Schnable David, Ung Gaël
Department of Chemistry, University of Connecticut, Storrs, Connecticut 06269, United States.
Inorg Chem. 2024 Apr 22;63(16):7378-7385. doi: 10.1021/acs.inorgchem.4c00417. Epub 2024 Apr 5.
We report two new circularly polarized luminescence (CPL)-active lanthanide complexes emissive in the near-infrared (NIR) region; using sphenol as a supporting ligand, we provide the first reported example of an NIR-emissive lanthanide complex supported by a chiral spirane. Inclusion of a quaternary carbon to impart axial chirality results in dramatic augmentation of the CPL strength of the resultant sphenolate complexes ( ≤ 0.77 for [(sphenol)ErNa(thf)]) compared to that of their contemporary biaryl-based axially chiral analogues ( ≤ 0.47 for [(binol)ErNa(thf)]). Despite similar structural parameters, the rigid spiro carbon of sphenol enables the strongest dissymmetry factors observed to date from Shibasaki-type complexes for both Yb and Er. We also demonstrate the sensitivity of the reported chiroptical measurements to small variations in instrumental parameters, such as bandpass, and suggest a standardized method or at least that additional detail should be included in future reports to allow for direct comparisons between newly published CPL emitters.
我们报道了两种新的在近红外（NIR）区域发射的圆偏振发光（CPL）活性镧系配合物；使用蝶酚作为辅助配体，我们提供了首个由手性螺环支撑的近红外发射镧系配合物的报道实例。引入季碳以赋予轴向手性导致所得蝶酚盐配合物（[(蝶酚)ErNa(thf)]的CPL强度（≤0.77）与其当代基于联芳基的轴向手性类似物（[(联萘酚)ErNa(thf)]的CPL强度（≤0.47）相比显著增强。尽管结构参数相似，但蝶酚的刚性螺碳使得Yb和Er的Shibasaki型配合物迄今观察到最强的不对称因子。我们还证明了所报道的手性光学测量对仪器参数（如带通）的微小变化的敏感性，并建议采用标准化方法，或者至少在未来的报告中应包含更多细节，以便能够直接比较新发表的CPL发射体。
