Gadolinium(III) Porpholactones as Efficient and Robust Singlet Oxygen Photosensitizers

详细信息    查看全文

• 作者：Dr. Xian-Sheng Ke ; Yingying Ning ; Juan Tang ; Ji-Yun Hu ; Hao-Yan Yin ; Gao-Xiang Wang ; Zi-Shu Yang ; Jialong Jie ; Dr. Kunhui Liu ; Dr. Zhao-Sha Meng ; Zongyao Zhang ; Prof. Dr. Hongmei Su ; Prof. Dr. Chunying Shu and Prof. Dr. Jun-Long Zhang
• 刊名：Chemistry - A European Journal
• 出版年：2016
• 出版时间：July 4, 2016
• 年：2016
• 卷：22
• 期：28
• 页码：9676-9686
• 全文大小：2721K
• ISSN：1521-3765

文摘

Construction of Gd^III photosensitizers is important for designing theranostic agents owing to the unique properties arising from seven unpaired f electrons of the Gd³⁺ ion. Combining these with the advantages of porpholactones with tunable NIR absorption, we herein report the synthesis of Gd^III complexes Gd-1–4 (1, porphyrin; 2, porpholactone; 3 and 4, cis- and trans-porphodilactone, respectively) and investigated their function as singlet oxygen (¹O₂) photosensitizers. These Gd complexes displayed ¹O₂ quantum yields (Φ_Δs) from 0.64–0.99 with the order Gd-1<Gd-2<Gd-3<Gd-4. The gradually enhanced ¹O₂ sensitization after β-oxazolone moiety replacement was ascribed to the narrowing of the energy gap (ΔE) between the lowest triplet states (T₁) of the ligand and the energy level of the ¹Δ_g→³Σ_g transition of ¹O₂. In particular, Gd-4 is capable of excitation in the visible to NIR region (400–700 nm) with a quantum yield near unity. These Gd complexes were first demonstrated as efficient photosensitizers in photocatalysis such as oxidative C−H bond functionalization of secondary or tertiary amines, and the oxygenation of the natural product cholesterol. Finally, after glycosylation, these water-soluble Gd complexes showed potential applications in photodynamic therapy (PDT) in HeLa cells. This work revealed that Gd^III complexes of “bioinspired” β-modified porpholactones are efficient NIR photosensitizers and form a chemical basis to construct appealing photocatalysts and theranostic agents based on lanthanides.