Nalidixic acid (Nal) is a quinolone antibiotic with activity against Gram-negative bacteria and is used to treat urinary tract infections caused by microorganisms belonging to the genera Escherichia, Proteus, Shigella, Enterobacter, and Klebsiella. The complexation of this molecule with zinc and auxiliary ligands such as phenanthroline (Phen) and 2,2’-bipyridine (Bipy) could modify its pharmacological and pharmacokinetic properties. This work presents the synthesis and characterization of the ZnNal complex ([Zn(Nal)₂(H₂O)₂]·2MeOH). Its molecular structure in the solid state was determined by X-ray diffraction. The complex crystallizes in the monoclinic space group P2₁/n with Z = 2 molecules per unit cell. In the solid state, the nalidixic acid (Nal) molecule appears as its anionic form (Nal⁻), deprotonated in the carboxyl group. The complex is centrosymmetric, with the Zn(II) ion at the center of a slightly elongated octahedral geometry, equatorially coordinated to a bidentate nalidixate anion and axially to a water molecule. The study includes the evaluation of antimicrobial activity of the binary complex and its derivatives with phenanthroline (ZnNalPhen) and bipyridine (ZnNalBipy) against both ATCC strains and clinical isolates. Additionally, compound safety was assessed using the Artemia salina model. ZnNal preserves the antimicrobial potency of the free ligand while exhibiting attenuated toxicity in this model, suggesting a more favorable biocompatibility profile for potential therapeutic applications. Notably, ZnNalPhen was the only complex active against Candida strains, highlighting that coordination with 1,10-phenanthroline expanded the antimicrobial spectrum of the parent ligand Nal to include antifungal activity. Furthermore, both ternary complexes showed an improved safety profile compared to Nal alone. Besides, zinc(II) complexes can be efficiently transported by albumin, which is a key factor in their potential therapeutic application.

Two new 1,3-dicarbonyl compounds bearing an o-hydroxyphenyl moiety (for short, I and II) were synthesized and subjected to structural, experimental and theoretical studies. Vibrational spectroscopy (IR and Raman) and X-ray diffraction were used for solid phase studies, while NMR and electron spectroscopy allowed analysis in solution. The crystal structures of I and II, determined by X-ray diffraction methods, are closely related to each other (rms deviation of homologous atoms from their best fit is 0.147 & Aring;). The observed planarity of beta-hydroxyphenylcarbonyl enols fragment in the compounds is enforced by both extended pi-bonding and intramolecular OH & ctdot;O bonds. Molecules in I are arranged in the lattice as center-symmetric dimers held by relatively weak intermolecular OH & ctdot;O bonds. Hirshfeld surface (HS) analysis, atoms in molecules (QTAIM), and natural bonding orbitals (NBO) approaches were employed to study theoretically selected dimers constructed from X-ray data. The results were combined with experimental ones to obtain deep insight into the strength and type of intermolecular interactions. A chalcogen bond interaction was detected in I. Although the O & ctdot;O interaction is unusual, it participates in the attractive forces that stabilize the crystal lattice. The title compounds are present in the solid state only as the keto-enol tautomer, while in solution the diketo tautomer is also detected at concentrations of 5%. In vitro studies showed that I have better antimicrobial properties than II, mainly against the S. aureus strain. Intra- and intermolecular contacts in 1,3-dicarbonyl compounds are dominated by O-H & ctdot;O bonds. When molecules face each other, the unusual intermolecular O & ctdot;O bonds can reinforce adjacent O-H & ctdot;O bonds and form centrosymmetric dimers.

The solid-state molecular structures of N-(butylcarbamothioyl)-4-methoxybenzamide (I) and N-(butylcarbamoyl)-4-methoxybenzamide (II) were used as examples for structural analyses of carbonylthioureides and carbonylureides. Both compounds crystallize in the monoclinic P21/c space group and form nearly identical hydrogen-bonded dimeric aggregates. A thorough examination of intermolecular interactions using X-ray diffraction data, Hirshfeld surface analysis, molecular electrostatic potential maps, NBO and QTAIM approaches, and spectroscopic techniques reveals that the larger size of the sulfur atom has a significant impact on the strength and nature of the interactions within the crystal lattice. Furthermore, the isosteric exchange was evaluated by testing the activity of both compounds as antibiofilm and anti-quorum sensing agents. Structural study of carbonyl(thio)ureides and a comprehensive analysis on the intermolecular interactions that stabilize the crystal packing. Sulfur, rather than oxygen, promotes Quorum Sensing inhibition by reducing cell viability in a developed biofilm.

The solid-state molecular structure of dilapacholate (diaqua) zinc(II) bis(dimethylsulfoxide), for short [Zn(Lap)(2)(H2O)(2)]center dot 2DMSO, was determined by X-ray diffraction methods. It crystallizes in the monoclinic space group P2(1)/c with Z = 2 molecules per unit cell. The complex is at a crystallographic inversion center with the Zn(II) ion in a rectangular base bipyramidal environment of approximate D-2h local symmetry, coordinated at the pyramid base to two lapacholate anions acting as bidentate ligands through their phenolic and adjacent carbonyl oxygen atoms and at the pyramid apexes to two water molecules. We report spectroscopic data on the vibrational and electronic structure of the complex and also its thermal properties. The new lapacholate complex exhibits antibacterial activity against several clinic strains of Staphylococcus aureus. (c) 2022 Elsevier B.V. All rights reserved.

The zwitterionic form of a Schiff base in the solid state was found by the structural characterization of a coproduct and a mechanistic proposal of its formation.

Single crystal X-ray and NMR investigations on multidomain structured N-(4,6-di-O-acetyl-2,3-dideoxy-α-D-threo-hex-2-en-2-iodo-pyranosyl)-methylsulfonamide are reported. This is the first crystallographic diffraction data report related to a 2-halo-2,3-unsaturated galactoside derivative. A complete structural study, including conformations and crystal packing, was performed by analyzing the spectroscopic data in solid state (XRD) and in solution (NMR).

The present study is devoted to the synthesis of 4-chloro-2-{[5-(diethylamino)-2-hydroxybenzylidene]amino}phenol and its transition metal complexes. Synthesis of the ligand has been achieved by the condensation reaction of N,N-diethylsalicylaldehyde with 4-chloro-2-aminophenol in acidic medium. Metals complexes of the ligand with different transition metal ions [M2+= Mn(II), Fe(II), Co(II), Ni(II), Cu(II), Zn(II), Cd(II), Hg(II), and Pd(II)] have been accumulated in alcoholic media and characterized by spectroscopic methods. UV-Vis analysis of the complexes indicates the ligand coordination to the metal ions via both OH groups and the azomethine nitrogen atom, acting as a tridentate ligand. Anticancer tests of selected complexes demonstrate moderate in vitro activity of Cu(II) complex against HeLa cell line.

We obtained a series of novel N-(2-iodo-2,3-dideoxy-2-en-glycopyranosides)-sulfonamides via the Aza-Ferrier rearrangement of protected-2-iodoglycals in good yields and high stereoselectivity. Their structure and conformation features were determined by NMR. Moreover, we report here the first in detail structure analysis by X-ray diffraction techniques of a 2-iodo-pseudoglycal. (C) 2020 Elsevier Ltd. All rights reserved.

Comprehensive theoretical, structural and spectroscopic investigations on new substituted 1,2,3-triazoles in the solid state.

Bis - (methylsulfonylmethyl) sulfone, BMSMS, was synthesized and characterized through vibrational (IR, Raman) spectroscopy. The crystal structure of BMSMS, determined by X-ray diffraction methods, together with Hirshfeld surfaces analysis were used to evaluate intermolecular interactions. BMSMS can be considered as one-turn helix of about 7.13 Å, further stabilized by weak intra-molecular CH•••O bonds. The experimental results were supplemented by quantum chemical calculations. It was also analyzed the hyperconjugative effects of oxygen atoms lone pairs (LP) on the vibrational behavior of the SO2 group. Besides, biofilm formation and QS activity were evaluated on this new bis- (methylsulfonylmethyl) sulfone.

Two new thiourea (1) and urea (2) derivatives, substituted with 2-trifluoromethyl-4H-chromen-3-yl moieties at defined positions, were obtained by convenient synthetic methodologies. The pure compounds were studied in solid state by vibrational spectroscopy (FT-IR and Raman) and in solution by NMR and UV-Vis spectroscopy. The crystal structure of the urea derivative (compound 2) was also determined by X-ray diffraction. The crystal packing is governed by N-H center dot center dot center dot O intramolecular interactions of moderate strength in a self-assembled dimer of the terminal amide fragment (C(=O)-NH2). Hirshfeld surface and 2D-fingerprint plots were also performed to characterise the role in the packing stabilisation of all contacts, including weak C-H center dot center dot center dot F hydrogen bonds and pi-pi stacking interactions. For both compounds, the tentative assignment of vibrational and electronic spectra was assisted by theoretical calculations. Besides, to evaluate the influence on the pharmacokinetic and pharmacodynamic properties of molecules with -CF3 groups, the anti-microbial activity of the title compounds was tested against the standard strains of various Gram-positive and Gram-negative organisms with noteworthy antimicrobial effect over Staphylococcus aureus, Klebsiella pneumoniae and Salmonella typhi.

The solid state molecular structure of dilapacholate diaquo cobalt (II) di-dimethylformamide, for short [Co(Lap)(2)(H2O)(2)].2DMF, was determined by X-ray diffraction methods. It crystallizes in the monoclinic space group P2(1)/n with Z = 2 molecules per unit cell. The complex is at a crystallographic inversion centre with the Co (II) ion in a distorted octahedral environment of approximate D-2h local symmetry, coordinated to two lapacholate anions acting as bidentate ligands through their carbonyl and phenolic oxygen atoms, and to two water molecules nearly along the bisector of their oxygen electron lone-pair lobes. The IR absorption spectrum, electronic absorption, TGA data and also a comparison of IR characteristic bands with the corresponding ones of other Co-lapacholates are also discussed. At a concentration of 25 ppm, the new metal complex shows biological activity against several clinical Staphylococcus aureus strains. (C) 2018 Elsevier B.V. All rights reserved.

The study of two new acylthiourea derivatives (Ar-CO-NH-CS-NH-R) are focused on the bonding interactions supported by X-ray, NMR, UV–Vis, Raman and IR spectroscopy, and NBO, AIM and Hirshfeld surface analysis. The RAHB model is proposed to explain some structural properties. The molecules are stabilized by intra-molecular NH⋯O bonds arranged in the lattice as centre-symmetric dimers held by inter-molecular NH⋯S bonds. The dimers are linked to each other through NH⋯O bonds giving rise to a chain, ribbon-like structure in the network. In vitro bacterial growth inhibition, biofilm formation, biosensor and biofilm metabolic activity were tested considering the broad bioactivity of acylthioureas.

We show here that the phenomenon of spontaneous resolution of enantiomers occurs during the crystallization of the sodium and rubidium double salts of the transition metal complex tris(oxalato)ferrate(III), namely sodium pentarubidium bis[tris(oxalato)ferrate(III)], NaRb5[Fe(C2O4)3]2. One enantiomer of the salt crystallizes in the cubic space group P4332 with Z = 4 and a Flack absolute structure parameter x = −0.01 (1) and its chiral counterpart in the space group P4132 with x = −0.00 (1). All metal ions are at crystallographic special positions: the iron(III) ion is on a threefold axis, coordinated by three oxalate dianions in a propeller-like conformation. One of the two independent rubidium ions is on a twofold axis in an eightfold coordination with neighbouring oxalate oxygen atoms, and the other one on a threefold axis in a sixfold RbO6 coordination. The sodium ion is at a site of D3 point group symmetry in a trigonal–antiprismatic NaO6 coordination.

An entry from the Cambridge Structural Database, the world’s repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.

The new copper complex, [Cu(HL)(OH2)(2)](NO3), including the tridentate N-acyhydrazone derived from 4-hydroxy-benzohydrazide and 2-hydroxy-3-methoxybenzaldehyde, (H2L), has been synthesized and characterized in the solid state and in solution by spectroscopic (FTIR, Ra, UV-vis, EPR) methods. The results were compared with those obtained for the hydrazone ligand and complemented with computational methods based on DFT. The crystal structure of the complex has been determined by X-ray diffraction. It crystallizes in the triclinic P (1) over bar space group with Z = 2. The Cu(II) ion is in a distorted square pyramidal environment, coordinated to a planar HL anion acting as a tridentate ligand. The 5-fold coordination is completed with two water molecules. It is arranged in the lattice as H-bonded ribbon-like polymers that extends along the [1 2 1] crystal direction. The cytotoxicity of the complex together with that of the H2L ligand and the copper ion were evaluated in vitro against five different human cancer cell lines namely A549 (lung), MG-63 (bone), MCF-7 and MDA-MB-231 (breast) and Jurkat (leukemia). The copper complex inhibits the cell viability in a dose dependent manner with a greater potency than the H2L ligand and the free copper ion displaying even higher antitumor activity than the well-known anticancer metallodrug cisplatin.

A detailed structural and spectroscopic study of a new thiourea derivative 1-butyl-3-(1-naphthoyl) thiourea (1) is presented with the assistance of theoretical calculations. The X-ray diffraction structure analysis reveals a planar carbonylthiourea group, favoured by intra-molecular NH center dot center dot center dot O bond. The compound is arranged in the lattice as NH center dot center dot center dot O and NH center dot center dot center dot S bonded polymeric ribbons, that extend along the crystal b-axis. Molecular pairs involving N-H center dot center dot center dot S hydrogen bonds are a dominant contribution to packing stabilisation coming from coulombic component. Hirshfeld surfaces and two-dimensional-fingerprint plots show different intermolecular contacts and its relative contributions to total surface in each compound. The AIM approach shows the nature and strength of the strong and weak intramolecular interactions and the solvent effect, while NBO analysis reveals that the sulphur atom is responsible for the higher hyperconjugative stabilising energy. [GRAPHICS] .

This is a study of structure – reactivity relationship of clomesone.

Epoxidation of 4HMBA, the main metabolite of the medicinal plant Sencecionutans, produces an unstable epoxide eventually giving rise to a mixture of four derivatives, three of them previously reported as natural products. The epoxide product easily undergoes an intra-molecular attack of the phenolic hydroxyl against the epoxide group carbons to produce either a benzofuran or a chromane derivative. When dissolved in methanol-water mixture at room temperature the epoxide is completely solvolyzed to give the corresponding diol (hydrolysis) or vicinal hydroxyl-methoxy (methanolysis) derivative. All the compounds involved in the above reactions were characterized by IR, Raman, H NMR and UV-vis spectroscopies, and by mass spectrometry. Density functional theory (DFT) computations were used to optimize the structure conformations. The optimized structures were further subjected to a Natural Bond Orbital (NBO) and electrostatic potentials analysis. The crystal structures of the title compounds (for short, 3 and 4 respectively) were determined by X-ray diffraction methods. Compound 3 crystallizes in the triclinic P-1 space group with a = 6.4289 (6) angstrom, b = 8.7120 (6) angstrom, c = 10.952 (1) angstrom, alpha = 92.280 (7)degrees, beta = 95.738 (7)degrees, gamma = 103.973 (7)degrees, and Z = 2 molecules per unit cell and 4 in the monoclinic P2(1)/c space group with a = 11.2891 (6) angstrom, b = 9.1902 (4) angstrom, c = 12.4272 (7) angstrom. B = 113.689 (7)degrees, and Z = 4. In 3 neighboring molecules are linked to each other by OH center dot center dot center dot O (keto) bonds giving rise to a polymeric structure. In 4 the OH group is a bifurcate H-bond donor. It forms a weak intra-molecular OH center dot center dot center dot O (furan) bond and also a much stronger inter-molecular O-H center dot center dot center dot O (keto) bond giving rise to a zig-zag polymeric structure. A detailed analysis of the solid state molecular interactions of compounds 3 and 4 has been performed using Hirshfeld surface analysis and their associated 2D fingerprint plots. (C) 2017 Published by Elsevier B.V.

The compound 4-(4-dimethylaminobenzylidene)aminoacetophenone was synthesized by condensation of 4-aminoacetophenone and 4-(dimethylamino) benzaldehyde in ethanol. This compound was characterized by CG-MS, infrared, Raman, UV–Vis, 1H and 13C NMR spectroscopy. The crystal structure was solved by single-crystal X-ray diffraction methods. The crystallographic data reveals that there are four independent molecules per asymmetric unit, that mainly differ from one another in rotations around the σ-bond of the azomethine N-atom with the phenyl ring. A detailed analysis of the intermolecular interactions in the four conformers of the compound has been performed using Hirshfeld surfaces and their associated two-dimensional fingerprint plots. The optimized geometrical parameters and calculated spectroscopic features obtained by quantum chemical calculations at B3LYP method show a very good agreement with the experimental data. Moreover, Natural Bond Orbital (NBO) analysis confirms the strong hyper-conjugative LP N(n1)→ σ* C(n9)H interaction between the lone pair located in the N-atom of the azomethine group and the CH bond. Liquid crystalline properties of the Schiff base were studied by differential scanning calorimetry (DSC), polarizing optical microscopy (POM) and Powder X-ray diffraction techniques. Mesomorphic behaviour was observed in this unsymmetrical azomethine. Based on POM and DSC measurements, the hexatic Smetic B phase was detected.