Chorbacher Johannes, Klopf Jonas, Friedrich Alexandra, Fest Maximilian, Schneider Johannes S, Engels Bernd, Helten Holger
Julius-Maximilians-Universität Würzburg, Institute of Inorganic Chemistry and Institute for Sustainable Chemistry & Catalysis with Boron (ICB), Am Hubland, 97074, Würzburg, Germany.
Julius-Maximilians-Universität Würzburg, Institute for Physical and Theoretical Chemistry, Emil-Fischer-Strasse 42, 97074, Würzburg, Germany.
Angew Chem Int Ed Engl. 2025 Mar 10;64(11):e202416088. doi: 10.1002/anie.202416088. Epub 2024 Dec 10.
Incorporation of BN units into π-conjugated organic compounds, as substitutes for specific CC couples, often leads to new hybrid materials with modified physical and chemical properties. Poly(p-phenylene iminoborane)s are derived from well-known poly(p-phenylene vinylene) (PPV) by replacement of the vinylene groups by B=N linking units. Herein, an unprecedented poly(p-phenylene iminoborane) is presented that features a strictly alternating sequence of BN units along the main chain. The synthesis thereof was achieved by AB-type polymerization of a monomer featuring an N and a B terminus. Monodisperse oligomers with up to three BN units in the chain were additionally prepared and structurally characterized. Associated with the introduction of a dipole in the regioregular backbone structure, they display notable fluorescence already in solution and large Stokes shifts, distinct from their previously reported BBNN-sequenced congeners. All compounds show aggregation-induced emission enhancement (AIEE) properties. Computational studies provided evidence for emission from either locally excited (LE) or twisted intramolecular charge transfer (TICT) states. These processes can be optionally addressed by various stimuli, giving rise to dual emission, solvatochromic, thermochromic, and reversible mechanochromic behavior.
将硼氮单元引入π共轭有机化合物中，作为特定碳-碳双键的替代物，通常会产生具有改性物理和化学性质的新型杂化材料。聚（对亚苯基亚胺硼烷）是由著名的聚（对亚苯基亚乙烯基）（PPV）通过用B=N连接单元取代亚乙烯基而衍生而来的。在此，我们展示了一种前所未有的聚（对亚苯基亚胺硼烷），其主链上具有严格交替的硼氮单元序列。其合成是通过一种具有N端和B端的单体的AB型聚合实现的。此外，还制备了链中含有多达三个硼氮单元的单分散低聚物并对其进行了结构表征。由于在区域规整主链结构中引入了偶极，它们在溶液中已经表现出显著的荧光和大的斯托克斯位移，这与之前报道的具有BBNN序列的同系物不同。所有化合物都表现出聚集诱导发光增强（AIEE）特性。计算研究为从局部激发（LE）或扭曲分子内电荷转移（TICT）态发射提供了证据。这些过程可以通过各种刺激选择性地实现，从而产生双发射、溶剂致变色、热致变色和可逆机械变色行为。
