Work

Bifunctional Co(II)-porphyrin 1D-coordination polymer for selective cyanide sensing in tobacco smoke and efficient solid-liquid extraction

Year: 2025

Type: article

Abstract: : Selective chromogenic sensing and extraction of cyanide (CN-) is a central issue of supramolecular chemistry and analytical sciences that impact biological and environmental chemistry. In this work, we reported a 1D coordination polymer [Co(TPyP)] (TPyP= 5,10,15,20-tetrapyridyl-21H,23H porphyrin) that contains an open coordination site on Co(II) atom that acts as a high-affinity binding point for CN- recognition. This Co(II)-polymer was structurally described by X-ray diffraction and Hirschfeld surfaces. Also, it was thoroughly characterized by several spectroscopic tools and SEM with energy-dispersive X-ray spectroscopy. This Co(II) polymer was found to be an exceptionally high overall binding constant for CN- (log b= 10.04) with an equilibrium model 1:2 in CH3CN and highly selectivity over common interfering anions including halides and basic oxyanions. Under these conditions, CN- can be sense with a limit of detection of 5.40 mM by UV-Vis and visual change of the solution. On the basis of analytical tools (MS-ESI, X-ray single-crystal diffraction, ATR-IR, UV-Vis) and TD-DFT calculations the spectrophotometric change is attributed to the coordination of two CN- ions in the axial positions of the Co(II) atom, with simultaneous formation of anionic complex [Co(TPyP)(CN)2]-2. [Co(TPyP)] can operate efficiently as an optical selective sensor for CN- in commercial cigarettes in the micromolar concentration range. Additionally, this Co(II)-polymer can capture CN- in solid-liquid extractions. The development of bifunctional molecules able to visually sense CN- ions and extract them from solid crystalline salts has not been explored until now.

Source: Journal of Molecular Structure

DOI: 10.1016/j.molstruc.2025.141912