Synthesis and Structural Analysis of a Piperazine-Containing Chalcone: Experimental and Theoretical Insights

Abstract

A novel piperazine-based chalcone derivative, 3-(4-fluorophenyl)-1-(4-(4-(2-hydroxyethyl)piperazin-1-yl)phenyl)prop-2-en-1-one, was synthesized through a base-catalyzed Claisen–Schmidt condensation reaction using 4-fluorobenzaldehyde and 4′-piperazinoacetophenone. The molecular structure of the synthesized compound was elucidated by ¹H NMR, APT-¹³C NMR, and ¹³C{¹H,¹⁹F} NMR spectroscopic techniques. Spectral data confirmed the successful formation of the chalcone framework, while the large coupling constant observed for the olefinic protons (J ≈ 15.9 Hz) verified the E-configuration of the α,β-unsaturated carbonyl system. Single-crystal X-ray diffraction studies performed on 3-(4-fluorophenyl)-1-(4-(4-(2-hydroxyethyl)piperazin-1-yl)phenyl)prop-2-en-1-one established that the compound crystallizes in the monoclinic crystal system with space group C2. The refined unit-cell dimensions were determined as a = 22.641 (8) Å, b = 5.9045 (19) Å, c = 15.628 (7) Å, and β = 117.17 (2)°. Experimental structural parameters were compared with geometries optimized using Hartree–Fock and density functional theory calculations at the 6-311+G(d,p) level, showing excellent agreement and supporting the reliability of the computational approach. To gain deeper insight into the electronic properties of the molecule, molecular electrostatic potential, frontier molecular orbital analysis, and Hirshfeld surface investigations were performed. These studies provided valuable information regarding charge distribution and intermolecular interactions within the crystal lattice. The combined experimental and theoretical findings indicate that this piperazine-containing chalcone derivative possesses favorable structural and electronic characteristics, highlighting its potential as a promising candidate for advanced nonlinear optical (NLO) applications.

Keywords

• Chalcone
• X-ray
• Theoretical calculations
• Hirshfeld surface analysis
• Spectroscopy
• NLO

Ethical Statement

Ethics committee approval was not required for this study because of there was no study on animals or humans.

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