School of Chemical Sciences, National Institute of Science Education and Research (NISER), Bhubaneswar - 752050, India.
Homi Bhabha National Institute, Training School Complex, Anushakti Nagar, Mumbai, 400 094, India.
Dalton Trans. 2022 Sep 13;51(35):13236-13245. doi: 10.1039/d2dt01959k.
Presented herein are two fully characterized gold tetrathiocyanocorroles representing a potentially significant new class of NIR-emissive 5d-metallocorroles. The four SCN groups on the bipyrrole unit of the corrole exert a powerful electron-withdrawing effect, upshifting both the oxidation and reduction potentials by roughly half a volt relative to their unsubstituted counterparts. That said, the upshift of the LUMO is somewhat higher than that of the HOMO so these complexes also exhibit a smaller HOMO-LUMO gap, as evinced in both electrochemical measurements and Q band energies (∼595 nm relative to ∼571 nm for their SCN-free counterparts). The new compounds exhibit NIR phosphorescence under ambient conditions with emission maxima around 900 nm (compared with 790 nm for simple Au triarylcorroles), phosphorescence quantum yields around 0.3%, phosphorescence lifetimes around 10 μs, and singlet oxygen sensitization with a quantum yield of around 50 ± 5% in solution, together signifying wide-ranging potential applications as triplet photosensitizers in oxygen sensing and photodynamic therapy.
本文介绍了两个完全表征的金四硫氰基四吡咯，代表了一类具有潜在重要意义的新型近红外发光 5d 金属卟啉。卟啉单元上的四个 SCN 基团具有很强的吸电子效应，与未取代的相应物相比，氧化还原电位向上移动约半伏特。也就是说，LUMO 的上移幅度略高于 HOMO，因此这些配合物的 HOMO-LUMO 能隙也较小，这在电化学测量和 Q 带能量中都可以看出（与无 SCN 对应物相比，分别为∼595nm 和∼571nm）。新化合物在环境条件下表现出近红外磷光，发射峰在 900nm 左右（与简单的 Au 三芳基卟啉相比为 790nm），磷光量子产率约为 0.3%，磷光寿命约为 10μs，在溶液中具有约 50±5%的单线态氧敏化量子产率，这表明它们作为三重态光敏剂在氧气传感和光动力治疗中具有广泛的潜在应用。
