Departamento de Química Orgánica, Facultad de Química, Campus de Espinardo, Universidad de Murcia , E-30100 Murcia, Spain.
Inorg Chem. 2013 Jul 1;52(13):7487-96. doi: 10.1021/ic400365c. Epub 2013 Jun 19.
The preparation of 2,7-disubstituted benzobisimidazoles decorated with substituents displaying different electrooptical properties is described. The presence of redox, chromogenic, and fluorescent groups at the heteroaromatic core, which acts as ditopic binding site, made these receptors potential candidates as multichannel probes for ions. The triad 4 behaves as a selective redox and fluorescent chemosensor for HSO4(-) and Hg(2+) ions, whereas receptor 5 acts as a redox and chromogenic chemosensor molecule for AcO(-) and SO4(2-) anions. The change in the absorption spectra is accompanied by a color change from yellow to orange, while sensing of Zn(2+), Hg(2+), and Pb(2+) cations is carried out only by electrochemical techniques. Receptor 6 exhibits a remarkable cathodic shift of the oxidation wave only in the presence of AcO(-), H2PO4(-), and HP2O7(3-) anions, whereas addition of Pb(2+) induces an anodic shift. A new low energy band in the absorption spectra, which is responsible for the color change from colorless to pale yellow, and an important increase of the monomer emission band is observed only in the presence of H2PO4(-), and HP2O7(3-) anions. The most salient feature of the receptor 6 is its ability to act as a multichannel (redox, chromogenic, and fluorescent) chemodosimeter for Cu(2+), and Hg(2+) metal cations.
描述了带有显示不同光电性质取代基的 2,7-取代苯并双咪唑的制备。作为双位点结合部位的杂芳环核上存在氧化还原、生色和荧光基团，使这些受体成为多通道离子探针的潜在候选物。三嗪 4 可作为 HSO4(-)和 Hg(2+)离子的选择性氧化还原和荧光化学传感器，而受体 5 可作为 AcO(-)和 SO4(2-)阴离子的氧化还原和生色化学传感器分子。吸收光谱的变化伴随着颜色从黄色变为橙色的变化，而 Zn(2+)、Hg(2+)和 Pb(2+)阳离子的传感仅通过电化学技术进行。受体 6 仅在存在 AcO(-)、H2PO4(-)和 HP2O7(3-)阴离子的情况下表现出氧化波的显著阴极位移，而添加 Pb(2+)会引起阳极位移。在吸收光谱中观察到一个新的低能量带，该带负责颜色从无色变为浅黄色的变化，并且仅在存在 H2PO4(-)和 HP2O7(3-)阴离子的情况下，单体发射带会显著增加。受体 6 的最显著特征是其能够作为 Cu(2+)和 Hg(2+)金属阳离子的多通道（氧化还原、生色和荧光）化学计量传感器。
