已发现一个1 on 8硼烷修饰的萘分子2与N,N'-二甲基咪唑-2-亚烷基(IMe)反应,该化合物是N-杂环卡宾(NHC)家族的流行成员,可以将其转化分为两个乙烯基胺片段,其中一个通过形成C-C和B-N键而被困在phospho和硼烷单元之间。对于较大的NHC分子未观察到相同的反应性。对照实验和机理研究确定,除了IMe卡宾外,叶立烷-硼烷分子和咪唑鎓盐还参与了NHC的这一新转化。
A Dual-Emissive Phosphine–Borane Lewis Pair with a U-Shaped Linker: Impact of Methylation and Complexation on Fluoride Binding Affinity
摘要:
To investigate phosphine to borane through-space charge transfer and its utility in anion sensing and the formation of metal complexes, a phosphine-borane Lewis pair (1) connected by a U-shaped linker has been synthesized. 1 could be readily converted to a phosphonium salt (2) and two 2:1 complexes with Au(I) (1-Au) and Pt(II) (1-Pt). The photophysical properties of the new compounds were examined and compared. Compound 1 displayed an intense P -> B CT transition and a bright solvent-dependent dual emission that is switchable by fluoride ions. 2 and 1-Pt showed a turn-off and a turn-on fluorescent response, respectively, toward fluoride ions. The binding constant of 2 with F- was found to be 2 orders of magnitude greater than that of 1. The mechanism that is responsible for the distinct fluorescence response of 1, 2, and 1-Pt toward fluoride ions is proposed.