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41.
Shingo KomatsuYouichi Sakamoto Toshiyasu Suzuki Shizuo Tokito 《Journal of solid state chemistry》2002,168(2):470-473
Perfluoro-1,3,5-tris(p-quaterphenyl)benzene (PF-13Y) and perfluoro-1,3,5-tris(p-quinquephenyl)benzene (PF-16Y) have been synthesized and characterized. They showed higher glass transition temperatures compared with perfluoro-1,3,5-tris(p-terphenyl)benzene (PF-10Y). Organic light-emitting diodes were fabricated using these materials as the electron-transport layers. PF-13Y and -16Y are better electron transporters than PF-10Y. The electron mobilities of PF-10Y and Alq3 were measured by the time-of-flight technique. PF-10Y showed higher electron mobilities (10−4 cm2/V s) and weaker electric field dependence compared with Alq3. 相似文献
42.
Miyasaka H Nezu T Sugimoto K Sugiura K Yamashita M Clérac R 《Inorganic chemistry》2004,43(18):5486-5488
Heterometallic linear tetramers [Mn(5-R-saltmen)Ni(pao)(bpy)(2)](2)(ClO(4))(4) (5-R-saltmen(2-) = N,N'-1,1,2,2-tetramethylethylene bis(5-R-salicylideneiminate); pao(-) = pyridine-2-aldoximate; bpy = 2,2'-bipyridine, R = H, 1; Cl, 2; Br, 3; MeO, 4) have been synthesized and structurally characterized. These compounds exhibit a [Ni(II)-NO-Mn(III)-(O)(2)-Mn(III)-ON-Ni(II)] skeleton where -ON- is an oximate bridge between Mn(III) and Ni(II) ions and -(O)(2)- is a bi-phenolate bridge between Mn(III) ions. These tetramers can be seen as oligomeric units of the heterometallic Mn(III)(2)-Ni(II) chain observed in a family of single-chain magnets (Clérac, R.; Miyasaka, H.; Yamashita, M.; Coulon, C. J. Am. Chem. Soc. 2002, 124, 12837. Miyasaka, H.; Clérac, R.; Mizushima, K.; Sugiura, K.; Yamashita, M.; Wernsdorfer, W.; Coulon, C. Inorg. Chem. 2003, 42, 8203.). Magnetic measurements on these tetramers confirm the nature of the magnetic interactions reported for the Mn(III)(2)-Ni(II) chains: a strong antiferromagnetic Mn(III)/Ni(II) coupling via the oximate bridge (J(Ni-Mn) ranges from -23.7 to -26.1 K) and a weak ferromagnetic Mn(III)/Mn(III) coupling through the bi-phenolate bridge (J(Mn-Mn) ranges from +0.4 to +0.9 K). These magnetic interactions lead to tetramers with an S = 2 ground state. 相似文献
43.
Miyasaka H Nezu T Sugimoto K Sugiura K Yamashita M Clérac R 《Chemistry (Weinheim an der Bergstrasse, Germany)》2005,11(5):1592-1602
Mn(III)-Ni(II)-Mn(III) linear-type trinuclear complexes bridged by oximate groups were selectively synthesized by the assembly reaction of [Mn2(5-Rsaltmen)2(H2O)2](ClO4)2 (5-Rsaltmen2-=N,N'-(1,1,2,2-tetramethylethylene) bis(5-R-salicylideneiminate); R=Cl, Br) with [Ni(pao)2(phen)] (pao-=pyridine-2-aldoximate; phen=1,10-phenanthroline) in methanol/water: [Mn2(5-Rsaltmen)2Ni(pao)2(phen)](ClO4)2 (R=Cl, 1; R=Br, 2). Structural analysis revealed that the [Mn(III)-ON-Ni(II)-NO-Mn(III)] skeleton of these trimers is in every respect similar to the repeating unit found in the previously reported series of 1D materials [Mn2(saltmen)2Ni(pao)2(L1)2](A)(2) (L(1)=pyridine, 4-picoline, 4-tert-butylpyridine, N-methylimidazole; A=ClO4-, BF4-, PF6-, ReO4-). Recently, these 1D compounds have attracted a great deal of attention for their magnetic properties, since they exhibit slow relaxation of the magnetization (also called single-chain magnet (SCM) behavior). This unique magnetic behavior was explained in the framework of Glauber's theory, generalized for chains of ferromagnetically coupled anisotropic spins. Thus, in these 1D compounds, the [Mn(III)-ON-Ni(II)-NO-Mn(III)] unit was considered as an S(T)=3 anisotropic spin. Direct-current magnetic measurements on 1 and 2 confirm their S(T)=3 ground state and strong uniaxial anisotropy (D/k(B) approximately -2.4 K), in excellent agreement with the magnetic characteristic deduced in the study on the SCM series. The ac magnetic susceptibility of these trimers is strongly frequency-dependent and characteristic of single-molecule magnet (SMM) behavior. The relaxation time tau shows a thermally activated (Arrhenius) behavior with tau0 approximately 1x10(-7) s and Delta(eff)/k(B) approximately 18 K. The effective energy barrier for reversal of the magnetization Delta(eff) is consistent with the theoretical value (21 K) estimated from |D| S2T. The present results reinforce consistently the interpretation of the SCM behavior observed in the [Mn2(saltmen)2Ni(pao)2(L1)2](A)2 series and opens new perspectives to design single-chain magnets. 相似文献
44.
A mononuclear five-coordinate molybdenum(IV) monosulfide complex, (Et4N)2[MoS(L)2] (L = cyclohexene-1,2-dithiolate) (1), was obtained and characterized by IR, UV-vis spectroscopic methods, and X-ray crystallography. 1 was oxidized by an equivalent ferrocenium cation to give the corresponding mononuclear molybdenum(V) complex, (Et4N)[MoS(L)2] (2), which was stable for a few minutes under a lower concentration than 0.3 mM and then further dimerized to (Et4N)2[Mo(L)2]2(mu-S)2 (3). 相似文献
45.
Seiichi Nakamura Jun Inagaki Tomohiro Sugimoto Yasuyuki Ura Shunichi Hashimoto 《Tetrahedron》2002,58(52):10375-10386
An efficient, highly stereoselective synthesis of the C10–C31 (BCDEF ring) portion of pinnatoxin A has been achieved utilizing tandem double hemiketal formation/intramolecular hetero-Michael addition to construct the 6,5,6-dispiroketal (BCD ring) system and subsequent intramolecular ketalization to form the 5,6-bicycloketal (EF ring) system as key steps. 相似文献
46.
Miyoji Hanaoka Shingo Yasuda Kazuyoshi Nagami Keiko Okajima Takeshi Imanishi 《Tetrahedron letters》1979,20(39):3749-3752
Irradiation of the berberinephenolbetaines (, , and ) effected valence tautomerization to give the 8,14-cycloberbines (, , and ), the aziridine derivatives, in high yield. The 8,14-cycloberbines were efficiently converted to the spirobenzylisoquinolines by regioselective C bond cleavage. 相似文献
47.
Ruthenium‐Catalyzed Cycloisomerization of 2,2′‐Diethynyl‐ biphenyls Involving Cleavage of a Carbon–Carbon Triple Bond
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Prof. Dr. Takanori Matsuda Kotaro Kato Tsuyoshi Goya Shingo Shimada Prof. Dr. Masahiro Murakami 《Chemistry (Weinheim an der Bergstrasse, Germany)》2016,22(6):1941-1943
A ruthenium complex catalyzes a new cycloisomerization reaction of 2,2′‐diethynylbiphenyls to form 9‐ethynylphenanthrenes, thereby cleaving the carbon–carbon triple bond of the original ethynyl group. A metal–vinylidene complex is generated from one of the two ethynyl groups, and its carbon–carbon double bond undergoes a [2+2] cycloaddition with the other ethynyl group to form a cyclobutene. The phenanthrene skeleton is constructed by the subsequent electrocyclic ring opening of the cyclobutene moiety. 相似文献
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