Green Emissive Copper(I) Coordination Polymer Supported by the Diethylpyridylphosphine Ligand as a Luminescent Sensor for Overheating Processes

• Published in: Molecules (Basel, Switzerland) Vol. 28; no. 2; p. 706
• Main Authors: Enikeeva, Kamila R., Shamsieva, Aliia V., Strelnik, Anna G., Fayzullin, Robert R., Zakharychev, Dmitry V., Kolesnikov, Ilya E., Dayanova, Irina R., Gerasimova, Tatiana P., Strelnik, Igor D., Musina, Elvira I., Karasik, Andrey A., Sinyashin, Oleg G.
• Format: Journal Article
• Language: English
• Published: Switzerland MDPI AG 10.01.2023; MDPI
• Subjects: Copper; copper(I) complexes; Cu4I4 clusters; Ligands; luminescent complexes; P,N-ligands; phosphines; Polymers; phosphines; copper(I) complexes; luminescent complexes; Cu4I4 clusters; P,N-ligands
• ISSN: 1420-3049; 1420-3049
• DOI: 10.3390/molecules28020706

Tertiary diethylpyridylphosphine was synthesized by the reaction of pyridylphosphine with bromoethane in a suberbasic medium. The reaction of phosphine with the copper(I) iodide led to the formation of a copper(I) coordination polymer, which, according to the X-ray diffraction data, has an intermediate structure with a copper-halide core between the octahedral and stairstep geometries of the Cu4I4 clusters. The obtained coordination polymer exhibits a green emission in the solid state, which is caused by the 3(M+X)LCT transitions. The heating up of the copper(I) coordination polymer to 138.5 °C results in its monomerization and the formation of a new solid-state phase. The new phase exhibits a red emission, with the emission band maximum at 725 nm. According to the experimental data and quantum chemical computations, it was concluded that depolymerization probably leads to a complex that is formed with the octahedral structure of the copper-halide core. The resulting solid-state phase can be backward-converted to the polymer phase via recrystallization from the acetone or DMF. Therefore, the obtained coordination polymer can be considered a sensor or detector for the overheating of processes that should be maintained at temperatures below 138 °C (e.g., engines, boiling liquids, solar heat systems, etc.).