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991.
The reaction of [60]fullerene with an arylzinc halide in a mixture of THF and DMF produces a mono(2-tetrahydrofuranyl) adduct of [60]fullerene C60(C4H7O)H instead of the expected arylated fullerene. The reaction involves a C-H bond activation at the 2-position of THF that probably takes place through a radical mechanism. In the presence of a copper(I) complex, the reaction does not stop at the stage of mono-addition, with the aryl group of the zinc reagent adding four times regioselectively to the mono(2-tetrahydrofuranyl) adduct to produce a penta-adduct C60Ar4(C4H7O)H. This product can be converted further to the corresponding buckyferrocene Fe[C60Ar4(C4H7O)]Cp and its derivatives. 相似文献
992.
Yutaka Matsuo Dr. Keiko Matsuo Dr. Takeshi Nanao Renata Marczak Dr. S. Shankara Gayathri Dr. Dirk M. Guldi Prof. Dr. Eiichi Nakamura Prof. Dr. 《化学:亚洲杂志》2008,3(5):841-848
New fullerene–ferrocene arrays, [Ru(C60Me5)(C4H6Fc)(CO)2] (Fc=ferrocenyl) and [Ru(C60Me5)(CCFc)(CO)2], in which the ruthenium complex functions as a conjugative bridge, were synthesized by the reaction of [Ru(C60Me5)Cl(CO)2] with FcC6H4MgBr and FcCCLi, respectively. These compounds were investigated by electrochemical measurement, single‐crystal X‐ray structural analysis, and photophysical measurement. Upon photoirradiation, the former compound was converted rapidly into the corresponding triplet state in toluene (τsinglet=21 ps), whereas the charge‐separated state was predominant in THF (τsinglet=10.5 ps; τCS=355 ps). The latter compound, on the other hand, formed the charge‐separated state in both toluene and THF (τsinglet=3.0 ps; τCS=152 ps). Thus, the structural difference between the phenylene and acetylene bridges in 1 and 2 , respectively, was found to change the outcome of the photophysical processes. 相似文献
993.
A total coloring of a graph G is a coloring of all elements of G, i.e., vertices and edges, in such a way that no two adjacent or incident elements receive the same color. Let L(x) be a set of colors assigned to each element x of G. Then a list total coloring of G is a total coloring such that each element x receives a color contained in L(x). The list total coloring problem asks whether G has a list total coloring. In this paper, we first show that the list total coloring problem is NP-complete even for series-parallel graphs. We then give a sufficient condition for a series-parallel graph to have a list total coloring, that is, we prove a theorem that any series-parallel graph G has a list total coloring if |L(v)|min{5,Δ+1} for each vertex v and |L(e)|max{5,d(v)+1,d(w)+1} for each edge e=vw, where Δ is the maximum degree of G and d(v) and d(w) are the degrees of the ends v and w of e, respectively. The theorem implies that any series-parallel graph G has a total coloring with Δ+1 colors if Δ4. We finally present a linear-time algorithm to find a list total coloring of a given series-parallel graph G if G satisfies the sufficient condition. 相似文献
994.
Sakurai S Nishino H Futaba DN Yasuda S Yamada T Maigne A Matsuo Y Nakamura E Yumura M Hata K 《Journal of the American Chemical Society》2012,134(4):2148-2153
Here we show that essentially any Fe compounds spanning Fe salts, nanoparticles, and buckyferrocene could serve as catalysts for single-walled carbon nanotube (SWNT) forest growth when supported on AlO(x) and annealed in hydrogen. This observation was explained by subsurface diffusion of Fe atoms into the AlO(x) support induced by hydrogen annealing where most of the deposited Fe left the surface and the remaining Fe atoms reconfigured into small nanoparticles suitable for SWNT growth. Interestingly, the average diameters of the SWNTs grown from all iron compounds studied were nearly identical (2.8-3.1 nm). We interpret that the offsetting effects of Ostwald ripening and subsurface diffusion resulted in the ability to grow SWNT forests with similar average diameters regardless of the initial Fe catalyst. 相似文献
995.
H Arii M Matsuo F Nakadate K Mochida T Kawashima 《Dalton transactions (Cambridge, England : 2003)》2012,41(36):11195-11200
The reaction of SnCl(2) with the lithio derivative of a bis(oxazoline) ligand precursor afforded the enantiomeric chlorostannylene whose chloride ion can be substituted by several neutral or anionic Lewis donors. Abstraction of the chloride ion from the chlorostannylene with silver salts gave the corresponding tetrahydrofuran (THF) complexes of a chiral tin(ii) cation in 1,2-dimethoxyethane (DME) containing THF. That is, the reaction with silver hexafluoroantimonate (AgSbF(6)) afforded the THF complex without interaction with the counteranion. In contrast, reaction with silver triflate (AgOTf) gave the THF complex whose tin center had a pseudo-trigonal bipyramidal structure with two nitrogen atoms of a bidentate ligand and a lone pair at the equatorial positions and one of the oxygen atoms of triflate and an oxygen atom of THF at the apical positions in the solid state. Use of 3-methyltetrahydrofuran (3-MeTHF) instead of THF afforded the 3-MeTHF complexes, where the R-enantiomer of 3-MeTHF predominantly coordinates to the tin center. The previously reported germanium(ii) analogue of the tin(ii) cation indicated a similar enantioselectivity for the coordination of 3-MeTHF on the germanium center. 相似文献
996.
FeCl3-mediated synthesis of fullerenyl esters as low-LUMO acceptors for organic photovoltaic devices
Hashiguchi M Obata N Maruyama M Yeo KS Ueno T Ikebe T Takahashi I Matsuo Y 《Organic letters》2012,14(13):3276-3279
C(60) reacted with aromatic and aliphatic carboxylic acids in the presence of inexpensive FeCl(3) at room temperature to produce hydroxyfullerenyl esters C(60)(OCOR)(OH) in up to 68% isolated yield. The hydroxyl group was utilized in functional group transformations to obtain a diester derivative C(60)(OCOAr)(OCOPh) (Ar = 2,6-xylyl) and a siloxyl derivative C(60)(OCOAr)(OSiMe(3)). The diester and siloxyl derivatives were found to possess low-lying LUMO levels were utilized in organic photovoltaic devices showing 1.3% power conversion efficiency. 相似文献
997.
Matsuo T Imai C Yoshida T Saito T Hayashi T Hirota S 《Chemical communications (Cambridge, England)》2012,48(11):1662-1664
An L-phenylalanyl chloromethylketone-based inhibitor equipped with a Hoveyda-Grubbs catalyst moiety was regioselectively incorporated into the cleft of α-chymotrypsin through the intrinsic inhibition mechanism of the protein to construct an artificial organometallic protein. 相似文献
998.
Dr. Toshihiro Okamoto Tsuyoshi Suzuki Dr. Hideyuki Tanaka Dr. Daisuke Hashizume Prof. Yutaka Matsuo 《化学:亚洲杂志》2012,7(1):105-111
We have designed and synthesized a new donor/acceptor‐type tetracene derivative by the introduction of dicarboxylic imide and disulfide groups as electron‐withdrawing and ‐donating units, respectively. The prepared compounds, tetracene dicarboxylic imide (TI) and its disulfide (TIDS) have high chemical and electrochemical stability as well as long‐wavelength absorptions of up to 886 nm in the thin films. The crystal packing structure of TIDS molecules features face‐to‐face π‐stacking, derived from dipole–dipole interactions. Notably, TIDS exhibited ambipolar properties of both electron‐donating and ‐accepting natures in p–n and p–i–n heterojunction organic thin‐film photovoltaic devices. Accordingly, TI and TIDS are expected to be promising compounds for designing new organic semiconductors. 相似文献
999.
Efficient carbon-carbon bond formation at the alpha-position of nitrogen was established by one-pot oxidative Mannich reaction of N-carbobenzyloxy (Cbz) amines with 1,3-dicarbonyl compounds using N-tert-butylbenzenesulfinimidoyl chloride as an oxidant. 相似文献
1000.
[reaction: see text] A three-step route from sclareol oxide (6) to bromo ester 4 in 53% overall yield was achieved using the efficient oxidation of an allylic bromide to an enal with bis(2,4,6-trimethylpyridine)silver(I) hexafluorophosphate in DMSO. Stille coupling of bromo ester 4 with stannylpyridine 5 gave the trimethyl ester of ent-thallusin in 54-92% yield by the stoichiometric conversion of 4 to a vinyl palladium intermediate prior to the addition of 5 to the reaction. 相似文献