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排序方式: 共有2495条查询结果,搜索用时 265 毫秒
941.
In this paper, the concept of right generalized semi-w-regular rings is defined. We prove that these rings are non-trival generalizations of both right GP-injective rings and semi- π-regular rings. Some properties of these rings are studied and some results about generalized semiregular rings and GP-injective rings are extended. 相似文献
942.
The new ferrole Fe2(CO)6[μ-η2,η4-(Fc)CC{C(H)C(R)S}CC(SiMe3)] [R = SiMe3 (1) and R = Fc (2)] and ruthenoles Ru2(CO)6[μ-η2,η4-(Me3Si)CC{SC(Fc)C(H)}CC(Fc)] 3 and Ru2(CO)6[μ-η2,η4-(Me3Si)CC(SCCFc)C(H)C(Fc)] 4, have been obtained from the reactions of M3(CO)12 (M = Fe, Ru) and FcCCSCCSiMe3 through S-C bond activations and C-C coupling reactions. Thermolysis of Ru2(CO)6[μ3-η2,η4,η3-(Me3Si)CC{SC(Fc)C(SCCSiMe3}Ru(CO)3}CC(Fc)] alone and in the presence of HCCFc, yielded the compounds Ru2(CO)6[μ-η2,η4-(Me3Si)CC{SC(Fc)C(SCCSiMe3)}CC(Fc)] 5 and Ru2(CO)6[μ-η2,η4-(Me3Si)CC{SC(Fc)C(SCCSiMe3)C(H)C(Fc)}CC(Fc)] 6, respectively. The crystal structures of the compounds 1, 3, 4 and 6 are reported. 相似文献
943.
Yusuke Ohba Mayuko Takatsuji Kenji Nakahara Hiromichi Fujioka Dr. Yasuyuki Kita Prof. Dr. 《Chemistry (Weinheim an der Bergstrasse, Germany)》2009,15(14):3526-3537
Facile and efficient macrolactonization of hydroxycarboxylic acid via ethoxyvinyl esters (EVEs), which can give 9‐ to 14‐membered macrolactones in good yields, has been developed (see scheme; DCE = 1,2‐dichloroethane). The method is useful for acid‐/base‐sensitive substrates and applicable to the compound with many functional groups.
944.
Ines Raabe Dr. Katrin Wagner Kristin Guttsche Mingkui Wang Dr. Michael Grätzel Prof. Dr. Gustavo Santiso‐Quiñones Dr. Ingo Krossing Prof. Dr. 《Chemistry (Weinheim an der Bergstrasse, Germany)》2009,15(8):1966-1976
Weak and robust ? Tetraalkylammonium salts of weakly coordinating fluorinated alkoxyaluminates are easily accessible, chemically robust materials that show interesting physico‐chemical properties like low melting points, high electrochemical stability and electric conductivity in weakly polar solvents such as CH2Cl2, Ph‐F and toluene.
945.
戴执中 《南昌大学学报(理科版)》2015,39(2):103
对有乘法单位元的交换环上的非精简显赋值定义一种"完全性"。首先就Von Neumann正则环成为完全赋值环给出一个充分必要条件(定理1);并对正则的完全赋值环证明在它的代数扩环上也能给出完全的拓展赋值(定理2)。其次,再对另一种特殊的环给出与定理1和定理2相同的结论(定理3,4)。更多还原 相似文献
946.
We introduce, in this paper, the right weakly p.p. rings as the generalization of right p.p. rings. It is shown that many properties of the right p.p. rings can be extended onto the right weakly p.p. rings. Relative examples are constructed. As applications, we also characterize the regular rings and the semisimple rings in terms of the right weakly p.p. rings. 相似文献
947.
Going Homoleptic: Synthesis and Full Characterization of Stable Manganese Tetranitrosyl Cation Salts
Jan Bohnenberger Brandon Derstine Michael Daub Ingo Krossing 《Angewandte Chemie (International ed. in English)》2019,58(28):9586-9589
Although similar to carbon monoxide, the chemistry of homoleptic nitrogen monoxide complexes is fundamentally unexplored compared to their carbonyl analogues. Herein we report the synthesis of the first truly homoleptic transition‐metal nitrosyl cation as the salt of the weakly coordinating anions (WCAs) [Al(ORF)4]? and [F{Al(ORF)3}2]? (RF=C(CF3)3). These salts are easily accessible in good yields, phase pure, and were fully characterized by IR/Raman, NMR and UV/Vis spectroscopy as well as single‐crystal and powder X‐ray diffraction. They may serve as unprecedented simple model systems for theoretical and experimental studies of nitrosyl complexes. 相似文献
948.
Mark Niemann Beate Neumann Hans‐Georg Stammler Berthold Hoge 《Angewandte Chemie (International ed. in English)》2019,58(26):8938-8942
Weakly coordinating anions (WCAs) are important for academic reasons as well as for technical applications. Tetrakis(pentafluoroethyl)gallate, [Ga(C2F5)4]?, a new WCA, is accessible by treatment of [GaCl3(dmap)] (dmap=4‐dimethylaminopyridine) with LiC2F5. The anion [Ga(C2F5)4]? proved to be reluctant towards deterioration by aqueous hydrochloric acid or lithium hydroxide. Various salts of [Ga(C2F5)4]? were synthesized with cations such as [PPh4]+, [CPh3]+, [(O2H5)2(OH2)2]2+, and [Li(dec)2]+ (dec=diethyl carbonate). Thermolysis of [(O2H5)2(OH2)2][Ga(C2F5)4]2 gives rise to a dihydrate of tris(pentafluoroethyl)gallane, [Ga(C2F5)3(OH2)2]. All products were characterized by NMR and IR spectroscopy, mass spectrometry, X‐ray diffraction, and elemental analysis. Furthermore, an outlook for the application of [Li(dec)2][Ga(C2F5)4] as a conducting salt in lithium‐ion batteries is presented. 相似文献
949.
Herein, we present a new synthetic approach to achieve selective supramolecular transformations and construct different interlocked metallacycles featuring a π‐electron‐deficient thiazolo[5,4‐d]thiazole‐derived ligand. We demonstrate that the formation of mono‐rings, interlocked rings ([2]catenanes) and Borromean rings can be controlled by adjusting the length of the binuclear half‐sandwich RhIII and IrIII building blocks. Furthermore, a concentration effect or D‐A stacking interaction between the pyrene guest and the thiazolo[5,4‐d]thiazole‐based ligand promotes a unique and reversible conversion between catenane structures and metalla‐rectangles. The synthetic results are supported by single‐crystal X‐ray diffraction analysis. 相似文献
950.