Experimental and quantum chemical studies of a novel synthetic prenylated chalcone

A novel substituted chalcone has been synthetized. In order to identify the functional groups present in the new synthesized compound and confirm its chemical structure, experimental and theoretical 1H-NMR and 13C-NMR spectra were analyzed. The theoretical molecular structure and NMR spectra were calculated at both the Hartree-Fock and Density Functional (meta: TPSS; hybrid: B3LYP and PBE1PBE; hybrid meta GGA: M05-2X and M06-2X) levels of theory in combination with a 6-311++G(d,p) basis set. The structural parameters showed that the best method for geometry optimization was DFT:M06-2X/6-311++G(d,p), whereas the calculated bond angles and bond distances match experimental values of similar chalcone derivatives. The NMR calculations were carried out using the Gauge-Independent Atomic Orbital (GIAO) formalism in a DFT:M06-2X/6-311++G(d,p) optimized geometry.Considering all HF and DFT methods with GIAO calculations, TPSS and PBE1PBE were the most accurate methods used for calculation of 1H-NMR and 13C-NMR chemical shifts, which was almost similar to the B3LYP functional, followed in order by HF, M05-2X and M06-2X methods. All calculations were done using the Gaussian 09 software package. Theoretical calculations can be used to predict and confirm the structure of substituted chalcones with good correlation with the experimental data.Chalcones are ubiquitous substances found in a diversity of plants. They are precursors to other natural products, such as flavonoids, which have reported a wide range of biological activities such as antioxidant, antibacterial, antitumoral among others [1]. Due to the importance of these compounds, diverse studies on synthesis and biological activities of molecules containing the chalcone ring system, have been reported recently [2]. The prenyloxychalcones are important derivatives of chalcones, which contain a prenyl-type side chain with different length, including 2,2-dimethylallyl, geranyl or farnesyl chains; these compounds have shown i