The construction of novel complexes can lead to the manifestation of unexpected structures and properties, thereby making chemical exploration in experiments a potential source for novel discoveries. In this study, by reacting 6,6′-dihydrazineyl-2,2′-bipyridine with acyl chlorides and subsequently coordinating with boron trifluoride, two different boron-tetradentate ligand complexes were simultaneously generated. One of these complexes exhibited a unique structure in which tetra-BF₂ moieties coordinated to all four coordination sites of the ligand molecule, forming a flag-hinged structure around the bipyridine part. The second complex featured a helical structure formed by the hybridization of two BF₂ and one B–O–B moieties, representing a highly unusual form of the complex. The structures of these two boron complexes were consistently observed when various substituted acyl chlorides were employed. Furthermore, it was found that enhancing electron-donor properties could induce a redshift in emissions. Utilizing the dimethylamino group as the proton receptor promoted a yellow-to-blue fluorescence switch in the tetra-BF₂ complex and an OFF/ON fluorescence in the B–O–B bridged complex upon protonation. The helical chirality observed in the latter complex resulted in stable (P)/(M)-enantiomers after optical resolution. This complex exhibited circular dichroism with a |g_abs| of up to 1.2 × 10⁻² and circularly polarized luminescence with a |g_lum| on the order of 10⁻³ in solution and polymer film.

中文翻译：

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同时发现手性和非手性染料：阐明螺旋和旗铰接硼四齿络合物的光学功能

新型配合物的构建可以导致意想不到的结构和性质的表现，从而使实验中的化学探索成为新发现的潜在来源。在这项研究中，通过将6,6'-二肼基-2,2'-联吡啶与酰氯反应，随后与三氟化硼配位，同时生成了两种不同的硼-四齿配体配合物。其中一个复合物表现出独特的结构，其中四-BF ₂部分与配体分子的所有四个配位位点配位，在联吡啶部分周围形成旗形铰接结构。第二个复合物具有由两个_BF2和一个 B-O-B 部分杂交形成的螺旋结构，代表了该复合物的一种非常不寻常的形式。当使用各种取代的酰氯时，一致地观察到这两种硼配合物的结构。此外，发现增强电子供体特性可以引起发射红移。利用二甲氨基作为质子受体，在质子化时促进了 tetra-BF ₂复合物中的黄色到蓝色荧光转换以及 B-O-B 桥复合物中的 OFF/ON 荧光。在后一种复合物中观察到的螺旋手性在光学拆分后产生稳定的 ( P )/( M )-对映体。该配合物表现出圆二色性 |腹肌|_​高达 1.2 × 10 ^-2的圆偏振发光，具有 |克伦|_​在溶液和聚合物薄膜中约为10 ^{-3 。}