KANAGAWA University Repository
Not a member yet
13891 research outputs found
Sort by
A THIRD-MOMENT EXPONENTIAL NORMAL TRANSFORMATION AND ITS APPLICATION IN STRUCTURAL RELIABILITY
Get PDF神奈川大学博士（工学）doctoral thesi
Laser-Synchronized Time-Resolved ESR Spectroscopy of Elementary Process Involving Radical Addition to C=S Double Bond
Get PDFA time-resolved (TR-ESR) method was applied to observe an elementary process of the radical addition reaction to the C=S double bond of the reversible addition fragmentation chain transfer (RAFT) polymerization reagent (thiobenzoylthio)acetic acid. As for the radical, 1-hydroxycyclohexyl (Hy-CyH), which is easily prepared by UV laser photodissociation of an aromatic ketone compound, was examined. Time evolution of TR-ESR spectra in the reaction system of Hy-CyH and (thiobenzoylthio)acetic acid shows prompt generation of Hy-CyH after UV laser photolysis, followed by the clear appearance of the adduct radical with new bond formation at the S atom at the C=S group in the RAFT reagent. The TR-ESR spectrum of the adduct radical was analyzed according to the hyperfine coupling constants obtained by DFT calculation. Although the spectrum was broad and showed no clear hyperfine structure, the bandwidth of the spectrum was reproduced by the theoretical simulation spectrum. The g value of the adduct radical was larger than that of Hy-CyH, which is a conventional organic free radical. This agrees well with the electronic structure of the adduct radical with two S atoms neighboring the C atom with an unpaired electron. Thus, large spin-orbit coupling of the two S atoms gives rise to a higher g value than Hy-CyH. The addition reaction rate of Hy-CyH and the RAFT reagent was estimated by the time evolution of TR-ESR spectra.原著 2024年度神奈川大学総合理学研究所共同研究助成論文departmental bulletin pape
Organometallic Chemistry Based on Reaction Types and Anecdote of Discoveries (final)
Get PDFOrganic compounds containing carbon-metal bonds are called organometallic compounds. Such compounds have been known and studied since the 19th century and have been widely used to promote synthetic transformation in modern organic chemistry. Many educational benefits could result from the use of reaction types and discoveries for undergraduate and graduate classes in organic and organometallic chemistry. As a final part of this approach, this report deals with the later development of Ziegler-Natta catalysts polymerization. Although Ziegler-Natta catalysts such as TiCl4/Et3Al are known to be insoluble with heterogeneous systems, metallocene catalysts (Cp2MX2, M=Ti, Zr/Me3Al) are soluble with homogeneous systems. However, metallocene catalysts are less active regarding polymerization. In 1976, Kaminsky and a coworker found that Cp2ZrCl2 becomes a very active polymerization catalys the by addition of Me3Al treated water. The adventitious water can promote polymerization via the formation of methyl almoxanes (MAO: [AlCH3(-o-)]n), which are extremely effective cocatalyzed metallocene catalysts. Metallocene catalysts later developed can polymerize α-olefin with very high stereoregularity to yield either isotactic or syndiotactic polymers. It was ,also proposed that Cp2ZrMe+ ions are active species in soluble systems. Watson, Bercow, Marks and coworkers demonstrated the neutral isoelectronic group 3 and lanthanoid system Cp*2M(R) (M=Sc, Y, Ln), while Jordan finally isolated cationic group 4 metal alkyls (Cp2Zr(R)(L)+, which undergo olefin insertion and polymerization. Lastly, even late transition metal as reported by alkyl cation complexes of Pd(II) and Co(III) function as polymerization catalysts reported by Brookhardt, which have diamine ligands as well as agostic protons of alkyl ligands.教育論文departmental bulletin pape