Combined experimental and theoretical studies on molecular structures, spectroscopy of 4-(3-(2-amino-3,5-dibromophenyl)-1-(benzoyl)-4,5-dihydro-1H-pyrazol-5-yl)benzonitriles through NBO, FT-IR, HOMO-LUMO and NLO analyzes

Abstract

The pyrazole compounds 4-(3-(2-amino-3,5-dibromophenyl)-1-(4-substitutedbenzoyl)-4,5-dihydro-1H-pyrazol-5-yl) benzonitriles (4–6) have been synthesized and characterized by elemental, IR, 1HNMR spectral methods. In addition, the synthesized compounds were subjected to density functional theory for further understanding of the molecular architecture and optoelectronic properties. The optimized geometric parameters were in support of the corresponding experimental values. The FT-IR spectra of 4–6 have been investigated extensively using DFT employing B3LYP/6-31G (d,p) level theory. The molecular electrostatic potential analysis has been utilized to identify reactive sites of title compounds. Natural bonding orbital analysis proved the inter- and intra-molecular delocalization and acceptor–donor interactions based on the second-order perturbation interactions. The calculated band gap energies revealed that charge transfer occurs within the molecule. The polarizability and hyperpolarizability were calculated which show that compounds posses nonlinear optical nature.

Molecular properties and In silico bioactivity evaluation of (4-fluorophenyl)[5)-3-phen-(4-nitrophenyl yl-4,5-dihydro-1H-pyrazol-1-yl]methanone derivatives: DFT and molecular docking approaches

“…The results were compared with the geometries of 4-(3-(2-amino-3,5-dibromophenyl)-1-(4-nitrobenzoyl)-4,5-dihydro-1 H -pyrazol-5-yl)benzonitrile predicted at the same level of theory. 28 The calculated C3–N7 bonds were 1.299, 1.298, 1.300, 1.299, 1.299 and 1.298 Å for M1–M6 , respectively, in agreement with the 1.299 Å calculated for Ma . This type of bond has been experimentally observed to be 1.275 Å and calculated to be 1.287 Å for bis-spiropipridinon/pyrazole derivatives.…”

“…The results have indicated inter- and intra-molecular delocalization and acceptor–donor interactions based on second-order perturbation interactions; moreover, polarizability and hyperpolarizability calculations have indicated that the compounds possess good NLO properties. 28 …”

“…In this work, DFT calculations were performed on 4-(3-(2-amino-3,5-dibromophenyl)-1-(benzoyl)-4,5-dihydro-1 H -pyrazol-5-yl)benzonitriles reported by Santhi and Bharathi. 28 Structural modifications were used to design six new compounds, as shown in Table 1 . The molecular structures, spectroscopic properties, charge distributions, frontier orbital energies, NLO properties and molecular docking simulations were analyzed to examine the bio-usefulness of the studied compounds.…”

Synthesis, characterization, thermal, anticancer studies, and density functional theory for potentially active pyrimidine‐based complexes

“…Figure 1 depicted the ligand's mass spectrum and described its monomeric structure 25 . A molecular ion peak at m / z = 436.13 amu in the spectrum was found to represent the anhydrous parent molecular weight.…”

Synthesis, spectral characterization (FT-IR and NMR) and DFT (Conformational analysis, molecular structure, HOMO-LUMO, UV-vis, NLO) computational studies on 2,2’-((1E,1’E)-phenazine-2,3 dilbis(azanylylidene))bis(methanyly- lidene))diphenol

“…NLO is at the forefront of current research because it provides the key functions of frequency shifting, optical modulation, optical switching, optical logic and optical memory for the emerging areas such as telecommunications, signal processing and optical interconnections [Bharathi et al 2017;Srinivasan et al 2015]. In discussing nonlinear optical properties, the polarization of the molecule by an external radiation field is often approximated as the creation of an induced dipole moment by an external electric field.…”