Infrared spectrum, structural and optical properties and molecular docking study of 3-(4-fluorophenyl)-5-phenyl-4,5-dihydro-1H-pyrazole-1-carbaldehyde

Development of Novel Phase-Change Materials Derived from Methoxy Polyethylene Glycol and Aromatic Acyl Chlorides

In this research, novel, organic, solid-liquid phase-change materials (PCMs) derived from methoxy polyethylene glycol (MPEG) and aromatic acyl chlorides (ACs) were prepared through a condensation reaction. The MPEGs were used as phase-change functional chains with different molecular weights (350, 550, 750, 2000, and 5000 g/mol). The aromatic ACs, terephthaloyl chloride (TPC) and isophthaloyl chloride (IPC), were employed as bulky linker cores. Solubility tests demonstrated that this family of PCMs is soluble in protic polar solvents such as H₂O and MeOH, and insoluble in nonpolar solvents such as n-hexane. Fourier-ransform infrared spectroscopy (FT-IR UATR) and nuclear magnetic resonance (¹H, ¹³C, DEPT 135°, COSY, HMQC, and HMBC NMR) were used to confirm the bonding of MPEG chains to ACs. The crystalline morphology of the synthesized materials was examined using polarized optical microscopy (POM), revealing the formation of spherulites with Maltese-cross-extinction patterns. Furthermore, it was confirmed that PCMs with higher molecular weights were crystalline at room temperature and exhibited an increased average spherulite size compared to their precursors. Thermal stability tests conducted through thermogravimetric analysis (TGA) indicated decomposition temperatures close to 400 °C for all PCMs. The phase-change properties were characterized by differential scanning calorimetry (DSC), revealing that the novel PCMs melted and crystallized between -23.7 and 60.2 °C and -39.9 and 45.9 °C, respectively. Moreover, the heat absorbed and released by the PCMs ranged from 57.9 to 198.8 J/g and 48.6 to 195.6 J/g, respectively. Additionally, the PCMs exhibited thermal stability after undergoing thermal cycles of melting-crystallization, indicating that energy absorption and release occurred at nearly constant temperatures. This study presents a new family of high-performance organic PCMs and demonstrates that the orientation of substituent groups in the phenylene ring influences supercooling, transition temperatures, and thermal energy storage capacity depending on the MPEG molecular weight.

Investigation of the reactivity properties of a thiourea derivative with anticancer activity by DFT and MD simulations

Spectroscopic analysis of 1-(2-fluorophenyl)-3-[3-(trifluoromethyl)phenyl]thiourea (FPTT) is reported. Experimental and theoretical analyses of FPTT, with molecular dynamics (MD) simulations, are reported for finding different parameters like identification of suitable excipients, interactions with water, and sensitivity towards autoxidation. Molecular dynamics and docking show that FPTT can act as a potential inhibitor for new drug. Additionally, local reactivity, interactivity with water, and compatibility of FPTT molecule with frequently used excipients have been studied by combined application of density functional theory (DFT) and MD simulations. Analysis of local reactivity has been performed based on selected fundamental quantum-molecular descriptors, while interactivity with water was studied by calculations of radial distribution functions (RDFs). Compatibility with excipients has been assessed through calculations of solubility parameters, applying MD simulations. Graphical abstract Reactive sites identified.

Concentration dependent SERS, DFT and molecular docking studies of a ureido derivative with antitubercular properties

Spectroscopic analysis, density functional theory (DFT) studies and surface enhanced Raman scattering (SERS) of antimycobactetial 4-[3-(4-acetylphenyl)ureido]-2-hydroxybenzoic acid (AUHB) have been studied on different silver sols. For Raman and SERS wavenumbers, very large changes are observed. Observed variations in the modes of ring may be due to surface π-electron interactions and presence of this indicated that poly substituted ring is more inclined than para substituted phenyl ring and assumes a inclined position for concentration 10^-3 M. Changes in orientation are seen in SERS spectra depending on concentration. In order to find electron-rich and poor sites of AUHB, molecular electrostatic potential was also constructed. The molecular docking results show that binding affinity and interactions with the receptor DprE1 may be supporting evidence for further studies in design further AUHB pharmaceutical applications. Based on antitubercular activity of 4-aminosalicylic acid (PAS) and urea derivatives we designed, synthesized and investigated mutual PAS-urea derivatives as potential antimycobacterial agents.

Spectroscopic investigations, concentration dependent SERS, and molecular docking studies of a benzoic acid derivative

Spectroscopic analysis, density functional theory (DFT) studies and surface enhanced Raman scattering of 4-((3-bromo-5-chloro-2-hydroxybenzylidene)amino)benzoic acid (BCHB) have been studied on different silver colloids concentrations in order to know the particular chemical species responsible for the spectra. For Raman and surface enhanced Raman scattering (SERS) wavenumbers, changes are observed. Observed variations in the modes of ring may be due to interaction of the π-electrons and presence of this indicated that RingII is more inclined than RingI and the BCHB assumes inclined orientation for concentration 10^-3 M. Changes in orientation are seen in SERS spectra depending on concentration. In order to determine the electron-rich and poor sites of BCHB, the molecular electrostatic potential was also constructed. The molecular docking studies show that the bindings and interactions with the receptors may be supporting evidence for further studies in design further BCHB pharmaceutical applications.

Detailed quantum mechanical studies on bioactive benzodiazepine derivatives and their adsorption over graphene sheets

Estazolam (Z1) and related derivatives, adinazolam (Z2), alprazolam (Z3), 4-hydroxyalprazolam (Z4) and triazolam (Z5) have been studied by using various computational tools to analyze their geometry and spectral characteristics. The compounds were found to interact with graphene monolayer results shows that there is enhancement in various physico-chemical descriptors and surface enhanced Raman spectra (SERS). The various reactive descriptors obtained from the FMO analysis predict the reactive nature of the compound. The various lone pair/sigma to pi conjugation was analyzed using NBO formalism, which provides valuable information about intra molecular electron transfer which is vital in predicting the inherent stability of the molecule. Simulated electronic spectra using TD-DFT and CAM-B3LYP functional are discussed in detail with respect to electronic transitions and light harvesting efficiency. Suitability of candidates as a photo sensitizer in dye sensitized solar cells was studied and 4-Hydroxyalprazolam is identified as a suitable candidate. Nucleophilic and electrophilic regions of the molecules are identified using MESP, which adds to the reactivity information. It can be seen that the highest interaction energy has been obtained in the case of the Z5-graphene system, while the lowest interaction energy has been obtained in the case of the Z1-graphene system. Docking indicates that the ligands adsorbed over graphene also form stable complexes with the receptors as indicated by the high binding affinity energy values.

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

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.

Spectroscopic, single crystal X-ray, Hirshfeld, in vitro and in silico biological evaluation of a new series of potent thiazole nucleus integrated with pyrazoline scaffolds

In the present study, the spectroscopic characterization of a new series of substituted thiazole linked pyrazoline scaffolds 4a-l was performed. The formation of 4a-l from the intermediate 3-(4-chlorophenyl)-5-[4-(propan-2-yl)phenyl]-4,5-dihydro-1H-pyrazole-1-carbothioamide 2 and substituted 2-bromo-1-phenylethanone 3a-l was evidenced through the changes in FTIR, ¹H NMR, ¹³C NMR, LCMS data. The X-ray diffraction studies revealed that compound 2 and 4g crystallized in monoclinic crystal system with P2₁/n space group. Compound 4j crystallized in triclinic system, P1̄ space group with Z=4. The percentage of intermolecular contacts and distribution of electrostatic potential of molecular crystal structures was resolved by Hirshfeld surface analysis with 2D finger plots and electrostatic potential map. The newly synthesized derivatives were screened for their in vitro antioxidant and antimicrobial activity. The single crystal studies revealed that, for compounds 2, 4g and 4j the isopropyl phenyl ring is positioned at near right angle with the other rings. Due to the lack of planarity of bulkier group substituted to phenyl ring (ring B), all the synthesized molecules showed weak to moderate radical scavenging capacity owing to the destabilization of the radical formed during oxidation. Also, on performing molecular docking studies to explore the interactions of ligand with the target pyrimidine nucleoside hydrolase YbeK with bound ribose complex (PNH, PDB ID-3GHW), disclosed that active compounds emerged for in vitro studies also bound to PNH more efficiently. The compounds with polar group substitution interacted through hydrogen bonding while other molecules with non-covalent interactions.