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排序方式: 共有313条查询结果,搜索用时 0 毫秒
151.
Shotaro Iwata Hidenori Takahashi Asami Ihara Kumiko Hiramatsu Junya Adachi Soichiro Kawamorita Naruyoshi Komiya Takeshi Naota 《Transition Metal Chemistry》2018,43(2):115-125
The syntheses, structures, and solid-state emission characteristics of trans-bis(salicylaldiminato)Pt(II) complexes bearing N-aromatic functionalities are described herein. A series of Pt complexes bearing various N-phenyl (1) and N-(1-naphthyl) (2) groups on the salicylaldiminato ligands were prepared by reacting PtCl2(CH3CN)2 with the corresponding N-salicylidene aromatic amines, and the trans-coordination and crystal packing of these complexes were unequivocally established based on X-ray diffraction (XRD). Complexes with 2,6-dimethylphenyl (1c), 2,6-diisopropylphenyl (1d), 1-naphthyl (2a), and 1-(2-methylnaphthyl) (2b) groups on the N atoms exhibited intense phosphorescent emission at ambient temperature in the crystalline state, while those with phenyl (1a), 2,6-dibromophenyl (1b), and 2,6-bis(N,N-dimethylamino)phenyl (1e) functionalities were either less emissive or non-emissive under the same conditions. XRD analyses identified significant intramolecular interactions between Pt and H atoms of the N-aryl functionalities in the emissive crystals of 1c, 1d, and 2a. These interactions were evidently an important factor associated with intense emission at ambient temperature. 相似文献
152.
Kumiko Nishioka 《Monatshefte für Mathematik》1997,123(2):135-148
Algebraic independence of the numbers
, where{R
n
}
n
0 is a sequence of integers satisfying a binary linear recurrence relation, is studied by Mahler's method. 相似文献
153.
154.
Sensuke Ogoshi Takuma Nishida Yoshiaki Fukunishi Ken Tsutsumi Hideo Kurosawa 《Journal of organometallic chemistry》2001,620(1-2):190-193
Isomerization of phenyl-substituted propargylplatinum(II) complex, trans-Pt(CH2CCPh)(Cl)(PPh3)2 (1) to allenyl complex, trans-Pt(CPh=C=CH2)(Cl)(PPh3)2 (2) was found to be catalyzed by zerovalent complex Pd(PPh3)4. The reaction was proposed to proceed through the transfer of the propargyl/allenyl ligand both from Pt(II) to Pd(0) and Pd(II) to Pt(0). The former transfer, which seemingly has a thermodynamic disadvantage, has unambiguously been confirmed to take place; treatment of 1 with Pd(PPh3)4 or a mixture of Pd2(dba)3 and PPh3 resulted in the formation of Pd(I) complex, Pd2(μ-PhCCCH2)(μ-Cl)(PPh3)2 which lies in equilibrium with a mixture of propargyl/allenylpalladium(II) and Pd(0) complexes. 相似文献
155.
S Ogoshi T Yoshida T Nishida M Morita H Kurosawa 《Journal of the American Chemical Society》2001,123(9):1944-1950
The reaction of alpha,beta-unsaturated carbonyl compounds, a palladium(0) complex, and Lewis acids led to the formation of a new class of complexes showing a wide variety of structures with eta(2)-type and eta(3)-type coordination of the carbonyl compounds. The reaction of Pd(PhCH=CHCOCH(3))(PPh(3))(2) with BF(3).OEt(2) or B(C(6)F(5))(3) quantitatively gave palladium complexes 1a,b having BX(3)-coordinated eta(2)-enonepalladium structure, as revealed by X-ray structure analysis of the B(C(6)F(5))(3) adduct 1b. On the other hand, the reaction of Pd(PhCH=CHCHO)(PPh(3))(2) with BF(3).OEt(2) or B(C(6)F(5))(3) gave distorted zwitterionic eta(3)-allylpalladium complexes 3a,b, where the Pd-carbonyl carbon distance in 3a (2.413(4) A) is much shorter than that (2.96(1) A) in 1b. The values of the P-P coupling constant and (13)C chemical shift for carbonyl carbon are useful criteria for predicting how the eta(3)-coordination mode contributes to the structure of the enone-palladium-Lewis acid system. Molecular orbital calculations on the series of model complexes suggest that orbital overlap in the highest occupied molecular orbital between the palladium and carbonyl carbon is enlarged by coordination of the Lewis acid to the carbonyl group. Palladium-catalyzed conjugate addition of R-M (R-M = AlMe(3), AlEt(3), ZnEt(2)) and its plausible reaction path are also reported. 相似文献
156.
Shojiro Kaita Kumiko Matsushita Morika Tobita Yooichiroh Maruyama Yasuo Wakatsuki 《Macromolecular rapid communications》2006,27(20):1752-1756
Summary: In non‐polar solvents such as toluene, Cp‐Ni and ‐Pd complexes (Cp = η5‐C5H5) with appropriate activators have been found to induce the addition polymerization of norbornene in excellent yields, for example (Cp)Pd(allyl)/[Ph3C][B(C6F5)4] gave 105 120 kg‐polymer/cat‐mol · h at room temperature. While the Cp‐Pd system was not suitable in the presence of ester‐substituted norbornenes, the Cp‐Ni system, for example (Cp)Ni(Cl)(PPh3)/AlMe3/B(C6F5)3 can copolymerize norbornene with 5‐norbornene‐2‐carboxylic acid methyl ester in toluene to give high yields (up to 68% in 2 h at room temperature) of copolymer with variable contents of the methyl ester monomer unit (17.4–60.7 mol‐%). These copolymers have high molecular weights ( = 234 100–109 500) and narrow molecular weight distributions ( = 1.78–1.89). In addition, they are soluble in common organic solvents giving flexible and transparent films on casting, that show very high Tg in the range of 352.8 to 316.0 °C. The same Ni‐catalyst system can also copolymerize norbornene derivatives with bulky substituents, i.e., 2‐butyl‐5‐norbornene and 5‐norbornene‐2‐carboxylic acid butyl ester. The Tg of these copolymers are lower (294.9–267.3 °C) than the methyl ester‐based copolymers, demonstrating that the Tg of the polynorbornene copolymer film can be tailored simply by changing the alkyl group of the monomer to within the range of 352 to 267 °C.
157.
Murahashi T Usui K Tachibana Y Kimura S Ogoshi S 《Chemistry (Weinheim an der Bergstrasse, Germany)》2012,18(29):8886-8890
Sandwich time! The mixed-metal triangular-trinuclear sandwich complexes of Pd(2)Pt and PdPt(2) were selectively synthesized. The Pd(2)Pt and PdPt(2) triangles in a cycloheptatrienyl sandwich framework were identified by (31)P?NMR analyses of the tris-triphenylphosphine complexes (see scheme). 相似文献
158.
Ogoshi T Yamafuji D Aoki T Yamagishi TA 《Chemical communications (Cambridge, England)》2012,48(54):6842-6844
A [2]rotaxane constructed from a per-ethylated pillar[6]arene as a wheel and a pyridinium derivative as an axle was prepared. The wheel segment of the per-ethylated pillar[6]arene moved from one station to another along the axle as a result of thermal stimuli. 相似文献
159.
160.
Ogoshi T Takashima Y Yamaguchi H Harada A 《Chemical communications (Cambridge, England)》2006,(35):3702-3704
Water-soluble poly(phenylene ethynylene) carrying beta-cyclodextrin was prepared; the polymer exhibited a fluorescence color change or quenching, depending on the kind of guest. 相似文献