Nishina Haruka, Hoshino Shota, Ohtani Yuta, Ishida Tamao, Shimada Tetsuya, Takagi Shinsuke
Department of Applied Chemistry, Graduate School of Urban Environmental Sciences, Tokyo Metropolitan University, 1-1 Minami-ohsawa, Hachioji, Tokyo 192-0397, Japan.
Department of Applied Chemistry, Sanyo-Onoda City University, 1-1-1 Daigaku-dori, Sanyo-Onoda, Yamaguchi, 756-0884, Japan.
Phys Chem Chem Phys. 2020 Jul 1;22(25):14261-14267. doi: 10.1039/d0cp02263b.
The adsorption orientation behavior of tetrakis(1-methylpyridinium-3-yl)porphyrin (m-TMPyP) and tetrakis(1-methylpyridinium-4-yl)porphyrin (p-TMPyP) on the clay monolayer prepared by the Langmuir Blodgett (LB) technique was investigated using the absorption and dichroic spectra obtained on a waveguide. It was revealed that the orientation of m-TMPyP and p-TMPyP on the clay monolayer, that is parallel and tilted with respect to the clay surface, depends on the surrounding environments such as water and N,N-dimethylformamide (DMF). The anisotropic photochemical energy transfer between m-TMPyP as a donor and p-TMPyP as an acceptor in the layered system was investigated in water and in DMF-water (9/1 (v/v)) by a fluorescence observation. As a result, while energy transfer efficiency (ηET) was 60% for the parallel-parallel orientation in water, that was 10% for the tilted-tilted orientation in DMF-water (9/1 (v/v)). The major factor for the change of ηET could be a change of the distance between m-TMPyP and p-TMPyP, and the J value that is a parameter for spectral overlap between energy donor's fluorescence and acceptor's absorption.
利用在波导上获得的吸收光谱和二向色光谱，研究了通过朗缪尔-布洛杰特（LB）技术制备的粘土单分子层上四（1-甲基吡啶-3-基）卟啉（m-TMPyP）和四（1-甲基吡啶-4-基）卟啉（p-TMPyP）的吸附取向行为。结果表明，m-TMPyP和p-TMPyP在粘土单分子层上相对于粘土表面的取向，即平行和倾斜，取决于周围环境，如水和N，N-二甲基甲酰胺（DMF）。通过荧光观测，研究了在水和DMF-水（9/1（v/v））的层状体系中，作为供体的m-TMPyP和作为受体的p-TMPyP之间的各向异性光化学能量转移。结果显示，在水中，平行-平行取向的能量转移效率（ηET）为60%，而在DMF-水（9/1（v/v））中，倾斜-倾斜取向的能量转移效率为10%。ηET变化的主要因素可能是m-TMPyP和p-TMPyP之间距离的变化，以及J值，J值是能量供体荧光和受体吸收之间光谱重叠的一个参数。
