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Organic triplet-triplet annihilation photon upconversion (TTA-UC) systems have attracted considerable attention owing to their promising applicability in solar energy harvesting, optoelectronic devices, photocatalysts, and bio-imaging. In this study, a series of BODIPYs prepared by incorporating substituted/ unsubstituted arylselenium groups, 1 (R = H), 2 (R = OMe), and 3 (R = F), were evaluated as triplet photosensitizers for TTA-UC. Direct Se-C bond formation on the BODIPY core provided a facile intersystem crossing (ISC) channel from the excited singlet state to the metastable triplet state, being the most effective in 2, as inferred from the singlet oxygen generation experiments, possibly because of the n-electron arising from the OMe group. The UC behavior of systems comprising the sensitizers and perylene as the acceptor in deaerated toluene was investigated using a 524 nm-wavelength laser to detect upconverted emission at 449 nm; thus, the UC yield decreased in the order of 21% for 3 > 16% for 2 > 12% for 1. This trend is consistent with the Stern-Volmer constants calculated from the quenched triplet state lifetimes of the sensitizers as a function of the concentration of the perylene quencher. This suggests that the UC efficiency was mainly governed by the intermolecular triplet-triplet energy transfer (TTET) process between arylselanyl-BODIPY photosensitizers and the perylene acceptor. This result was rationalized by the efficient population of the long-lived triplet excited state of the sensitizer, which is advantageous for diffusion-controlled TTA-UC behavior.

Chemometrics-assisted QSPR analysis between the nanostructure and room-temperature phosphorescence properties of boronate assemblies led us to understand their RTP behavior.

The formation of an imine between 1 and chiral amine analyte enabled Zn(ii)-assisted CD response, fluorescence and CPL signals.

Fluorescent carboxyamidoquinolines form ensembles with Eu3+ that can be successfully leveraged in sensing of phosphates showing off–on fluorescence signaling.

A turn-on type afterglow probe was developed by Hg2+-triggered desulfurization of 1. The emission was activated by benzoylphenyl boronate-crosslinked PVA.

A thiophene-derived boronate ester-cross-linked polyvinyl alcohol, 1-PVA, has been prepared, which was found to exhibit room-temperature phosphorescence (RTP) at 475 nm upon UV irradiation (λem = 2...

Asymmetric benzo[a]-fused BODIPYs with benzo(thieno)[1,3,2]oxazaborinine units 1–4 were synthesized for the first time. The structural feature was elucidated by X-ray crystallography and NICS(0) calculation, indicating that the isoindole ring may possess azafulvene character. The photophysical properties of the dyes were investigated, demonstrating that they absorb far-red and NIR light with a λmax value of 663–709 nm in THF. Replacement of benzo[1,3,2]oxazaborinine with the thieno-counterpart caused a red-shift in the absorption band. Interestingly, the effect of thiophene insertion on the photophysical properties is dependent on the position of the thiophene in the chromophore, as determined from cyclic voltammetry (CV) measurement and theoretical calculations. Further, N2O2-ligated sp3-boron induces chirality into the chromophore, facilitating optical resolution of 2 by chiral high-pressure liquid chromatography; helical dyes P-2 and M-2 were successfully characterized. As a potential device application, a single component device (ITO/dye 2/Al) was fabricated to produce a photocurrent of 8.42 × 10−7 A cm−2 at a bias potential of 1 V under photoirradiation at 750 nm (128 μW cm−2). Compared to the dark current, the on/off current ratio at the same bias potential was determined to be 1.42 × 102. The result suggests that a sophisticated combination of asymmetrical BODIPY with a n-type acceptor would allow for NIR photodiodes with a p–n interface.

A benzofuran[b]-fused BODIPY-based photosensitizer type 1 was synthesized for the first time by using an unsymmetrical π-conjugated system composed of benzofuro[3,2-b]pyrrole and pyrromethene units with anchoring groups that are bound to TiO2. Dye 1 has an intense absorption band in the visible to red region with a λmax value of 605 nm and a molar extinction coefficient (e) of 1.07 × 105 M−1 cm−1. Benzofuran fusion at the b-band of the pyrrole unit causes stabilization of both the highest occupied molecular orbital (HOMO) energy levels and lowest unoccupied molecular orbital (LUMO) energy levels, endowing it with long-term stability. After deposition on the P25/Pt photocatalyst to produce P25/Pt/1, the photocatalytic activity was investigated in the presence of ascorbic acid as a sacrificial agent in aqueous phosphate buffer solution (pH 3.6) under irradiation with λ > 400 nm using a 300 W Xe lamp at 100 mW cm−2 light intensity. After light irradiation for 10 h, the system achieved a remarkable catalytic activity for H2 production with a turnover number (TON) value of 11 700. The dye grafted onto TiO2 remains almost unchanged even after photoirradiation for 30 h. The electron dynamics between the dye and TiO2 were investigated by time-resolved fluorescence spectroscopy, photocurrent measurements and electrochemical impedance spectroscopy. The apparent quantum yields (AQYs) were evaluated by monitoring H2 production for each monochromatic light irradiation. The values of AQY for P25/Pt/1 were 3.80% and 3.72% at λ = 420 nm and 600 nm, respectively, indicating an excellent light harvesting capability as a sensitizer.

Owing to the growing interest in the development of novel triplet sensitizers, the introduction of arylselanyl (ArSe) groups at the 2 and 7 positions of bis(difluoroboron)-1,2-bis((1H-pyrrol-2-yl)methylene) hydrazine (BOPHY) scaffold was investigated for producing dyes 1 and 2. Direct Se–C bond formation was effective in facilitating the intersystem crossing (ISC) channel to the corresponding triplet state, endowing them with triplet sensitization. The quantum yield (ΦΔ) of the singlet oxygen (1O2) generation was determined using diphenylisobenzofuran (DPBF), resulting in preferable ΦΔ values of 73% and 74% for 1 and 2, respectively, which were significantly higher than those of halogenated BOPHY. This was ascribed to the selenium-based heavy-atom effect on the photophysical properties of BOPHY dye, which was rationalized by estimating the spin–orbit coupling (SOC) values of the S1 →Tn transitions. The favorable ability to generate 1O2 under photoirradiation motivated us to apply the dye as a sensitizer to triplet–triplet annihilation upconversion (TTA-UC). Photoexcitation of a toluene solution of 1 and 9,10-diphenylanthracene (DPA) as the triplet energy acceptor with a 524 nm-wavelength laser allowed to detect upconverted emission with λem values of 412 nm and 430 nm, which were attributed to the DPA fluorescence. A significant anti-Stokes shift of approximately 94 nm was observed in the UC process with a of 3.9%. This study suggests that a judicious introduction of ArSe units into chromophores provides a facile but effective strategy for designing triplet sensitizers.

Natto is a traditional Japanese fermented soy product high in γ-polyglutamic acid (γ-PGA), whose beneficial effects have been reported. We prepared high-γ-PGA natto and compared the dietary influence on liver lipids and cecal microbiota in mice fed a diet containing it or a standard diet. The mice were served a 30% high-γ-PGA natto diet (PGA group) or standard diet (Con group) for 28 days. Liver lipids, fecal lipids, and fecal bile acids were quantified. Cecal microbiota were analyzed by PCR amplification of the V3 and V4 regions of 16S rRNA genes and sequenced using a MiSeq System. Additionally, the cecal short-chain fatty acid profile was assessed. The results revealed that the liver lipid and triglyceride contents were significantly lower (p

An afterglow is beneficial as an emission signal in the field of displays and imaging probes. Here, boronic acid-appended and spirolactam ring-containing rhodamine dye 1 was synthesized and grafted onto the surface of room-temperature phosphorescence-active boronate nanoparticles (BPs), composed of polymeric 3-benzo-2,4,8,10-tetraoxa-3,9-diboraspiro[5.5]undecane. The resultant ensemble, 1@BP, exhibited a greenish afterglow. However, the addition of Al

Background Several effective therapies have been developed for spinal muscular atrophy (SMA), but there are multiple diseases that show SMA-like symptoms, necessitating efficient differential genetic diagnostic methods. Advancements in next-generation sequencing (NGS) technology have facilitated the successful diagnosis of many undiagnosed genetic diseases. Here, we applied NGS along with conventional methods for the molecular diagnosis of undiagnosed patients with lower motor neuron (LMN) symptoms who were initially suspected to have SMA. Methods We enrolled 157 patients with LMN symptoms who visited the Institute of Medical Genetics, Tokyo Women’s Medical University, between 2005 and 2016. We excluded 86 patients diagnosed with SMA after confirming the causative SMN1 gene deletion or variants. Finally, we examined 12 undiagnosed patients from eight families by targeted resequencing using NGS. Variants were selected on the basis of literature search and databases, and mutations in a gene where loss of function is a known mechanism of disease were considered as pathogenic. Candidate variants were validated by Sanger sequencing. Results We detected novel variants for three patients from two families. Patients 1 and 2 (siblings) showed compound heterozygous TTN variants (c.6621delG, p.W2207Cfs*28 and c.23718T>A, p.F7906L), while patient 3 displayed compound heterozygous KIF1A variants of (c.3871C>T, p.R1291C and c.3898G>A, p.V1300M). Conclusions We detected appropriate variants using our approach of obtaining candidate pathogenic variants by targeted resequencing through NGS and narrowed down the variants in light of patient clinical symptoms. We successfully identified novel causative variants in three undiagnosed patients, which indicated the effectiveness of our approach.

The current work proposes a novel determination method for enantiomeric excess (ee) in (mono- and di-) amines using molecular self-assembly. A pyridine-attached binaphthyl derivative ((R)-1) exhibits fluorescence responses based on imine formation between the aldehyde group of (R)-1 and target chiral amines (i.e. cyclohexane diamine (CHDA), 2-amino-1,2-diphenylethanol (ADPE), 1,2-diphenylethylenediamine (DPDA), 1-amino-2-indanol (AID), and leucinol) in the presence of zinc(II) ions (Zn2+). Because of the multi-optical responses which are derived from the variation of chiral complexes, pattern recognition-based discrimination (i.e. linear discriminant analysis (LDA)) has been achieved for five types of enantiomeric pairs of amines. Possessing such a discrimination capability in combination with data processing (LDA and an artificial neural network) allows accurate determination (prediction error < 1.8%) of the % ee of individual targets such as CHDA which is one of the main components of pharmaceutical drugs. The simple molecular self-assembled system enabled simultaneous multi-chiral discrimination and % ee determination of unknown samples.

As part of an ongoing study of near infrared (NIR) absorbing dyes applicable to optoelectronics, thieno[1,3,2]oxazaborinine-containing aza-BODIPYs were synthesized for the first time. 3,5-Di(thiophene)-substituted N2O2-type 1 showed a NIR absorption band centered at 780 nm, with a molar extinction coefficient (emax) of 5.51 × 104 M−1 cm−1 in CH2Cl2; however, it was easily hydrolyzed in solution. In comparison, 3-thiophene-containing N2O-type analogues 2 and 3 had greater stability, and NIR absorption bands at 768 nm (emax = 8.62 × 104 M−1 cm−1) and 779 nm (emax = 6.32 × 104 M−1 cm−1), respectively, in CH2Cl2. Notably, these dyes had longer absorption bands than those of all of the structurally constraining aza-BODIPYs reported thus far. CV measurements and theoretical calculations indicated that this shift was the result of a higher-lying HOMO energy level generated by incorporation of thiophene into the aza-BODIPY core. As a potential device application, the 3-loaded film was prepared on indium tin oxide (ITO). The film showed a NIR absorption band at 827 nm, with a wide spectral range, and a λonset value of 897 nm; thus, its applicability as a NIR photodetector was evaluated through fabrication of a single-component device. The ITO/3 (85 nm)/Al (100 nm) device produced a photocurrent of 9.57 × 10−7 A cm−2 at a bias potential of 1 V upon illumination at 850 nm and a fluence of 130 μW cm−2. This demonstrated the potential of thieno[1,3,2]oxazaborinine-containing aza-BODIPY materials in optoelectronic applications such as NIR photodetectors.

Two types of boronic acid-appended D-π-A cyanostilbenes were synthesized to produce chiral boronate ensembles via dehydration with tartaric acid. The aggregation-induced high sensitivity and positional effect of the CN group on the emission properties allowed for chemometrics-coupled chiral recognition.

To implement precision oncology, analytical validity as well as clinical validity and utility are important. However, proficiency testing (PT) to assess validity has not yet been systematically performed in Japan. To investigate the quality of next-generation sequencing (NGS) platforms and cancer genome testing prevalent in laboratories, we performed pilot PT using patient samples. We prepared 5 samples from patients with lung or colorectal cancer, extracted genomic DNA from the cancer tissue and peripheral blood, and distributed these to 15 laboratories. Most participating laboratories successfully identified the pathogenic variants, except for two closely located KRAS variants, and 25-bp delins in the EGFR exon 19, not identified by the in vitro diagnostics testing. Conversely, the EGFR L858R variant was successfully identified, and the allele frequency was similar for all the laboratories. A high DNA integrity number led to excellent depth and reliable NGS results. All NGS platforms and bioinformatics pipelines have advantages and disadvantages. We propose the use of a PT program using patient samples to ascertain the quality status of cancer gene testing in laboratories and to ensure that laboratories have sufficient information to develop advancements in precision medicine for cancer.

The newly prepared fluorescent carboxyamidoquinolines (1-3) and their Zn(II) complexes (Zn@1-Zn@3) were used to bind and sense various phosphate anions utilizing a relay mechanism, in which the Zn(II) ion migrates from the Zn@1-Zn@3 complexes to the phosphate, namely adenosine 5'-triphosphate (ATP) and pyrophosphate (PPi), a process accompanied by a dramatic change in fluorescence. Zn@1-Zn@3 assemblies interact with adenine nucleotide phosphates while displaying an analyte-specific response. This process was investigated using UV-vis, fluorescence, and NMR spectroscopy. It is shown that the different binding selectivity and the corresponding fluorescence response enable differentiation of adenosine 5'-triphosphate (ATP), adenosine 5'-diphosphate (ADP), pyrophosphate (PPi), and phosphate (Pi). The cross-reactive nature of the carboxyamidoquinolines-Zn(II) sensors in conjunction with linear discriminant analysis (LDA) was utilized in a simple fluorescence chemosensor array that allows for the identification of ATP, ADP, PPi, and Pi from 8 other anions including adenosine 5'-monophosphate (AMP) with 100 % correct classification. Furthermore, the support vector machine algorithm, a machine learning method, allowed for highly accurate quantitation of ATP in the range of 5-100 μM concentration in unknown samples with error

In material science, organic compound-based white-light emission (WLE) systems that emit in the entire visible region have received much attention due to low-cost, lightweight, easy fabrication of thin film, and so on. Synthesis of single molecules with WLE function has been still a challenge because of constraints imposed by Kasha’s rule, whereas it is easier to fabricate multicomponent-based emissive systems. In the latter case, supramolecular organization of the related components is promising, where well-tailored intermolecular interactions between them would tune their interplay on the physical properties to give WLE. Toward this end, the use of Forester resonance energy transfer (FRET) is benefitable for the interplay between the emissive components. Significant overlap between the emission spectrum of donor dye and absorption band of adjacent acceptor one is indispensable. This chapter describes supramolecular ensembles capable of tuning the primary colors, i.e., red, green, and blue, or two complementary colors, e.g., cyan and orange, with dynamic and reversible non-covalent bonds involving hydrogen bonds, metal coordination, electrostatic interactions, hydrophobic interactions, and π–π stacking interactions. Emissive systems other than FRET behavior are also introduced in this chapter.

We found that boronate particles (BP), as a self-assembled system prepared by sequential dehydration of benzene-1,4-diboronic acid with pentaerythritol, showed greenish room-temperature phosphorescence (RTP). This emission was observed in both solid and dispersion state in water. To understand the RTP properties, X-ray crystallographic analysis, and density functional theory (DFT) and time-dependent DFT at M06-2X/6-31G(d,p) level were performed using 3,9-dibenzo-2,4,8,10-tetraoxa-3,9-diboraspiro[5.5]undecane (1) as a model compound. Our interest in functionalizing the RTP-active particles led us to graft Rhodamine B onto their surface. The resulting system emitted a dual afterglow via a Forster-type resonance energy transfer process from the BP in the excited triplet state to Rhodamine B acting as an acceptor fluorophore. This emission behavior was used for ratiometric afterglow sensing of water content in THF with a detection limit of 0.28 %, indicating that this study could pave the way for a new strategy for developing color-variable afterglow chemosensors for various analytes.

The steep demand for developing photodetector with NIR absorption led us to prepare monolayer devices composed of indium tin oxide, NIR dibenzo-BODIPYs with naphtho[1,3,2]oxazaborinines 1 or 2 , and Al were fabricated. When 1-loaded device was irradiated with 800 nm light at a fluence of 130 μW cm−2, an on-to-off current ratio of 4.44 × 102 was produced at a 1 V bias potential, with a dark current density of 8.49 × 10−9 A cm−2. This excellent light-associated cycle of photocurrent production and non-productions warrants further investigation as a high-resolution photodetector in image sensing applications.

Stability, electrochemical and photoelectrochemical studies of a new ruthenium polypyridyl complex [Ru(nbipy)2(bipydipa)]2+ (P2), where nbipy = 4,4′-dinonyl-2,2′-bipyridine and bipydipa = 2,2′-bipyridine-4,4′-diphosphonic acid, immobilised as FTO/TiO2/P2 electrode were investigated and compared with the parent complex [Ru(bipy)2(bipydipa)]2+ (P1), where bipy = 2,2′-bipyridine. Upon immersion in pH 5.9 and pH 8.1 solutions, P2 absorbed in TiO2 proved to be less prone to desorption from the surface in comparison with P1. The immobilised P2 in FTO/TiO2/P2 electrode displays higher RuIII/RuII oxidation potential (1.47 V vs. NHE) than that of the P1 counterpart (1.33 V vs. NHE). The DSPEC assembled with FTO/TiO2/P2 electrode shows greater photocurrent densities, higher amount of hydrogen gas, better Faradaic efficiency and greater photostability during the photolysis experiments at 0.2 V NHE.

In this study, two new selenium-containing BODIPY dyes were synthesized as photosensitizers for triplet–triplet annihilation upconversion (TTA-UC). Bis(phenylselanyl)-BODIPY 1 absorbed visible light at 518 nm (emax = 7.84 × 104 cm−1 M−1) and exhibited fluorescence at 594 nm with a low fluorescence quantum yield (ΦF) of 0.03. The low ΦF value was ascribed to heavy atom effects. When a TTA-UC system comprising 1 and the triplet acceptor perylene was set up, a purplish white emission was observed with a significant anti-Stokes shift of 77 nm and a high UC quantum yield (ΦUC′) of 17% in CH2Cl2. Notably, the intramolecular charge transfer of 1 enabled us to tune the emission color of the TTA-UC system. On the other hand, the use of selenophene derivative 2 as a sensitizer instead of 1 led to a decrease in the UC efficiency. The relationship between structure and sensitizer properties in the TTA-UC system is discussed herein.

Boronic acids are proposed to be used as molecular inks. This allows chemical modification of the surface of polyvinyl alcohol (PVA) and PVA-related materials with boronic acid-containing molecules through boronate esterification using marker pen applicators. The resulting materials exhibit functional properties, such as fluorescence, halochromism, chemical sensing abilities, and water repellency.

[2+2] Macrocycles composed of two tetraphenylethylenes (TPEs) and two linkers, namely 1a (R = H) and 1b (R = NO2), were prepared in a facile manner through the one-pot dehydration of gem-di(boronic acid)-appended TPEs 2a (R = H) and 2b (R = NO2) with di(trimethylolpropane) 3 in MeOH. Considering that use of THF instead of MeOH as the reaction solvent gave a mixture of boronate esters, hydrophobicity-induced non-covalent interactions involving mono(boronate ester) intermediates produced by the dehydration of 2 and 3, may be responsible for the selective cyclization in MeOH. We found that these boronate macrocycles formed emissive nanoparticles of 1a (λem = 483 nm, λex = 365 nm, ΦF = 31%) and 1b (λem = 539 nm, λex = 365 nm, ΦF = 11%) in H2O, with average diameters of 312 ± 44.6 nm and 146 ± 25.5 nm, respectively. The dynamic features of these particles endow them with reversible thermoresponsive properties; indeed, emissiveness responded linearly to temperature over the tested range. The hysteresis-free temperature sensitivity (S) of the 1a-based nanoparticles was determined to be 0.75% K−1 in H2O. Such behavior was rationalized by dynamic light scattering (DLS) experiments, which facilitated the detection of particle-size changes in response to temperature. As a control, bis(pinacolboryl)-appended TPE 6, which does not form nanoparticles in H2O, was poorly responsive to changes in temperature. Furthermore, effective emission quenching was observed upon addition of 2,6-dichloro-4-nitroaniline (DCN), a toxic pesticide, at a detection limit of 2.00 ppm in H2O/MeOH (3 : 2 v/v). Although DCN-induced quenching is ascribable to the nature of the TPE units, the self-assembled nanoparticle morphologies were altered upon addition of DCN, as determined by DLS and field-emission scanning electron microscopy (FE-SEM), and appeared to involve an Ostwald ripening process.

Polymer-based materials with white-light emission have attracted much attention because of their potential applications as organic light-emitting diodes (OLEDs) and bright sensor materials. Synthesizing one polymer to cover the entire region of visible light is not easy. In addition, facile mixing of multiple kinds of emissive polymers can cause unfavorable interactions between them, making it difficult for chemists to prepare materials with this type of emission. Recently, much effort has been devoted to proposing efficient strategies toward this end, which involve multilayer systems with blends of different color-emitting polymers, single-layer polymer blends, and polymer hosts doped with fluorescent or phosphorescent dyes. By fine tuning the primary colors, i.e., red, green, and blue, or two complementary colors, e.g., cyan and orange, supramolecular polymerization can create one-dimensional assemblies with dynamic and reversible non-covalent bonds, such as hydrogen bonds, metal coordination, electrostatic interactions, hydrophobic interactions, and π‒π stacking interactions. Such adaptive and alterable features could control the amount of color-emissive components in systems where the management of energy transfer is possible. Furthermore, orthogonal polymerization provides well-defined three-dimensional assemblies. In this context, dynamic covalent bond-based polymers are also suitable to create white-light emissive materials that are relevant to supramolecular polymers. This review describes the preparation of white-light emissive materials using a rational approach based on dynamic polymerization in supramolecular chemistry.

Polyamines have beneficial properties to prevent aging-associated diseases. Raw soybean has relatively high polyamine contents; and the fermented soybean natto is a good source of polyamines. However, detailed information of diversity of polyamine content in raw soybean is lacking. The objectives of this study were to evaluate differences of polyamines among raw soybeans and select the high polyamine-containing cultivar for natto production. Polyamine contents were measured chromatographically in 16 samples of soybean, which showed high variation among soybeans as follows: 93–861 nmol/g putrescine, 1055–2306 nmol/g spermidine, and 177–578 nmol/g spermine. We then confirmed the high correlations of polyamine contents between raw soybean and natto (r = 0.96, 0.95, and 0.94 for putrescine, spermidine, and spermine, respectively). Furthermore, comparison of the polyamine contents among 9 Japanese cultivars showed that ‘Nakasen-nari’ has the highest polyamine contents, suggesting its suitability for enhancement of polyamine contents of natto.

For the application of metal-free organic sensitizers in dye-sensitized solar cells (DSSCs), a boron dibenzopyrromethene (dibenzo-BODIPY)-conjugated phenothiazine dye with cyanoacrylic acid as an anchoring group 1 was synthesized and characterized. It showed an intense absorption band at 638 nm as the λmax value and a molar extinction coefficient (e) of 1.23 × 105 M−1 cm−1. In addition, a relatively small but significant peak was observed at 440 nm (e = 1.80 × 104 M−1 cm−1). Such panchromatic features allowed the fabrication of a DSSC with an excellent short-circuit current density (Jsc) of 19.09 mA cm−2 under 100 mW cm−2 AM1.5G simulated light. The corresponding external quantum efficiency (EQE) indicated that the cell converted the light to a photocurrent in a wide wavelength region up to 780 nm, resulting in a power conversion efficiency (PCE; η) of 7.69% in an I−/I3− redox couple electrolyte without the addition of any coadsorbents. When compared to the control cell loaded with a cycanoacrylic acid-appended phenothiazine 2, the PCE value of the 1-loaded cell was 1.5 times larger than that of the control cell because of significant enhancements in both Jsc and open-circuit voltage (Voc). Electrochemical impedance analysis (EIS) suggested attenuation of the charge recombination when using 1 as a sensitizer. In this way, the 1-loaded cell showed relatively good DSSC properties comparable to those of the cell with N719 (η = 7.15%) under the same conditions.

Chiral ensembles were spontaneously formed in solution through boronate esterification of structurally defined di(boronic acid)-appended tetraphenylethylene (DB-TPE) and commercially available l- or d-tartaric acid, showing enantioselective aggregation behavior for chiral diamines as well as cinchona alkaloids enabling the fluorescent recognition of their chirality.

Driven by our motivation to develop a chemodosimeter for the visual detection of hydrogen peroxide (H2O2), we synthesized for the first time a dipyrrin (1) with 4-pinacolborylbenzyloxy groups. An EtOH solution of Zn2+-coordinated 1 was reddish-violet in color, with a λmax value of 538 nm. However, the addition of H2O2 into the solution induced a remarkable color change from reddish-violet to blue. The time-dependent change in the absorption band showed two step kinetic processes in their kinetic profiles, where a new peak with λmax = 581 nm appeared within 13 min (k1 = 0.370 min−1), followed by a slower change in the spectra (k2 = 0.00371 min−1) concomitant with a further bathochromic shift of 18 nm. NMR and mass spectroscopic analyses indicated that the kinetically slower process may be responsible for a change in the coordination mode of the Zn2+ ion through a H2O2-triggered self-immolative reaction in the 4-pinacolborylbenzyloxy groups. Basic conditions achieved through the addition of tetrabutylammonium hydroxide (TBAOH) led to the acceleration of not only the H2O2-triggered colorimetric change but also the turn-on fluorescence, thus allowing dual-mode sensing of H2O2. For practical applications, the related drop-cast paper strips were fabricated to visually detect H2O2 vapor.

The self-assembly of polyvinyl alcohol (PVA) and benzene-1,4-diboronic acid (DBA) is employed as a sol–gel method for one-step fabrication of hydrogel coatings with versatile functionalities. A mixture of PVA and DBA in aqueous ethanol is prepared as a coating agent. The long pot life of the mixture allows for the coating of a wide range of materials with hydrogel films by simple cast- and dip-coating techniques. The resultant films show negligible dissolution in water and the intrinsic hydrophilicity of PVA provides the films with functional properties, such as improved antifogging property and resistance to protein and cell fouling. The self-assembling process shows adaptive inclusion properties toward nanoscale materials, such as metal–organic coordination polymers and inorganic nanoparticles, affording composite films. Furthermore, the coating film exhibits a unique secondary functionalization reactivity toward boronic acid-appended fluorescent dyes, through which a variety of materials are converted into fluorescent materials.

The dye-sensitized photoelectrochemical cells (DSPECs) incorporating a family of ruthenium complexes [RuII(bipyP)(bipy)2] (P1), [RuII(bipyP)(dmb)2] (P2), [RuII(bipyP)(dtbb)2] (P3) and [RuII(bipyP)(dnb)2] (P4), where bipyP = 2,2′-bipyridine-4,4′-diphosphonic acid, bipy = 2,2′-bipyridine, dmb = 4,4′-dimethyl-2,2′-bipyridine, dtbb = 4,4′-di-tert-butyl-2,2′-bipyridine, and dnb = 4,4′-dinonyl-2,2′-bipyridine, were fabricated in a dye-only system (do-DSPEC) and in a system where the electrolyte solution was loaded with EDTA sacrificial agent (sa-DSPEC). The increasing number of the alkyl chains of the ancillary bipy ligand shifts the ground- and excited-state potentials to the more negative values, although the introduction of the longer nonyl chain in P4 shows the opposite effect. In do-DSPECs, the photocurrent and hydrogen production performance follows the order P4 > P3 > P2 > P1, which correlates well with the degree of the excited-state quenching by electron injection to the conduction band of TiO2. The photoelectrochemistry of the sa-DSPECs reveals 10 times as many photocurrents as that measured in do-DSPECs, suggesting the ability of the hole to oxidize EDTA molecule. The hydrogen production performance of sa-DSPECs over five hours follows the order P2 > P1 > P3 > P4, which is consistent with the RuIII/RuII reorganization energies and the hole mobility on the TiO2 surface. The present study provides evidence that the subtle alkyl chain variation of the ruthenium photosensitizers can fine tune the electron injection capacity, RuIII/RuII self-exchange energetics and photostability of the complexes, which significantly influence the performance of the DSPECs.

Tricyanopyrroline (TCP)-based intermolecular charge transfer (ICT) dye 1 was synthesized by incorporating phenothiazine and diphenylamine groups, and it was shown to absorb near-infrared light at 734 nm with a molar extinction coefficient (emax) of 1.67 × 104 M−1 cm−1 in toluene, resulting in a broad absorption band ranging from 600 to 900 nm. By combining the properties of the amide (–NHCO–) group of the TCP acceptor with its ICT character, the photophysical properties of 1 were found to be environment-sensitive. Moreover, its absorption profile was significantly dependent on the nature of the solvent; for instance, in CH2Cl2, a λmax value of 781 nm was observed with an optical absorption edge (λonset) of 1018 nm, whereas the use of DMSO instead of CH2Cl2 led to a significant hypsochromic shift to a λmax value of 532 nm. Nonetheless, an increase in dye concentration caused a significant bathochromic shift in the absorption band, which was ascribable to the self-dimerization of the dye (Kd = (1.26 ± 0.84) × 104 M−1) through intermolecular hydrogen bonding between the amide moieties. The amide unit also served as a binding site for anions to generate a selective colorimetric response in the presence of AcO− and F−. Notably, 1 offers the potential to detect F− quantitatively in commercially available toothpaste. The chemical stimuli-sensitivity of the absorption properties was elucidated through several analytical techniques and theoretical calculations.