Synthesis, structural characterization and quantum chemical calculations on 1-(isomeric methylbenzoyl)-3-(4-trifluoromethylphenyl)thioureas

Effect of Terminal Hydroxy Groups on the Structural Properties of Acyl Thioureas

The 1-acyl thiourea family [R1C(O)NHC(S)NR2R3] exhibits the flexibility to incorporate a wide variety of substituents into their structure. The structural attributes of these compounds are intricately tied to the type and extent of substitution. In the case of 3-mono-substituted thioureas (R2=H), the conformational behavior is predominantly shaped by the presence of an intramolecular N-H ⋅ ⋅ ⋅ O=C hydrogen bond. This study delves into the structural consequences stemming from the inclusion of substituents possessing hydrogen-donor capabilities within four novel 1-acyl-3-mono-substituted thiourea derivatives. A comprehensive suite of analytical techniques, encompassing FTIR, Raman spectroscopy, multinuclear (1H and 13C) NMR spectroscopy, single-crystal X-ray diffraction, and supported by computational methods, notably NBO (Natural Bond Orbital) population analysis, Hirshfeld analysis, and QTAIM (Quantum Theory of Atoms in Molecules), was harnessed to scrutinize and characterize these compounds. In the crystalline state, these compounds exhibit an intricate interplay of intermolecular interactions, prominently featuring an expansive network of hydrogen bonds between the hydroxy (-OH) groups and the carbonyl and thiocarbonyl bonds within the 1-acyl thiourea fragment. Notably, the topological analysis underscores significant distinctions in the properties of the acyl thiourea fragment and the intramolecular >C=O ⋅ ⋅ ⋅ H-N bond when transitioning from the isolated molecule to the crystalline environment.

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.

Synthesis and characterization of novel acylthiourea compounds used in ions recognition and sensing in organic media

A series of novel N-acyl-N'-aryl thiourea derivatives were designed and prepared with the aim to develop dual responsive receptors for anions and cations. The structure of the new products was confirmed by NMR spectroscopy (¹³C and ¹H), elemental analysis, and IR spectroscopy. Their thermal stability was studied by thermogravimetric analysis (TG) and it was found that these acyl thiourea derivatives are stable up to 160 °C. The ion recognition and sensing properties of the acyl thiourea compounds were investigated by UV-VIS absorption spectroscopy in organic media upon the addition of various salts. The UV-VIS studies revealed that these acyl thiourea derivatives are able to sense biological important ions such as fluoride and copper (II) ions.

Synthesis, characterization, antimicrobial and cytotoxic activity of novel half-sandwich Ru(II) arene complexes with benzoylthiourea derivatives

Three new ruthenium(II)-arene complexes, [Ru(η⁶-p-cymene)(L¹)Cl₂] (C1) where L¹ is N-((4 methoxyphenyl)carbamothioyl)benzamide; [Ru(η⁶-p-cymene)(L²)Cl₂] (C2) where L² is 4-(3-benzoylthioureido)benzoic acid and [Ru(η⁶-p-cymene)(L³)Cl₂] (C3) where L³ is methyl 4-(3- benzoylthioureido)benzoate have been synthetized, characterized and evaluated for their antimicrobial and anticancer activity. Characterization was performed using ¹H and ¹³C NMR, IR spectroscopy, mass spectrometry, electrical conductivity measurements and X-Ray diffraction analysis. X-Ray diffraction analysis of C1 showed typical expected "piano-stool" geometry with ruthenium coordinated to ligand via nitrogen and sulfur atoms of benzoylthiourea derivatives. Interesting, in herein described complex, upon coordination the four-membered ring was formed, instead of six-membered chelate common for this type of ligands. Cytotoxic activity was determined in human cervix adenocarcinoma (HeLa) cell line and IC₅₀ values ranged from 29.68 to 52.36 μM and the complexes were more active than related ligands (except in case of C2 where it is found that IC₅₀ value is close to IC₅₀ value of related ligand). Complex [Ru(η⁶-p-cymene)(L¹)Cl₂] (C1) expressed the highest cytotoxic activity with IC₅₀ value of 29.7 μM. Complexes and ligands were tested against nine Gram-positive and Gram-negative bacteria and one yeast- Candida albicans. Clinical Candida spp. strains from microbiological laboratories were included in testing processes as well. Minimum inhibitory concentrations values ranged from 62.5 μg/ml for complexes against Candida albicans to over 1000 μg/ml for several bacterial species.

Discotic Liquid Crystals Based on Cu(I) Complexes with Benzoylthiourea Derivatives Containing a Perfluoroalkyl Chain

Mesomorphic three-coordinate copper(I) complexes ([Cu(BTU)2X], where X = Cl or Br) based on a new N-benzoylthiourea (BTU) ligand with two decyloxy and one perfluorooctyl groups at its periphery were designed and prepared. The BTU ligand coordinates via the S atom in a neutral monodentate fashion as confirmed by IR and NMR spectroscopy data. The liquid crystalline behavior of these copper(I) complexes was investigated by a combination of polarized optical microscopy (POM), differential scanning calorimetry (DSC), and X-ray diffraction analysis (XRD), while their thermal stability was studied by thermogravimetric analysis (TGA). These new copper(I) complexes have mesomorphic properties and exhibit a hexagonal columnar mesophase over a large temperature range, more than 100°C.

Crystal structure of bis(2-((allylcarbamothioyl)imino)-4-methylthiazol-3-ido-κ2 N,S)palladium(II), C16H20N6PdS4

C16H20N6PdS4, monoclinic, C2/c (no. 15), a = 13.2801(8) Å, b = 18.5771(8) Å, c = 10.2577(5) Å, β = 121.906(2)°, V = 2148.29(19) Å3, Z = 4, R gt(F) = 0.0300, WR ref(F 2) = 0.0721, T = 293 K.