Acid induced acetylacetonato replacement in biscyclometalated iridium(iii) complexes
作者:Yanfang Li、Yang Liu、Ming Zhou
DOI:10.1039/c2dt12119k
日期:——
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 Hg2+ 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 Hg2+–S affinity and its effect on the photophysical properties of iridium(III) luminophores did not play a role.
具有辅助乙酰丙酮配体的双环金属化铱(III)配合物,Ir(L)2(acac),其中L = 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 = 去质子化乙酰丙酮,在酸性条件下表现出其紫外-可见吸收和发光发射光谱的变化。这些变化与某些汞盐存在于系统中时观察到的变化相同。由于一些铱(III)配合物含有含硫配体(即btp和bt),因此提出了光谱变化是否与Hg2+对硫原子的特定亲和力有关的问题。本工作中进行的广泛研究表明,观察到的光谱变化仅仅是酸诱导的acac离去以及随后溶剂乙腈与铱(III)中心配位的结果,而普遍预期的Hg2+–S亲和力及其对铱(III)发光体光物理性质的影响并未发挥作用。