Bojinov Vladimir B, Georgiev Nikolai I, Bosch Paula
Department of Organic Synthesis, University of Chemical Technology and Metallurgy, Kliment Ohridsky 8, 1756, Sofia, Bulgaria.
J Fluoresc. 2009 Jan;19(1):127-39. doi: 10.1007/s10895-008-0394-2. Epub 2008 Jul 30.
Two highly photostable yellow-green emitting 1,8-naphthalimides 5 and 6, containing both N-linked hindered amine moiety and a secondary or tertiary cation receptor, were synthesized for the first time. Novel compounds were configured as "fluorophore-spacer-receptor" systems based on photoinduced electron transfer. Photophysical characteristics of the dyes were investigated in DMF and water/DMF (4:1, v/v) solution. The ability of the new compounds to detect cations was evaluated by the changes in their fluorescence intensity in the presence of metal ions (Cu2+, Pb2+, Zn2+, Ni2+, Co2+) and protons. The presence of metal ions and protons was found to disallow a photoinduced electron transfer leading to an enhancement in the dye fluorescence intensity. Compound 5, containing secondary amine receptor, displayed a good sensor activity towards metal ions and protons. However the sensor activity of dye 6, containing a tertiary amine receptor and a shorter hydrocarbon spacer, was substantially higher. The results obtained indicate the potential of the novel compounds as highly photostable and efficient "off-on" pH switchers and fluorescent detectors for metal ions with pronounced selectivity towards Cu2+ ions.
首次合成了两种具有高光稳定性的黄绿色发光的1,8-萘二甲酰亚胺5和6，它们既含有N-连接的受阻胺部分，又含有仲或叔阳离子受体。基于光致电子转移，将新型化合物构造成“荧光团-间隔基-受体”体系。在二甲基甲酰胺（DMF）和水/二甲基甲酰胺（4:1，v/v）溶液中研究了染料的光物理特性。通过在金属离子（Cu2+、Pb2+、Zn2+、Ni2+、Co2+）和质子存在下荧光强度的变化，评估了新化合物检测阳离子的能力。发现金属离子和质子的存在会阻止光致电子转移，从而导致染料荧光强度增强。含有仲胺受体的化合物5对金属离子和质子表现出良好的传感活性。然而，含有叔胺受体和较短烃间隔基的染料6的传感活性要高得多。所得结果表明，这些新型化合物具有作为高光稳定性和高效“关-开”pH开关以及对Cu2+离子具有明显选择性的金属离子荧光探测器的潜力。
