ChemPhotoChem最新文献

The Front Cover illustrates the molecular structure of 2′,5′-bis(triphenylsiloxy)-p-terphenyl in the center as a representative example of fluorophores that efficiently emit ultraviolet light in the solid state with emission maxima below 400 nm. Although UV light is invisible to the naked eye, the pale pink shadow of the molecular model is an expression of the efficient luminescence. Cover design by Shinji Muranaka. More information can be found in the Research Article by Masaki Shimizu and co-workers.

DNA nanostructures have been regarded as promising platforms for molecular information coding for their high programmability and nanoscale addressability. However, steganography based on DNA nanostructures still needs further investigation. Here, we designed and synthesized a coumarin derivative structure with selective photo responsiveness in the visible light spectrum and developed a DNA origami steganography system that can only be decrypted through specific light exposure conditions. Under right light treatment, the effective cleavage of photoresponsive groups would cause some of the streptavidin binding sites to detach from the origami, thereby allowing the steganographic information to be read correctly.

The rapid advancement of biotechnology over the recent decades has amplified the importance of DNA detection and quantification assays. Many of these assays, such as gel electrophoresis, microscopy, flow cytometry, and the detection of amplification in quantitative polymerase chain reaction (qPCR), rely on the use of DNA-binding fluorescent dyes. This article presents a comprehensive study of six Thiazole-Orange-based fluorescent DNA-binding dyes: SYBR Safe, SYBR Green, Pico Green, SYTO-16, SYTO-9, and the benzothiazole-based analogue (TOPhBu) of the latter. The selected DNA markers were synthesized at a 10-milligram scale and characterised spectroscopically to quantify their fluorescence enhancement upon binding to double-stranded DNA. The ability of the dyes to detect DNA at low concentrations was evaluated using two new metrics, absolute fluorescence enhancement (AFE) and relative fluorescence enhancement (RFE). Quantum chemical calculations shed new light on the mechanism of their fluorogenicity through modelling the excited state behaviour and DNA binding of the dyes. Their analytical performance was further tested in qPCR experiments. The experimental results of this work highlight some important differences in the sensitivity and qPCR efficiency of the studied DNA-binding dyes which will facilitate the DNA marker selection for analytical purposes and the future development of novel DNA sensors.

Organic luminescent solid materials have attracted much attention due to practical applications such as sensor materials and optical waveguides. We have previously reported that inverse type diarylethenes exhibit strong emission in crystal without causing aggregation-caused quenching. However, the emission color was limited to mainly green. To tune the emission color, in this work, we newly synthesized inverse type diarylethenes having a shortened π-conjugation length or a polar substituent and investigated their fluorescence properties in solutions and crystals. The crystals exhibited various emission colors from blue, green, yellow to red depending on the molecular structure. The emission color changes of the crystals were induced by the intermolecular interactions such as CH-π interactions in addition to the shortened π-conjugation length and the intramolecular charge transfer character.

The surface plasmon resonance (SPR) effect has garnered extensive attention in semiconductor photocatalysis for solar energy conversion, thanks to its remarkable optical properties. However, the majority SPR-induced photocatalytic systems have been limited to achieving hydrogen evolution or oxygen evolution half reactions, and attaining overall water splitting on a SPR-induced photocatalyst under visible light remains a formidable challenging. In this study, we employed a plasmonic photocatalyst Au/SrTiO₃, and further enhanced its performance by doping aluminum (Al) into the SrTiO₃ lattice (denoted as Au/SrTiO₃:Al). By constructing reduction cocatalyst (RhCrO_x) and oxidation cocatalyst (CoOOH), the Au/SrTiO₃:Al photocatalyst successfully realizes photocatalytic overall water splitting with a stoichiometric ratio of H₂ and O₂ under visible light (λ≥440 nm). We revealed that the introduction of Al species effectively modified the electronic structure of SrTiO₃, thereby enhancing the hydrogen evolution reaction in Au/SrTiO₃:Al. Simultaneously, the RhCrO_x and CoOOH cocatalysts synergistically capitalized on the short-lived hot electrons and holes generated by the plasmonic Au/SrTiO₃:Al photocatalyst, enabling to realize photocatalytic overall water splitting. This work offers a promising avenue for the rational design of plasmon-induced overall water splitting photocatalysts through the integration of suitable cocatalysts and surface/interface engineering strategies.

This Perspective analyses the perfluoroalkylation reactions by electron donor-acceptor (EDA) complexes since 2018, while summarizes, in Tables 123, the vast majority of representative perfluoroalkylation reactions of various classes of organic compounds by EDA complexes and halogen-bonding interactions. Numerous intriguing reaction methodologies and valuable synthetic instances have emerged. We aim to delve into these new examples comprehensively, while also contemplating the future directions in the field. Subsequent sections will elaborate on the perfluoroalkylation of (hetero)aromatic compounds, carbon-carbon multiple bonds, perfluoroalkylation of carbonyl compounds, and perfluoroalkylation of isocyanides, covering their synthetic scope and mechanistic insights.

The consumption of fossil fuels releases large amounts of carbon dioxide (CO₂) in the atmosphere, causing a serious greenhouse effect. Photoelectrochemical (PEC) reduction of CO₂ to chemical fuels is an effective way to alleviate the current energy and environmental crisis. However, it is still difficult to rationally design efficient PEC CO₂ reduction photocathodes. Cuprous oxide (Cu₂O) is a promising photocathode material, but its surface is susceptible to the accumulation of photogenerated electrons leading to corrosion and activity reduction, and is accompanied by hydrogen evolution reaction (HER), both of which lead to the overall low conversion efficiency of CO₂ reduction by Cu₂O. In this study, the PEC CO₂ conversion efficiency was improved by the synergistic effect of the C electron transport layer to accelerate the electron transfer to alleviate the Cu₂O corrosion problem and the polytetrafluoroethylene (PTFE) hydrophobic layer to inhibit the HER. The test showed that the CO yield of Cu₂O/C/PTFE at the optimum potential (−0.7 V vs. RHE) was 54.6 μmol cm⁻² h⁻¹, which was 3.2 times higher than that of pure Cu₂O. This study provides a facile strategy for constructing an efficient photocathode with great potential for CO₂ reduction.

Two new p-type molecules, namely TAT-TY3 and TAT-TY4, featuring triazatruxene endcaps and carbazole π-bridges, were synthesized. The photophysical and electrochemical properties of synthesized materials were comparatively investigated based on their 2,7- and 3,6-carbazole conjugation pathways. Optical characterizations revealed the impact of non-bonding electron delocalization of triazatruxene through carbazole moieties, resulting in a significant increase in absorption intensity corresponding to n-π* energy transitions and a red shift of triazatruxene moieties. Consequently, the optical band gaps of TAT-TY3 and TAT-TY4 were measured at 3.0 and 3.2 eV, respectively. Moreover, the molecules′ first oxidation potentials exhibited a drastic difference due to the electrochemical behavior of 2,7- and 3,6-carbazole moieties. The highest occupied molecular orbital (HOMO) level for TAT-TY3 was measured to be −5.02 eV, while for TAT-TY4, it was measured as −4.67 eV. Hole-extraction properties were explored using steady-state and time-resolved photoluminescence spectroscopy, revealing enhanced charge transfer between the TAT-TY3/Perovskite interface due to the better alignment of HOMO energy levels. The photovoltaic performances of the hole-transporting materials (HTMs) were successfully characterized in triple-cation perovskite solar cells and efficiencies of up to 17.9 %, 16.2 %, and 9.8 % were achieved for Spiro-OMeTAD, TAT-TY3, and TAT-TY4, respectively.

Hypoxic tumor microenvironments pose significant challenges to the clinical translation of cancer photodynamic therapy (PDT). While heavy atom-free Type-I boron dipyrromethenes (BODIPYs) photosensitizers can alleviate this challenge by reducing oxygen dependency, but they remain scarce. Herein, heavy-atom-free α,meso-linked bisBODIPYs were designed and synthesized. These bisBODIPYs exhibit remarkable red-shifted emission (λemmax ~670 nm), large Stokes shifts (~4480 cm⁻¹) and they are capable of producing both superoxide anion (O₂⋅⁻) and singlet oxygen (¹O₂) in solution and cells. Additionally, they offer a wide PDT treatment window, ranging from 0.26 to 83.5 μM. Furthermore, these bisBODIPYs also demonstrate superior two-photon fluorescence, promising for surgical navigation and integrating diagnosis with treatment.

The development of multi-responsive nanohybrid systems that combine photothermia, thermo-responsive effects and photocatalysis is a challenging topic in the research of multifunctional materials with a large field of applications. Here, we report the first example of a three-components light-responsive nanosystem consisting of titania, gold nanoparticles and poly-N-isopropylacrylamide (TiO₂-Au-PNM). The hybrid nanostructure exhibited photothermal conversion effect upon green-light excitation and capacity to entrap methylene blue and curcumin selected as cargo models. The formation of the nanohybrid–cargo adducts, the photothermal-controlled cargo release triggered by green-light irradiation (532 nm) and mediated by lower critical solution temperature (LCST), as well as the photocatalytic effect prompted by UV-light excitation (300 nm) were demonstrated by spectroscopic techniques. The mechanism involved in the interaction of the polymeric component with the cargos was investigated by molecular modelling calculations.