Kotásková Lucie, Jewula Pawel, Herchel Radovan, Nemec Ivan, Neugebauer Petr
Central European Institute of Technology, Brno University of Technology Purkyňova 656/123 61200 Brno Czech Republic
Department of Inorganic Chemistry, Palacký University 17 listopadu 1192/12 77900 Olomouc Czech Republic.
RSC Adv. 2024 Jul 1;14(29):20856-20866. doi: 10.1039/d4ra02909g. eCollection 2024 Jun 27.
The ,-photoisomerization of pyridine-based hydrazone switches is typically suppressed due to the presence of pyridine-based rotors. The crystal structures of studied compounds were investigated using theoretical methods combining DFT and QT-AIM calculations to unveil the nature and properties of the intramolecular hydrogen bonding. In this study, we introduced a new series of pyridine-based hydrazones anchored with -halogen substituents (2-X) and investigated their photoswitching abilities using H NMR and UV-Vis spectroscopy. The efficiency of the photoisomerization from initial 2-X- to the 2-X- isomer varied, with the highest yield observed for 2-Cl- (55%). Our findings, supported by DFT calculations, revealed the formation of a new diastereomer, 2-X-*, upon back-photoisomerization. We demonstrated that hydrazones from the 2-X series can be reversibly photoswitched using irradiation from the UV-Vis range, and additionally, we explored the effect of the halogen atom on their switching capabilities and also on their thermodynamics and kinetics of photoswitching, determining their molecular solar thermal energy storage potential.
由于吡啶基转子的存在，吡啶基腙开关的光异构化通常受到抑制。使用结合密度泛函理论（DFT）和量子拓扑原子分子理论（QT-AIM）计算的理论方法研究了所研究化合物的晶体结构，以揭示分子内氢键的性质和特性。在本研究中，我们引入了一系列新的以卤代基（2-X）锚定的吡啶基腙，并使用核磁共振氢谱（H NMR）和紫外可见光谱研究了它们的光开关能力。从初始的2-X-到2-X-异构体的光异构化效率各不相同，其中2-氯-（55%）的产率最高。我们的研究结果得到DFT计算的支持，揭示了在反向光异构化时形成了一种新的非对映异构体2-X-*。我们证明了2-X系列的腙可以通过紫外可见光谱范围内的照射进行可逆光开关，此外，我们还探索了卤原子对其开关能力以及光开关的热力学和动力学的影响，确定了它们的分子太阳能热能存储潜力。
