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Your search keyword '"Morihashi, Kenji"' showing total 187 results
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187 results on '"Morihashi, Kenji"'

7. MC/MO study of the solvent effect on the excitation energies of the (CH (sub)3) (sub)2 NO radical in hydrogen-bonding and non-hydrogen-bonding solvents

Author

Yagi, Toru, Morihashi, Kenji, and Kikuchi, Osamu

Subjects
Chemistry, Physical and theoretical -- Research, Solvents -- Physiological aspects, Radicals (Chemistry) -- Physiological aspects, Hydrogen bonding -- Physiological aspects, Monte Carlo method -- Analysis, Molecular orbitals -- Research, Nitric oxide -- Physiological aspects, Carbon -- Physiological aspects, Chemicals, plastics and rubber industries
Published
2001

18. Novel 1,8-Naphthalimide derivative with an open space for an anion: Unique fluorescence behaviour depending on the binding anion’s electrophilic property

Author

Izawa, Hironori, Nishino, Shoji, Sumita, Masato, Akamatsu, Masaaki, Morihashi, Kenji, Ifuku, Shinsuke, Morimoto, Minoru, Saimoto, Hiroyuki, Izawa, Hironori, Nishino, Shoji, Sumita, Masato, Akamatsu, Masaaki, Morihashi, Kenji, Ifuku, Shinsuke, Morimoto, Minoru, and Saimoto, Hiroyuki

Abstract

We have designed a novel 1,8-naphthalimide derivative with an open space for an anion. Computational calculation has predicted that the space could trap various anion species and photo-induced charge transfer depending on the anion's electrophilic properties. Indeed, the fluorescence behaviour of the 1,8-naphthalimide derivative complexes with each anion is consistent with the computational prediction.

Published
2019

25. Effect of heme modification on oxygen affinity of myoglobin and equilibrium of the acid-alkaline transition in metmyoglobin

Author

Shibata, Tomokazu, Nagao, Satoshi, Fukaya, Masashi, Hulin Tai, Nagatomo, Shigenori, Morihashi, Kenji, Matsuo, Takashi, Hirota, Shun, Suzuki, Akihiro, Imai, Kiyohiro, and Yamamoto, Yasuhiko

Subjects
Fluorocarbons -- Structure, Fluorocarbons -- Chemical properties, Fluorocarbons -- Electric properties, Heme -- Chemical properties, Heme -- Structure, Heme -- Electric properties, Myoglobin -- Chemical properties, Myoglobin -- Structure, Oxygen -- Chemical properties, Substitution reactions -- Analysis, Chemistry
Abstract

Strongly electron-withdrawing perfluoromethyl (C[F.sub.3]) groups are substituted as heme side chains of myoglobin (Mb) to obtain larger alterations of the heme electron structure in order to analyze the relationship between the [O.sub.2] affinity of Mb and the electronic properties of heme peripheral side chains. The introduction of electron-withdrawing groups has increased the preferential binding of CO to the protein over that of [O.sub.2].

Published
2010

28. Vibrational frequencies of the HF dimer from the coupled cluster method including all single and double excitations plus perturbative connected triple excitations.

Author

Collins, Charlene L., Morihashi, Kenji, Yamaguchi, Yukio, and Schaefer, Henry F.

Subjects
*DISSOCIATION (Chemistry), *DIMERS, *MONOMERS, *DIPOLE moments, *ANGULAR momentum (Mechanics)
Abstract

Dissociation energies, equilibrium structures, equilibrium dipole moments, harmonic vibrational frequencies, infrared (IR) intensities, and zero-point vibrational energies (ZPVEs) are presented for the hydrogen fluoride monomer and dimer at the coupled cluster with single and double excitations plus perturbative connected triple excitations [CCSD(T)] level of theory with a series of large basis sets. Discussion focuses on the results from the largest basis set, triple zeta plus double polarization and one set of higher angular momentum functions [TZ2P(f,d)]. The structural parameters and dissociation energy agree well with the recent theoretical values reported in a high level ab initio study by Peterson and Dunning [J. Chem. Phys. 102, 2032 (1995)] and with experimental results. Here, the harmonic vibrational frequencies and IR intensities for the dimer are also predicted. The predicted vibrational frequency shifts relative to the monomer for the HF and DF stretching coordinates in the dimer are close to the experimental estimates. © 1995 American Institute of Physics. [ABSTRACT FROM AUTHOR]

Published
1995
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34. Novel 1,8-Naphthalimide derivative with an open space for an anion: Unique fluorescence behaviour depending on the binding anion’s electrophilic property

Author

Izawa, Hironori, Nishino, Shoji, Sumita, Masato, Akamatsu, Masaaki, Morihashi, Kenji, Ifuku, Shinsuke, Morimoto, Minoru, Saimoto, Hiroyuki, Izawa, Hironori, Nishino, Shoji, Sumita, Masato, Akamatsu, Masaaki, Morihashi, Kenji, Ifuku, Shinsuke, Morimoto, Minoru, and Saimoto, Hiroyuki

Abstract

We have designed a novel 1,8-naphthalimide derivative with an open space for an anion. Computational calculation has predicted that the space could trap various anion species and photo-induced charge transfer depending on the anion's electrophilic properties. Indeed, the fluorescence behaviour of the 1,8-naphthalimide derivative complexes with each anion is consistent with the computational prediction.

Published
2015

38. Calculation of contributions of one- and two-electron spin-orbit coupling terms to the....

Author

Kiyonaga, Hiroshi and Morihashi, Kenji

Subjects
*ATOMIC orbitals, *AMINO acids, *ALKANES, *QUANTUM perturbations
Abstract

Examines the role of one- and two-electron spin-orbit coupling terms to the parity-violating energy shifts for amino acids and helical alkanes. Use of sum-over-state perturbation theory in the study; Effect of weak neutral-current interaction between an electron and nucleus; Inclusion of one-center terms for amino acid and n-alkane calculations.

Published
1998
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39. Syntheses and characterization of bis(silacyclopropene) and disilabenzvalene

Author

Ando, Wataru, Shiba, Tadahiro, Hidaka, Takahiro, Morihashi, Kenji, and Kikuchi, Osamu

Subjects
Silicon compounds -- Analysis, Inorganic compounds -- Synthesis, Cyclic compounds -- Analysis, Chemistry
Abstract

A novel method for the synthesis of the precursor bis(silacyclopropane) was developed based on the reaction of magnesium with diphenyltetrakis(1-bromo-1-methylethyl)disilane. The synthetic strategy involved the formation of bis(silacyclopropene) from the reaction of the precursor bis(silacyclopropane) with bis(trimethylsilyl)acetylene. The isomerization of bis(silacyclopropene) also led to the initial formation of an intermediate Dewar silabenzene or 1,4-disilabenzene.

Published
1997

40. Assessment of Methodology and Chemical Group Dependences in the Calculation of the pKafor Several Chemical Groups

Author

Matsui, Toru, Shigeta, Yasuteru, and Morihashi, Kenji

Abstract

We have investigated the dependencies of various computational methods in the calculation of acid dissociation constants (pKavalues) of certain chemical groups found in protonatable amino acids based on our previous scheme [Matsui; Phys. Chem. Chem. Phys.2012, 14, 4181−4187]. By changing the quantum chemical (QC) method (Hartree–Fock (HF) and perturbation theory, and composite methods, or exchange–correlation functionals in density functional theory (DFT)), basis sets, solvation models, and the cavities used in the solvent models, we have exhaustively tested about 2,200 combinations to find the best combination for pKaestimation among them. Of the tested parameters, the choice of the basis set and cavity is the most crucial to reproduce experimental values compared to other factors. Concerning the basis set, the inclusion of diffuse functions is quite important for carboxyl, thiol, and phenol groups judging from the mean absolute errors (MAEs) measured from the experimental values. Of the cavity models, between the Pauling, Klamt, and the universal force field (UFF) definitions, the UFF defined cavity is the best choice, resulting in the smallest MAEs. Concerning the QC methods, hybrid DFTs and range-separated DFTs always provide better results than pure DFTs and HF. As a result, we found that LC-ϖPBE/6-31+G(d) with PCM-SMD/UFF provides the best pKaestimation with a MAE within 0.15 pKaunits.

Published
2017
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