Department of Biophysics and Physical Chemistry, Faculty of Pharmacy in Hradec Kralove, Charles University in Prague, Heyrovskeho 1203, Hradec Kralove, Czech Republic.
Chemistry. 2011 Dec 9;17(50):14273-82. doi: 10.1002/chem.201101123. Epub 2011 Nov 3.
New unsymmetrical zinc azaphthalocyanines, bearing one substituted aniline as a peripheral substituent, were prepared by using a statistical condensation approach. Both fluorescence and singlet oxygen quantum yields were extremely low in DMF (Φ(F)<0.01, Φ(Δ)<0.02, respectively), but increased after the addition of sulfuric acid, reaching values comparable to controls without aniline substituents (Φ(F)=0.22-0.29, Φ(Δ)=0.40-0.59, respectively). This behavior was attributed to the deactivation of excited states by intramolecular charge transfer from a donor site (aniline), which was blocked after protonation in acidic media. In the protonated form, all of the compounds efficiently emitted light with λ(em) in the region of 662-675 nm. The investigated compounds were anchored to dioleoylphosphatidylcholine (DOPC) unilamellar vesicles and showed response to buffer pH. They were highly fluorescent at low pH values and almost nonfluorescent in neutral solutions. The pK(a) values were determined in DOPC vesicles and ranged between 2.2 and 4.2.
新的非对称锌氮杂卟啉，带有一个取代的苯胺作为外围取代基，通过使用统计缩合方法制备。在 DMF 中，荧光和单线态氧量子产率都极低（Φ(F)<0.01，Φ(Δ)<0.02），但在加入硫酸后增加，达到与没有苯胺取代基的对照物相当的值（Φ(F)=0.22-0.29，Φ(Δ)=0.40-0.59）。这种行为归因于受激态的失活通过分子内从供体部位（苯胺）的电荷转移，这在酸性介质中质子化后被阻断。在质子化形式中，所有化合物都能有效地发射出λ(em)在 662-675nm 区域的光。研究的化合物被固定在二油酰基磷脂酰胆碱（DOPC）单层囊泡上，并对缓冲液 pH 值有响应。它们在低 pH 值下具有高荧光性，在中性溶液中几乎无荧光。pK(a)值在 DOPC 囊泡中测定，范围在 2.2 和 4.2 之间。
