Sterically driven synthesis of ruthenium and ruthenium–silver N-heterocyclic carbene complexes
作者:C. Cesari、S. Conti、S. Zacchini、V. Zanotti、M. C. Cassani、R. Mazzoni
DOI:10.1039/c4dt02747g
日期:——
A sterically driven synthetic route from non-bulky silver NHC to novel Ru(NHC) complexes and from bulky Ag(NHC) to unprecedented heterobimetallic Ru–Ag(NHC) complexes is presented.
On the Dual Role of N-Heterocyclic Carbenes as Bases and Nucleophiles in Reactions with Organic Halides
作者:Axel Jacobi von Wangelin、Christiane Knappke、Anthony Arduengo, III、Haijun Jiao、Jörg-Martin Neudörfl
DOI:10.1055/s-0031-1289593
日期:2011.12
nucleophilicities, and sterics of N-heterocyclic carbenes have been studied in reactions of imidazolin-2-ylidenes with organic halides. Highly nucleophilic and less basic carbenes cleanly gave alkylideneimidazolines, the deoxy analogues of Breslow-type intermediates. More basic NHCs engaged in unwanted deprotonation or dehydrohalogenation reactions. N-heterocyclic carbenes - enamines - umpolung - imidazoles - nucleophilicity
Group 10 Metal Dithiolene Bis(isonitrile) Complexes: Synthesis, Structures, Properties, and Reactivity
作者:Antony Obanda、Kendra Valerius、Joel T. Mague、Stephen Sproules、James P. Donahue
DOI:10.1021/acs.organomet.0c00375
日期:2020.8.10
yields [(Ph2C2S–S•)Pt(C≡NtBu)2]+, identified spectroscopically, but in the crystalline state [[(Ph2C2S–S•)Pt(C≡NtBu)2]2]2+ prevails, which forms via axial Pt···S interactions and pyramidalization at the metal. Complete substitution of MeNC from [(Ph2C2S2)Ni(C≡NMe)2] by 2,6-Me2py under forcing conditions yields [(2,6-Me2py)Ni(μ2-η1,η1-S′,η1-S″-S2C2Ph2)]2 (8), which features a folded Ni2S2 core. In most cases
[(Ph 2 C 2 S 2)2 M](M = Ni 2 +,Pd 2 +,Pt 2+)与2当量的RN≡C(R = Me(a),Bn(b), Cy(c),t Bu(d),1-Ad(e),Ph(f))产生[(Ph 2 C 2 S 2)M(C≡NR)2 ](M = Ni 2 +,4a – f; M = Pd 2 +,5a – f; M = Pt 2+,6a – f),它们是空气稳定的,并且可以进行色谱纯化。所有成员均经过晶体学表征。在结构上,随着M从Ni到Pt的变化,趋于逐渐显示出更大的平面性,并且从Ni向Pt移动时,配位C≡NR的C≡N键长适度下降。振动光谱(CH 2氯2溶液)揭示了ν C≡N为[(PH频率2 c ^ 2 s ^ 2)M(C≡NR)2基本上高于游离C = NR的那些],并且随着M从Ni到Pt的增加而增加。这种趋势被解释为是由于M处正电荷的增加,该电荷稳定了配体的线性,电荷分离
Simple synthesis of neutral and cationic Cu-NHC complexes
作者:Bo Liu、Xueji Ma、Feifei Wu、Wanzhi Chen
DOI:10.1039/c4dt02986k
日期:——
Simple synthesis of [(NHC)CuX] and [(NHC)2Cu]PF6 complexes with cheap copper powder in both organic solvent and water is described.
<sup>13</sup>C NMR Spectroscopic Determination of Ligand Donor Strengths Using N-Heterocyclic Carbene Complexes of Palladium(II)
作者:Han Vinh Huynh、Yuan Han、Ramasamy Jothibasu、Jie An Yang
DOI:10.1021/om900667d
日期:2009.9.28
Werner-type and organometallic ligands have been experimentally determined and ranked on a unprecedented unified 13C NMR scale using safe and easily obtainable complexes of the type trans-[PdBr2(iPr2-bimy)L]n− (iPr2-bimy = 1,3-diisopropylbenzimidazolin-2-ylidene; L = ligand in question) as spectroscopic probes. The methodology is based on the sensitivity of the constant iPr2-bimy carbene signal to the
已经通过实验确定了25个Werner型和有机金属配体的电子参数,并使用安全且易于获得的反式-[PdBr 2(i Pr 2 -bimy)L] n-型络合物在前所未有的统一13 C NMR规模上进行了排名(i Pr 2 -bimy = 1,3-二异丙基苯并咪唑啉-2-亚基; L =所讨论的配体)作为光谱探针。该方法基于常数i Pr 2的灵敏度-双生卡宾向不同共配体的供体强度发出信号,与以前的基于羰基的系统相比,它甚至可以更准确地检测到骨架和取代基的作用。为了评估N-杂环卡宾(NHC),介绍了一种一锅法处理带有两个不同NHC的新型杂双(卡宾)配合物。此外,还提出了第一个配合物强效提供的吲唑啉-3-亚基配体。10种复杂探针的分子结构已通过单晶X射线衍射分析进行了表征。