We reevaluate the absolute fluorescence and phosphorescence quantum yields of standard solutions by using a novel instrument developed for measuring emission solutions. The consists an integrating sphere equipped with monochromatized Xe arc lamp as light source multichannel spectrometer. By back-thinned CCD (BT-CCD) detector, sensitivity spectral detection in both short long wavelength regions is greatly improved compared that optical system uses conventional photodetector. Using this...

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTElectrochemical CO2 reduction catalyzed by ruthenium complexes [Ru(bpy)2(CO)2]2+ and [Ru(bpy)2(CO)Cl]+. Effect of pH on the formation CO HCOO-Hitoshi. Ishida, Koji. Tanaka, Toshio. TanakaCite this: Organometallics 1987, 6, 1, 181–186Publication Date (Print):January 1987Publication History Published online1 May 2002Published inissue 1 January 1987https://pubs.acs.org/doi/10.1021/om00144a033https://doi.org/10.1021/om00144a033research-articleACS...

We found catalyst concentration dependence of the product ratio in photochemical reduction CO₂, and proposed a new mechanism involving Ru(<sc>i</sc>)–Ru(<sc>i</sc>) dimer intermediate.

N,N-Dimethylacetamide (DMA) was used for the first time as reaction solvent in photocatalytic reduction of CO2. DMA is highly stable against hydrolysis and does not produce formate even if it hydrolyzed. We report catalytic activities [Ru(bpy)2(CO)2](PF6)2 (bpy = 2,2'-bipyridine) presence [Ru(bpy)3](PF6)2 a photosensitizer 1-benzyl-1,4-dihydronicotinamide (BNAH) an electron donor DMA/water. In photochemical CO2 reduction, carbon monoxide (CO) are catalytically produced, while dihydrogen (H2)...

Abstract All of the lanthanide(III) (La3+–Lu3+) efficiently catalyzed dehydration hexose in water at 140 °C to produce 5-hydroxymethyl-2-furaldehyde (HMF) without accompanying further hydrolysis levulinic acid, which is routinely obtained as a by-product conventional Brønsted acid-catalyzed reactions. The relationships between catalytic activity and ionic radius (ri) lanthanides(III) for d-fructose d-glucose were found have double-peak profile maximizing Pr or Nd (ri 1.00 Å) Er Yb 0.87 with...

Electrochemical reduction of CO2catalysed by [RuL1(L2)(CO)2]2+[L1,L2=(bipy)2, (bipy)(dmbipy), (dmbipy)2, or (phen)2], [Ru(phen)2(CO)Cl]+(phen = 1,10-phenanthroline), and [RuL(CO)2Cl2][L 2,2′-bipyridine (bipy) 4,4′-dimethyl-2,2′-bipyridine (dmbipy)] were carried out controlled-potential electrolysis at –1.30 V vs. saturated calomel electrode in acetonitrile–water (4 : 1, v/v), MeOH, MeCN–MeOH v/v). In v/v) no difference activities between the catalysts was observed, however MeOH amounts...

Abstract All lanthanide(III) ions were found to catalyze dehydration of saccharides 5-hydroxymethyl-2-furfural (HMF) in DMSO at 100 - 120 °C. Particularly, d-fructose was almost quantitatively converted HMF without generating any byproducts. The results the reaction with di- and trisaccharides indicated that moiety substrates selectively HMF.

The selectivity for the formation of HCOO– in electrochemical CO2 reduction catalysed by [Ru(bpy)2(CO)2]2+(bpy = 2,2′-bipyridine) increases on increasing pKa value proton source, and highly selective is achieved using Me2NH·HCl or PhOH as a source MeCN.

Abstract Guidelines for measuring the luminescence of inorganic compounds, metal complexes, and organometallic compounds are described. Common textbooks manuals describing measurements usually targeted organic not always suitable which emit room-temperature phosphorescence. The report describes problems that researchers may confront while recording emission data elaborates clear procedures to avoid these provide adequate standardized protocols.

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTNew synthesis and some selected reactions of the potential ergot alkaloid precursor indole-4-carboxaldehydeAlan P. Kozikowski, Hitoshi Ishida, Yon-Yih ChenCite this: J. Org. Chem. 1980, 45, 16, 3350–3352Publication Date (Print):August 1, 1980Publication History Published online1 May 2002Published inissue 1 August 1980https://pubs.acs.org/doi/10.1021/jo01304a043https://doi.org/10.1021/jo01304a043research-articleACS PublicationsRequest reuse...

A series of trans-(Cl)-[Ru(L)(CO)2 Cl2 ]-type complexes, in which the ligands L are 2,2'-bipyridyl derivatives with amide groups at 5,5'-positions, synthesized. The C-connected group bound to bipyridyl ligand through carbonyl carbon atom is twisted respect plane, whereas N-connected plane. DFT calculations reveal that structure raises level LUMO, results a negative shift first reduction potential (Ep ) ruthenium complex. catalytic abilities for CO2 evaluated photoreactions (λ>400 nm)...

A periodic mesoporous organosilica (PMO) containing 2,2'-bipyridine (bpy) ligands within the framework (BPy-PMO) has great potential for designing novel catalysts by modifying metal complexes. photosensitizing site (Ru(PS)) was introduced treating cis-[Ru(bpy)2 (dimethylsulfoxide)Cl]Cl with BPy-PMO. Then a catalytic (Ru(Cat)) brought in Ru(PS)x -BPy-PMO reaction ruthenium polymer [Ru(CO)2 Cl2 ]n . The stepwise modification of BPy-PMO successfully affords photocatalyst -Ru(Cat)y -BPy-PMO....

The asymmetric synthesis of (R)-(+)-1,1′-bi-2-naphthol [or (R)-(+)-1,1 ′-bi-3-methoxy-2-naphthol] from 2-naphthol (or 3-methoxy-2-naphthol) is performed photocatalytically by using the chiral ruthenium complex, M(C3)-Δ-[Ru(menbpy)3]2+[M(C3)= counterclockwise molecular helicity along C3 axis, menbpy = 4,4′-di(1R,2S,5R)-(–)-menthoxycarbonyl-2,2′-bipyridine] as a photosensitizer and[Co(acac)3](acac–= acetylacetonato) an oxidant.

Abstract The catalytic reduction of CO2 has been succesfully performed under the controlled potential electrolysis [Ru (bpy)2 (CO)2](PF6)2 (bpy=2,2′-bipyridine) in a CO2-saturated H2O/DMF solution. Formic acid and CO as well H2 are formed alkaline conditions, while only evolved acidic conditions.

The anticoagulative principles were isolated from Curcumae Rhizoma by a combination of partition and column chromatographies on silica gel, identified as 1, 7-bis (4-hydroxy-3-methoxyphenyl)-1, 6-heptadiene-3, 5-dione (curcumin), p, p'-dihydroxydicinnamoylmethane p-hydroxycinnamoylferuloylmethane. During the isolation process plasma recalcification time in mice was used to follow activity material.

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTIntramolecular [3 + 2] cycloaddition reactions in the indole series "The nitrile oxide route to ergot alkaloids". 1. Chanoclavine IAlan P. Kozikowski and Hitoshi IshidaCite this: J. Am. Chem. Soc. 1980, 102, 12, 4265–4267Publication Date (Print):June 1, 1980Publication History Published online1 May 2002Published inissue 1 June 1980https://doi.org/10.1021/ja00532a051RIGHTS & PERMISSIONSArticle Views559Altmetric-Citations42LEARN ABOUT THESE...

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTHighly Effective Binding of Phosphomonoester with Neutral Cyclic Peptides which Include a Non-natural Amino AcidHitoshi Ishida, Mamoru Suga, Kiyoshi Donowaki, and Katsutoshi OhkuboCite this: J. Org. Chem. 1995, 60, 17, 5374–5375Publication Date (Print):September 1, 1995Publication History Published online1 May 2002Published inissue 1 September 1995https://pubs.acs.org/doi/10.1021/jo00122a005https://doi.org/10.1021/jo00122a005research-articleACS...

A series of novel cyclic peptides composed 3 to 5 dipeptide units with alternating natural−unnatural amino acid units, have been designed and synthesized, employing 5-(N-alkanoylamino)-3-aminobenzoic a long alkanoyl chain as the unnatural acid. All systematically varying pore size, shape, lipophilicity are found form ion channels conductance ca. 9 pS in aqueous KCl (500 mM) upon examination by voltage clamp method. These peptide cation selective permeability ratio PCl−/PK+ around 0.17. The...

Playing into our hands: The achiral bipyridine amino acid fluorenylmethyloxycarbonyl 5-amino-3-oxapentanoic (Fmoc-O1PenBpy-OH) has been used for the solid-phase synthesis of metallopeptides. Circular dichroism, molecular modeling, and NMR spectroscopic studies show that chirality resulting metal complexes in aqueous solution is determined, can thus be controlled, by stereochemistry one proline residue loop between two coordinating O1PenBpy residues. Detailed facts importance to specialist...