Kazuhiko Mizuno

Name:

Organization: Osaka Prefecture University

Department: Department of Applied Chemistry, Graduate School of Engineering

Title:

Chemicals
References

Formation of a new benzotriquinane skeleton via intramolecular photocycloaddition reactions of a phenylethynes moiety to a 1-cyanonaphthalene ring system

Co-reporter:Kazuhiko Mizuno, Naoki Negoro, Yoshinori Nagayama, Hajime Maeda and Hiroshi Ikeda

Photochemical & Photobiological Sciences 2014 vol. 13(Issue 2) pp:145-148

Publication Date(Web):10 Oct 2013

DOI:10.1039/C3PP50243K

Photoirradiation of 1-cyano-2-(2,2-dicyano-5-phenylpentyn-4-yl)naphthalene and its analogues promotes sequential intramolecular [2π + 2π] photocycloaddition and cyclobutene ring opening to form benzocyclooctatetraenes, which are then transformed to benzotriquinanes in good yields via a photochemical transannular cyclization process.

Substitution effects of CC triple bonds on the fluorescent properties of perylenes studied by emission and transient absorption measurements

Co-reporter:Minoru Yamaji, Hajime Maeda, Yasuaki Nanai, Kazuhiko Mizuno

Chemical Physics Letters 2012 Volume 536() pp:72-76

Publication Date(Web):21 May 2012

DOI:10.1016/j.cplett.2012.03.108

Abstract

Perylenes substituted with trimethylsilylethynyl, tert-butylethynyl and trimethylsilylbutadiynyl groups were prepared, and their photophysical and photochemical properties were investigated through measurements of fluorescence yields, lifetimes, and triplet–triplet absorption. Introduction of these groups caused little change in the rates of fluorescence, but decreased the fluorescence yields and substantially enhanced the rates of non-radiative processes. Observation of the triplet absorption was evident for the origin of the enhanced non-radiative process by the substitution with the triple bond(s).

Density functional theory study of silole-fused tetramethyleneethane biradicals with orbital interactions

Co-reporter:Yusuke Kano;Hiroshi Ikeda

Journal of Physical Organic Chemistry 2011 Volume 24( Issue 10) pp:921-928

Publication Date(Web):

DOI:10.1002/poc.1891

The geometries, energy gap between singlet and triplet states (S–T gap), electronic transitions, and molecular orbitals of the diphenyl derivative of the silole-fused tetramethyleneethane (TME) (3,4-dimethylenesilole) biradical 7^•• were determined by using the density functional theory method at the unrestricted Becke, three-parameter, Lee–Yang–Parr/cc-pVDZ level. In a manner similar to that of the parent TME biradical, the S–T gap of 7^•• is small. The wavelengths of electronic transitions of ³7^•• (λ_ET = 450 nm) are calculated to be different from that of ¹7^•• (λ_ET = 673 nm). These differences are attributed to interactions between orbitals of the two allyl radical moieties, especially, the existence of double σ*–π* conjugation, that is, π*–σ*–π* conjugation, that takes place in the silole subunit. Copyright © 2011 John Wiley & Sons, Ltd.

A Probable Hydrogen-Bonded Meisenheimer Complex: An Unusually High SNAr Reactivity of Nitroaniline Derivatives with Hydroxide Ion in Aqueous Media

Co-reporter:Mitsutaka Imoto, Yasunori Matsui, Motonori Takeda, Akihiro Tamaki, Hisaji Taniguchi, Kazuhiko Mizuno, and Hiroshi Ikeda

The Journal of Organic Chemistry 2011 Volume 76(Issue 15) pp:6356-6361

Publication Date(Web):July 13, 2011

DOI:10.1021/jo2007219

Observations show that nitroanilines exhibit an unusually high SNAr reactivity with OH– in aqueous media in reactions that produce nitrophenols. SNAr reaction of 4-nitroaniline (2a) in aqueous NaOH for 16 h yields 4-nitrophenol (4a) quantitatively, whereas a similar reaction of 4-nitrochlorobenzene (1a) gave 4a in 2% yield together with recovered 1a in 97%, suggesting that the leaving ability of the NH2 group far surpasses that of Cl under these conditions. An essential feature of SNAr reactions of nitroanilines is probably that the NH2 leaving group participates in a hydrogen-bonding interaction with H2O. Density functional theory (DFT) calculations for a set of 4-nitroaniline, OH–, and H2O suggest a possible formation of a Meisenheimer complex stabilized by hydrogen-bonding interactions and a six-membered ring structure. The results obtained here contrast with conventional SNAr reactivity profiles in which nitroanilines are nearly unreactive with nucleophiles in organic solvents.

Chemistry of Vinylidenecyclopropanes

Co-reporter:Min Shi, Li-Xiong Shao, Jian-Mei Lu, Yin Wei, Kazuhiko Mizuno, and Hajime Maeda

Chemical Reviews 2010 Volume 110(Issue 10) pp:5883

Publication Date(Web):June 2, 2010

DOI:10.1021/cr900381k

Contrasting Intermolecular and Intramolecular Exciplex Formation of a 1,4-Dicyano-2-methylnaphthalene−N,N-Dimethyl-p-toluidine Dyad

Co-reporter:Mitsutaka Imoto, Hiroshi Ikeda, Takayuki Fujii, Hisaji Taniguchi, Akihiro Tamaki, Motonori Takeda and Kazuhiko Mizuno

Organic Letters 2010 Volume 12(Issue 9) pp:1940-1943

Publication Date(Web):March 30, 2010

DOI:10.1021/ol100324b

An intramolecular exciplex is formed upon excitation of the cyclohexane solution of the 1,4-dicyano-2-methylnaphthalene−N,N-dimethyl-p-toluidine dyad, but little if any intramolecular CT complex exists in the ground state of this substance in solution. In contrast, in the crystalline state, the dyad forms an intermolecular mixed-stack CT complex in the ground state and an intermolecular exciplex when it is photoexcited.

Control of the CT interaction between electron-donor and -acceptor moieties of a 1,4-dicyanonaphthalene–arene dyad for intermolecular exciplex or excimer formation in crystals

Co-reporter:Mitsutaka Imoto, Hiroshi Ikeda, Maki Ohashi, Motonori Takeda, Akihiro Tamaki, Hisaji Taniguchi, Kazuhiko Mizuno

Tetrahedron Letters 2010 Volume 51(Issue 45) pp:5877-5880

Publication Date(Web):10 November 2010

DOI:10.1016/j.tetlet.2010.08.086

Colorless crystals of 1,4-dicyano-2-(4′-methoxybenzyloxy)methylnaphthalene (2), which is a 1,4-dicyano-2-methylnaphthalene (DCMN)–4-methylanisole (MA) dyad linked by an ether unit, selectively form a fluorescent intermolecular DCMN–MA exciplex (greenish blue, λfexciplex=456nm). In contrast, 1,4-dicyano-2-(4′-methylbenzyloxy)methylnaphthalene (3), which is a DCMN–p -xylene dyad, forms a fluorescent intermolecular DCMN–DCMN excimer in the crystalline state (blue, λfexcimer=404nm). These findings demonstrate that a moderate charge transfer interaction takes place between the DCMN moiety of 2 and MA moieties of the adjacent molecules of 2, which successfully facilitates the preparation of light-emissive organic crystals.

Intramolecular polar addition reactions of active methylene moieties to aryl-substituted alkenes via photoinduced electron transfer

Co-reporter:Maki Ohashi, Keisuke Nakatani, Hajime Maeda, Kazuhiko Mizuno

Tetrahedron Letters 2010 Volume 51(Issue 42) pp:5537-5539

Publication Date(Web):20 October 2010

DOI:10.1016/j.tetlet.2010.07.165

The synthesis of cycloalkane derivatives with ring sizes of 5–7 was achieved in moderate yields by photoirradiation of aqueous acetonitrile solutions, containing compounds that consist of active methylene moieties tethered to aryl-substituted alkenes along with sodium hydroxide and 9-cyanophenanthrene. When the substrate contains ethyl cyanoacetate as an asymmetric active methylene moiety, the reaction proceeds in a highly diastereoselective manner.

Selective photochemical monoalkylation of active methylene compounds by alkenes. A green pathway for carbon–carbon bond formation

Co-reporter:Maki Ohashi, Keisuke Nakatani, Hajime Maeda, Kazuhiko Mizuno

Journal of Photochemistry and Photobiology A: Chemistry 2010 Volume 214(2–3) pp:161-170

Publication Date(Web):15 August 2010

DOI:10.1016/j.jphotochem.2010.06.020

Effects of magnesium salts on photoinduced electron transfer reaction between ammonia, 2,5-dimethylhexa-2,4-diene, and 9-cyanophenanthrene

Co-reporter:Maki Ohashi, Yusuke Kano, Hiroshi Ikeda, Kazuhiko Mizuno

Tetrahedron 2010 66(21) pp: 3770-3774

Publication Date(Web):

DOI:10.1016/j.tet.2010.03.056

Synthesis and Solvatochromatic properties of 9-(4-Aminophenylethynyl)-10-(4-nitrophenylethynyl)anthracene

Co-reporter:Mitsutaka Imoto;Motonori Takeda;Akihiro Tamaki

Research on Chemical Intermediates 2009 Volume 35( Issue 8-9) pp:

Publication Date(Web):2009 November

DOI:10.1007/s11164-009-0086-9

9-(4-Aminophenylethynyl)-10-(4-nitrophenylethynyl)anthracene (2) was synthesized in high yield by using a route involving sequential Sonogashira cross coupling reactions of 9-bromo-10-iodoanthracene with 4-nitrophenylacetylene and 4-aminophenylacetylene. Solvatochromism was observed in the absorption and fluorescence spectra of 2 in a variety of solvents. In less polar solvents, such as hexane and benzene, the fluorescence emission band of 2 appears in the green to orange region while this substance does not fluoresce in polar solvents, such as acetonitrile and DMF.

Photochromic behavior of tetrathienylethene in condensed systems—attempts to control 1,2-dyotropic rearrangement of the closed isomer

Co-reporter:Hiroshi Ikeda;Akinori Kawabe;Azusa Sakai

Research on Chemical Intermediates 2009 Volume 35( Issue 8-9) pp:

Publication Date(Web):2009 November

DOI:10.1007/s11164-009-0072-2

Tetrakis(2-methyl-5-methylthiothien-3-yl)ethene (1) exhibits incomplete photochromism in the powder state, KBr pellet, the amorphous state and a polystyrene film. In contrast, 1 in the single crystalline state does not show any photoreactivity. This chromic system involves three possible photon-modes involving the starting open isomer 1, the corresponding closed isomer trans-2 and the rearranged isomer trans-3. Unfortunately, efforts to control the interconversions between these isomers, especially the rearrangement of trans-2 to trans-3, have not been fruitful. A possible mechanism for photocyclization of 1 to form trans-2 is also discussed on the basis of the results of density functional theory calculations together with that for the 1,2-dyotropic rearrangement of trans-2 to give trans-3.

One-Step Synthesis of Benzotetra- and Benzopentacyclic Compounds through Intramolecular [2+3] Photocycloaddition of Alkenes to Naphthalene

Co-reporter:Hirofumi Mukae;Hajime Maeda Dr. Dr.

Angewandte Chemie 2006 Volume 118(Issue 39) pp:

Publication Date(Web):5 SEP 2006

DOI:10.1002/ange.200602553

Die Bestrahlung von Acetonitrillösungen, die 1-Cyan-2-(4-pentenyl)naphthalinderivate enthalten, liefert über eine intramolekulare [2+3]-Photocycloaddition der Alkeneinheit an die 2,4-Positionen der Cyannaphthalineinheit in hohen Ausbeuten benzotetra- und benzopentacyclische Verbindungen mit Tri- und Tetrachinangerüsten (siehe Schema; n=1, 2).

Alkynylpyrenes as Improved Pyrene-Based Biomolecular Probes with the Advantages of High Fluorescence Quantum Yields and Long Absorption/Emission Wavelengths

Co-reporter:Hajime Maeda Dr.;Tomohiro Maeda ;Kazuhisa Fujimoto Dr.;Hisao Shimizu;Masahiko Inouye

Chemistry - A European Journal 2006 Volume 12(Issue 3) pp:

Publication Date(Web):3 NOV 2005

DOI:10.1002/chem.200500638

The photochemical properties of various alkynylpyrene derivatives have been investigated in detail with a view to developing a new class of pyrene-based biomolecular probes. The absorption maxima of the alkynylpyrenes were seen to be shifted to longer wavelengths compared with those of the unsubstituted parent pyrene. Fluorescence quantum yields of the alkynylpyrenes dramatically increased up to 0.99 in ethanol, and only slight quenching of the fluorescence occurred even under aerated conditions. The alkynylpyrenes have been successfully introduced into representative biomolecules such as peptides, proteins, and DNAs. The detectabilities of the labeled biomolecules were significantly improved, with the unique photochemical characteristics of the pyrene nucleus being maintained.

One-Step Synthesis of Benzotetra- and Benzopentacyclic Compounds through Intramolecular [2+3] Photocycloaddition of Alkenes to Naphthalene

Co-reporter:Hirofumi Mukae;Hajime Maeda Dr. Dr.

Angewandte Chemie International Edition 2006 Volume 45(Issue 39) pp:

Publication Date(Web):5 SEP 2006

DOI:10.1002/anie.200602553

Rings from light: Irradiation of acetonitrile solutions containing 1-cyano-2-(4-pentenyl)naphthalene derivatives afforded benzotetra- and benzopentacyclic compounds with tri- and tetraquinane skeletons in high yields, through intramolecular [2+3] photocycloaddition of the alkene at the 2,4-positions of the cyanonaphthalene (see scheme; n=1, 2). The structures of these adducts were confirmed by their spectral properties and by X-ray crystallographic analyses.

Enhancement effect of Mg(ClO4)2 on TiO2-catalyzed photooxygenation of 1,2-diarylcyclopropanes

Co-reporter:Hajime Maeda, Hideyuki Nakagawa and Kazuhiko Mizuno

Photochemical & Photobiological Sciences 2003 vol. 2(Issue 11) pp:1056-1058

Publication Date(Web):09 Sep 2003

DOI:10.1039/B306186H

The TiO2-catalyzed photooxygenation of electron-rich 1,2-diarylcyclopropanes via electron transfer in acetonitrile is significantly accelerated by the addition of Mg(ClO4)2.