Waki Minoru, Yamanaka Ken-Ichi, Shirai Soichi, Maegawa Yoshifumi, Goto Yasutomo, Yamada Yuri, Inagaki Shinji
Toyota Central R&D Laboratories, Inc., Nagakute, Aichi, 480-1192, Japan.
Chemistry. 2018 Mar 12;24(15):3846-3853. doi: 10.1002/chem.201705792. Epub 2018 Feb 14.
This paper describes the physicochemical properties of a rhenium (Re) complex [Re(bpy)(CO) Cl] immobilized on a bipyridine-periodic mesoporous organosilica (BPy-PMO) acting as a solid support. The immobilized Re complex generated a metal-to-ligand charge transfer absorption band at 400 nm. This wavelength is longer than that exhibited by Re(bpy)(CO) Cl in the polar solvent acetonitrile (371 nm) and is almost equal to that in nonpolar toluene (403 nm). The photocatalytic activity of this heterogeneous Re complex was lower than that of a homogeneous Re complex due to the reduced phosphorescence lifetime resulting from immobilization. However, the catalytic activity was enhanced by the co-immobilization of the ruthenium (Ru) photosensitizer [Ru(bpy) ] on the PMO pore surfaces. Quantum chemical calculations suggest that electron transfer between the Ru and Re complexes occurs through interactions between the molecular orbitals in the pore walls. These results should have applications to the design of efficient heterogeneous CO reduction photocatalysis systems.
本文描述了一种固定在联吡啶-周期性介孔有机硅（BPy-PMO）固体载体上的铼（Re）配合物[Re(bpy)(CO)Cl]的物理化学性质。固定化的Re配合物在400 nm处产生了一个金属到配体的电荷转移吸收带。该波长比Re(bpy)(CO)Cl在极性溶剂乙腈中显示的波长（371 nm）更长，并且几乎与在非极性甲苯中的波长（403 nm）相等。由于固定化导致磷光寿命缩短，这种非均相Re配合物的光催化活性低于均相Re配合物。然而，通过在PMO孔表面共固定钌（Ru）光敏剂[Ru(bpy)]，催化活性得到了增强。量子化学计算表明，Ru和Re配合物之间的电子转移是通过孔壁中分子轨道之间的相互作用发生的。这些结果应可应用于高效非均相CO还原光催化系统的设计。
