The bonding modes of 2-aminopyridine (apy)
(1 equiv.) with some ruthenium(II) fragments were studied. In the reaction with [RuCp(CH3CN)3]+
(1) one acetonitrile ligand is replaced with apy being κ1(N-pyridine) bonded. This complex is very air-sensitive transforming into dinuclear [RuCp(μ3-dapy)]22+ where dapy is deprotonated apy. On the other hand, [RuCl2(PPh3)3] exchanges one phosphine ligand for apy which is coordinated in the κ2N,N′ mode. Similar to 1, the complexes [RuCp(CH3CN)2L]+(L = PMe3, PPh3 or CO), also react with apy to give [RuCp(CH3CN)(L)(κ1N-apy)]+. These compounds were reacted with HCCPh with appreciable differences depending on L. While with L = CH3CN no clean reaction took place, with L = PMe3 an η3-allyl carbene is formed with release of apy. With L = PPh3 or CO, dapy stabilizes a Fischer carbene through chelation. Finally, if 1 is reacted with 2-N,N-dimethylaminopyridine (dmapy), all acetonitriles are displaced in favor of η6-coordinated dmapy.
研究了2-
氨基吡啶(apy)与一些
铑(II)片段的结合模式。在与[RuCP(CH3CN)3]+(1)的反应中,一个
乙腈配体被κ1(N-
吡啶)结合的apy替换。该复合物对空气非常敏感,转变为二核[RuCP(μ3-dapy)]22+,其中dapy是去质子化的apy。另一方面,[RuCl2(PPh3)3]交换一个
磷配体为apy,后者以κ2N,N′模式配位。与1类似,复合物[RuCP(CH3CN)2L]+(L = PMe3、PPh3或CO)也与apy反应,生成[RuCP(CH3CN)(L)(κ1N-apy)]+。这些化合物与HCCPh反应时,依赖于L有显著差异。当L = CH3CN时,没有发生干净反应;当L = PMe3时,形成η3-烯丙基卡宾并释放apy。若L = PPh3或CO,dapy通过螯合稳定Fischer卡宾。最后,如果将1与2-N,N-二甲
氨基吡啶(dmapy)反应,则所有的
乙腈都被η6配位的dmapy取代。