Affiliation:
1. Clausthal University of Technology Institute of Organic Chemistry Leibnizstraße 6 D-38678 Clausthal-Zellerfeld Germany
2. Fraunhofer Heinrich Hertz Institute HHI, Fiber Optical Sensor Systems Am Stollen 19 H D-38640 Goslar Germany
3. Clausthal University of Technology Institute of Physical Chemistry Arnold-Sommerfeld-Straße 4 D-38678 Clausthal-Zellerfeld Germany
Abstract
AbstractBi‐substituted acetylenes with a quinolinium and an isoquinolinium substituent are described, which reversibly form intensely colored adducts with O‐nucleophiles and thus enable the detection of >0,5 ppm hydroxide on the surfaces of various glasses. Acids reconstitute the colorless bi‐substituted acetylenes. The quinolinium and isoquinolinium rings are bound via their 2‐, 3‐, 4‐ and 1‐, 3‐, 4‐positions to the triple bond, respectively. The choice of substitution sites of the hetarenium rings enables the design of mixed conjugated/cross‐conjugated π‐electron systems. Depending on the combination of binding sites, the frontier orbital profile, the triple bond polarization, the fluorescence behaviour, and the sensitivity to hydroxide differs.