Abstract
Charge-transfer complexes of tamoxifen (breast cancer) with DDQ and TCNQ have been synthesized and characterizes experimentally and confirmed theoretically.
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•Charge transfer complexes formed by reaction of tamoxifen and electron acceptors.•The synthesized complexes were characterized using various spectroscopic techniques.•The characteristic physical parameters data have been reported.•The theoretical study of TAM and their CT complexes was conducted using DFT.•The experimental results confirm the CT structures of the complexes.
To understand bioactive molecule-receptor interactions it is important to understand the molecular complexation and structural recognition properties of the materials in question. To this aim, the electron donating bioactive molecule tamoxifen (TAM) was combined with the electron accepting molecules 2,3-dichloro-5,6-dicyano-1,4-benzoquinone (DDQ) and 7,7,8,8-tetracyanoquinodimethane (TCNQ) to form TAM–DDQ and TAM–TCNQ charge transfer (CT) complexes. The properties of the complexes in solution and solid, their donor–acceptor interactions were investigated, and their stability was assessed in acetonitrile. Solid complexes of TAM–DDQ and TAM–TCNQ were characterized using nuclear magnetic resonance (NMR) and Fourier transform infrared (FTIR) spectroscopies to confirm their formation. Job’s and modified Benesi–Hildebrand methods were used to study the stoichiometries and association constants of TAM–DDQ and TAM–TCNQ, from which their stoichiometries were found to be 1:1. The physical parameters of the CT complexes in terms of their molar extension constants, dipole moments, and formation constants were determined to study their stability in solution. The results obtained in this study indicate that the complexes are suitable for assessing TAM in pharmaceutical preparations. The experimental results were complemented by density functional theory (geometry optimization, energy transition, and molecular electrostatic potential maps) at DFT/B3LYPlevel of theory.