摘要研究了三(氨基甲基)氧化膦(tampo)对选定过渡金属离子的配位行为。对于金属配比为1:2的Co(III),Ni(II)和Cu(II)配合物,双(三脚架)tampo配位形成八面体配位球(对于Cu(II)配合物X射线衍射分析发现有明显的Jahn-Teller畸变)。根据电位研究,溶液中也可能存在标题配体的三脚架配位。金属配合物的稳定性遵循Irving-Williams趋势。与结构上的“母体” 1,1,1-三(氨基甲基)乙烷(tame)配体相比,由于较低的配体碱度,tampo的络合在较低的pH下发生[log K 1 = 6.72(1),log K 2 = 5.34(1),log K 3 = 3.82(1)],
Lithium-selective phosphine oxide-based ditopic receptors show enhanced halide binding upon alkali metal ion coordination
作者:Jesse V. Gavette、Juven Lara、Linda L. Reling、Michael M. Haley、Darren W. Johnson
DOI:10.1039/c2sc21501b
日期:——
Previous work on a ditopic receptor based on a tripodal phosphine oxide core demonstrated preferential enhancement of bromide binding over chloride or iodide in the presence of lithium cation. Current studies on an elongated receptor provide evidence that preferential bromide binding enhancement in the presence of lithium cation is common to this receptor class in general, and that lengthening of the receptor results in an overall increase in halide association. Furthermore, the extended receptor shows a strong preference for Li+ binding in solution.