Mukherjee Anurag, Barman Shubhankar, Ghosh Anupam, Datta Ayan, Datta Anuja, Ghosh Suhrit
School of Applied and Interdisciplinary Sciences, Indian Association for the Cultivation of Science, 2A and 2B Raja S. C. Mullick Road, Jadavpur, Kolkata, 700032, India.
School of Chemical Sciences, Indian Association for the Cultivation of Science, 2A and 2B Raja S. C. Mullick Road, Jadavpur, Kolkata, 700032, India.
Angew Chem Int Ed Engl. 2022 Jun 20;61(25):e202203817. doi: 10.1002/anie.202203817. Epub 2022 Apr 20.
This communication reveals co-assembly of an electron-deficient naphthalene-diimide (NDI)-appended polyurethane (P1) and electron-rich pyrene (Py), forming an organogel with prominent room-temperature ferroelectricity. In a non-polar medium, intra-chain hydrogen-bonding among the urethane groups of P1 produces a folded structure with an array of the NDIs in the periphery, which intercalate Py by charge-transfer (CT)-interaction. Such CT-complexation enables slow crystallization of the peripheral hydrocarbons, causing gelation with nanotubular morphology, in which the wall consists of the alternating NDI-Py stack. Such D-A assembly exhibits ferroelectricity (saturation polarization P ≈0.8 μC cm and coercive field E ≈8 kV cm at 500 V and 10 Hz frequency) with Curie temperature (T ) of ≈350 K, which can be related to the disassembly of the CT-complex. In the absence of Py, P1 forms spherical aggregates, showing dielectric behaviour.
本通讯揭示了缺电子的萘二亚胺（NDI）连接的聚氨酯（P1）与富电子的芘（Py）的共组装，形成了具有显著室温铁电性的有机凝胶。在非极性介质中，P1的聚氨酯基团之间的链内氢键产生了一种折叠结构，其外围排列着一系列NDI，这些NDI通过电荷转移（CT）相互作用插入Py。这种CT络合作用使外围碳氢化合物缓慢结晶，导致形成具有纳米管形态的凝胶，其管壁由交替的NDI-Py堆叠组成。这种供体-受体组装表现出铁电性（在500 V和10 Hz频率下，饱和极化P≈0.8 μC cm，矫顽场E≈8 kV cm），居里温度（T）约为350 K，这可能与CT络合物的分解有关。在没有Py的情况下，P1形成球形聚集体，表现出介电行为。
