An insight into triel bonds in O,O′-diarylphosphorodithioates of thallium(i): experimental and theoretical investigations

Two new thallium(i) compounds have been synthesized and structurally characterized. The existence of triel bonds in these compounds has been confirmed by HSA and DFT calculations using QTAIM and NCI plot index methods.

Design, synthesis, characterization, and antioxidant activity studies of novel thienyl-pyrazoles

In a sustained search for novel and effective antioxidants, a potential therapeutic leads against renal, and neurological disorders. Amongst the heterocycles, pyrazole and their derivatives have been extensively studied for their biological potencies, particularly to a larger extent for their antioxidant properties. Although many of pyrazole derivatives displayed antioxidant activities, still there is a need of developing efficient protocol for their synthesis, involving ecofriendly conditions, molecules of greater antioxidant efficacy and lesser toxicity, etc. In this context, the current study presents an amberlyst-15 catalysed efficient synthesis of 2-pyrazoline derivatives, 5(a-g) via (3 + 2) annulation of chalcones with phenylhydrazines. Structure proofs of new pyrazoles offered by spectral studies, and the molecular structure of compound 5d of the series by crystallographic studies, which revealed an intra molecular hydrogen bond interactions (C–H⋯N type), and stabilization by C–H...π and π---π molecular interactions. Of the series, compounds 5g and 5h show excellent DPPH (IC₅₀ = 0.245 ± 0.01, and 0.284 ± 0.02 μM); and hydroxyl (IC₅₀ = 0.905 ± 0.01, and 0.892 ± 0.01μM) radical scavenging activities comparable with respective controls, ascorbic acid (IC₅₀ = 0.483 ± 0.01μM) and BHA (IC₅₀ = 1.739 ± 0.01μM). The molecular docking and ADME/Tox studies indicate that, these compounds have good antioxidant activity through π-π stacking with Catalase via Try337 and Phe140, and therefore, might be lead antioxidants for further study.

Crystal structure and Hirshfeld surface analysis of [2-(1H-benzimidazol-2-yl-κN 3)aniline-κN]di-chlorido-zinc(II) N,N-di-methyl-formamide monosolvate

The title compound, [ZnCl2(C13H11N3)]·C3H7NO, crystallized in the monoclinic crystal system in space group P21/n. The asymmetric unit contains one neutral complex mol-ecule, which consists of a zinc ion, a bidentate ligand, and two chlorido ligands with di-methyl-formamide monosolvate. The ligand has two moieties, a benzimidazole and an aniline group. The benzimidazole and aniline planes are not coplanar, subtending a dihedral angle of 18.24 (8)°. The Zn(II) ion shows distorted tetra-hedral geometry, being coordinated by an imidazole N atom, the aniline N atom, and two chlorido ligands. The packing features N-H⋯O, N-H⋯Cl, C-H⋯Cl hydrogen bonding.

Role of non-covalent interactions in the supramolecular architectures of mercury(ii) diphenyldithiophosphates: An experimental and theoretical investigation

The H-bond, spodium bond and CH⋯π interactions playing an important role in the supramolecular organization of two mercury(ii) diphenyldithiophosphate complexes have been discussed.

Coordination versus spodium bonds in dinuclear Zn(ii) and Cd(ii) complexes with a dithiophosphate ligand

Two new d10-metal dithiophosphate complexes have been synthesized in purely aqueous media and characterized by elemental and spectral analyses. DFT calculations, QTAIM and NCI Plot index methods are preformed to differentiate the coordination and spodium bonds in the complexes.

C-demethylation and 1, 2-amino shift in (E)-2-(1-(3-aminophenyl) ethylidene)hydrazinecarboxamide to (E)-2-(2-aminobenzylidene)hydrazinecarboxamide and their applications

A Novel (E)-2-(1-(3-aminophenyl)ethylidene)hydrazinecarboxamide 1 was synthesized by traditional method and converted to (E)-2-(2-aminobenzylidene)hydrazinecarboxamide 2 by single step in DMSO at room temperature. Synthesized compound 1 was analysed by spectroscopy (NMR and LC–MS) techniques and molecule 2 was characterized using single crystal X-ray diffraction and spectroscopy (NMR and GC–MS) techniques. These analytical technique results revealed that, C-demethylation and 1, 2 amino shift in phenyl ring of compound 1 gives molecule 2. DNA binding studies of compounds 1 and 2 was carried out by electronic absorption spectroscopy. This result revealed that, compounds 1 and 2 showed hyperchromism with bathochromic shift. Anticancer activity of compounds 1 and 2 is carried out by molecular docking with five receptors.Computer aided virtual screening demonstrated that the synthesized molecules possess ideal drug likeliness, pharmacokinetics features, toxicity profile for structure based drug discovery. The molecular docking studies revealed that the synthesized molecules are significant binding with the five selected cancer receptors with minimum binding energy (kcal/mol), number of hydrogen bonds, weak interaction, docking score and cluster RMS. The docking studies also suggested that the molecules showed interactions with DNA and the theoretical values of the binding are comparable with that of the experimental values. Hirshfeld surface analysis was used to analyze and quantify the intermolecular interactions in the crystal structure of compound 2.

Design and synthesis of coumarin-triazole hybrids: biocompatible anti-diabetic agents, in silico molecular docking and ADME screening

The current study demonstrates the synthesis of coumarin-triazole hybrids 8 (a-e) in four steps starting from substituted salicylaldehyde 1 (a-e), and diethyl malonate 2. The spectroscopic studies provide the structure proofs of the new compounds, and the molecular structure of an intermediate 3a by crystallographic studies. The crystal structure analysis revealed the C–H...O, C–H... π, C–O...π and π...π molecular interactions. Further, the intermolecular interactions were quantified using Hirshfeld surface analysis and the DFT method B3LYP functional with 6–311++ G (d,p) basis set was employed to optimize the molecular geometry. The synthesized new coumarin-triazole hybrids, 8 (a–e) were screened for their α-amylase inhibitory potentials, and the results suggest that amongst the series, compounds 8c, and 8e show the promising inhibition of the enzyme, and might act as lead molecules for anti-diabetic activities. To understand the mode of action in silico molecular docking and ADME screening were performed.

Novel Pb(II) Complexes: X-Ray Structures, Hirshfeld Surface Analysis and DFT Calculations

Herein we report the synthesis and detailed structural characterization of two new centrosymmetric dinuclear coordination compounds of Pb(II) [Pb2L2(NCS)4] (1) and [Pb2L2(NO3)4]∙2MeOH (2), using the organic ligand 1,2-diphenyl-1,2-bis((methyl(pyridin-2-yl)methylene)hydrazono)ethane (L). In both complexes, each subunit [PbLX2 (X = NO3 or NCS)] adopts a quasi-aromatic Möbius metal chelate structure. Each ligand L is coordinated in a tetradentate coordination mode to Pb(II), yielding the 12π electron chelate ring via two pyridyl-imine units. In compound (1), the coordination sphere is completed by one disordered N,S-coordinated thiocyanate anion and two μ1,1-bridging N-coordinated thiocyanate anions. In compound (2), the coordination sphere of Pb(II) is completed by two monodentate and two bidentate nitrato ligands (two of them acting as bridging ligands). Crystal packing of both compounds is stabilized by intermolecular hydrogen bonds, intra- and intermolecular C–H∙∙∙π interactions. The Hirshfeld molecular surfaces of (1) and (2) demonstrate that their packing is dominated by C–H∙∙∙O/N/S interactions as well as by far less favored H∙∙∙H contacts.

New 1D diorganotin(iv) dithiolate coordination polymers: crystallographic, computational, Hirshfeld surface and thermal analyses

Three new 1D coordination polymers of diorganotin(iv) dithiolates synthesized and the nature of their weak interactions addressed using computational techniques.

Exploring catecholase activity in dinuclear Mn(ii) and Cu(ii) complexes: an experimental and theoretical approach

Two dinuclear Mn(ii) and Cu(ii) complexes were prepared, characterised and assessed for non-covalent interactions and catecholase oxidase properties. The catecholase activity of2is further corroborated by theoretical calculations using DFT.

A multiple hydrogen-bonded three-dimensional supramolecular architecture composed of a unique three-fold interlocked anionic Zn(ii)-coordination architecture

A multiple hydrogen bonded 3D supramolecular architecture composed of interlocked anionic Zn(ii)-coordination architecture possesses two kinds of distinct cavities in the interlocked positions and between adjacent self-knitting layers respectively.

Enol-imino-Keto-enamine Tautomerism in a Diazepine Derivative: How Decisive Are the Intermolecular Interactions in the Equilibrium?

The strange tautomeric equilibrium behavior exhibited by a new o-hydroxyphenyl diazepine derivative when the compound is analyzed both in solution and solid state opens the structural study of the enol-imino-keto-enamine forms and the influence of the intermolecular interactions in their equilibrium. The expected enol-imino form, in which the enol is part of a phenyl system and a strong O-H···N intramolecular hydrogen bond is established, results the most stable tautomer in gas phase (theoretical calculations) and was detected by NMR spectroscopy when the compound was dissolved in aprotic solvents. Nevertheless, the keto-enamine form ,in which the keto group integrates a cyclohexadienone moiety and the aromaticity of the phenol is lost, was the only tautomer in the crystal lattice according to single-crystal X-ray diffraction, vibrational spectroscopy, and diffuse reflectance results. The last form was also found as the main tautomer in UV-vis and NMR spectroscopy when a protic solvent was employed.

Supramolecular Assemblies in Pb(II) Complexes with Hydrazido-Based Ligands

Herein, we describe the synthesis and single crystal X-ray diffraction characterization of several Pb(II) complexes using Schiff base hydrazido-based ligands and different counterions (NO3−, I– and ClO4). In the three complexes reported in this work, the lead(II) metal exhibits a high coordination number (n > 8) and thus it is apparently not involved in tetrel bonding interactions. Moreover, the aromatic ligands participate in noncovalent interactions that play an important role in the formation of several supramolecular assemblies in the solid state of the three Pb(II) complexes. These assemblies have been analyzed by means of Hirshfeld surface analysis and DFT calculations.

Syntheses, structures, and magnetic properties of mixed-ligand complexes based on 3,6-bis(benzimidazol-1-yl)pyridazine

Six new metal-organic coordination polymers (CPs) [Ni(L)(2,5-TDC)(H2O)] n (1), [Ni(L)(1,3-BDC)(H2O)] n (2), [Ni(L)(1,4-BDC)(H2O)] n (3), [Mn(L)(2,5-TDC)(H2O)] n (4), [Mn(L)(2,6-PYDC)(H2O)] n (5) and [Mn(L)(1,4-NDC)] n (6) were achieved by reactions of the corresponding metal salt with mixed organic ligands (L = 3,6-bis(benzimidazol-1-yl)pyridazine, 2,5-H2TDC = thiophene-2,5-dicarboxylic acid, 1,3-H2BDC = isophthalic acid, 1,4-H2BDC = terephthalic acid, 2,6-H2PYDC = pyridine-2,6-dicarboxylic acid, 1,4-H2NDC = naphthalene-1,4-dicarboxylic acid) under solvothermal condition. CPs 1-6 were characterized by single-crystal X-ray diffraction, IR, TG, XRD and elemental analyses. Their structures range from the intricate 3D CPs 1, 3, 4 and 6 to the 2D coordination polymer 2 and the infinite 1D chain 5. The CPs 1-4 and 6 underlying networks were classified from the topological viewpoint, disclosing the distinct sql (in 1), pcu (in 3 and 6), new topology (in 2), and dia (in 4) topological nets. Moreover, analysis of thermal stability shows that they had good thermal stability. Finally, magnetic properties of CPs 1-6 have been studied, the results showed that complex 2 had ferromagnetic coupling and complexes 1, 3-6 were antiferromagnetic.