Federal University of ABC - UFABC, Av. dos Estados 5001, Santo Andre, SP 09210-170, Brazil.
Photochem Photobiol Sci. 2018 Oct 10;17(10):1443-1449. doi: 10.1039/c8pp00274f.
Di-nuclear {(NN)(CO)3Re}2(trans-bpe)2 complexes, NN = 4,7-diphenyl-1,10-phenanthroline (ph2phen) or 4,7-dichloro-1,10-phenanthroline (Cl2phen) and trans-bpe = trans-1,2-bis(4-pyridyl)ethylene, were synthesized and characterized by 1H NMR and UV-visible spectroscopy. Irradiation of acetonitrile solutions led to 1H NMR and UV-visible spectral changes ascribed to trans-to-cis photoisomerization processes showing that the presence of another Re(i)-moiety does not preclude the photoisomerization process. Quantum yields for the di-nuclear isomerization of [{(ph2phen)(CO)3Re}2(trans-bpe)]2+ were higher than those for the corresponding mono-nuclear compound process. Additionally, the higher quantum yield obtained with 254 nm irradiation for [{(Cl2phen)(CO)3Re}2(trans-bpe)]2+ showed, for the first time, that the singlet pathway could also be accessed in addition to the usually observed triplet one. The luminescence in fluid solution observed for the [{(NN)(CO)3Re}2(cis-bpe)]2+ complexes is able to efficiently photosensitize the generation of singlet O2.
双核 [{(NN)(CO)3Re}2(trans-bpe)] (PF6)2 配合物，NN = 4,7-二苯基-1,10-菲咯啉 (ph2phen) 或 4,7-二氯-1,10-菲咯啉 (Cl2phen) 和 trans-bpe = 反式-1,2-双(4-吡啶基)乙烯，通过 1H NMR 和紫外可见光谱进行了合成和表征。在乙腈溶液中辐照导致 1H NMR 和紫外可见光谱的变化归因于顺式到反式光异构化过程，表明另一个 Re(i)-部分的存在并不排除光异构化过程。[{(ph2phen)(CO)3Re}2(trans-bpe)]2+的双核异构体化的量子产率高于相应的单核化合物过程。此外，[{(Cl2phen)(CO)3Re}2(trans-bpe)]2+在 254nm 照射下获得的较高量子产率首次表明，除了通常观察到的三重态途径外，还可以通过单重态途径进行。在 [{(NN)(CO)3Re}2(cis-bpe)]2+配合物在流体溶液中观察到的发光能够有效地敏化单重态 O2 的产生。
