Organic-polyoxometalate (POM) hybrids have recently attracted considerable interest because of their distinctive properties and wide-ranging applications. For the construction of organic-POM hybrids, porphyrins are promising building units owing to their optical properties and reactivity, including strong visible-light absorption and subsequent singlet-oxygen (O*) generation. However, the practical utilization of porphyrins as photocatalysts and photosensitizers is often hindered by their own degradation by O*.
View Article and Find Full Text PDFAlthough chiral semiconductors have shown promising progress in direct circularly polarized light (CPL) detection and emission, they still face potential challenges. A chirality-switching mechanism or approach integrating two enantiomers is needed to discriminate the handedness of a given CPL; additionally, a large material volume is required for sufficient chiroptical interaction. These two requirements pose significant obstacles to the simplification and miniaturization of the devices.
View Article and Find Full Text PDFSomatostatin (somatotropin release-inhibiting factor, SRIF) is a growth hormone inhibitory factor in the form of a 14- or 28-amino acid peptide. SRIF affects several physiological functions through its action on five distinct SRIF receptor subtypes (sst1-5). Native SRIF has only limited clinical applications due to its rapid degradation in plasma.
View Article and Find Full Text PDFA stepwise two-photon, red light excitation of organorhodium(III) phthalocyanine complexes was found to induce the activation of the axial metal-carbon bond to generate alkyl radicals/aldehydes. The cooperative action of the photouncaging reaction and the photochemical generation of reactive oxygen species were indicated to induce the cell deaths.
View Article and Find Full Text PDFThis report demonstrates organic vapor-induced dissolution of several molecular salts (, organic deliquescence), like water vapor-induced deliquescence. Systematic experiments indicate that appropriate organic deliquescent responses to volatile organic compounds can be designed according to the principle, "like dissolves like". The phenomena will be useful for developing agents to collect various volatile organic compounds.
View Article and Find Full Text PDFIntroduction: There is no standardized aerosol exposure apparatus to deliver heated tobacco products (HTPs) for in vivo experiments. Therefore, we developed a novel HTPs aerosol exposure apparatus for mice and demonstrated that nicotine and other chemicals in HTPs aerosol generated by the apparatus can be delivered to mice which replicate human smoke.
Aims And Methods: The amounts of nicotine, tar, and carbon monoxide (CO) in IQOS (Marlboro Regular HeatSticks) aerosol generated by two types of apparatuses were determined.
Angew Chem Int Ed Engl
August 2021
Chiral induction is an emerging topic of interest in various areas of chemistry because of its relationship to the elusive mechanism of spontaneous symmetry breaking in nature. Buckminsterfullerene (C ) with the shape of a highly symmetric truncated icosahedron has rarely been referred for chiral induction due to the difficult symmetry breaking. In this work, we demonstrate that a chiral metal-organic framework (MOF) can provide a key field for chiral induction.
View Article and Find Full Text PDFMono- and di-nuclear tricarbonyl Re(I) tetraazaporphyrin complexes (Re TAP and Re TAP) are investigated and compared with Re(I) phthalocyanine complexes (Re Pc and Re Pc). Although Re Pc is unstable in polar solvents, and easily undergoes demetallation reaction, the coordination of the TAP ligand significantly improves the tolerance toward polar solvents, affording more stability to Re TAP. Additionally, the incorporation of [Re(CO) ] unit(s) and the TAP ligand results in remarkable positive shifts in both oxidation and reduction potentials.
View Article and Find Full Text PDFMutat Res Genet Toxicol Environ Mutagen
April 2021
Time varying magnetic fields (MFs) are used for the wireless power-transfer (WPT) technology. Especially, 85 kHz band MFs, which are included in the intermediate frequency (IF) band (300 Hz - 10 MHz), are commonly used WPT system for charging electric vehicles. Those applications of WPT technology have elicited public concern about health effects of IF-MF.
View Article and Find Full Text PDFAn understanding of macroscopic vortex-induced chirality can provide insights into the origin of the homochirality of life. While circular dichroism measurements in stirred solutions are useful for the analysis of chiral supramolecular structures induced by vortex motion, there are no reports on the application of other spectroscopic methods. To obtain a deeper understanding of macroscopic vortex-induced chirality, it is essential to develop novel spectroscopic methods that provide information about changes in both the size and chirality in stirred solutions.
View Article and Find Full Text PDFWe herein report a case involving a 32-year-old Japanese man with recurrent cerebral venous thrombosis due to hereditary protein C deficiency. He was admitted to our hospital with impaired consciousness. Brain magnetic resonance imaging demonstrated high intensities diffusely along the bilateral sulci and magnetic resonance venography revealed left transverse sinus and superior sagittal sinus stenoses.
View Article and Find Full Text PDFRational design of near-infrared (NIR) absorbing molecules is crucial for developing photofunctional materials. Here, we synthesized dinuclear and mononuclear Re(i) tricarbonyl phthalocyanine complexes that exhibit a sharp intense Q band in the NIR region. The unsymmetric coordination of electron-deficient metal unit(s) concomitantly produced a remarkable red shift of the Q band and improved the tolerance of the phthalocyanine ring to oxidation.
View Article and Find Full Text PDFIn recent years, the importance of analyzing excited triplet states has increased dramatically because of their relevance in the design and development of photofunctional molecules. Since the second lowest excited triplet (T) state plays an important role in enhancing the nonradiative intersystem crossing (ISC) process from the lowest excited singlet (S) state to the lowest excited triplet (T) state, it is strongly desired to develop direct observation methods for the nonluminescent, short-lived T state. In this study, the excited triplet states of platinum(II) octaethylporphyrin (PtOEP), which was used as the first phosphorescent organic light emitting diode and oxygen sensor, are investigated using UV-vis absorption, magnetic circular dichroism, and phosphorescence spectroscopies.
View Article and Find Full Text PDFPhotochem Photobiol Sci
January 2020
Magneto-chiral dichroism (MChD) is an interesting phenomenon in which the absorbance of a chiral molecule depends on the direction of the magnetic field. As the MChD of two enantiomers is opposite in nature, MChD has received considerable attention for the development of magneto-optical devices and new asymmetric synthetic methods, as well as being an explanation for the origin of the homochirality of life. In this perspective, the theoretical background behind MChD is introduced, and then, the first examples of metal complexes and aromatic π-conjugated systems are discussed.
View Article and Find Full Text PDFHere, we report an unprecedented chirality transfer from a metal-organic framework (MOF) to a polymer. In this work, unsubstituted polythiophene (PTh) was prepared in the nanochannels of a chiral MOF. Circular dichroism spectroscopy revealed that nanoconfinement of the polymer chains could endow optically inactive PTh with a chiral nature.
View Article and Find Full Text PDFFluid dynamics, resulting from the macroscopic mechanical rotation of either a rotary evaporator or a magnetic stirrer, has been shown to selectively induce one of two enantiomers (mirror-image structures) in certain nanoscale supramolecules. As an alternative to giving a chiral twist to synthesized supramolecules or polymers, it is a challenge to reproducibly prepare chiral species by only using macroscopic mechanical rotations. Demonstrated here is a highly reproducible method for rotary-evaporation-induced enantioselective H-aggregation of achiral phthalocyanines.
View Article and Find Full Text PDFPeroxiredoxins (Prxs) detoxify hydrogen peroxide (HO), peroxynitrite, and various organic hydroperoxides. However, the differential oxidative status of Prxs reacted with each peroxide remains unclear. In the present study, we focused on the oxidative alteration of Prxs and demonstrated that, in human red blood cells (RBCs), peroxiredoxin 2 (Prx2) is readily reactive with HO, forming disulfide dimers, but was not easily hyperoxidized.
View Article and Find Full Text PDFSelective bond cleavage via vibrational excitation is the key to active control over molecular reactions. Despite its great potential, the practical implementation in condensed phases have been hampered to date by poor excitation efficiency due to fast vibrational relaxation. Here we demonstrate vibrationally mediated, condensed-phase molecular dissociation by employing intense plasmonic near-fields of temporally-shaped mid-infrared (mid-IR) pulses.
View Article and Find Full Text PDFBackground: Intermediate frequency magnetic fields (IF-MFs) at around 85 kHz are a component of wireless power transfer systems used for charging electrical vehicles. However, limited data exist on the potential health effects of IF-MFs. We performed a comprehensive analysis of transcriptional expression in mice after IF-MF exposure.
View Article and Find Full Text PDFIn molecular rotors, a type of molecular machine, spontaneous rotors without the need for an external stimulus are promising because conventional molecular rotors require a continuous energy supply. In this study, we demonstrate spontaneous transformation from kinetically favored metastable right-handed helical aggregates to thermodynamically stable left-handed helical aggregates after an evaporation procedure. In addition, we propose the conditions for preparation of metastable right-handed helical aggregates, whose chirality can be spontaneously inverted, based on kinetic analysis.
View Article and Find Full Text PDFA new material concept of soft crystals is proposed. Soft crystals respond to gentle stimuli such as vapor exposure and rubbing but maintain their structural order and exhibit remarkable visual changes in their shape, color, and luminescence. Various interesting examples of soft crystals are introduced in the article.
View Article and Find Full Text PDFWe established whole-cell circular dichroism difference spectroscopy to identify the inter-heme interaction in deca-heme cytochrome protein MtrC in whole cell. Our data showed that the heme alignment of reduced MtrC in whole cell is distinct from that in purified one, suggesting the in vivo specific electron transport kinetics.
View Article and Find Full Text PDFA spiral-type chiral Eu(iii) coordination polymer showed strong luminescence (emission quantum yield Φf-f = 57% and photosensitized energy transfer efficiency ηsens = 53%) and effective CD and CPL properties (gCPL = 0.17) when compared with a mono-nuclear chiral Eu(iii) complex in the solid state (Φf-f = 36%, ηsens = 14%, and gCPL = 0.09).
View Article and Find Full Text PDFWe have investigated the demagnetization of a ferrimagnetic substrate, Bi, Al-substituted dysprosium iron garnet (Bi0.8Dy2.2Fe4.
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