Navrátil Michal, Císařová Ivana, Štěpnička Petr
Department of Inorganic Chemistry, Faculty of Science, Charles University, Hlavova 2030, 128 40 Prague, Czech Republic.
Dalton Trans. 2022 Oct 4;51(38):14618-14629. doi: 10.1039/d2dt02514k.
Combining a phosphinoferrocene fragment with extended multidonor moieties affords novel, flexible multidonor pro-ligands. This contribution describes the synthesis of two structurally similar functional phosphines, PhPfcNHC(O)CHPPh (1) and PhPfcNHCHCHPPh (2, fc = ferrocene-1,1'-diyl), and their coordination behaviour towards Pd(II). The former amidophosphine reacts with [PdCl(MeCN)] to produce the chelate complex [PdCl(1-κ,')] as a mixture of and isomers, which convert into bis-chelate [PdCl(PhPfcNC(O)CHPPh-κ,',)] upon reacting with a strong base (KO-Bu). In contrast, the more flexible and more basic phosphinoamine 2 directly forms the cationic bis-chelate complex [PdCl(2-κ,',)]Cl spontaneous self-ionisation. Subsequent halogen abstraction with Ag[SbF] results either in counter ion exchange to give [PdCl(2-κ,',)][SbF] or in the formation of a structurally unique complex [PdCl(2-κ,,',)][SbF] with an Fe → Pd dative interaction, depending on the amount of silver(I) salt used (1 or 2 equiv.).
将膦基二茂铁片段与扩展的多供体部分相结合，可得到新型的、灵活的多供体前体配体。本文描述了两种结构相似的功能性膦PhPfcNHC(O)CHPPh (1)和PhPfcNHCHCHPPh (2, fc = 二茂铁-1,1'-二亚基)的合成及其与Pd(II)的配位行为。前一种酰胺膦与[PdCl(MeCN)]反应生成螯合配合物[PdCl(1-κ,')]，为 和 异构体的混合物，在与强碱(KO-Bu)反应时转化为双螯合[PdCl(PhPfcNC(O)CHPPh-κ,',)]。相比之下，更灵活且碱性更强的膦基胺2通过自发的自电离直接形成阳离子双螯合配合物[PdCl(2-κ,',)]Cl。随后用Ag[SbF]进行卤素抽取，根据所用银(I)盐的量(1或2当量)，要么导致反离子交换生成[PdCl(2-κ,',)][SbF]，要么形成具有Fe→Pd给体相互作用的结构独特的配合物[PdCl(2-κ,,',)][SbF]。
