共查询到20条相似文献,搜索用时 453 毫秒
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Matthias Driess Markus Faulhaber Hans Pritzkow 《Angewandte Chemie (International ed. in English)》1997,36(17):1892-1894
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Inside Back Cover: Concurrent Stabilization of π‐Donor and π‐Acceptor Ligands in Aromatized and Dearomatized Pincer [(PNN)Re(CO)(O)2] Complexes (Angew. Chem. Int. Ed. 32/2014) 下载免费PDF全文
Michael G. Mazzotta Dr. Kothanda Rama Pichaandi Dr. Phillip E. Fanwick Prof. Dr. Mahdi M. Abu‐Omar 《Angewandte Chemie (International ed. in English)》2014,53(32):8523-8523
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Werner H 《Angewandte Chemie (International ed. in English)》2004,43(8):938-954
Until recently, tertiary phosphanes, arsanes, and stibanes were considered to bind to transition-metal centers only in a terminal coordination mode. Investigations on the reactivity of square-planar trans-[RhCl(=CRR')(L)(2)] compounds revealed that compounds in which L=SbiPr(3) can be converted upon heating into dinuclear complexes [Rh(2)Cl(2)(micro-CRR')(2)(micro-SbiPr(3))] with the carbene and stibane ligands in bridging positions. Although attempts to replace the stibane in these complexes with a tertiary arsane or phosphane failed, substitution of the chloro ligands for acetylacetonates followed by bridge-ligand exchange allowed the preparation of the phosphane- and arsane-bridged compounds [Rh(2)(acac)(2)(micro-CRR')(2)(micro-PR(3))] and [Rh(2)(acac)(2)(micro-CRR')(2)(micro-AsMe(3))]. The acac ligands can be replaced by anionic Lewis bases to give either monomeric [Rh(2)X(2)(micro-CRR')(2)(micro-ER(3))] or dimeric chain-like [XRh(micro-CRR')(2)(micro-ER(3))Rh(micro-X)(2)Rh(micro-CRR')(2)(micro-ER(3))RhX] molecules. 相似文献
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Prof. Jamie L. Manson Michelle L. Warter Dr. John A. Schlueter Dr. Tom Lancaster Andrew J. Steele Prof. Stephen J. Blundell Dr. Francis L. Pratt Dr. John Singleton Dr. Ross D. McDonald Dr. Changhoon Lee Prof. Myung‐Hwan Whangbo Alex Plonczak 《Angewandte Chemie (International ed. in English)》2011,50(7):1726-1726
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Protic N‐Heterocyclic Carbene Versus Pyrazole: Rigorous Comparison of Proton‐ and Electron‐Donating Abilities in a Pincer‐Type Framework 下载免费PDF全文
Tatsuro Toda Akihiro Yoshinari Prof. Dr. Takao Ikariya Prof. Dr. Shigeki Kuwata 《Chemistry (Weinheim an der Bergstrasse, Germany)》2016,22(46):16675-16683
Evaluation of the acidity of proton‐responsive ligands such as protic N‐heterocyclic carbenes (NHCs) bearing an NH‐wingtip provides a key to understanding the metal–ligand cooperation in enzymatic and artificial catalysis. Here, we design a CNN pincer‐type ruthenium complex 2 bearing protic NHC and isoelectronic pyrazole units in a symmetrical skeleton, to compare their acidities and electron‐donating abilities. The synthesis is achieved by direct C?H metalation of 2‐(imidazol‐1‐yl)‐6‐(pyrazol‐3‐yl)pyridine with [RuCl2(PPh3)3]. 15N‐Labeling experiments confirm that deprotonation of 2 occurs first at the pyrazole side, indicating clearly that the protic pyrazole is more acidic than the NHC group. The electrochemical measurements as well as derivatization to carbonyl complexes demonstrate that the protic NHC is more electron‐donating than pyrazole in both protonated and deprotonated forms. 相似文献
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Back Cover: Peroxide Coordination of Tellurium in Aqueous Solutions (Chem. Eur. J. 9/2016) 下载免费PDF全文
Dr. Alexey A. Mikhaylov Dr. Alexander G. Medvedev Dr. Andrei V. Churakov Dmitry A. Grishanov Dr. Petr V. Prikhodchenko Prof. Dr. Ovadia Lev 《Chemistry (Weinheim an der Bergstrasse, Germany)》2016,22(9):3184-3184
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Inside Back Cover: The Formazanate Ligand as an Electron Reservoir: Bis(Formazanate) Zinc Complexes Isolated in Three Redox States (Angew. Chem. Int. Ed. 16/2014) 下载免费PDF全文
Mu‐Chieh Chang Thomas Dann Dr. David P. Day Dr. Martin Lutz Dr. Gregory G. Wildgoose Dr. Edwin Otten 《Angewandte Chemie (International ed. in English)》2014,53(16):4249-4249
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Dr. Erli Lu Dr. Oliver J. Cooper Dr. Jonathan McMaster Dr. Floriana Tuna Prof. Eric J. L. McInnes Dr. William Lewis Prof. Alexander J. Blake Prof. Stephen T. Liddle 《Angewandte Chemie (International ed. in English)》2014,53(26):6696-6700
We report the uranium(VI) carbene imido oxo complex [U(BIPMTMS)(NMes)(O)(DMAP)2] ( 5 , BIPMTMS=C(PPh2NSiMe3)2; Mes=2,4,6‐Me3C6H2; DMAP=4‐(dimethylamino)pyridine) which exhibits the unprecedented arrangement of three formal multiply bonded ligands to one metal center where the coordinated heteroatoms derive from different element groups. This complex was prepared by incorporation of carbene, imido, and then oxo groups at the uranium center by salt elimination, protonolysis, and two‐electron oxidation, respectively. The oxo and imido groups adopt axial positions in a T‐shaped motif with respect to the carbene, which is consistent with an inverse trans‐influence. Complex 5 reacts with tert‐butylisocyanate at the imido rather than carbene group to afford the uranyl(VI) carbene complex [U(BIPMTMS)(O)2(DMAP)2] ( 6 ). 相似文献
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Cabeza JA del Río I García-Granda S Martínez-Méndez L Pérez-Carreño E 《Chemistry (Weinheim an der Bergstrasse, Germany)》2005,11(20):6040-6052
The reactions of the hydrido-triruthenium cluster complex [Ru3(mu-H)(mu3-kappa(2)-HNNMe2)(CO)9] (1; H2NNMe2 = 1,1-dimethylhydrazine) with alkynes that have alpha-hydrogen atoms give trinuclear derivatives containing edge-bridging allyl or face-capping alkenyl ligands. Under mild conditions (THF, 70 degrees C) the isolated products are as follows: [Ru3(mu3-kappa(2)-HNNMe2)(mu-kappa(3)-1-syn-Me-3-anti-EtC3H3)(mu-CO)2(CO)6] (2) and [Ru3(mu3-kappa(2)-HNNMe2)(mu-kappa(3)-1-syn-Me-3-syn-EtC3H3)(mu-CO)2(CO)6] (3) from 3-hexyne; [Ru3(mu3-kappa(2)-HNNMe2)(mu-kappa(3)-3-anti-PhC3H4)(mu-CO)2(CO)6] (4), [Ru3(mu3-kappa(2)-HNNMe2)(mu-kappa(2)-MeCCHPh)(mu-CO)2(CO)6] (5) and [Ru3(mu3-kappa(2)-HNNMe2)(mu3-kappa(2)-PhCCHMe)(mu-CO)2(CO)6] (6) from 1-phenyl-1-propyne; [Ru3(mu3-kappa(2)-HNNMe2)(mu-kappa(2)-3-anti-PrC3H4)(mu-CO)2(CO)6] (7), [Ru3(mu3-kappa(2)-HNNMe2)(mu3-kappa(2)-BuCCH2)(mu-CO)2(CO)6] (8), and [Ru3(mu3-kappa(2)-HNNMe2)(mu3-kappa(2)-HCCHBu)(mu-CO)2(CO)6] (9) from 1-hexyne; [Ru3(mu3-kappa(2)-HNNMe2)(mu3-kappa(2)-HOH2CCCH2)(mu-CO)2(CO)6] (10) from propargyl alcohol; and [Ru3(mu3-kappa(2)-HNNMe2)(mu3-kappa(2)-MeOCH2CCH2)(mu-CO)2(CO)6] (11) from 3-methoxy-1-propyne. The regioselectivity of these reactions depends upon the nature of the alkyne reagent, which affects considerably the kinetic barriers of important reaction steps and the stability of the final products. It has been established that the face-capped alkenyl derivatives are not precursors to the allyl products, which are formed via edge-bridged alkenyl intermediates. At higher temperature (toluene, 110 degrees C), the complexes that have allyl ligands with an anti substituent are isomerized into allyl derivatives with that substituent in the syn position, for example, 4 into [Ru3(mu3-kappa(2)-HNNMe2)(mu-kappa(3)-3-syn-PhC3H4)(mu-CO)2(CO)6] (14). The diene complex [Ru3(mu-H)(mu3-kappa(2)-HNNMe2)(mu-kappa(4)-trans-EtC4H5)(CO)7] (13) has been obtained from the thermolysis of compounds 2 and 7 at 110 degrees C (3 and [Ru3(mu3-kappa(2)-HNNMe2)(mu-kappa(2)-3-syn-PrC3H4)(mu-CO)2(CO)6] (12) are also formed in these reactions). A DFT theoretical study has allowed a comparison of the thermodynamic stabilities of isomeric compounds and has helped rationalize the experimental results. Mechanistic proposals for the synthesis of the allyl complexes and their isomerization processes are also provided. 相似文献
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Cover Picture: Coordination Chemistry of N‐Heterocyclic Nitrenium‐Based Ligands (Chem. Eur. J. 19/2015) 下载免费PDF全文
Dr. Yuri Tulchinsky Dr. Sebastian Kozuch Dr. Prasenjit Saha Assaf Mauda Dr. Gennady Nisnevich Dr. Mark Botoshansky Dr. Linda J. W. Shimon Prof. Mark Gandelman 《Chemistry (Weinheim an der Bergstrasse, Germany)》2015,21(19):6965-6965