Suzhou Institute of Nano-Tech and Nano-Bionics, Chinese Academy of Sciences, Suzhou Industrial Park, Jiangsu, PR China.
Dalton Trans. 2012 Apr 7;41(13):3807-16. doi: 10.1039/c2dt12119k. Epub 2012 Feb 22.
Biscyclometalated iridium(III) complexes with an ancillary acetylacetone ligand, Ir(L)(2)(acac), (L = 2-(benzo[b]thiophen-2-yl)pyridine (btp), 1-phenylisoquinoline (piq), 2-phenylbenzothiazole (bt), 2-phenylpyridine (ppy), acac = deprotonated acetylacetone), demonstrate spectroscopic changes in their UV-Vis absorption and luminescent emission under acidic conditions. Such changes were found to be the same as those observed when certain mercury salts exist in the systems. Because some iridium(III) complexes have sulfur-containing ligands (i.e., btp and bt), a question was then raised as for whether or not the spectroscopic changes are associated with the specific affinity of Hg(2+) to the sulfur atom. Extensive studies performed in this work unambiguously proved that the observed spectroscopic changes were solely the results of the acid induced departure of acac and the follow-up coordination of solvent acetonitrile to the iridium(III) center and that the generally anticipated Hg(2+)-S affinity and its effect on the photophysical properties of iridium(III) luminophores did not play a role.
双环金属铱(III)配合物带有辅助乙酰丙酮配体 Ir(L)(2)(acac)，其中 L 为 2-(苯并[b]噻吩-2-基)吡啶(btp)、1-苯基异喹啉(piq)、2-苯基苯并噻唑(bt)、2-苯基吡啶(ppy)，acac 为去质子化的乙酰丙酮。这些配合物在酸性条件下，其紫外-可见吸收和发光发射光谱会发生变化。这些变化与某些汞盐存在于体系中时观察到的变化相同。由于某些铱(III)配合物具有含硫配体(即 btp 和 bt)，因此人们提出了这样一个问题，即光谱变化是否与 Hg(2+)与硫原子的特定亲和力有关。本工作进行了广泛的研究，明确证明观察到的光谱变化仅是由酸诱导的 acac 离去以及随后溶剂乙腈与铱(III)中心的配位引起的，而通常预期的 Hg(2+)-S 亲和力及其对铱(III)发光体光物理性质的影响并未起作用。
