Department of Chemistry, National University of Singapore, 117543, Singapore, Singapore.
Laboratory of Bioimaging Probe Development, Singapore Bioimaging Consortium, 138667, Singapore, Singapore.
Angew Chem Int Ed Engl. 2016 Feb 18;55(8):2815-9. doi: 10.1002/anie.201511151. Epub 2016 Jan 25.
A diradical approach to obtain stable organic dyes with intense absorption around λ=1100 nm is reported. The para- and meta-quinodimethane-bridged BODIPY dimers BD-1 and BD-2 were synthesized and were found to have a small amount of diradical character. These molecules exhibited very intense absorption at λ=1088 nm (ɛ=6.65×10(5) M(-1) cm(-1) ) and 1136 nm (ɛ=6.44×10(5) M(-1) cm(-1) ), respectively, together with large two-photon-absorption cross-sections. Structural isomerization induced little variation in their diradical character but distinctive differences in their physical properties. Moreover, the compounds showed a selective fluorescence turn-on response in the presence of the hydroxyl radical but not with other reactive oxygen species.
报道了一种获得稳定的近红外吸收有机染料的自由基方法。合成了para-和 meta-醌二亚甲基桥联 BODIPY 二聚体 BD-1 和 BD-2，发现它们具有少量的自由基特性。这些分子在 λ=1088nm（ɛ=6.65×10(5) M(-1) cm(-1) ）和 1136nm（ɛ=6.44×10(5) M(-1) cm(-1) ）处表现出非常强的吸收，并且具有较大的双光子吸收截面。结构异构化几乎没有改变它们的自由基特性，但在物理性质上有明显的差异。此外，这些化合物在羟基自由基存在下表现出选择性荧光开启响应，但与其他活性氧物种没有响应。
