Synthesis and Optical Properties of All-Inorganic Low-Dimensional Cesium Copper Halide Nanocrystals.

Low-dimensional metal halides have recently attracted extensive attention owing to their unique structure and photoelectric properties. Herein, we report the colloidal synthesis of all-inorganic low-dimensional cesium copper halide nanocrystals (NCs) by adopting a hot-injection approach. Using the same reactants and ligands, but different reaction temperatures, both 1D CsCu I nanorods and 0D Cs Cu I NCs can be prepared.

Substitution Dependent Ultrafast Ultraviolet Energy Dissipation Mechanisms of Plant Sunscreens.

An ultraviolet energy dissipation mechanism plays a critical role in the photoprotection effect of sunscreens. In this work, we discovered substitution dependent UV energy dissipation mechanisms of model plant sunscreen methyl sinapate (MS). We found that the initially populated V(ππ*) states of MS and -OMeMS relax to the ground state nonradiatively along an ultrafast trans-cis photoisomerization in tens of picoseconds.

Hetero-bichromophore Dyad as a Highly Efficient Triplet Acceptor for Polarity Tuned Triplet-Triplet Annihilation Upconversion.

Triplet-triplet annihilation upconversion (TTA UC) was intensively investigated for developing efficient photosensitizers and emitters. But an emission wavelength tunable TTA UC system with only one emitter was rarely reported. A novel hetero-bichromophore dyad, HB-An, showing solvatochromic emission and high fluorescence quantum yields in weakly polar solvents (such as -hexane, dichloromethane (DCM), and so on) was used as triplet energy acceptor/emitter for polarity tuned TTA UC.

New Insight into the Photoprotection Mechanism of Plant Sunscreens: Adiabatic Relaxation Competing with Nonadiabatic Relaxation in the → Photoisomerization of Methyl Sinapate.

A great deal of thermally instable form photoisomerization products will be formed from the thermally stable form of the plant sunscreens sinapate esters upon ultraviolet radiation. To reveal the photoisomerization mechanism of the -isomer, we explore the photodynamics of a model plant sunscreen methyl sinapate (MS) in the form in organic solution. The high photoisomerization quantum yield of the -isomer results in the relatively higher photostability of -MS.

The MMCT excited state of a localized mixed valence cyanido-bridged Ru-Ru-Ru complex.

To investigate MMCT excited states of MV complexes, two symmetrical tetranuclear cyanido-bridged localized MV complexes RuIICNRuIII,III2NCRuII have been designed and synthesized. The ultrafast time-resolved transient absorption (TA) spectroscopy experiment reveals that the MMCT rate of 1 and 2 is 0.18 × 1014 s-1 (τ = 5.

Surface-Halogenation-Induced Atomic-Site Activation and Local Charge Separation for Superb CO Photoreduction.

Solar-energy-driven CO conversion into value-added chemical fuels holds great potential in renewable energy generation. However, the rapid recombination of charge carriers and deficient reactive sites, as two major obstacles, severely hampers the photocatalytic CO reduction activity. Herein, a desirable surface halogenation strategy to address the aforementioned concerns over a Sillén-related layer-structured photocatalyst Bi O (OH)(NO ) (BON) is demonstrated.

Notable effect of water on excess electron attachment to aqueous DNA deoxyribonucleosides.

Computations using the combined quantum mechanical/molecular mechanical (QM/MM) method were performed to investigate excess electron attachment to and detachment from aqueous deoxyribonucleosides (dRNs). The QM/MM vertical electron affinities (VEAs) of four dRNs are higher than the values of the corresponding nucleobases by ∼0.20 eV.