Eight new bismuth(III) complexes (1-8) of substituted hydrazones having general formula; [Bi(RCONHNCHC5H4N)Cl-x] and [Bi(RCONHNCHC9H6N)Cl-x], where R = C10H7O (1, and 8), C4H3S (2), C6H5O (3, and 6), C7H7 (4), C-5 H-4 N (5, and 7), x = 2 or 3 have been prepared. The substituted hydrazones (I-1-I-8) were synthesized by reacting the stoichiometric amounts of the respective hydrazides such as p-toluic hydrazide, 4-hydroxybenzhydrazide, thiophene-2-carboxylic acid hydrazide, 3-hydroxy-2-naphthoic acid hydrazide, Isonicotic acid hydrazide and appropriate aromatic aldehydes like pridine-2-carboxaldehyde and quinoline-2-carboxyaldehyde. These hydrazones (ligands),then complexed to Bi(III) species to yield the target compounds. They were characterized by FTIR, and NMR spectroscopy to find out an explicit evidence about their structural motifs. The X-ray data for (1 & I-6) further validate the chemical structures of the synthesized compounds. The molecular geometry for (1) is predominately distorted pentagonal bipyramidal where hepta-coordinated Bi(III) center is attached to the nitrogens of pyridine and of azomethine moieties along with the carbonyl oxygen, two chloro and two oxygens of the (two) DMSO molecules. The bond lengths for Bi(1)-O(1), Bi(1)-N(1) and Bi(1)-N(2) are 2.323(5), 2.539(6), 2.390(5) o A respectively indicating Bi(1)-O(1) as the strongest linkage to the metal center. The H-bonding, present in (1), contributed an extra stability to the structure. The synthesized compounds were initially screened for their possible antimicrobial, alpha-amylase, and protein kinase inhibition, some (1,2,6,8) exhibit significant activity. The experimental results are further endorsed by molecular docking studies against helicobacter pylori urease (1E9Y), epidermal growth factor receptor tyrosine kinase (1M17) and human pancreatic alpha amylase (5U3A) inhibition activity. The significant ligand-receptor interactions, observed at the binding pocket of the selected drug targets, further revealed the enzyme inhibition potential of the compounds and highlighting their possible roles as therapeutic agents in future drug discovery processes. (C) 2021 Elsevier B.V. Allrights reserved.

The crystal structure of a palladium(II) complex of imidazolidine-2-thione (Imt), [Pd(Imt)4]Cl2 (I) was determined by X-ray crystallography (CIF file CCDC no. 1946290). The structure of complex I is ionic consisting of [Pd(Imt)4]2+ cation and two chloride counter ions. The palladium atom in the complex ion assumes a distorted square planar geometry. The complex cation and non-coordinated chloride ions are connected to each other through electrostatic and hydrogen bonding interactions. To compare the stability of I with its corresponding non-ionic species [Pd(Imt)2Cl2] . 2Imt (Ia), DFT calculations were performed in the gas phase as well as in the DMSO solvent. The IR spectra of the ligand Imt and complex I were reliably interpreted theoretically. The structures of two related cyanide complexes; [Pd(Imt)2(CN)2]2 (II) and [Pd(Imt)4][Pd(CN)4] (IIa) were also predicted by DFT calculations in terms of geometries and stability. The DFT results reveal that in the gas phase, the structure I is less stable in comparison to the calculated structure Ia by 11.26 kcal/mol (ΔG) but reverse is true when the DMSO solvent is included in the quantum chemical calculations. For the cyanide analogues, the ionic dinuclear form IIa is more stable than the dimer II of the mononuclear complex [Pd(Imt)2(CN)2] in gas phase by 13.37 kcal/mol but is less stable in calculations with DMSO by 6.86 kcal/mol.

The coordination polymer [Cu 2 (TDPH) 4 (QNX)].DMF, (QNX = Quinoxaline; TDPH = 3,3-thiodipropionic acid), has been prepared by reaction of copper acetate, TDPH, and quinoxaline. The compound was characterized by elemental analysis, FTIR spectroscopy, and single-crystal X-ray diffraction. The crystal is monoclinic with a P21/n space group and dimensions of a = 12.889(3) Å, b = 14.983(4) Å, c = 14.091(3) Å, α = 90°, β = 90.200(11)°, γ = 90°, V = 2721.18 (2) Å 3 , Z = 4. The ligands are hexagonally coordinated to the Cu(II) centre in the form of Cu 2 O 4 N with one nitrogen atom from the quinoxaline ligand, and four oxygen atoms from four TDPH molecules in a monodentate fashion. The Cu–Cu bond length was 2.642(1) and 2.629(1) Å for the Cu1–Cu1 and Cu2–Cu2 bonds. The QNX ligand bridged the two copper atoms. The catalytic reduction of 4-nitrophenol to 4-aminophenol using NaBH 4 in the presence of [Cu 2 (TDPH) 4 (QNX)].DMF, as catalyst was completed within 11 min. The 4-aminophenol product was confirmed using 1 H NMR spectroscopy.

A Schiff base 1-((3-nitrophenylimino)methyl)naphthalen-2-olate (HL) and its two novel complexes with Zn(II) and Co(II) metals were successfully synthesized and characterized by FTIR, 1H NMR, 13C NMR, elemental analysis, magnetic susceptibility, TGA and EIS-MS. Crystal of Schiff base was also characterized by X-ray analysis and experimental parameters were found in line with the theoretical parameters. Quantum mechanical approach was also used to compare structural and calculated parameters and to ensure the geometry of metal complexes. The photometric behaviors of all the synthesized compounds were investigated in a wide pH range using BR buffers. Appearance of isosbestic point suggested the existence of Schiff base molecules in different tautomeric forms. Binding of synthesized complexes with calf thymus DNA was explored by photometric and voltammetric titrations and binding constants were calculated. The results indicated that ligand and its metal complexes bind to DNA by intercalation mode. Docking studies indicate their binding possibilities with topoisomerase II. Moreover, all these prepared compounds were screened for enzyme inhibition, antibacterial, cytotoxic and in vivo antidiabetic activities and found active against one or other activity. This effort just provides preliminary data for some biological properties and which can act as foundation stone for their application in drug development.

Four new 3-(2-(3-Phenyl-5-substituted phenyl-4,5-dihydropyrazol-1-yl)thiazol-4-yl)-2H-chromen-2-one derivatives (1-4) were synthesized and fully characterized by spectroscopic techniques. The final structures of all chromenone analogues (1-4) were confirmed by single crystal X-ray diffraction analysis. Quantum chemical studies were performed to compare the results from the theoretical studies with the experimental (X-ray as well as spectroscopic) ones. The theoretically simulated geometric parameters and other spectroscopic properties agreed nicely with the experimental data. All compounds were evaluated for biological activity (acetyl cholinesterase inhibition potential). Compound 3 emerged as the most potent derivative in acetylcholine esterase (AChE) inhibition assay with IC50 = 27.29 mu M. The IC50 of compound 3 is greater than the standard drug galantamine (IC50 = 44.02 mu M). To rationalize the potencies, molecular docking studies were also carried out. These docking results revealed a good correlation between binding energies values and in vitro AChE inhibition assay. (C) 2018 Elsevier B.V. All rights reserved.

Ethyl-6-(4-(ethoxycarbonyl)-1H-1,2,3-triazol-1-yl)pyridine-3-carboxylate (1), was synthesized via click reaction between ethyl tetrazolo[1,5-a] pyridine-6-carboxylate and ethyl propiolate in tetrahydrofuran (THF) in the presence of catalytic amount of a copper acetate. The structure was confirmed by single-crystal X-ray diffraction, NMR, FT-IR and MS. The compound crystallizes in the triclinic system, space group P(-)1 with a = 4.9122 (5), b = s9.5891 (11), c = 15.4851 (18)angstrom, a = 92.371 (5), beta = 90.015 (4), gamma = 101.722 (5) Z = 2 and V (angstrom(3)) = 713.55 (14). Packing diagram indicates that there is dimeric interaction between two units via N(2)...H(7). The crystal structure of the title compound 1 is stabilized by several nonboding interactions. Space filling model also revealed C-H ... pi and the pi-pi interactions in the molecule. Theoretical investigations were executed by using the Gaussian 09 software to enable comparison with X-ray structure as well as spectroscopic results, and to further probe the structural properties. The molecular electrostatic potential (MEP) analysis gave the idea about chemical reactivity and the Mulliken charge analysis gave quantitative estimate of the charges on the atoms. Frontier molecular orbitals analysis (electronic properties) was used to find the energy gap between the HOMO and the LUMO. The target compound was screened against three different bacterial strains like S. typhimurium, M. luteus and B. bronchiseptica as well as three different fungal strains i.e Aspergilus niger, Mucor specie and Aspergilus flavus. Moderate activities have been displayed by the target compound against tested strains.

A dysprosium complex, [Dy2 (TEA)2(O2CPh)4·2H2O] has been synthesized using TEA (tri-ethanolamine) and benzoic acid. The obtained complex is a dimer in which both of the TEA is linked with two dysprosium ions through the protonated oxygen atoms and the resultant molecule is Centro symmetric. The nature of bonding and structure of the synthesized dimer was explored from infrared, magnetic studies and single crystal X-ray crystallographic technique. The crystal structure of the complex has triclinic crystal system and P-1 space group. Unit cell parameters are: a = 10.0931(4) Å, b = 10.8841(5) Å, c = 10.9441(5) Å, and α = 73.915(2)°, β = 74.833(2)°, γ = 67.764(2)°, V = 1052.54(8) Å3, Dx = 1.801 Mg/m3 and Mr = 1141.84. The complex possesses small value of coercivity which indicates that it is a soft ferromagnetic material and can resist with external magnetic field without becoming demagnetized.

In the title compound, C 10 H 9 NS, the C—S—C bond angle is 99.41 (9)° and the dihedral angle between the trans -alkene fragment and the benzene ring is 16.49 (19)°. In the crystal, inversion dimers linked by pairs of extremely weak C—H...N interactions occur, as does a short S...N contact [3.2258 (19) Å].

Alkoxy/halostyrylbenzoic acids were synthesized and evaluated for their mesomorphic and photophysical properties. The trans geometry of the molecules was established by the presence of large coupling constants in H-1-NMR spectra and confirmed further by X-ray diffraction (XRD) analysis of two of the compounds. The straight-chain acids were found fairly stable showing first sign of decomposition above 290 degrees C. The enantiotropic mesophases could only be studied in acids with seven or more methylene groups in the alkoxy chain. Textures of nematic and smectic phases were exhibited by these acids under polarizing optical microscope. Photophysical behavior of the compounds in solution was also investigated.

1,3,4-Oxadiazoles are important class of heterocyclic compounds, with diverse biological applications. In this study, the synthesis of three different 1,3,4-oxadiazoles bearing pentadecyl moiety is reported. All compounds were synthesized with significant (70–82%) yields, characterized by using different spectroanalytical techniques such as UV–vis., FT-IR, NMR (1H and 13C), and finally structures were confirmed unequivocally by single crystal X-ray diffraction analysis. Quantum chemical studies by using GAUSSIAN software at DFT/B3LYP/6-31G (d, p) level of theory have been exercised to compare and validate the spectroscopic and X-ray results. Frontier molecular orbitals (FMOs) analysis of all compounds was performed by utilizing optimized geometries and gave the idea about kinetic stability and reactivity. Molecular electrostatic potential (MEP) analysis indicated the regions for electrophilic as well as nucleophilic attack. Compounds were also screened to check their antibacterial and antifungal potential.

A series of aromatic/aliphatic ferroceneyl-esters (E1–E10) was synthesized by condensation of 4-ferrocenyl benzoic acid (FB) with various alcohols (A1–A10). Structural elucidation of these esters was carried out by FT-IR, 1HNMR and UV–visible spectroscopic studies. Single crystal X-ray analysis was used to investigate solid state structure of E1, E4 and E8. DFT calculations were carried out at hybrid B3LYP level of theory using Density Gauss Double-Zeta with polarization functions full-electron basis sets to support the experimental data. Calculated structural parameters and FTIR vibrational frequencies of the optimized geometries were congruent to the experimental data. The interaction of the esters with double stranded chicken blood DNA was studied by cyclic voltammetry and absorption spectroscopic methods. Negative potential shift in cyclic voltammetric and the hyperchromic shift in UV–vis spectroscopy suggested external interaction (groove binding). Interaction of ferrocenyl esters with DNA were found electrostatic in nature. Free energies of ferrocenyl esters-DNA complexes indicated spontaneity of their binding.

A new phthalonitrile (1) was synthesized and characterized using different spectroscopic techniques, elemental analyses, and single-crystal X-ray diffractometry. The crystal structure is stabilized by p-p stacking interactions between the benzene rings with two methyl groups. Metal free (2), Mg (3), Zn (4), and Pd (5) phthalocyanine complexes of the phthalonitrile were synthesized with metal salts, and the complexes showed good solubility in a wide range of organic solvents with no aggregation observed within a wide concentration range. The complexes were characterized by elemental analyses, UV-Vis, FT-IR, NMR, and mass spectrometry, and show good prospect for application in photodynamic therapy of cancer.

Methyl-2-(1-benzyl-4-phenyl-1H-1,2,3-triazol-5-yl)-2-oxoacetate (1) and ethyl-2-(1-benzyl-4-phenyl-1H-1,2,3-triazol-5-yl)-2-oxoacetate (2) were synthesized by one pot three component strategy, and characterized by FT-IR, NMR (1H and 13C) spectroscopy and TOF-MS spectrometry. Finally, the structures were unequivocally confirmed by single crystal X-ray diffraction analyses. Both compounds, 1 and 2 exist in monoclinic crystal packing having space group P21/n and P21/c, respectively. Crystal structures investigations revealed that the molecular structures of the title compounds are stabilized by weak intermolecular hydrogen bonding interactions to form dimers. Density functional theory (DFT) calculations were performed not only to compare with the experimental spectroscopic results but also to probe structural properties. The molecular electrostatic potential (MEP) mapped over the entire stabilized geometries of the molecules delivered information about the electrophilic and nucleophilic sites. Furthermore, frontier molecular orbital analysis gave the idea about stability and reactivity of compounds. Both compounds were also screened for brine shrimp cytotoxicity assay.

The reactions of ZnCl2 and cysteamine hydrochloride (Cym-H · HCl) in the presence of diamines; 1,3-diaminopropane (dap) and tetramethylethylenediamine (tmen) yielded a Zn-cysteaminate complex, [Zn4Cym4Cl4] (1). In the similar reaction with cis-1,2-diaminocyclohxane (dach), a diamine complex, [Zn(dach)Cl2] (2) was obtained. The compounds, 1 and 2 were characterized by elemental analysis, IR and NMR (1H and 13C) spectroscopy. The crystal structure of 1 was determined by X-ray crystallography. The structure of 1 shows that the complex exists in the form of a tetranuclear molecule in which zinc atoms are bridged by S atoms of Cym forming an eight-membered ring. The complex consists of two crystallographically independent Zn(II) ions. Zn1 and symmetry related ion are coordinated with two sulfur atoms and two nitrogen atoms of Cym, while Zn2 and symmetry related ion exhibit a ZnS2Cl2 setup. In both coordination environments zinc atom adopts a distorted tetrahedral geometry. Antimicrobial activities of the complex 1 were evaluated by minimum inhibitory concentration and the results showed that the complex exhibited remarkable activities against gram-negative bacteria (E. coli, P. aeruginosa) and yeasts (C. albicans, S. cerevisiae).

The title compound, 4-hexyl-1-(4-nitrophenyl)-1-H-1,2,3-triazole (C14H18N4O2), was synthesized using one -pot strategy via click reaction and the structure was characterized mainly by single -crystal X-ray diffraction, NMR, FT-IR and MS. C14H18N4O2 was crystallized from an EtOH/EtOAc solution in triclinic system, space group P1, with a = 5.3679(3), b = 7.5499(5), c = 17.5534(11) A, a = 92.360(4), beta = 90.359(4), gamma = 98.864(4), V (angstrom(3)) = 702.24(8), Z = 2, crystal size (mm) = 0.42 x 0.26 x 0.18, R-int = 0.096. Packing diagram indicates that there is dimeric interaction between two units via N(3)center dot center dot center dot=H(6). The crystal structure of the title compound (1) is stabilized by intermolecular interactions. In addition, X-ray analysis also reveals C-H center dot center dot center dot pi and pi-pi interactions in the molecule. Theoretical investigations were performed by using Gaussian 09 software at the B3LYP/6-31G (d,p) level of density finctional theory (DFT) to compare the theoretical results with the experimental and to probe structural properties. The molecular electrostatic potential (MEP) mapped over the entire stabilized geometry of the molecule indicated their chemical reactivities. Furthermore, frontier molecular orbital (electronic properties) was computed at the same level of DFT as used for energy minima structure.

The title Schiff base, C14H11NO3, crystallizes as a zwitterion (i.e. proton transfer from the carb-oxy-lic acid group to the imine N atom). The dihedral angle between the aromatic rings is 19.59 (6)° and an intra-molecular N-H⋯O hydrogen bond closes an S(6) ring. In the crystal, inversion dimers linked by pairs of O-H⋯O hydrogen bonds generate R 2 (4)(24) loops. The dimers are linked by C-H⋯O inter-actions, generating (211) sheets.

Six organotin(IV) complexes of 2-(4-ethoxybenzylidene) butanoic acid, have been synthesized, characterized and evaluated for antimicrobial, cytotoxic and anti-tumor activities. DNA interactions studies were performed to find out drug-DNA mechanism. a r t i c l e i n f o

In the title compound, C13H14N4O2, which has approximate mirror symmetry, the dihedral angles between the triazole ring and the cyclopropane and pyridine rings are 87.1 (2) and 7.60 (9)°, respectively. In the crystal, inversion dimers linked by pairs of both C—H...N and C—H...O interactions generate R22(6) and R22(18) loops, respectively. Further C—H...N interactions form R22(10) loops and link the dimers into [110] chains.

The asymmetric unit of the title salt, C16H21N2O2+·PF6−, contains half of the whole ion pair, which has crystallographic mirror symmetry. Two F atoms related by the mirror plane are disordered over two sites of equal occupancy. The dihedral angle between the central ring and the furan ring is 59.3 ()°. In the crystal, the anions and cations are linked through C—H...F interactions, forming a three-dimensional network.