Zinc(II) Complex Containing Oxazole Ring: Synthesis, Crystal Structure, Characterization, DFT Calculations, and Hirshfeld Surface Analysis

A new complex of Zn(II), with 5-chloro-2-methylbenzoxazole ligand (L), has been synthesized by the reaction of zinc dichloride with the ligand (L= C8H6ClNO) in ethanol solution: dichloridobis(5-chloro-2-methyl-1,3-benzoxazole)-zinc(II), C16H12Cl4N2O2Zn. The synthesized complex has been fully characterized by elemental analysis, molar conductivity, FT‑IR, UV‑Vis, and single-crystal X-ray diffraction (XRD). The XRD analysis reveals that the complex has a 1:2 metal-to-ligand ratio. The zinc(II) complex has a distorted tetrahedral geometry with two coordinated nitrogen atoms from the ligand. Density Functional Theory (DFT) calculations were performed at the B3LYP level of theory using the LANL2DZ basis set for metal complex and the 6–31G(d) basis set for non-metal elements to determine the optimum geometry structure of the complex, and the calculated HOMO and LUMO orbital energies were presented. A natural bond orbital (NBO) analysis was carried out on the molecules to analyze the atomic charge distribution before and after the complexation of the ligand. The Hirshfeld surface mapped over dnorm, shape index, and curvature exhibited strong H... Cl/Cl...H and H...H intermolecular interactions as the principal contributors to crystal packing.

Synthesis, optical and structural characterisation of ZnS nanoparticles derived from Zn(ii) dithiocarbamate complexes

Zinc sulphide nanoparticles represented as ZnS1, ZnS2 and ZnS3 have been prepared from Zn(ii) N-methyl-N-ethanoldithiocarbamate (1) complex and its 2,2′-bipyridine (2) and 1,10′-phenanthroline (3) adducts, respectively. Both the parent complex (1) and the adducts (2) and (3) were characterised by spectroscopic techniques and elemental analysis. In the solid state, the structures of complexes (1) and (2) were established using single-crystal X-ray analysis. Complex (1) possessed a distorted trigonal bipyramidal geometry about the zinc centre, whilst forming a dimer via bidentate bridging coordination between two opposite dithiocarbamate motifs. On the other hand, complex (2) formed a trigonal prismatic geometry about the Zn centre with a ZnS4N2 chromophore. The decomposition of the complexes in hexadecylamine afforded spherical-shaped ZnS nanoparticles of the cubic sphalerite crystal phase. The transmission electron microscopy (TEM) micrographs showed that the average particles size of ZnS1, ZnS2 and ZnS3 were 2.63, 5.27 and 6.52 nm, respectively. In the optical study, the estimated bandgap energies were found in the range between 4.34 and 4.08 eV, which indicated a blue shift when compared with the bandgap energy of bulk ZnS.

Synthesis, Characterization and Biological Activity of Some Dithiourea Derivatives

Novel dithiourea derivatives have been designed as HIV-1 protease inhibitors using Autodock 4.2, synthesized and characterized by spectroscopic methods and microanalysis. 1-(3-Bromobenzoyl)-3-[2-([(3-bromophenyl)formami-do]methanethioylamino)phenyl]thiourea (10) and 3-benzoyl-1[(phenylformamido)methanethioyl]aminothiourea (12) gave a percentage viability of 17.9 ± 5.6% and 11.2 ± 0.9% against Trypanosoma brucei. Single crystal X-ray dif-fraction analysis of 1-benzoyl-3-(5-methyl-2-[(phenylformamido)methanethioyl]aminophenyl)thiourea (1), 3-ben-zoyl-1-(2-[(phenylformamido)methanethioyl]aminoethyl)thiourea (11), 3-benzoyl-1-[(phenylformamido)methan-ethioyl]aminothiourea (12) and 3-benzoyl-1-(4-[(phenylformamido)methanethioyl]aminobutyl)thiourea (14) have been presented. 1-(3-Bromobenzoyl)-3-[2-([(3-bromophenyl)formamido]methanethioylamino)phenyl]thiourea (10) gave a percentage inhibition of 97.03 ± 0.37% against HIV-1 protease enzyme at a concentration of 100 ?M.

Metal-mediated reactions towards the synthesis of a novel deaminolysed bisurea, dicarbamolyamine

A new selective cobalt acetate tetrahydrate or cerium nitrate hexahydrate mediated cleavage of the C–N bond of a benzoyl isothiocyanate derivative to give (carbamoylamino)methanethioamide is presented. The cleavage of the C–N could not be achieved in the absence of thione. The novel silver-mediated conversion of a thione to the carbonyl was achieved on 1-((benzamido)formyl)urea and replicated on (carbamoylamino)methanethioamide to give the deaminolyzed bisurea (dicarbamolyamine). The compounds were characterized by IR, NMR, microanalysis and GC–MS. The single crystal X–ray diffraction studies of the crystal structures of compounds I, II, III and V is discussed.

Crystal structure of (6E,20E)-3,24-di-fluoro-13,14,28,29-tetra-hydro-5H,22H-tetra-benzo[e,j,p,u][1,4,12,15]tetra-oxa-cyclo-docosine-5,22-dione

The conformation of the title compound, C34H26F2O6, is cone-shaped, partially determined by intra-molecular C-H⋯O short contacts. The benzene rings at the top of the cone are inclined to one another by 73.10 (7)°, while the benzene rings at the bottom of the cone are inclined to one another by 35.49 (8)°. In the crystal, mol-ecules are linked by C-H⋯O and C-H⋯F hydrogen bonds, forming a three-dimensional supra-molecular structure. There are also C-H⋯π contacts present within the framework structure.

Selective removal of isoquinoline and quinoline from simulated fuel using 1,1′-binaphthyl-2,2′-diol (BINOL): crystal structure and evaluation of the adduct electronic properties

1,1′-Binaphthyl-2,2′-diol/quinoline (BINOL/QUN) and 1,1′-binaphthyl-2,2′-diol/isoquinoline (BINOL/ISOQUN) adducts were successfully synthesized. Isothermal titration calorimetry (ITC) involving 1,1′-binaphthyl-2,2′-diol (BINOL) and isoquinoline confirming interaction.

Benzimidazole or Diamide From a Reaction of Diamines and Carboxylic Acids or Acid Chlorides: Crystal Structures and Theoretical Studies

A reaction of an acid chloride with a diamine yielded a diamide. m-Toluic acid was chlorinated to m-toluoyl chloride and subsequently reacted with 4-methyl-o-phenylenediamine in pyridine to obtain 3-methyl-N-[2-(3-methylbenzamido)phenylbenzamide (I). 2-(3-Methylphenyl)-1H-benzimidazole (II) has been obtained upon reacting o-phenylenediamine with m-toluic acid in polyphosphoric acid and toluene. The compounds have been characterized by IR, NMR, microanalyses and GC-MS. The crystal structures of the compounds have been discussed. DFT calculations of the frontier orbitals of the precursor compounds have been carried out to ascertain the groups that contribute to the HOMO and LUMO, and to study their contribution to the reactivity in the formation of the diamides and benzimidazoles. The synthesis of the amide from a diamine was seen to be favoured in the presence of a good leaving group attached to the carbonyl as in the case of acid chloride. However, the synthesis of benzimidazoles was found to be favoured in the presence of an excess of a protonating agent and high temperature.

pH-metric chemical speciation modeling and studies of in vitro antidiabetic effects of bis[(imidazolyl)carboxylato]oxidovanadium(IV) complexes

A range of bidentate N,O-donor ligands of the imidazolyl-carboxylate moiety, which partially mimic naturally occurring bioligands, were prepared and reacted with the oxidovanadium(IV) ion to form the corresponding bis-coordinated oxidovanadium(IV) complexes. The aqueous pH-metric chemical speciation was investigated using glass electrode potentiometry, which allowed for the determination of protonation and stability constants of the ligands and complexes, respectively. The species distribution diagrams generated from this information gave evidence that the bis[(imidazolyl)carboxylato]oxovanadium(IV) complexes possess a broad pH-metric stability. The complexes improved glucose uptake in cell cultures using 3T3-L1 adipocytes, C2C12 muscle cells and Chang liver cells. The PTP inhibition studies indicated that the mechanism underlying insulin-stimulated glucose uptake was possibly via the protein tyrosine phosphorylation through the inhibition of the protein tyrosine phosphatase 1B (PTP 1B). The vanadium compounds also demonstrated the inhibition of D-dimer formation, suggesting that these compounds could potentially relieve a hypercoagulative state in diabetic patients.

Redetermination of the crystal structure of N,N-diphenylacetamide, at 200 K, C14H13NO

C14H13NO, orthorhombic, Pbca (no. 61), a = 10.9317(3) Å, b = 11.9675(4) Å, c = 17.2285(5) Å, V = 2253.9 Å3, Z = 8, Rgt(F) = 0.0340, wRref(F2) = 0.0879, T = 200 K.

Redetermination of the crystal structure of ammonium formiate at 200 K, CH5NO2

CH5NO2, monoclinic, Pc (no. 7), a = 3.7747(3) Å, b = 4.6743(3)Å, c = 9.0947(8) Å, β = 90.642(4)°, V = 160.5 Å3, Z = 2, Rgt(F) = 0.0168, wRref(F2) = 0.0427, T = 200(2) K.

Redetermination of the crystal structure of diphenylcarbonate, C13H10O3, at 200 K – Localization of hydrogen atoms

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Synthesis, spectral and thermal studies of pyridyl adducts of Zn(ii) and Cd(ii) dithiocarbamates, and their use as single source precursors for ZnS and CdS nanoparticles

The synthesis and characterization of pyridyl adducts of Zn(ii) and Cd(ii) dtc: precursors to ZnS and CdS nanoparticles are reported.

The formation of 2,2,4-trimethyl-2,3-dihydro-1H-1,5-benzodiazepine from 1,2-diaminobenzene in the presence of acetone

In an attempt to synthesize a 2-substituted benzimidazole from the reaction of o-phenylenediamine and isophthalic acid in the presence of acetone and ethanol under microwave irradiation, a salt of the isophthalate ion and 2,2,4-trimethyl-2,3-dihydro-1H-1,5-benzodiazepin-5-ium ion was obtained. The condensation of two moles of acetone with the amine groups resulted in the formation of the benzodiazepine which crystallized as an iminium cation forming a salt with the isophthalate anion. The formation of benzodiazepine was also confirmed by performing the reaction of o-phenylenediamine with excess acetone in ethanol under conventional heating conditions. The compounds were characterized by NMR, FTIR, HRMS and microanalysis as well as X-ray crystallography. The reaction mechanism leading to the formation of benzodiazepine is also discussed.

Crystal structure of ethyl 6-methyl-4-oxo-1,4-dihydroquinoline-3-carboxylate, C13H13NO3

C13H13NO3, monoclinic, C2/c (no. 15), a = 22.886(3) Å, b = 12.763(2) Å, c = 8.175(1) Å, β = 107.756(4)°, V = 2274.3 Å3, Z = 8, Rgt(F) = 0.0599, wRref(F2) = 0.1487, T = 200 K.

Redetermination of the crystal structure of N-acetyl glycine (2-acetamidoacetic acid), C4H7NO3

C4H7NO3, monoclinic, P21/c (no. 14), a = 4.8110(2) Å, b = 11.5030(5) Å, c = 9.7660(4) Å, β = 97.864(2)°, V = 535.4 Å3, Z = 4, Rgt(F) = 0.0356, wRref(F2) = 0.1099, T = 200 K.

Redetermination of the structure of 7-chloro-1,3-dihydro-1-methyl-5- phenyl-1,4-benzodiazepin-2(3H)-one, C16H13ClN2O

C16H13ClN2O, monoclinic, P21/c (no. 14), a = 7.9510(2) Å, b = 13.2274(3) Å, c = 12.8923(3) Å, β = 90.172(1)°, V = 1355.9 Å3, Z = 4, Rgt(F) = 0.0314, wRref(F2) = 0.0834, T = 200 K.

Redetermination of the structure of N-(2-benzoyl-4-chlorophenyl)-2- chloroacetamide, C15H11Cl2NO2

C15H11Cl2NO2, triclinic, P1¯ (no. 2), a = 5.9681(3) Å, b = 9.9888(5) Å, c = 11.9936(6) Å, α = 81.800(2)°, β = 77.113(2)°, γ = 81.364(2)°, V = 684.6 Å3, Z = 2, Rgt(F) = 0.0314, wRref(F2) = 0.0818, T = 200 K.

Redetermination of the structure of 1,4-diethoxybenzene, C10H14O2

C10H14O2, monoclinic, P21 (no. 4), a = 7.0647(2) Å, b = 7.4686(3) Å, c = 9.4212(3) Å, β = 110.615(2)°, V = 465.3 Å3, Z = 2, Rgt(F) = 0.0332, wRref(F2) = 0.0898, T = 200 K.

Redetermination of the crystal structure of (1R,2S)-2-((dimethylphenyl)- carbamoyl)-1-propylpiperidin-1-ium chloride monohydrate, C17H29ClN2O2

C17H29ClN2O2, monoclinic, P21 (no. 4), a = 9.5140(5) Å, b = 7.2916(4) Å, c = 13.0720(8) Å, β = 97.658(2)°, V = 898.8 Å3, Z = 2, Rgt(F) = 0.0343, wRref(F2) = 0.0957, T = 200 K.