Synthesis, X-Ray, spectroscopic characterization (FT-IR, NMR, UV–Vis) and quantum chemical calculations of some substituted benzoylthiourea derivatives

Spectroscopic characterization, DFT, antimicrobial activity and molecular docking studies on 4,5-bis[(E)-2-phenylethenyl]-1H,1'H-2,2'-biimidazole

The newly synthesized imidazole derivative namely, 4,5-bis[(E)-2-phenylethenyl]-1H,1'H-2,2'-biimidazole (KA1), was studied for its molecular geometry, docking studies, spectral analysis and density functional theory (DFT) studies. Experimental vibrational frequencies were compared with scaled ones. The reactivity sites were determined using average localized ionization analysis (ALIE), electron localized function (ELF), localized orbital locator (LOL), reduced density gradient (RDG), Fukui functions and frontier molecular orbital (FMO). Due to the solvent effect, a lower gas phase energy gap was observed. Through utilization of the noncovalent interaction (NCI) method, the hydrogen bond interaction, steric effect and Vander Walls interaction were investigated. Molecular docking simulations were employed to determine the specific atom inside the molecules that exhibits a preference for binding with protein. The parameters for the molecular electrostatic potential (MESP) and global reactivity descriptors were also determined. The thermodynamic characteristics were determined through calculations employing the B3LYP/cc-pVDZ basis set. Antimicrobial activity was carried out using the five different microorganisms like Escherichia coli, Streptococcus pneumoniae, Staphylococcus aureus, Klebsiella pneumoniae and Candida albicans.

A Dual Approach on Experimental, Theoretical Insight of Structural Elucidation, Hirshfeld Surface Analysis, Optical and Electrochemical Properties of Acyl Thiourea-Ethynyl Hybrid Derivatives

Hybrid moieties of ethynylated-thiourea, Th1 and Th2 have been synthesised via the addition reaction between ethynyl derivatives and 4-tert-butylbenzoyl isothiocyanate in acetone, and were characterised by selected spectroscopic methods (i.e., ¹H and ¹³C NMR, UV-visible, FT-IR) and elemental analysis. Thermogravimetric analysis indicated that Th1 and Th2 were relatively stable up to ca. 210 °C. Single-crystal X-ray diffraction was used to identify the crystal structure of Th2 in which the centre of 1-acyl thiourea moiety (-C(O)NHC(S)NH) exhibits S conformation. The Hirshfeld surface analysis has allowed visualizing the crystal packing, which is characterised by the prolonged intermolecular N-H⋯O = C and N-H⋯S = C hydrogen-bonding interactions within Th2 molecule. Electrochemical data of both compounds correspondingly exhibit irreversible redox potential processes. Besides, frontier molecular orbitals and Natural Bond Orbital population analysis were computed at the B3LYP/6-31G (d, p) level of approximation, suggesting strong delocalization of the electronic density through a conjugated π-system involving the ethynyl-phenyl and thiourea groups.

GRAPHICAL ABSTRACT

Figure of molecular structure for acyl thiourea-ethynyl derivative. Two derivatives of acyl thiourea-ethynyl were synthesised and characterised by selected spectroscopic methods such as 1H and 13C NMR, UV-visible, FT-IR, elemental, thermal, electrochemical, X-ray diffraction, and density functional theory (DFT) calculation for molecular orbitals and natural bond orbital population analysis.

Novel benzoylthiourea derivatives had differential anti-inflammatory photodynamic therapy potentials on in vitro stimulated mammalian macrophages

Novel benzoylthioureas, N-((5-chloropyridin-2yl)carbamothioyl)benzamide, (HL¹), N-((2-chloropyridin-3yl)carbamothioyl)benzamide, (HL²), N-((5-bromopyridin-2yl)carbamothioyl)benzamide, (HL³) and N-(Naphthalene-1-yl(phenyl)carbamothioyl)benzamide, (HL⁴), were synthesized. Their characterizations were made by FT-IR,¹H NMR and ¹³C NMR spectrophotometric analysis. Single crystal X-ray diffraction measurements were conducted to determine the crystal structure of HL¹ and HL⁴.  The HL¹ crystallization conditions are: in the monoclinic crystal system with P2₁/c space group, Z = 2, a = 8.118(2) Å, b = 12.056(3) Å, c = 13.753(4) Å. HL⁴crystallization conditions are: in the orthorhombic crystal system with Pbca space group, Z = 8, a = 19.597(9) Å, b = 8.270(4) Å, c = 24.299(11) Å. Investigation of photodynamic and antiinflamatory effects of these compounds revealed that they are potent adducts. Using these derivatives, mammalian macrophages were stimulated with LPS to test their anti-inflammatory activity. Based on pro-inflammatory cytokine production levels, the photodynamic anti-inflammatory activity of these adducts were found to differ. Our results showedthat benzoylthioureas can be used as potential photodynamic therapy agents to suppress the excessive inflammatory reactions encountered in autoimmune and inflammatory disorders.

Crystal structure of ethyl-2-(3-benzoylthioureido)propanoate, C13H16N2O3S

C13H16N2O3S, triclinic, P 1 ‾ $P\bar{1}$ (no. 2), a = 8.1998(4) Å, b = 9.1320(4) Å, c = 10.7062(6) Å, α = 106.183(5)°, β = 111.506(5)°, γ = 97.589(4)°, V = 691.27(7) Å3, Z = 2, R gt(F) = 0.0346, wR ref(F 2) = 0.0957, T = 293(2) K.

Probing the Effect of Halogen Substituents (Br, Cl, and F) on the Non-covalent Interactions in 1-(Adamantan-1-yl)-3-arylthiourea Derivatives: A Theoretical Study

The effect of halogen substituents (X = Br, Cl, and F) on the crystal packing and intra- and intermolecular interactions in four adamantane-thiourea hybrid derivatives is investigated using different theoretical tools. The bromo and chloro derivatives exhibit 3D isostructurality as evident from lattice parameters, molecular conformation, and crystal packing. The density functional theory study suggests that the molecular conformation of the parent (unsubstituted) and fluoro derivatives exhibits a stable low energy anti-syn conformation. In contrast, bromo and chloro derivatives adopt stable and relatively high energy minima on their potential energy surfaces. Hirshfeld surface analysis reveals the effect of halogen substituents on the intermolecular contacts. The halogen atoms mainly reduce the contribution of H···H contacts toward crystal packing. PIXEL energy analysis indicates the strong dimer formed by N-H···S hydrogen bonds in all four structures. It also revealed that a vast number of H···H contacts observed in different dimers of these structures either presented along with other conventional interactions or solely stabilize the dimeric topology. The topological parameters for intermolecular interactions in these structures suggest an intermediate bonding character between shared and closed-shell interactions for N-H···S hydrogen bonds in the parent and chloro derivatives. In contrast, the N-H···S hydrogen bond in other structures is of a closed-shell interaction. Among four derivatives, the fluoro derivative is weakly packed in the solid state based on the PIXEL method's lattice energy calculation.