Titanium dioxide doped with Pt(IV) ions was synthesized via a sol-gel method, incorporating a sol purification process through dialysis. The doped Pt(IV) ions were reduced by UV light irradiation to obtain a transparent Pt-TiO sol, with Pt(0) acting as a cocatalyst for hydrogen evolution. The hydrogen evolution activity of Pt-TiO sol was evaluated under UV light irradiation using methanol as a sacrificial reagent.
View Article and Find Full Text PDFTo facilitate water splitting using MoSe as a light absorber, we fabricated water-dispersible MoSe/C-dendron nanohybrids via physical modification of the basal plane of MoSe. Upon photoirradiation, the mixed-dimension MoSe/C (2D/0D) heterojunction generates a charge-separated state (MoSe⋅/C⋅) through electron extraction from the exciton in MoSe to C. This process is followed by the hydrogen evolution reaction (HER) from water in the presence of a sacrificial donor (1-benzyl-1,4-dihydronicotinamide) and co-catalyst (Pt-PVP).
View Article and Find Full Text PDFMultidisciplinary therapy centered on radical surgery for resectable pancreatic cancer is expected to prolong prognosis, but relies on CA19-9 biomarker levels to determine treatment strategy. Boron neutron capture therapy (BNCT) is a chemoradiotherapy using tumor hyperaccumulator boron drugs and neutron irradiation. The purpose of this study is to investigate novel boron drug agents for BNCT for pancreatic cancer.
View Article and Find Full Text PDFSingle-walled carbon nanotube (SWCNT)/TiO2 hybrids were synthesized using 1,10-bis(decyloxy)decane-core PAMAM dendrimer as a molecular glue. Upon photoirradiation of a water dispersion of SWCNT/TiO2 hybrids with visible light (λ > 422 nm), the hydrogen evolution reaction proceeded at a rate of 0.95 mmol/h·g in the presence of a sacrificial agent (1-benzyl-1,4-dihydronicotinamide, BNAH).
View Article and Find Full Text PDFThe thermally and photolytically induced disproportionation of 6,13-dihydropentacene derivatives into tetrahydropentacenes and pentacenes results in unique solid-state fluorescence. The fluorescence thereby depends on the molecular structure and the molecular arrangement in the solid state.
View Article and Find Full Text PDFDye-encapsulated single-walled carbon nanotubes (SWCNTs) were employed for the construction of a coaxial three-component dye/SWCNT/C heterojunction. Despite the larger diameter (∼1.4 nm) of the SWCNTs relative to that set by Flavel's rule (0.
View Article and Find Full Text PDFTo observe a clear-cut example of the formation of mobile carriers from excitons on semiconducting single-walled carbon nanotubes (s-SWCNTs) surrounded by a medium with a high dielectric constant, water-dispersible s-SWCNT nanocomposites were fabricated by physical modifications using poly(amidoamine) dendrimers that contain an aliphatic core. The evolution of H from water using these s-SWCNT/dendrimer nanocomposites as photosensitizers under irradiation with visible light demonstrated a photo-induced electron transfer from the s-SWCNTs to the co-catalysts.
View Article and Find Full Text PDFSingle-walled carbon nanotubes (SWCNTs) are potentially strong optical absorbers with tunable absorption bands depending on their chiral indices (n, m). Their application for solar energy conversion is difficult because of the large binding energy (>100 meV) of electron-hole pairs, known as excitons, produced by optical absorption. Recent development of photovoltaic devices based on SWCNTs as light-absorbing components have shown that the creation of heterojunctions by pairing chirality-controlled SWCNTs with C is the key for high power conversion efficiency.
View Article and Find Full Text PDFA new phenacene-type molecule, [8]phenacene, which is an extended zigzag chain of coplanar fused benzene rings, has been synthesised for use in an organic field-effect transistor (FET). The molecule consists of a phenacene core of eight benzene rings, which has a lengthy π-conjugated system. The structure was verified by elemental analysis, solid-state NMR, X-ray diffraction (XRD) pattern, absorption spectrum and photoelectron yield spectroscopy (PYS).
View Article and Find Full Text PDFA coaxial nanohybrid consisting of a single-walled carbon nanotube (SWCNT), fullerodendron, and SiO(2) shows high-efficiency light-driven hydrogen evolution from water. Upon visible light irradiation, SWCNT/fullerodendron/SiO(2) coaxial nanohybrid shows hydrogen evolution activity in the presence of methyl viologen (MV(2+)), benzyldihydronicotinamide (BNAH), and a colloidal polyvinyl alcohol(PVA)-Pt.
View Article and Find Full Text PDFA new poly(amidoamine) dendron having 1,5-diazabicyclo[4.3.0]non-5-ene (DBN) at the focal point was synthesized.
View Article and Find Full Text PDFOrg Biomol Chem
October 2008
A newly designed anthracene derivative having gluconamides at its peripheral branches formed a photo-responsive hydrogel. SEM observation of the xerogel showed a network structure consisting of fibrils. Upon photoirradiation (lambda >300 nm) of the hydrogel, regioselective photodimerization of the anthracene moiety occurred to give head-to-tail photodimers and the physical state changed from the gel to the sol.
View Article and Find Full Text PDFChem Commun (Camb)
January 2008
A new Cd10S16 molecular cluster dendrimer has been prepared and characterized; photooxygenation reaction using the molecular cluster dendrimer as a photosensitizer was successful.
View Article and Find Full Text PDF4,5-Bis(benzylthio)-3,6-diethylphthalonitrile (1) was mixed with 4 -t-butylphthalonitrile and then treated with lithium alkoxide in n-hexanol to produce the corresponding unsymmetrically substituted phthalocyanines (2) and (3) with two or four benzylthio groups, respectively. Treatment of phthalocyanine (2) with nickel(II) acetate yielded the corresponding metal complex 2-Ni. Two benzyl groups of 2 and 2-Ni were removed with lithium/THF/ammonia at -78 degrees C under argon, and the dithiolate anions generated were then reacted with elemental sulfur to give monotrithiolophthalocyanines (5) and (5-Ni).
View Article and Find Full Text PDFPhotoinduced charge separation of fullerodendrimers with carboxylates at terminal sites (C60 approximately COO-) has been found in aqueous media. Time-resolved transient absorption and fluorescence measurements of the fullerodendrimers demonstrated that charge separation takes place from the terminal carboxylate anion to the central excited singlet state of C60, generating C60*- approximately COO* with high quantum efficiency in aqueous solution. In the presence of viologen dication and a sacrificial donor, the persistent viologen radical cation was generated.
View Article and Find Full Text PDFBenzo[1,2,3]trichalcogenoles with two bromine atoms on the benzene ring, 5,6-dibromo-4,7-diethylbenzo[1,2,3]trichalcogenoles (1a) and (1b) (chalcogen: 1a = S; 1b = Se), were first prepared by treating 2,3,5,6-tetrabromo-1,4-diethylbenzene (TBDEB) with elemental sulfur or amorphous selenium in DBU at 140 degrees C (for 1a) and 100 degrees C (for 1b) for 24 h. The structures of 1a and 1b were verified by NMR spectroscopy, mass spectrometry, and elemental analysis. X-ray crystallographic analysis ultimately showed that the substitution reactions of TBDEB proceeded at the two adjacent bromine atoms.
View Article and Find Full Text PDFAutoxidation of the phosphonate carbanions derived from 9-phosphono-10-hydroacridanes provided chemiluminescence ascribed to the excited acridone anion. The intramolecular CIEEL (chemically initiated electron exchange luminescence) mechanism can be applied to this chemiluminescence because of the much higher emission efficiency compared to that of 9-phosphono-10-methylacridanes. The effect of the phosphonate substituents on the emission efficiency and especially on the rates of the chemiluminescence decay can be interpreted to originate from the valence deviation of the phosphorus atoms, which is connected with the substituent effect on the geometrical selectivity in the olefination reaction of the phosphonate carbanions.
View Article and Find Full Text PDF[reaction: see text] Thermotropic liquid crystallinity can be induced for an anthracene having a dendritic substituent. The photodimerization reaction of an anthracene moiety in the smectic phase proceeded quantitatively and regioselectively.
View Article and Find Full Text PDFA kinetic study of peroxyoxalate chemiluminescence reactions employing 2,4,6-trichlorophenyl N-aryl-N-tosyloxamates supports the 1,2-dioxetanones still bearing the eliminating group as the key intermediates that interact with the fluorophores rather than 1,2-dioxetanedione.
View Article and Find Full Text PDFThe title compound N,N'-bistosyl-1H,4H-quinoxaline-2,3-dione (TsQD) provides peroxyoxalate chemiluminescence (PO-CL) when reacted with hydrogen peroxide in the presence of fluorophores. The chemiluminescence (CL) efficiency of TsQD was superior to that of other related compounds such as bis(2,4,6-trichlorophenyl) oxalate (TCPO), a typical oxalate for the peroxyoxalate PO-CL, under an aqueous condition. Factors affecting the PO-CL efficiency are discussed from the viewpoint of the structures of the substrates and the electronic nature of the fluorophores.
View Article and Find Full Text PDF