Division of Applied Chemistry, Graduate School of Natural Science and Technology, Okayama University Tsushima, Okayama, 700-8530, Japan.
Chemistry. 2022 Jan 27;28(6):e202104212. doi: 10.1002/chem.202104212. Epub 2021 Dec 15.
Ruthenium complexes bearing three axially chiral bipyridyl ligands were synthesized as a new family of chiral complex dyes, and Δ-(S)- and Λ-(S)-diastereomers were obtained. The X-ray crystal structure analyses, spectroscopy, and DFT calculations suggested that all the bipyridyls maintained chirality in both the ground and excited states, and the Δ-(S)- and Λ-(S)-isomers are the matched (more relaxed) and mismatched (more constrained) pairs, respectively. The mismatched Λ-(S)-isomer exhibited red circularly polarized phosphorescence (CPP) both in solution and in the solid state. The solution state CPP is the most intense of ruthenium complexes, while the solid state CPP is the first example of them. It is supposed that, for the Λ-(S)-isomer, the six cumulative CH/π interactions suppress further distortion in the T state.
钌配合物带有三个轴向手性联吡啶配体，作为一类新的手性配合物染料被合成出来，得到了 Δ-(S)-和 Λ-(S)-非对映异构体。X 射线晶体结构分析、光谱和 DFT 计算表明，所有联吡啶在基态和激发态都保持手性，并且 Δ-(S)-和 Λ-(S)-异构体分别是匹配（更松弛）和不匹配（更受限）的对映异构体。不匹配的 Λ-(S)-异构体在溶液和固态中均表现出红色圆偏振磷光（CPP）。在溶液状态下，CPP 是钌配合物中最强的，而在固态中则是首例。据推测，对于 Λ-(S)-异构体，六个累积的 CH/π 相互作用抑制了 T 态下的进一步变形。
