Department of Physical Chemistry, University of Málaga , Campus de Teatinos s/n, Málaga 29071, Spain.
IMDEA-Nanociencia, C/Faraday 9, Ciudad Universitaria de Cantoblanco , 28049 Madrid, Spain.
J Am Chem Soc. 2017 Mar 1;139(8):3095-3105. doi: 10.1021/jacs.6b12520. Epub 2017 Feb 21.
New stilbenoid and thiophenic compounds terminally functionalized with donor-donor, acceptor-acceptor, or donor-acceptor moieties and possessing a central [2.2]paracyclophane unit have been prepared, and their properties interpreted in terms of through-bond and through space π-electron delocalization (i.e., π-conjugations). Based on photophysical data, their excited-state properties have been described with a focus on the participation of the central [2.2]paracyclophane in competition with through-bond conjugation in the side arms. To this end, two-photon and one-photon absorption and emission spectroscopy, as a function of temperature, solvent polarity, and pressure in the solid state have been recorded. Furthermore, charge delocalization through the [2.2]paracyclophane in the neutral state and in the oxidized species (radical cations, dications and radical trications) has been investigated, allowing the elucidation of the vibrational Raman fingerprint of through-space charge delocalization. Thus, a complementary approach to both "intermolecular" excitation and charge delocalizations in [2.2]paracyclophane molecules is shown which can serve as models of charge and exciton migration in organic semiconductors.
已制备出具有供体-供体、受体-受体或供体-受体末端官能团且具有中心 [2.2] 并环戊二烯单元的新的二苯乙烯和噻吩化合物，并根据通过键和通过空间π-电子离域（即π-共轭）来解释其性质。基于光物理数据，重点研究了中心 [2.2] 并环戊二烯在与侧臂中的通过键共轭竞争中的激发态性质。为此，记录了在固态下作为温度，溶剂极性和压力的函数的双光子和单光子吸收和发射光谱。此外，还研究了中性态和氧化态（自由基阳离子、二阳离子和自由基三阳离子）中通过 [2.2] 并环戊二烯的电荷离域，从而阐明了通过空间电荷离域的振动拉曼指纹。因此，展示了一种对[2.2]并环戊二烯分子中“分子间”激发和电荷离域的互补方法，该方法可作为有机半导体中电荷和激子迁移的模型。
