A5080360627- Fullerene Chemistry and Applications
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University of Electro-Communications
2013-2025
University of Tsukuba
1994-2015
Kyoto University
2012-2015
University of California, Davis
2015
Institute for Molecular Science
1998-2010
Tokyo Gakugei University
2005-2010
Japan Science and Technology Agency
2010
Niigata University
1998-2006
Tohoku University
1998-2006
Josai University
2005
Clear confirmation of recent theoretical studies concerning the structure endohedral complexes formed by La and C80 is provided NMR spectroscopic investigations presented here Complex La2@C80 present, its based on unstable "empty" Ih isomer C80. The two atoms circulate inside this round cage even at room temperature (shown schematically right).
ADVERTISEMENT RETURN TO ISSUEPREVCommunicationNEXT[email protected]82 Anion. An Unusually Stable MetallofullereneTakeshi Akasaka, Takatsugu Wakahara, Shigeru Nagase, Kaoru Kobayashi, Markus Waelchli, Kazunori Yamamoto, Masahiro Kondo, Shingo Shirakura, Okubo, Yutaka Maeda, Tatsuhisa Kato, Kako, Yasuhiro Nakadaira, Ritsuko Nagahata, Xiang Gao, Eric Van Caemelbecke, and Karl M. KadishView Author Information Graduate School of Science Technology Niigata University, 950-2181, Japan Institute for...
A stable diamagnetic monoanion of the La@C82 isomer was electrochemically prepared and isolated in order to disclose its cage symmetry. By measuring 13C NMR spectrum anion, it determined for first time that has Cs symmetry, as also confirmed by density functional calculations.
Sc3N@C80 has a lower thermal reactivity than La2@C80, although the same carbon cage (Ih) and oxidation state (C806-) as La2@C80. This result is attributed to difference in energy level distribution of LUMO between
The exohedrally functionalized derivative of endohedral metallofullerene, Ce2@C80(Mes2SiCH2SiMes2), was successfully synthesized and fully characterized. X-ray crystallographic NMR spectroscopic analyses reveal that the free random motion two metal atoms in Ce2@C80 is controlled inside cage by exohedral chemical functionalization.
Ce@C(82) is isolated by high-performance liquid chromatography (HPLC) and the cage symmetry determined as C(2)(v)() measuring (13)C NMR spectra of its anion. The peaks [Ce@C(82)](-) show temperature-dependent shifts ascribed to f electron remaining on Ce atom. Both are silent in spin resonance spectroscopy (ESR) because highly anisotropic g matrix well fast relaxation process originating from orbital angular momentum electron. This complementary relationship observation paramagnetic shift...
The photochemical reaction of Sc(3)N@C(80) with 1,1,2,2-tetramesityl-1,2-disilirane affords the adduct as a bis-silylated product. was characterized by NMR spectroscopy and single-crystal X-ray structure analysis. dynamic behavior disilirane moiety encapsulated Sc(3)N cluster were also investigated. unique redox property is reported means CV DPV. Experimental results confirmed density functional calculations.
Dimetallofullerene Ce(2)@C(78) and its bis-silylated derivative (1) were successfully prepared fully characterized.
(6,5)‐enriched single‐walled carbon nanotubes (SWCNTs) were reductively arylated using sodium naphthalenide and monosubstituted disubstituted iodobenzene derivatives to control their photoluminescence (PL) properties. In the reactions with substituted iodobenzenes, degree of functionalization was influenced by substituents on aryl groups depending position, which allowed us realize PL intensity. The at 2‐position methyl 3,5‐positions phenyl group respectively increased E11** E11* selectivity...
The photoreactions of C70 and mesityl‐substituted disilirane (disilacyclopropane) 1a afforded the corresponding adducts 2a 3a, former which was reported previously. structures 3a were unequivocally established respectively as a 1,4‐adduct structure at [d,d'] site 1,2‐adduct [a,b] bond, respectively, using single‐crystal X‐ray crystallographic analyses. latter represents first example study 1,3‐disilolane (1,3‐disilacyclopentane) derivatives fullerenes. electronic properties these products...
The (139)La NMR study of the exohedrally functionalized derivatives La(2)@C(80) metallofullerene, La(2)@C(80)(Ar(2)Si)(2)CH(2) (: Ar = Mes, Mes mesityl, : Dep, Dep 2,6-diethylphenyl), reveal that two La atoms hop between sites along equator C(80) cage.
The chemical reduction and oxidation of M@C82 (M = Y, La, Ce) afford the corresponding anion cation, respectively, which show unique interesting reactivities. It is found that successful reversible gain or loss electrons by ionization useful for controlling stability reactivity toward both nucleophiles electrophiles.
Introducing substituents onto SWNT sidewalls increases their solubility and tunes properties. Controlling the degree of functionalization is important because addition numerous functional groups on sidewall degrades intrinsic useful electronic We examined synthesis characterization sidewall-functionalized SWNTs in this study. The functionalized (1R-SWNTs-2R) were prepared a one-pot reaction with alkyllithium (1RLi) followed by alkyl bromide (2RBr). characterized absorption Raman spectroscopy...
Functionalization of endohedral metallofullerenes has been shown to differ depending on photochemical or thermal pathways. We report that Lu(3)N@I(h)-C(80) reacts with thermally generated bis(2,6-diethylphenyl)silylene high selectivity and forms monosilylated derivative 1b. Unexpectedly, 1b undergoes conversion afford isomer 1a under ambient light. These adducts were characterized using NMR, visible-near-IR spectroscopy, matrix-assisted laser desorption ionization time-of-flight mass...
The photochemical reaction of C60 with disilane 1 affords the adduct 2 as a bissilylated product. unique redox properties are reported by means differential pulse voltammetry. compound was characterized NMR, IR, and UV−vis spectroscopies. Spectroscopic theoretical investigation strongly support 1,16-addition structure having C2 symmetry which results from addition at 1,16 positions in C60. reasonably accounted for generation silyl radical is responsible formation 2.
Photochemical reactions of C(60) with siliranes (1a-d) afford adducts four types (2a-5b) as carbosilylated and hydrosilylated derivatives. Characterization these was conducted using MS, UV, NMR spectroscopy, single-crystal X-ray analyses. In particular, the first example crystal structure a closed 1,2-adduct at 5,6-ring junction cage is provided by analysis 3b. Electrochemical analyses also revealed unique redox properties products 2b-5b, which depend on regiochemistry functionality, in...
A two-step alkylation of single-walled carbon nanotubes was investigated. The functionalized SWNTs were characterized with vis-NIR and Raman spectrometers, scanning electron microscope, thermogravimetric analysis. This one-pot alkyllithium followed by alkyl halide is useful for the sidewall functionalization SWNTs. reaction shows significant substituent effects on degree upon may influence their characteristic properties effects.
Thermal carbosilylation of endohedral dimetallofullerene La(2)@I(h)-C(80) with silirane (silacyclopropane) is reported herein for the first time. Two diastereomers carbosilylated have been isolated and characterized. The fascinating molecular structure one diastereomer derivatives has determined unambiguously using X-ray crystallographic analysis. Detailed characteristics structures including their metal atom movements also revealed NMR spectroscopic studies computational calculations....
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTReaction of singlet oxygen with disiliranes: dioxygen insertion into silicon-silicon .sigma. bondsWataru Ando, Masahiro Kako, Takeshi Akasaka, and Shigeru NagaseCite this: Organometallics 1993, 12, 5, 1514–1522Publication Date (Print):May 1, 1993Publication History Published online1 May 2002Published inissue 1 1993https://pubs.acs.org/doi/10.1021/om00029a009https://doi.org/10.1021/om00029a009research-articleACS PublicationsRequest reuse...
Eindeutig stützen die hier vorgestellten NMR‐spektroskopischen Befunde aus Berechnungen abgeleiteten Aussagen zur Struktur des endohedralen Komplexes La und C 80 . Danach liegt der Komplex 2 @C vor, sich von dem im „leeren”︁ Zustand instabilsten ‐Isomer – I h ‐symmetrischen ableitet, beiden Lanthanatome zirkulieren in diesem runden Käfig sogar bei Raumtemperatur (rechts schematisch gezeigt). magnified image
Photochemical reactions of Lu(3)N@I(h)-C(80) with disiliranes 1 and 2 produce several isomeric adducts. Spectroscopic analyses characterize the most stable isomers as 1,4(AA) adducts, which consist paired twist conformers at rt. The electrochemical theoretical studies reveal that HOMO-LUMO energy gaps adducts are smaller than because electron-donating groups effectively raise HOMO levels.
N@C60 has a lower photochemical reactivity toward disilirane than C60, although does not differ from C60 in its thermal reactivity; theoretical calculations reveal that and have the same orbital levels N@3C60* shorter lifetime 3C60*.
The photochemical reaction of disilirane with C60 in benzonitrile affords the adduct and as a bis-silylated product. In this reaction, serves sensitizer. results are reasonably accounted for by novel metal-free bis-silylation an unsaturated compound via photoinduced electron-transfer process.