Related Experiment Video
Updated: Jan 30, 2026

Behavioral Tasks for Examining Identity Recognition In Mice
Published on: February 7, 2025
Integrated pyrazolo[1,5-a]pyrimidine-hemicyanine system as a colorimetric and fluorometric chemosensor for cyanide
Alexis Tigreros1, Hernán-Alejandro Rosero1, Juan-Carlos Castillo2
1Bioorganic Compounds Research Group, Department of Chemistry, Universidad de los Andes, Carrera 1 No. 18A-10, Bogotá, Colombia.
Abstract:
A new probe for cyanide detection based on the integrated pyrazolo[1,5-a]pyrimidine-hemicyanine (PpHe) system was synthesized in an efficient and straightforward manner using microwave-assisted heating. Photophysical studies in a 100% aqueous solution demonstrated high cyanide selectivity and detection limits as low as 600 and 86 nmol L-1 for UV-vis absorption and fluorescence emission, respectively. Both values are well below 1900 nmol L-1, which is the maximum concentration permitted for drinking water by the World Health Organization (WHO). HRMS analysis and NMR experiments were performed to confirm the mechanism of detection based on blocking the ICT phenomenon via nucleophilic addition of CN- on the C˭N+ bond (iminium salt moiety) of the probe.
Related Concept Videos
[3,3] Sigmatropic Rearrangement of 1,5-Dienes: Cope Rearrangement
Diazonium Group Substitution with Halogens and Cyanide: Sandmeyer and Schiemann Reactions
States of Water
Water freezes when the intermolecular forces are greater than the kinetic energy. Unlike most other substances, water is less dense in its solid state than in its liquid state. This is because each water molecule can form...
Integration by Parts: Indefinite Integrals
Integration by Parts: Definite Integrals
The Water Cycle

