Study on the colorimetric properties of 2,4,6-triarylpyridine derivative compound for imaging Formaldehyde

The derivative compound of 2,4,6-triarylpyridine was synthesized in two steps. The target compound was tested as colorimetric chemosensor against formaldehyde and the limit of detection was also determined using spectrophotometer UV-vis. The first step of the synthesis was the formation of 4-phenyl-2,6-bis(4-nitrophenyl)pyridine compound (1) from 4-nitroacetophenon and benzaldehyde. The second step of the synthesis was the formation of 4-phenyl-2,6-bis-(4-aminophenyl)pyridine (2) from reduction of the nitro group in compound 1 by HCl 37% solution and Sn metal. Compound 1 and 2 were characterized by spectrometers FTIR, ¹H NMR and direct inlet-mass spectrometry. The results showed that compound 1 was synthesized with a yield of 78.3% and compound 2 with a yield of 68.9%. Compound 2 as chemosensor showed color transition from colorless to yellow in chemosensor test against formaldehyde in ethanol solvent. The limit of detection of formaldehyde was measured as 4.7×10^-3 M using spectrophotometer UV-vis. (paper)