手性八配位镧系络合物的立体化学与固体CD光谱

Abstract

本文立体选择性地合成了八配位ln(Ⅲ)络合物[Eu(dbM)3lrr](1)、[Eu(dbM)3lSS](2)和[Tb(dbM)3lrr](3)(lrr/lSS=(-)/(+)-4,5-蒎烯基联吡啶,HdbM=二苯甲酰甲烷),利用单晶衍射、uV-VIS和固体Cd光谱对其进行了表征.晶体结构分析和固体Cd光谱表明1和2互为对映体.采用激子手性方法,通过与六配位和七配位的β-二酮络合物的固体Cd光谱的对比,提出含β-二酮的八配位ln(III)络合物的绝对构型关联规则.该系列络合物的畸变四方反棱柱的Δ或Λ绝对构型也被其单晶结构所证实.

Eight-coordinate chiral lanthanide complexes [Eu(dbm3LRR](1),[Eu(dbm)3LSS](2) and [Tb(dbm)3LRR](3) (LRR/L SS=(-)/(+)-4,5-pineno-2,2'-bipyridine,Hdbm=dibenzoylmethane) were synthesized stereoselectively,which were characterized by UV-vis,CD spectra and X-ray single-crystal diffraction.The mirror-image structure features of the complexes 1 and 2 were obtained by combination of the solid-state CD spectra and the crystal structure analysis.After further comparison with the solid-state CD spectra of six-coordinate and seven-coordinate metal complexes containing β-diketone ligands,the CD spectra-absolute configuration correlation rule for the eight-coordinate β-diketonate lanthanide complexes was proposed through the exciton chirality method for the first time.The Δ or Λ absolute configurations of the complexes 1～3 with the distorted square antiprism geometry were confirmed by X-ray single-crystal analysis.