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Abstract: Transparent and homogeneous organic–inorganic hybrids with poly(vinylidene fluoride) (PVdF) could be prepared by addition of zirconium oxide nanocrystals (ZrO2-NCs) in a polar aprotic solvent and the subsequent solvent evaporation. The polar aprotic solvents such as DMF, DMAc and DMSO would form hydrogen bonds with Zr-OH groups of the ZrO2-NC and play a role as compatibilizers between the PVdF and ZrO2-NCs. The interpenetration between PVdF and ZrO2-NCs resulted in the nanometer dispersion of PVdF chains in a ZrO2-NC matrix. High dosage of the ZrO2-NCs as physical inhibitors between PVdF polymer chains sufficiently prevented the PVdF chain mobility in the internal of hybrids. The transparency of the PVdF/ZrO2-NC hybrids was dramatically improved by controlling the content of ZrO2-NCs. Novel multifunctional hybrids with high transparency, high refractive index and good mechanical property were obtained by hybridization of PVdF and ZrO2-NCs. [Copyright &y& Elsevier]

Abstract: New colloidal polymer hybrids with polyoxazolines such as poly(2-methyl-2-oxazoline) (PMeOZO) and poly(2-ethyl-2-oxazoline) (PEtOZO) were obtained in an aqueous solution as a sol–gel solvent. The polyoxazoline segment was incorporated into the siliceous particle and formed strong hydrogen bonds with silanol moieties, judging from TGA and FT-IR studies. Colloidal polymer hybrids exhibited no glass transition temperature of the polyoxazoline and showed excellent thermal stability and solvent-resistant property. Porous silica obtained by charring the colloidal polymer hybrids at 600°C exhibited the peak at 3.5Å. These results strongly indicate the homogeneous molecular scale dispersion of polyoxazoline in the colloidal silica gel matrix. [Copyright &y& Elsevier]

Abstract: A simple and novel approach for synthesizing the benzene ring-layered polymers using [2.2]paracyclophane and xanthene skeletons was demonstrated. Palladium-catalyzed polymerization of pseudo-p-diethynyl[2.2]paracyclophane 1, 2,7-di-tert-butyl-4,5-diiodo-9,9-dimethylxanthene 2, and ethynylferrocene 3 gave the corresponding polymers 4a–c, which composed of 7–30 face-to-face benzene rings by changing the feed ratio of 1–3. [Copyright &y& Elsevier]

This research explores effects of introduction of the rigid phenylene ethynylene (PEy) moiety as a side chain in polyoxetanes. The synthesis of PEy-grafted polyoxetanes was carried out via Huisgen copper (I) catalyzed alkyne-azide cycloaddition. These polymers have a flexible main chain (low T g polyoxetane) and rigid side chains (phenylene ethynylene). Compositions for copolyoxetanes with PEy and alkynyl side chains were determined by 1H-NMR spectroscopy. Mole percents PEy, designated P-%, were P-21, P-44, P-69 and P-100. UV-VIS spectra for P-21, P-44, P-69, P-100 at 330 nm showed differentiation based on assignments to intramolecular charge-transfer (ICT) interactions between triazole and phenylene ethylene moieties. Interestingly, instead of a monotonic increase, absorption intensity is in the order P-69 ~ P-44 > P-100 > P-21. Low substitution and mainchain flexibility and account for P-21 having the lowest UV-VIS absorption at 330 nm. P-44 and P-69 have similar strong absorptions at 330 nm with overlapping curves. Steric effects culminate in P-100, which has the highest PEy content but a lower absorption at 330 nm than P-69 but higher than P-21. A model for optical absorptions for PEy copolyoxetanes is described that includes the effect of the rigid PEy side chain in decreasing molecular mobility. [Display omitted] • Synthesis of polyoxetanes with phenylene ethynylene (PEy) sidechains by click chemistry. • Intramolecular charge-transfer (ICT) between triazole and phenylene ethylene. • With increased sidechain substitution, increase then decrease in intramolecular charge-transfer (ICT) absorption at 330 nm. • Steric effects decrease interactions between triazole and phenylene ethylene moieties at high sidechain substitution. [ABSTRACT FROM AUTHOR]

The two types of conjugated polymers were synthesized with boron pyridinoiminate with or without the fused structure in the ligand moiety. From optical measurements, it was shown that the polymer involving the fused complex had intense luminescent property only in the solution state. In contrast, another polymer presented similar emission intensities both in the solution and film states. By introducing the simple ring fuse structure, solution and solid-state luminescent properties of conjugated polymer can be tuned. Finally, the aggregation-caused quenching-resistant luminescent polymer can be produced. [ABSTRACT FROM AUTHOR]

Homogeneous polymer hybrid consisting of poly( β -alanine) and silica gel was synthesized by an in-situ anionic polymerization method. Acrylamide (AAm) as an organic monomer was introduced into a sol–gel reaction of tetramethoxysilane (TMOS). The polymerization of AAm was initiated by potassium tert -butoxide ( t -BuOK), while sol–gel reaction of TMOS proceeded to generate a silica gel matrix. The obtained polymer hybrid was optically transparent and no phase separation was observed by SEM measurement. From the 1 H and 13 C NMR analysis, the anionic polymerization of AAm proceeded via a hydrogen-transfer process under in-situ hybridization conditions. [ABSTRACT FROM AUTHOR]

This manuscript presents the strategy for obtaining solid-emissive properties from the BODIPY dyes. It is demonstrated that the emission properties can be preserved from the aggregation-caused quenching (ACQ) by introducing the phenyl groups into their boron center. We established the synthetic procedures for the introduction of single or dual phenyl groups into the boron center in BODIPYs. The synthesized BODIPYs having single and dual-phenyl groups showed unimodal photoluminescence spectra both in the solution and solid states with sufficient quantum yields. The pristine and the single-phenyl substituted BODIPYs showed similar optical properties in the solution state. In contrast, the dual-phenyl substituted BODIPY provided broad and red-shifted photoluminescence spectrum. Interestingly, the emission property of the dual-substituted BODIPY was recovered not only in the solid state but also in the viscous solvent. It was revealed that the suppression of the molecular motion should play a crucial role in the enhancement of the emission properties of the dual-substituted BODIPY. Furthermore, it is also presented that the steric hindrance by the phenyl groups can inhibit ACQ in the condensed state. [ABSTRACT FROM AUTHOR]

We report herein the synthesis and properties of π-stacked dimeric and polymeric compounds that consisted of hexabenzocoronene (HBC) and xanthene as the stacked π-electron system and the scaffold, respectively; the compounds were obtained by Sonogashira–Hagihara coupling. The obtained polymer was separated into three fractions, and the through-space conjugation effect was estimated. HBC units were layered in proximity (approximately 3.4 Å), leading to π–π stacking in the ground and excited states. [ABSTRACT FROM AUTHOR]

We describe here the design and synthesis of the conjugated polymers containing dye-modified cardo fluorenes for the dual emissions. Mono and di-substituted cardo fluorenes with boron dipyrromethene (BODIPY) were introduced into alternating conjugated polymers using bis-thienyl-benzothiadiazole as a comonomer for constructing the donor (D)-acceptor (A) pairs through the main-chains. The polymeric products showed good solubility in the common organic solvents and good film-formability. Strong emissions were obtained from the synthesized polymers in both solution and film states. In particular, multi-color emissions in green and red regions derived from each component were observed from the solutions containing the synthesized polymers. From the emission lifetime measurements, it was found that the energy transfer should be suppressed between the side and the main-chains, leading to the dual emission from the polymers. Furthermore, we also observed that the synthesized polymers have the light-harvesting antenna (LHA) effects and the color tunability by changing the number of BODIPY dyes tethered to the cardo fluorene. [ABSTRACT FROM AUTHOR]

[Display omitted] We prepared high-molecular-weight block copolymers (BCPs) composed of polystyrene (PS) brush blocks and polyhedral oligomeric silsesquioxane (POSS)-tethered polynorbornenes with variable composition ratios. By changing the substituents at the vertex of POSS from isobutyl groups to cyclopentyl ones, we evaluated the substituent effect on structural color and thermal stability against annealing. The BCPs modified with isobutyl groups showed clear structural color, while color changes were observed after annealing. By replacing to cyclopentyl groups, structural color was also presented, and improvement of thermal resistance was observed by heating. From the series of thermal analyses, it was proposed that thermal enhancement of cyclopentyl-substituted POSS domains could be responsible for the improvement of thermal stability of structural color. [ABSTRACT FROM AUTHOR]

Thermal enzyme deactivation by the imidazolium-presenting silica nanoparticles with the microwave irradiation is presented in this manuscript. The modified nanoparticles were synthesized, and it was observed that the modified nanoparticles can be a heat source in the buffer under the weak-power microwave irradiation. Finally, based on the heat-generating ability of these nanoparticles, deactivation of glutathione reductase and alkaline phosphatase with the modified nanoparticles were demonstrated. [ABSTRACT FROM AUTHOR]

Abstract: Platinum(II) octaethylporphyrin (PtOEP)-loaded organic–inorganic hybrids were obtained via the microwave-assisted sol–gel condensation with methyltrimethoxysilane and poly(vinylpyrrolidone). From transparent and homogeneous hybrid films, the strong phosphorescence from PtOEP was observed. Next, the resulting hybrids were immersed in the aqueous buffer, and the emission intensity was monitored by changing the dissolved oxygen level in the buffer. When the hybrid with relatively-higher amount of the silica element, the strong phosphorescence was observed even under the aerobic conditions. In contrast, the emission from the hybrids with lower amounts of the silica element was quenched under the hypoxic conditions. This is, to the best of our knowledge, the first example to demonstrate that the responsiveness of the phosphorescence intensity of PtOEP in hybrid films to the dissolved oxygen concentration in water can be modulated by changing the percentage of the contents in the material. [Copyright &y& Elsevier]

Abstract: Facile synthesis of xanthene-based π-stacked compounds consisting of face-to-face p-oligophenyls has been described. Just by mixing xanthene-4,5-diboronic acid and p-oligophenyls containing a benzenetetraol unit yielded cyclic compounds selectively due to the reversibility of the boronate esterification. In the ground state, weak π–π interactions between two p-oligophenyl moieties were observed, whereas their π–π interactions were clearly shown in the excited state. [Copyright &y& Elsevier]

Abstract: For detecting reduced glutathione (GSH) with a 19F NMR spectroscopy with time-specificity, we developed the probes based on gold nanoparticles modified with the fluorinated groups via the thermally-cleavable linkers. Before the heating treatment with the probe, the maleimide moiety as a binding site with GSH in the probe is inactivated by cycloaddition of furan. At this silent state, the magnitude of 19F NMR signals from the fluorinated groups was suppressed. By heating for the activation of the probe, the maleimide moiety was produced via retro Diels–Alder reaction, and 19F NMR signals were observed. From this moment, GSH started the reaction with the probe via Michael addition to the maleimide moiety, leading to the observation of the new peak in 19F NMR spectra. Finally, the amounts of GSH were determined from the increase of the magnitude of 19F NMR signals. [Copyright &y& Elsevier]

Abstract: For the quantitative assessment of the glutathione reductase (GR) activity with a 19F NMR spectroscopy, we developed the heavy metal-free probes based on silica nanoparticles modified with water-soluble perfluorinated dendrimers via the disulfide linkers. Before enzymatic reaction, the molecular rotation of the perfluorinated dendrimers is highly restricted, and the magnitude of 19F NMR signals from the perfluorinated dendrimers can be suppressed. By the reductive cleavage of the disulfide linkers with the reduced glutathione-mediated enzymatic reaction of GR, perfluorinated dendrimers can be released from the surfaces of the nanoparticles. Consequently, the 19F NMR signals of perfluorinated dendrimers were recovered. The enzymatic activity of GR was determined from the increase of the magnitude of 19F NMR signals. Finally, to demonstrate the feasibility of the probe in the presence of miscellaneous molecules under bio-mimetic conditions, the comparison study was executed with the cancer cell lysate. The value determined from our method showed a good agreement with that from the conventional method. [Copyright &y& Elsevier]

Abstract: π-Conjugated systems connected to o-carborane undergo enhancement of luminescence from boron dipyrromethene (BODIPY) dyes via encapsulation and energy transfer in aqueous media. The inhibition of H-aggregation formation in aqueous media effectively regains the emission from luminophores. [ABSTRACT FROM AUTHOR]

Abstract: We have synthesized wedge-shaped BODIPY dyes with hydrophilic chains and studied their aggregational behavior in THF-containing water by UV–vis and photoluminescence spectroscopies, transmission electron microscopy, and dynamic light scattering. One of these dyes showed an aggregate derived from H-dimers and forms a high density nanoparticle in THF-containing water solution. [Copyright &y& Elsevier]

Abstract: We report the multi-functionalized cubic silsesquioxane (POSS) as the ratiometric multimodal chemosensors for monitoring solvent polarity with fluorescence and 19F NMR. The alteration of the dispersion state of the modified POSS by changing solvent polarity can be reflected into the orthogonal signal responses for the fluorescence and 19F NMR. In addition, the ratiometric dual monitoring for the enzymatic reaction was performed using the POSS-based chemosensor. [Copyright &y& Elsevier]

Abstract: Molecular wire, diacetylene-linked porphyrin dimer 6 having terminal alkenes, was synthesized. Porphyrin dimer 6 formed the 1:1 double-stranded ladder complex with 1,4-diazabicyclo[2.2.2]octane (DABCO). The co-planar stacked two porphyrin molecular wires in the ladder complex were connected by olefin metathesis in the presence of the Grubbs catalyst in order to make a covalently bonded tubular nanostructure. The obtained molecular tube 7 was characterized by 1H, 13C NMR spectroscopy, and MALDI-TOF MS spectrometry. [Copyright &y& Elsevier]

We describe unique crystal morphologies of hydrophobic CaCO3 crystals in a mixture of water and tetrahydrofuran (THF). After addition of sodium trisilanolate [(c–C5H9)7Si7O9(ONa)3] (1¯) into the mixture of water and THF, calcium reactants (0.1 M CaCl2 and 0.1 M (NH4)2CO3) were added to the reaction mixture at 30°C. FT-IR and SEM images showed that concave terraced calcite was obtained in 80% THF solution. In the absence of 1¯, the crystalline product was a mixture of rhombohedral calcite with aggregated vaterite particles. The hydrophobic modified surface of the concave terraced calcite was confirmed by the contact angle and dispersability in organic solvents. [Copyright &y& Elsevier]

The ternary polymer hybrids were prepared by organic polymers such as poly(2-methyl-2-oxazoline) (POZO) or poly( N -vinylpyrrolidone) (PVP) and aminopropylsilsesquioxane (Cube-aminopropyl) utilizing the sol–gel reaction of tetramethoxysilane (TMOS). The prepared polymer hybrids were characterized by IR, thermogravimetric analysis (TGA), X-ray diffraction (XRD), 1 H NMR, scanning electron microscopy (SEM), etc. In this hybrid system, hydrogen-bonding interactions played a critical role in the formation of the transparent polymer hybrids. Polymer hybrids using POZO showed high transparency and homogeneity in a wide range of the feed ratios of POZO to Cube-aminopropyl. On the other hand, in case of polymer hybrids using PVP, higher Cube-aminopropyl ratio brought about the phase separation, indicating the aggregation of the Cube-aminopropyl itself. The homogeneity of ternary polymer hybrids was found to be closely dependent on the difference between strength of hydrogen bonding interaction of polymer and residual silanol groups of silica gel and strength of that of polymer and Cube-aminopropyl. It is also observed that initial decomposition temperature of polymer hybrids was increased with increasing the Cube-aminopropyl ratio. [ABSTRACT FROM AUTHOR]

Development of near-infrared-emissive aza-boron dipyrromethene (aza-BODIPY) derivatives having furanyl groups is reported. From the optical measurements, it was clearly indicated that the emission bands were presented in the longer wavelength region than those of the conventional aza-BODIPYs. The emission bands with the peaks at 730 nm and 758 nm were observed from the bis- and tetra-substituted furanyl aza-BODIPYs with similar extents of emission efficiencies, respectively. According to the computer calculations, it was proposed that molecular planarity could be enhanced in the case of the furan groups. As a result, band-gap energy could be lowered comparing to those of the conventional benzene and thiophene-substituted aza-BODIPYs. [ABSTRACT FROM AUTHOR]

It was shown that water-soluble network polymers composed of polyhedral oligomeric silsesquioxane (POSS) had hydrophobic spaces inside the network because of strong hydrophobicity of the cubic silica cage. In this study, the water-soluble POSS network polymers connected with triphenylamine derivatives (TPA-POSS) were synthesized, and their functions as a sensor for discriminating the geometric isomers of fatty acids were investigated. Accordingly, in the photoluminescence spectra, different time-courses of intensity and peak wavelengths of the emission bands were detected from the TPA-POSS-containing solution in the presence of cis - or trans -fatty acids during incubation. Furthermore, variable time-dependent changes were obtained by changing coexisting ratios between two geometric isomers. From the mechanistic investigation, it was implied that these changes could be originated from the difference in the degree of interaction between the POSS networks and each fatty acid. Our data could be applicable for constructing a sensing material for generation and proportion of trans -fatty acids in the oil. [ABSTRACT FROM AUTHOR]

This manuscript reports the detection system with 19 F NMR probes for bioactive amine compounds at sub-micro molar concentrations. Water-soluble fluorinated polyhedral oligomeric silsesquioxane (POSS) derivatives were prepared, and the paramagnetic Ni-porphyrin (NiPor) with the fluorinated POSS (F-POSS) was adsorbed in the buffer. By adding the series of amine derivatives to the homogeneous dispersion containing the POSS-NiPor complexes, the changes in the signal intensity were evaluated. It was clearly observed from homogeneous dispersions that the signal intensity of 19 F NMR decreased especially in the presence of ethanediamine and hexylamine. From the dynamic light scattering measurements, it was revealed that the assembly of the F-POSS complexes was dramatically induced by the amine compounds when the signal intensity decreased. According to these data, it is proposed that the signal reduction of 19 F NMR from the POSS-NiPor complexes could be induced via the strong paramagnetic relaxation enhancement from NiPor in the assembly. Finally, based on the signal reduction by the assembly, we can detect the amine derivatives under 1 μM concentration which is similar sensitivity to the conventional fluorescence probes. Our system is valid to monitor the distribution of the bio-active molecules at cellular concentrations. [ABSTRACT FROM AUTHOR]

To demonstrate the validity of o -carborane as an electronic anchoring unit for constructing robust conjugation system, bi(benzo[ b ]thiophene)-fused o -carborane was designed and synthesized. From the optical measurements, clear vibrational bands not only in the absorption but also in the emission spectra were observed. These data mean that the electronic delocalization should occur on the rigid template. In the cyclic voltammograms, the reversible reduction waves at −1.72 eV and −2.37 eV were detected that originated from the electron-accepting ability of o -carborane. It is suggested that o -carborane should be the versatile unit for constructing robust conjugation with electron-accepting ability. [ABSTRACT FROM AUTHOR]

The organic liquid scintillators based on the emissive polymers are reported. A series of conjugated polymers containing organoboron complexes which show the luminescence in the near infrared (NIR) region were synthesized. The polymers showed good solubility in common organic solvents. From the comparison of the luminescent properties of the synthesized polymers between optical and radiation excitation, similar emission bands were detected. In addition, less significant degradation was observed. These data propose that the organoboron conjugated polymers are attractive platforms to work as an organic liquid scintillator with the emission in the NIR region. [ABSTRACT FROM AUTHOR]

We report the molecular recognition for nucleoside triphosphates inside the ligand-modified water-soluble organic–inorganic hybrid gels composed of polyhedral oligomeric silsesquioxane (POSS). The series of ligands were designed to make hydrogen bonds with each nucleobase and introduced into the hybrid gels. From the titration experiments, the binding constants between the ligand inside the gels and nucleosides were evaluated. Accordingly, it was found that the ligands inside the gels can form a stable complex only with the target nucleoside triphosphate which has the complementary pattern of the hydrogen bonds ( K a = G-gel/cytidine triphosphate (CTP), 3.5 × 10 8 M –1 ; U-gel/adenosine triphosphate (ATP), 1.6 × 10 3 M –1 ; A-gel/uridine triphosphate (UTP), 1.9 × 10 7 , respectively). With other nucleoside derivatives which have different numbers of phosphate units or different types of nucleobases, the much weaker interaction was detected. These data indicate that the complex formation only with nucleoside triphosphates should occur inside the hybrid gels, and selective recognition of each nucleoside triphosphate can be accomplished. [ABSTRACT FROM AUTHOR]

We present the dual-emissive dye containing heterogeneous organometallic units. The diad ligand composed of two diketonate moieties linked by fluorene was synthesized. By introducing boron and platinum elements, the emissive molecules were obtained. From optical measurements, it was confirmed that the boron and the platinum-containing diads showed the emissions from the charge transfer and the triplet π–π ∗ ligand centered transitions, respectively. Next, to observe these fluorescence and phosphorescence properties from the dye molecule, the diad composed of boron and platinum diketonates linked by the fluorene unit was prepared. Finally, the dual emission containing fluorescence from the boron complex and phosphorescence from the platinum complex was simultaneously observed. [ABSTRACT FROM AUTHOR]

Abstract: The photo-triggered molecular release from the organic–inorganic polymer hybrids is presented in this manuscript. Initially, the preparation of the auto-degradable polymer is explained with the photo-cleavable group at the end of the polymer main-chain. The silica-based dye-loaded hybrids containing these polymers were fabricated. It was found that by UV irradiation, the end capping was removed, and then the auto-degradation occurs through the polymer main-chain. Finally, the molecular release of the loaded dyes was accomplished in various media by the UV irradiation. In particular, it was shown that both of hydrophobic and hydrophilic dyes can be applied in this system. [Copyright &y& Elsevier]

Abstract: Efficient generation of the organic radicals is a fundamental technology for preparing the spintronic materials. In this Letter, we present the chemical reaction of the three radical generation from a single photon. A photo acid generator which can release the multiple acid molecules via the automatic amplification mechanism was synthesized. The synthesized acid generator immediately released methanesulfonic acid by UV irradiation. Due to the amplification system, a maximum of three acid molecules can be produced from the single acid generator. In addition, the release of acid is induced by UV irradiation and automatically proceeds until the release of three acid molecules is finished. Finally, by employing the acid-catalyzed radical generation of tetrathiafulvalene, we also demonstrate the efficient radical generation triggered by UV irradiation in the polymer film. [Copyright &y& Elsevier]

Abstract: A novel binuclear phthalocyanine tweezers, in which two zinc-phthalocyanine rings are linked to an optically active binaphthyl group through triazolyl linkages, was self-cyclized through triazolyl-to-zinc coordination bonds. An axially chiral S-binaphthyl group induced planar chirality in a slipped-cofacial stack of phthalocyanine moieties, and therefore displayed fluorescence with a good quantum yield (Φ F =0.23) and circularly polarized luminescence with a moderate intensity of dissymmetry factor (g lum =−4×10−4) in the near-infrared wavelength region. [Copyright &y& Elsevier]

Highlights: [•] Ionic liquid-coated silica nanoparticles were prepared. [•] Modified nanoparticles can work as an efficient heat generator under microwave irradiation. [•] The heating mechanism was cleared. [Copyright &y& Elsevier]

Abstract: We present the development of the thiophene-fused boron dipyrromethene derivatives as efficient light absorbers. The two strategies for the evolution of the optical properties such as the peak positions of absorption wavelengths and molar extinct coefficients were established by the substituent effects: by introducing iodine groups, the bathochromic shifts of the peak positions (+15nm) and the enhancement of molar extinct coefficients were simultaneously received owing to the heavy atom effect. Next, it was found that the modification with the trifluoromethyl group contributed to the large bathochromic shift (+60nm) because of the lowering effect on the lowest unoccupied molecular orbital of the dye by the substituent. Finally, we obtained the dyes with large molar extinct coefficients (184,140M−1 cm−1 at 592nm, 72,180M−1 cm−1 at 623nm), sharp absorption bands, and low emissions. [Copyright &y& Elsevier]