Development of benzaldehyde-pyrazoline hybrids for functionalization of polymers with fluorescent pendant moieties

An Acad Bras Cienc. 2024 Mar 18;96(1):e20220875. doi: 10.1590/0001-3765202420220875. eCollection 2024.ABSTRACTCompounds with a pyrazoline scaffold are useful as sensors for fluorescence detection of different types of analytes. Recovery of a pyrazoline-based sensor with a view to use it recurrently would be more facile when the sensing molecule is attached to a solid support. A reaction sequence has been designed to synthesize two benzaldehyde-pyrazoline hybrids as examples of a hitherto unknown type of compounds to be employed for the potential derivatization of polymers containing primary amino groups through azomethine formation. All intermediates, including the fairly unstable N1 -unsubstituted pyrazolines, along with the target compounds have been structurally characterized, with an emphasis on their particular NMR features. Examination of the photophysical properties of these benzaldehyde-pyrazoline hybrids showed that, despite the shortening of the extended N1-N2-C3 conjugated system common to 1,3,5-triarylpyrazolines through the replacement of the aryl at N1 by an aryloxyacetyl moiety, the novel compounds exhibit emission maxima at approximately 350 nm. Moreover, the introduction of a moderately electron-withdrawing substituent such as chlorine in the phenyl at C3 of pyrazoline leads to an amplification of fluorescence intensity.PMID:38511740 | DOI:10.1590/0001-3765202420220875

Source: An Acad Bras Cienc - March 21, 2024 Category: Science Authors: Gheorghe Roman Mihaela Balan-Porc ăraşu Liviu S ăcărescu Source Type: research