Facile preparation, characterization, SC-XRD and DFT/DTDFT study of diversely functionalized unsymmetrical bis-aryl-α, β-unsaturated ketone derivatives

The current research work is about the synthesis of diversely functionalized unsymmetrical mono-carbonyl curcuminoids: (1E,4E)-1-(2-methoxy-4-nitrophenyl)-5-(4-methoxyphenyl)-2-methylpenta-1,4-dien-3-one (MMMD), (1E,4E)-1-(2-methoxy-4-nitrophenyl)-5-(4-chlorophenyl)-2-methylpenta-1,4-dien-3-one (CMMD) and (1E,4E)-5-(4-bromophenyl)-1-(2- methoxy-4-nitrophenyl )-2-methylpenta-1,4-dien-3-one (BMMD). The spectroscopic techniques: H-1 NMR, C-13 NMR, FT-IR, UV-Vis and single crystal X-ray diffraction (SC-XRD) were utilized to characterize the synthesized compounds (MMMD, CMMD and BMMD). The quantum chemical insights: geometric parameters, nonlinear optical (NLO), natural bond orbitals (NBOs) and frontier molecular orbitals (FMOs) properties of titled compounds were determined by B3LYP/6-311+G(d,p) level.. Moreover, the photophysical properties were studied by UV-VIS analysis based on TD-DFT/B3LYP/6-311 + G (d,p) level. The computed structural parameters and spectroscopic results of the compounds are found in close concurrence to that experimental data. The molecular stability because of hyper conjugative interactions is figured out via NBO analysis. The charge transfer phenomenon in the title compounds is studied by FMOs. As CMMD contains highest energy gap value as 3.561 eV, while MMMD contains least energy gap as 3.195 eV which exposes the effective intra molecular charge transfer (ICT) communication within the MMMD. Overall, energy gap order is obtained to be CMMD > BMMD > MMMD. The information regarding chemical reactivity due to involvement of different sites is determined by molecular electrostatic potential (MEP) analysis. Among all studied compounds, MMMD contains highest mean polarizability value of 324 a. u. Nevertheless, CMMD contains lowest mean dipole polarizability value of 313 a. u. The mean linear polarizability value order of studied compounds is: MMMD > BMMD > CMMD. The decreasing order for beta(tot) of studied compounds is obtained like MMMD > BMMD > CMMD. (C) 2020 Elsevier B.V. All rights reserved.