AbstractThe photothermal properties of a series of neutral radical gold‐bis(dithiolene) complexes absorbing in the near‐infrared‐III window (1550–1870 nm) have been investigated. This class of complexes was found to be good photothermal agents (PTAs) in toluene under 1600 nm laser irradiation with photothermal efficiencies around 40 and 60 % depending on the nature of the dithiolene ligand. To the best of our knowledge, these complexes are the first small molecular photothermal agents to absorb so far into the near infrared. To test their applicability in water, these hydrophobic complexes have been encapsulated into nanoparticles constituted by amphiphilic block‐copolymers. Stable suspensions of polymeric nanoparticles (NPs) encapsulating the gold‐bis(dithiolene) complexes have been prepared which show a diameter around 100 nm. The encapsulation rate was found to be strongly dependent on the nature of the dithiolene ligands. The photothermal properties of the aqueous suspensions containing gold‐bis(dithiolene) complexes were then studied under 1600 nm laser irradiation. These studies demonstrate that water has strong photothermal activity in the NIR‐III region that, cannot be overcome even with the addition of gold complexes displaying good photothermal properties.
摘要 研究了一系列在近红外-III 窗口(1550-1870 纳米)吸收的中性自由基
金-双(二
硫代二烯)配合物的光热特性。研究发现,在 1600 纳米激光照射下,这类配合物在
甲苯中具有良好的光热效应(
PTAs),根据二
硫环戊烯配体的性质,光热效率约为 40% 和 60%。据我们所知,这些复合物是首批吸收近红外的小分子光热剂。为了测试它们在
水中的适用性,我们将这些疏
水性复合物封装到了由两性嵌段聚合物构成的纳米颗粒中。已制备出封装
金-双(二
硫烯)络合物的稳定聚合物纳米粒子(NPs)悬浮液,其直径约为 100 纳米。研究发现,封装率与二
硫环戊烯配体的性质密切相关。随后,在 1600 纳米激光照射下,研究了含有
金-双(二
硫代二苯)配合物的
水悬浮液的光热特性。这些研究表明,
水在近红外-III 区具有很强的光热活性,即使添加了具有良好光热特性的
金配合物,也无法克服这一特性。