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The synthesis of four novel amide compounds (R1C(O)NHR2) is reported, which contain both bulky (R1=phenyl and adamantyl) and hydrophilic (R2=hydroxyl, methoxyl) groups. The incorporation of such substituents provides compounds with unique properties that combine steric hindrance and hydrophilicity. The synthesized amides were fully characterized by 1H and 13C nuclear magnetic resonance (NMR) and analysed using infrared (IR) and Raman spectroscopy to investigate their vibrational properties in the solid phase, specifically focusing on the amide‐type normal modes of vibrations. Furthermore, the crystal structures of three derivatives were determined by single‐crystal X‐ray diffraction, which provided insights into their molecular arrangements. The occurrence of N−H⋅⋅⋅O=C hydrogen bonding intermolecular interaction is clearly observed and characterized by Hirschfeld surface analysis. Topology analysis using the Quantum Theory of Atom in Molecules and Crystals (QTAIM−C) were employed to investigate the electronic properties of the isolated amide molecules and to analyse the intermolecular interactions within the crystalline structure. The periodic calculations for the crystal revealed a higher electronic density in the C−N bond, indicating an increased covalent character in this bond compared with the C=O bond. This observation indicates the presence of resonance‐assisted hydrogen bonds within the amide core, leading to π electronic delocalization. [ABSTRACT FROM AUTHOR]

Chagas' disease (American Trypanosomiasis) is an ancient and endemic illness in Latin America caused by the protozoan parasite Trypanosoma cruzi. Although there is an urgent need for more efficient and less toxic chemotherapeutics, no new drugs to treat this disease have entered the clinic in the last decades. Searching for metal-based prospective antichagasic drugs, in this work, multifunctional Re(I) tricarbonyl compounds bearing two different bioactive ligands were designed: a polypyridyl NN derivative of 1,10-phenanthroline and a monodentate azole (Clotrimazole CTZ or Ketoconazol KTZ). Five fac-[Re(CO)3(NN)(CTZ)](PF6) compounds and a fac-[Re(CO)3(NN)(KTZ)](PF6) were synthesized and fully characterized. They showed activity against epimastigotes (IC50 3.48–9.42 μM) and trypomastigotes of T. cruzi (IC50 0.61–2.79 μM) and moderate to good selectivity towards the parasite compared to the VERO mammalian cell model. In order to unravel the mechanism of action of our compounds, two potential targets were experimentally and theoretically studied, namely DNA and one of the enzymes involved in the parasite ergosterol biosynthetic pathway, CYP51 (lanosterol 14-α-demethylase). As hypothesized, the multifunctional compounds shared in vitro a similar mode of action as that disclosed for the single bioactive moieties included in the new chemical entities. Additionally, two relevant physicochemical properties of biological interest in prospective drug development, namely lipophilicity and stability in solution in different media, were determined. The whole set of results demonstrates the potentiality of these Re(I) tricarbonyls as promising candidates for further antitrypanosomal drug development. [ABSTRACT FROM AUTHOR]

The structure of two perhalomethylated chromones, 2‐chlorodifluoromethylchromone (a) and its 6‐nitro substituted derivative (b), are investigated. The supramolecular assembly is governed by the hydrogen bond interaction (C−H···O) between the olefinic proton (OC−C(=C<)‐H) and the carbonyl oxygen atom (>C=O) giving rise to center‐symmetric R22(8)$R_2^2(8)$ graph‐set motifs. The H···O interatomic distance is shorter in (b) suggesting a stronger hydrogen bonding for this derivative. Quantum Theory of Atoms in Molecules (QTAIM) and natural bond orbital (NBO) calculated energies and the higher polarity computed for (b) agree with this experimental finding. The Molecular Electrostatic Potential (MEP) graph shows a distinctive C···Cl contact, found only for (b), involving a more electrophilic methine carbon atom. [ABSTRACT FROM AUTHOR]

The crystal structures of bis[1-ethyl-6-fluoro-4-oxo-7-(piperazin-1-ium-4-yl)-1,4- dihydroquinoline-3-carboxylato]copper(II) sulfate heptahydrate, [Cu(C16H18FN3O3) 2]SO4.7H2O or [Cu(nor)2]SO4.7H2O (nor is norfloxacin), and bis{1-[2- (ethylsulfonyl)ethyl]-2-methyl-5-nitroimide}dinitratocopper(II), [Cu(NO3)2- (C8H13N3O4S)2] or [Cu(NO3)2(tnz)2] (tnz is tinidazole), were solved by X-ray diffraction. Both complexes crystallize in the space group P21/c, with Z = 4 (for nor) and Z = 2 (for ntz) molecules per unit cell. In [Cu(nor)2]SO4.7H2O, the CuII ion is at the centre of a square-planar environment, trans coordinated to two independent norfloxacin molecules in the zwitterionic form acting as bidentate ligands through one of the carboxyl (cbx) and the carbonyl (cb) O atoms. The solid is further stabilized by an extensive network of N--H. . .O(sulfate), N--H. . .O(cbx), N--H. . .OW, OW--H. . .O(sulfate) and OW--H. . .OW hydrogen bonds. The [Cu(NO3)2(tnz)2] complex is centrosymmetric, with the CuII ion in a square planar environment, coordinated to a tinidazole molecule acting as a monodentate ligand through its imidazole N atom and to one nitrate O atom. The vibrational FT-IR absorption spectra and thermal behaviour of the complexes were also studied and are briefly discussed based on the crystal structures. [ABSTRACT FROM AUTHOR]

The crystal structures of bis[1‐ethyl‐6‐fluoro‐4‐oxo‐7‐(piperazin‐1‐ium‐4‐yl)‐1,4‐dihydroquinoline‐3‐carboxylato]copper(II) sulfate heptahydrate, [Cu(C16H18FN3O3)2]SO4·7H2O or [Cu(nor)2]SO4·7H2O (nor is norfloxacin), and bis{1‐[2‐(ethylsulfonyl)ethyl]‐2‐methyl‐5‐nitroimide}dinitratocopper(II), [Cu(NO3)2(C8H13N3O4S)2] or [Cu(NO3)2(tnz)2] (tnz is tinidazole), were solved by X‐ray diffraction. Both complexes crystallize in the space group P21/c, with Z = 4 (for nor) and Z = 2 (for ntz) molecules per unit cell. In [Cu(nor)2]SO4·7H2O, the CuII ion is at the centre of a square‐planar environment, trans coordinated to two independent norfloxacin molecules in the zwitterionic form acting as bidentate ligands through one of the carboxyl (cbx) and the carbonyl (cb) O atoms. The solid is further stabilized by an extensive network of N—H…O(sulfate), N—H…O(cbx), N—H…OW, OW—H…O(sulfate) and OW—H…OW hydrogen bonds. The [Cu(NO3)2(tnz)2] complex is centrosymmetric, with the CuII ion in a square planar environment, coordinated to a tinidazole molecule acting as a monodentate ligand through its imidazole N atom and to one nitrate O atom. The vibrational FT–IR absorption spectra and thermal behaviour of the complexes were also studied and are briefly discussed based on the crystal structures.The structural, spectroscopic and thermal characterization of the novel compounds [Cu(norfloxacin)2]SO4·7H2O and [Cu(NO3)2(tinidazole)2] with potential use as antimicrobial agents is presented. [ABSTRACT FROM AUTHOR]

A series of 2-(haloalkyl)-3-azidomethyl and 6-azido chromones has been synthetized, characterized and studied by theoretical (DFT calculations) and spectroscopic methods (UV-Vis, NMR). The crystal structure of 3-azidomethyl-2-difluoromethyl chromone, determined by X-ray diffraction methods, shows a planar framework due to extended π-bond delocalization. Its molecular packing is stabilized by F···H, N···H and O···H hydrogen bonds, π···π stacking and C–O···π intermolecular interactions. Moreover, AIM, NCI and Hirshfeld analysis evidenced that azido moiety has a significant role in the stabilization of crystal packing through weak intermolecular interactions, where analysis of electronic density suggested closed-shell (CS) interatomic interactions. [ABSTRACT FROM AUTHOR]

Two eucalyptol derivatives, namely 1,3,3-trimethyl-2-oxabicycle[2.2.2]oct-5-yl acetate (4) and 1,3,3-trimethyl-2-oxabicycle[2.2.2]oct-5,8-yl acetate (6) have been synthesized and characterized. Their crystal structures have been solved by single-crystal X-ray diffraction methods indicating that the molecular conformation of both compounds is stabilized by intramolecular C–H⋯O bonds between the H-atoms of the methyl group from the eucalyptol moiety and the O-atom of the acetoxy group. In addition, we have performed a detailed investigation of the intermolecular interactions that stabilize the crystal packing of both structures by using Hirshfeld surface analysis and their associated two-dimensional fingerprint plots. The analysis reveals that the solid-state structure of compounds 4 and 6 is mainly stabilized by C–H⋯O hydrogen bonds and H⋯H bonding interactions. These interactions have also been described and studied energetically using DFT calculations. The nature and strength of these intermolecular contacts have been rationalized by using several computational tools including molecular electrostatic potential (MEP) surfaces, natural bond orbital analysis (NBO), Bader's theory of atoms in molecules (QTAIM) and non-covalent interaction plot (NCI plot) index methods. Furthermore, the intermolecular contacts observed in the crystal lattice of both compounds were experimentally studied through vibrational (IR and Raman) and 1H and 13C NMR spectra. The computational molecular docking analysis of the compounds has been carried out against five potential leishmanial drug targets and the main protease of SARS-CoV-2. [ABSTRACT FROM AUTHOR]

An efficient synthesis of new 1‐O‐β‐glycosylmethyl isoxazoles is described. The title compounds are obtained by cycloaddition of nitrile oxides generated in situ in 2‐MeTHF/sodium hypochlorite solution. The developed approach provides the first use of this green methodology to prepare isoxazole derivatives. X‐ray diffraction structure and conformational analysis in solution show that glycosyl isoxazoles possess the structural features required to be substrates of GLUT‐1. [ABSTRACT FROM AUTHOR]

Two new transition metal complexes with 1-methylimidazole (1-MeIm) and azide as ligands, namely, [Co(1-MeIm)4(N3)2] (1) and [Ni(1-MeIm)4(N3)2] (2), have been synthesized and characterized by IR, Raman, UV-Vis and XPS spectroscopy. Their crystal structures were solved by single-crystal X-ray diffraction. The supramolecular self-assembly of the two complexes is governed by non-classical C–H⋯N hydrogen bonds and C–H⋯π interactions. Lattice energies and intermolecular interaction energies for various molecular pairs are quantified using the PIXEL method. DFT computational studies to assess the binding energy through modern tools like non-covalent interaction (NCI plots) analysis and reduced density gradient (RDG) analysis have also been carried out. A detailed analysis of geometric descriptors revealed the existence of quasi-isostructural pairs or 'main-part' isostructuralism in a series formed by 1, 2, and a related cadmium complex, being more evident in the 1/2 pair. DFT studies using theoretical models have been used to disclose the relative importance of the H-bond and C–H⋯π noncovalent interactions. Magnetic measurements for compound 1 show weak ferrimagnetic coupling between adjacent M(II) centers, mediated by H-bonding and C–H⋯π non-covalent interactions. [ABSTRACT FROM AUTHOR]

We report here the synthesis, crystal structure, characterization and anticancer activity of a copper(II)-hydrazone complex, [Cu(MeBHoVa)(H2O)2](NO3) (for short, CuHL), against human breast cancer cells on monolayer (2D) and spheroids/mammospheres (3D). The solid-state molecular structure of the complex has been determined by X-ray diffraction methods. The conformational space was searched and geometries were optimized both in the gas phase and including solvent effects by computational methods based on DFT. The compound has been characterized in the solid state and in solution by spectroscopic (FTIR, Raman, UV-vis) methods. The results were compared with those obtained for the hydrazone ligand and complemented with DFT calculations. Cell viability assays on MCF7 (IC50(CuHL) = 1.7 ± 0.1 μM, IC50(CDDP) = 42.0 ± 3.2 μM) and MDA-MB-231 (IC50(CuHL) = 1.6 ± 0.1 μM, IC50(CDDP) = 131.0 ± 18 μM) demonstrated that the complex displays higher antitumor activity than cisplatin (CDDP) on 2D and 3D human breast cancer cell models. Molecular docking and molecular dynamics simulations showed that CuHL could interacts with DNA, inducing a significant genotoxic effect on both breast cancer cells from 0.5 to 1 μM. On the other hand, CuHL increases the ROS production and induces cell programmed death on breast cancer cells at very low micromolar concentrations (0.5–1.0 μM). Moreover, the compound decreased the amount of breast CSCs on MCF7 and MDA-MB-231 cells reducing the percentage of CD44+/CD24−/low cells from 0.5 to 1.5 μM. In addition, CuHL overcame CDDP with an IC50 value 65-fold lower against breast multicellular spheroids ((IC50(CuHL) = 2.2 ± 0.3 μM, IC50(CDDP) = 125 ± 4.5 μM)). Finally, CuHL reduced mammosphere formation capacity, hence affecting the size and number of mammospheres and showing that the complex exhibits antitumor properties on monolayer (2D) and spheroids (3D) derived from human breast cancer cells. [ABSTRACT FROM AUTHOR]

Five new transition metal nitroprussides with 1-methylimidazole (1-MeIm) have been synthesized and characterized by IR, XPS and UV-vis spectroscopy, thermal analysis, and powder and single-crystal X-ray diffraction. The structural analyses have revealed that the complexes Mn(1-MeIm)2[Fe(CN)5NO] (1), Fe(1-MeIm)2[Fe(CN)5NO] (2), Cu(1-MeIm)4[Fe(CN)5NO] (3), Zn(1-MeIm)2[Fe(CN)5NO] (4) and Cd(1-MeIm)2[Fe(CN)5NO] (5) are 2D coordination polymers. The supramolecular self-assembly of all the five complexes is governed by non-classical C–H⋯N hydrogen bonds and lone-pair(O)⋯π interactions. N⋯O chalcogen and π⋯π contacts are also present in the crystal packing of complexes 1, 2, 4 and 5. A detailed analysis of four geometric descriptors revealed the existence of a high degree of isostructurality for the molecular pair 1/2, and a moderate one for the pairs 1/5 and 2/5. The dissimilarity index was also calculated for molecular pairs in two series of related compounds, showing that the degree of similarity is lower than those found in the pairs 1/2, 1/5 and 2/5. The results herein discussed for first time in the literature may be useful to understand property/structure relationships in these types of complexes. By using DFT calculations at the PBE0-D3/def2-TZVP level of theory and discrete models of the coordination polymers, we have analyzed cooperative lp–π/π–π/π–lp assemblies that are observed in the solid state of these compounds. This interesting assembly has been further analyzed by a combination of QTAIM, NCIplot and MEP surface calculations. The magnetic measurements indicate that compounds 1–3 are paramagnetic at 300 K and the Curie–Weiss constants are negative, suggesting weak antiferromagnetic coupling between the metal centers, at very low temperatures. [ABSTRACT FROM AUTHOR]

A new perfluoromethylated vinylogous amide, (Z)‐4,4,4‐trifluoro‐1‐(2‐hydroxyphenyl)‐3‐(2‐methoxyethylamino)‐2‐buten‐1‐one, is chosen as an example to investigate the bonding interactions in solid state. The Z, s‐cis form is the dominant conformation in both solution and solid state. Intramolecular hydrogen bonding determines this conformational preference in a nonpolar solvent (NMR spectra). Carbonyl and phenol groups are sensitive to the intra‐ and intermolecular contacts (vibrational spectra). The supramolecular assembly (X‐ray diffraction) is governed by NH⋯O and OH⋯O strong intermolecular hydrogen bonds giving rise to center‐symmetric R22(16) and R22(12) graph‐set motifs. The π‐stacking, F⋯H and F⋯F interactions are also discussed (Hirshfeld analysis). [ABSTRACT FROM AUTHOR]

The compound 1,3,3-trimethyl-2-oxabicyclo[2.2.2]octan-9-ol (9-hydroxyeucaliptol) has been prepared and characterized by single-crystal X-ray diffraction analysis, infrared, Raman, and UV-visible spectroscopies. The molecular geometry of the title compound was also investigated theoretically by density functional theory (DFT) calculations to compare with the experimental data. The substance crystallizes in the trigonal crystal system, space group P32 with Z = 9 molecules per unit cell. There are three independent molecules in the crystal asymmetric unit having the same chirality and showing some differences in the orientation of the H-atom of the hydroxyl group. The crystal structure of 9-hydroxyeucaliptol shows that the hydroxyl group presents an anti-conformation with respect to the O-atom of the ether group. The crystal packing of 9-hydroxyeucaliptol is stabilized by intermolecular O-H···O hydrogen bonds involving the hydroxyl groups of different molecules, which play a decisive role in the preferred conformation adopted in solid state. The intermolecular interactions observed in solid state were also studied through the Hirshfeld surface analysis and quantum theory of atoms in molecules (QTAIM) approaches. Energy framework calculations have also been carried out to analyze and visualize the topology of the supramolecular assembly, and the results indicate a significant contribution from electrostatic energy over the dispersion. [ABSTRACT FROM AUTHOR]

The synthesis, X-ray structure characterization, Hirshfeld surface analysis and DFT calculations of two new antipyrine derivatives are reported herein. Particularly, 2-bromo-N-(2,3-dihydro-1,5-dimethyl-3-oxo-2-phenyl-1H-pyrazol-4-yl)benzamide (1) and 2-chloro-N-(2,3-dihydro-1,5-dimethyl-3-oxo-2-phenyl-1H-pyrazol-4-yl)benzamide (2) are synthesized in good yields and characterized spectroscopically. Both compounds are isostructural and crystallize in the monoclinic P21/c space group. The crystal packing of both compounds is mainly stabilized by a combination of N–H⋯O and C–H⋯O hydrogen bonds. In addition, C–H⋯π and lone pair⋯π contacts were observed. Their solid-state structures have been analyzed through Hirshfeld surface analysis, including the evaluation of the different energy frameworks, indicating that the molecular sheets are primarily formed by hydrogen bonds and the stabilization is dominated via the electrostatic energy contribution. These studies are complemented with DFT calculations (B3LYP-D3/def2-TZVP), and a combination of QTAIM/NCIplot analyses disclosing that the H-bonding interactions are energetically relevant (ranging from 0.9 to 6.1 kcal mol−1), however the total binding energies of the different assemblies are dominated by a combination of π-interactions (of the type C–H⋯π, π⋯π, and lone pair halogen⋯π) that are able to stabilize cooperatively the assemblies up to 12 kcal mol−1. [ABSTRACT FROM AUTHOR]

M(II) complexes with sulfadiazine (SDZ) and imidazole (Im) acting as co‐ligand, [M(SDZ)2(Im)2] (M=Co, Ni, Cu and Zn), have been synthesized and characterized. The crystal structure of Co(II) complex (1) is reported, and a similar structure for the other three complexes is inferred by elemental analysis, IR and electronic spectra. The Co(II) complex is stabilized by intermolecular N–H⋅⋅⋅N, N–H⋅⋅⋅O and C–H⋅⋅⋅O hydrogen bonds, as well as C–H⋅⋅⋅π interactions. An investigation of those structural motifs via Hirshfeld surface analysis has been performed. Energy framework calculations have been carried out to analyze and visualize the 3D topology of the crystal assembly, indicating that the electrostatic energy is dominant over the dispersion one in the most energetic dimer (Motif 1), unlike two related cobalt‐sulfadiazine complexes with other co‐ligands where the dispersion component is more relevant. Further, the relative strength of the bifurcated N–H⋅⋅⋅N/O hydrogen bonds has been analyzed using the quantum theory of "atoms‐in‐molecules" (QTAIM) and molecular electrostatic potential (MEP) surface calculations. The strongest H‐bonds occurring with donor groups from co‐ligand species (Im, DMF and CH3OH) are found to be imperative in controlling the supramolecular architecture of the corresponding cobalt complex. [ABSTRACT FROM AUTHOR]

The reaction of N-phenyl-1-(pyridin-2-yl)methanimine with copper chloride dihydrate produced the title neutral complex, [CuCl2(C12H10N2)(H2O)]·H2O. The CuII ion is five-coordinated in a distorted square-pyramidal geometry, in which the two N atoms of the bidentate Schiff base, as well as one chloro and a water molecule, form the irregular base of the pyramidal structure. Meanwhile, the apical chloride ligand interacts through a strong hydrogen bond with a water molecule of crystallization. In the crystal, molecules are arranged in pairs, forming a stacking of symmetrical cyclic dimers that interact in turn through strong hydrogen bonds between the chloride ligands and both the coordinated and the crystallization water molecules. The molecular and electronic structures of the complex were also studied in detail using EPR (continuous and pulsed), FT-IR and Raman spectroscopy, as well as magnetization measurements. Likewise, Hirshfeld surface analysis was used to investigate the intermolecular interactions in the crystal packing. [ABSTRACT FROM AUTHOR]

We present the selective synthesis of novel aminooxy glycosyl derivatives bearing hydroxy phenyl moieties. A strict control over the anomeric and E/Z configurations has been achieved. The products obtained are α‐glycosides and the aromatic moiety substitute the Schiff's base trans to the O‐glycosidic bond. Single crystal X‐ray diffraction and NMR spectral data are reported and analysed. [ABSTRACT FROM AUTHOR]

A new series of CuII, NiII, CoII, and MnIII complexes have been synthesised from the (6 Z)-6-(7-trifluoromethyl-1,2,3,4-tetrahydro-5 H -1,4-diazepin-5-ylidene)cyclohexa-2,4-dien-1-one (HDZP) ligand. These complexes were characterised by elemental, spectroscopic (IR and UV-vis), and thermal analysis. The crystal structure of Cu-DZP was solved by X-ray diffraction methods. The complex crystallises in the monoclinic P 21/ c space group, with two molecules per unit cell. The crystal lattice is stabilised by different intra and intermolecular interactions. Hirshfeld surface analysis was employed to obtain additional information about interactions that are responsible for the crystal packing. Quantitative examination of the fingerprint plots indicated the dominant contribution of H⋯H and H⋯X (X = O, F) interactions in the crystal packing. In addition, C–H⋯chelate ring (CR) and C–H⋯π interactions are described in detail and evaluated using DFT calculations. The antibacterial properties and the mechanism of inhibition of the main bacterial resistant mechanism, the biofilm, of the metal complexes and free ligand were investigated. [Mn(DZP)3]·2H2O was the most active complex against the Pseudomonas aeruginosa biofilm formation with an inhibition of 40 %. However, none of the complexes inhibit more than 25 % of the Gram negative bacteria microbial development. The most meaningful result was the bactericidal effect of [Co(DZP)2(H2O)2]·2H2O against the Gram positive bacteria, Staphylococcus aureus , which inhibits the bacterial development and significantly reduces the biofilm formation at low concentration. A new series of CuII, NiII, CoII, and MnIII complexes have been synthesised from the (6 Z)-6-(7-trifluoromethyl-1,2,3,4-tetrahydro-5 H -1,4-diazepin-5-ylidene)cyclohexa-2,4-dien-1-one (HDZP) ligand. These complexes were characterised by elemental, spectroscopic (IR and UV-vis), and thermal analysis. The crystal structure of Cu-DZP was solved by X-ray diffraction methods. [ABSTRACT FROM AUTHOR]

An N,N,O,O donor Schiff base blocking ligand [H2L = 6,6′-((1E,1′E)-(ethane-1,2-diylbis(azaneylylidene))bis(methaneylylidene))bis(3-(diethylamino)phenol), 1] has been used to synthesize mononuclear [CuL]·H2O (2) and [VO(L)] (3) complexes. The ligand and complexes have been characterized by elemental, spectral (FTIR and UV-vis) and thermogravimetric analysis. The molecular structures of 1 and 2 have been confirmed by single crystal X-ray diffraction studies. The crystal structure of the ligand (1) indicates that the molecule is sited on a crystallographic inversion centre and the planar conformation of the salicylideneimine moiety is favored by two intramolecular O–H⋯N1 hydrogen bonds forming S(6) ring motifs. The copper(II) center in complex 2 is coordinated in a square planar fashion. The presence of an extended π-system in the complex (two chelate rings and two phenyl rings) facilitates the formation of chelate ring (CR)⋯π non-covalent interactions. DFT calculations have been performed to explore the energetic features of unconventional CR⋯π and hydrogen bonding interactions that are observed and described in the solid state of 2. Moreover, we have studied how the energy of the CR⋯π interaction is influenced by the substituent of the phenyl ring. In addition, the cytotoxic effect of the compounds has been tested against MG-63 (human osteosarcoma), HT-29 (human colorectal) and MCF7 (breast) cancer cell lines using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. [ABSTRACT FROM AUTHOR]

The novel 2-(difluoromethyl)-3-methylchromone, 2-(dichloromethyl)-3-methylchromone, and 3-methyl-2-(perfluoroethyl)chromone were synthesized by a one-pot method and characterized through MS spectrometry, cyclic voltammetry, and vibrational (IR, Raman), UV–Vis, fluorescence, and NMR (1H, 13C, and 19F) spectroscopy. The crystal structure of 2-(difluoromethyl)-3-methylchromone and 2-(dichloromethyl)-3-methylchromone determined by X-ray diffraction methods were used to calculate their intermolecular interactions and crystal lattice energies together with the Hirshfeld surface analysis. [ABSTRACT FROM AUTHOR]

In the search for a more effective chemotherapy for the treatment of Chagas’ disease and human African trypanosomiasis, caused by Trypanosoma cruzi and Trypanosoma brucei parasites, respectively, the use of organometallic compounds may be a promising strategy. In this work, eight new heterobimetallic compounds are described including four 5-nitrofuryl containing thiosemicarbazones as bioactive ligands (HL1–HL4) and dppf = 1,1′-bis(diphenylphosphino) ferrocene as an organometallic co-ligand. Complexes of the formula [MII(L)(dppf)](PF6) with M = Pd or Pt were synthesized and fully characterized in the solid state and in solution, including the determination of the molecular structure of four of them by single crystal X-ray diffraction methods. Most compounds showed activity in the low micromolar or submicromolar range against both parasites, with the platinum compounds being more active than the palladium analogues. Activity was significantly increased by generation of the M-dppf compounds (3–24 fold increase with respect to free ligands HL for T. cruzi and up to 99 fold increase with respect to HL for T. brucei). The inclusion of the organometallic co-ligand also led to lower toxicity in mammalian cells and higher selectivity towards both parasites when compared to the free HL compounds. The complexes interact with DNA and affect the redox metabolism of the parasites. Furthermore, the most active and selective compound of the new series showed no in vivo toxicity in zebrafish embryos. [ABSTRACT FROM AUTHOR]

The interaction of a poly-functional ligand derived from o-vanillin and 2-thiophenemethylamine (oVATPNH2) with transition metal ions Cu(ii) and Zn(ii) leads to the formation of stable coordination compounds, namely [Cu(oVATPNH2)2] and [Zn(oVATPNH2)2]. Their crystal structures have been determined by X-ray diffraction methods. Two molecules of the deprotonated ligand acting in a bidentate fashion build a nearly square planar environment around Cu(ii) and a distorted tetrahedral coordination arrangement for Zn(ii). The complexes were characterized by spectroscopic techniques, including solid state FTIR, Raman, EPR and diffuse reflectance and solution UV-vis and EPR. Their thermal behavior has been analyzed by means of TGA and DTA. DFT theoretical studies, using computational methods based on DFT, were employed to assist the interpretation and assignment of spectroscopic data. Cytotoxicity assays against two human breast cancer cell lines, namely MCF-7 and MDA-MB-231, revealed an enhancement of the effectiveness of the complexes as compared with both the ligand and the free metal ions. The results for the copper compound are promising, as its cytotoxic effect was stronger than the reference metallodrug cisplatin in both cancer cell lines tested. [ABSTRACT FROM AUTHOR]

A new losartan [2-butyl-5-chloro-3-[[4-[2-(2H-tetrazol-5-yl)phenyl]phenyl]methyl]imidazol-4-yl]methanol zinc(II) complex [Zn(Los)Cl], was synthesized and characterized. The crystal structure was determined by x-ray diffraction methods. When aqueous solutions of the ligand and the metal were mixed, the known and more soluble powder [Zn(Los)2].3H2O (ZnLos) complex has been obtained. The interactions with phosphatases showed a concerted mechanism displayed by the Zn ions and ZnLos up to 500 μM concentration: a decrease of the acid phosphatase (AcP) associated with an increase in the alkaline phosphatase (ALP) activities. The complex and ZnSO4 showed a cytotoxic behavior on human lung A549 cancer cell line at concentrations higher than 75 μM with reactive oxygen species (ROS) generation and GSH (and GSH/GSSG ratio) depletion. Apoptotic cells were observed using terminal deoxynucleotidyl transferase dUTP nick-end labeling (TUNEL) method, a mechanism accompanied by upregulation of BAX protein, downregulation of Bcl-XL and release of caspase-3. The BAX/Bcl-XL ratio was found to be significantly higher in cells exposure to ZnLos than cells treated with ZnSO4, in agreement with the higher apoptotic percentage of cells found for the complex. Cell death was found to be produced by apoptosis and no necrosis has been observed. On the contrary, losartan exerted low effects on phosphatases, produced some reduction of cancer cell viability (concentrations > 250 μM, number of apoptotic cells similar to the basal) with low ROS depletion, without alteration of the GSH/GSSG and low BAX/Bcl-XL ratios. In the MRC-5, normal lung fibroblasts cell line only ZnSO4 at concentrations higher than 200 μM displays cytotoxic effects.Interaction of Zn with losartan. Activation of intrinsic apoptotic signaling pathway in lung cancer cells and effects on alkaline and acid phosphatases [ABSTRACT FROM AUTHOR]

The crystal structure of pyridinium 6-methyl-1,2,3,-oxathiazine-4(3H)-one-2,2-dioxide [(C5NH6)(C4H4NO4S)], for short, pyH(ace), was determined by X-ray diffraction methods. It crystallizes as a twin in the monoclinic space group P21/c with a=6.9878(9), b=7.2211(7), c=21.740(2) Å, β=91.67(1)° and Z=4 molecules per unit cell. The structure was determined employing 1599 reflections with I>2σ(I) from one of the twin domains and refined employing 2092 reflections from both crystal domains to an agreement R1 factor of 0.0466. Besides electrostatic attractions, intermolecular pyH···O=C(ace) hydrogen bonds stabilize the acesulfamate anion and the pyridinium cation into planar discrete units parallel to the (100) crystal plane. The units form stacks of alternating ace− and pyH+ ions along the a axis that favors inter-ring π–π interactions. The Fourier transform-infrared (FT-IR) spectrum of the compound was recorded and is briefly discussed. Some comparisons with related pyridinium saccharinate salts are also made. [ABSTRACT FROM AUTHOR]

Attenuated total reflectance (ATR) from principal faces of orthorhombic (and higher symmetry) crystals in spectral regions including strongly polar optic modes is considered. A detailed, quantitative comparison between experimental and calculated ATR infrared (IR) spectra of orthorhombic sodium nitroprusside dihydrate (SNP), Na2[Fe(CN)5NO]·2H2O, single crystals in the 500–3800 cm-1 region is presented. Calculated ATR spectra are generated employing the dielectric tensor of SNP obtained from Kramers–Kronig analysis of external reflectance data. The dependence of intensities, profiles, and locations of bands in the spectra upon the relative refractive index of the sample against the ATR prism and the polarization state of the reflected IR beam will be discussed. Both theoretical and experimental evidence of the coupling of the TM-polarized evanescent wave with strong in-plane-polarized optic modes at about their LO frequencies will be given with reference to the case of the strong NO stretching mode of SNP. Finally, the computed and experimental ATR results in SNP single crystals will be critically compared with powder ATR data and reported polarized IR transmittance spectra of SNP single crystals plates. [ABSTRACT FROM AUTHOR]

Abstract: The accumulation of radical anions from 3,4‐disubstituted 1,2,5‐thiadiazole S,S‐dioxides (1) in solution of organic solvents is achieved by electrochemical, chemical and photoinduced pathways. Electrolytic and chemical reduction of 1 produces the radical anions (1•–) in high molar yields (> ca. 80%). The survival of 1•– is measured for ca. three months. The stability of the reduced state depends on its structure and the composition (solvent, reducing agent, and supporting electrolyte) of the medium in which it is generated by the chemical and electrochemical routes. In solution of polar aprotic solvents, 1•– persists even in the presence of water or oxygen. Irradiation with 254 nm light generates 1•– but only in DMF solution; the proposed reaction mechanism involves the participation of the solvent. Radical anions are characterized by cyclic voltammetry, UV‐Vis spectrophotometry and electron spin resonance spectroscopy. The chemical stability and the properties of 1/1•– make them suitable for the development of novel materials for technological applications. [ABSTRACT FROM AUTHOR]

The term ‘organic minerals’ means naturally occurring crystalline organic compounds including metal salts of formic, acetic, citric, mellitic, methanesulfonic and oxalic acids. As for the rest of the (inorganic) minerals, the primary tool to disclose their crystal and molecular structure and therefore to understand their mutual relationship with each other and with synthetic analogues and also their physicochemical properties is X-ray diffraction crystallography ever since the dawn of this methodology in 1913. The structure of several synthetic organic minerals was solved well before the discovery of their natural counterpart. On the other hand, complete crystal structure determination of early discovered organic minerals had to await the advent of combined synthetic and advanced X-ray diffraction methods to fully unveil their crystal structures. We review here the crystal chemistry of organic minerals and show the importance of structural studies on their synthetic analogues. This will be highlighted by case studies on the recently reported synthetic novgorodovaite, Ca2(C2O4)Cl2·2H2O, and its heptahydrate analogue, Ca2(C2O4)Cl2·7H2O, and the isotypic to each other stepanovite, NaMg[Fe(C2O4)3]·9H2O, and zhemchuzhnikovite, NaMg[AlxFe1−x(C2O4)3]·9H2O. [ABSTRACT FROM AUTHOR]

Synthetic novgorodovaite analog Ca2( C2O4) Cl4·2H4O is identical to its natural counterpart. It crystallizes in the monoclinic I2/m space group with a = 6.9352(3), b = 7.3800(4), c = 7.4426(3) Å, β = 94.303(4)°, V = 379.85(3) Å3 and Z = 2. The heptahydrate analog, Ca2( C2O4)Cl4·7H4O, crystallizes as triclinic twins in the P1 space group with a = 7.3928(8), b = 8.9925(4), c = 10.484(2) Å, α = 84.070(7), β = 70.95(1), γ = 88.545(7)°, V = 655.3(1) Å3 and Z = 2. The crystal packing of both calcium oxalate-chloride double salts favors the directional bonding of oxalate, C2O4 2-, ligands to calcium ions as do other related calcium oxalate minerals. The π-bonding between C and O atoms of the C2O4 2- oxalate group leaves sp2-hydridised orbitals of the oxygen atoms available for bonding to Ca. Thus, the Ca-O bonds in both calcium oxalate-chloride double salts are directed so as to lie in the plane of the oxalate group. This behavior is reinforced by the short O...O distances between the oxygens attached to a given carbon atom, which favors them bonding to a shared Ca atom in bidentate fashion. Strong bonding in the plane of the oxalate anion and wide spacing perpendicular to that plane due to repulsion between oxalate π-electron clouds gives rise to a polymerized structural units which are common to both hydrates, explaining the nearly equal cell constants ~7.4 Å which are defined by the periodicity of Ca-oxalate chains in the framework (monoclinic b ≈ triclinic a). When compared with novgorodovaite, the higher water content of Ca2( C2O4) Cl4·7H4O leads to some major differences in their structures and ensuing physical properties. While novgorodovaite has a three-dimensional framework structure, in the higher hydrate, the highly polar water molecules displace chloride ions from the calcium coordination sphere and surround them through OwH···Cl hydrogen bonds. As a result, polymerization in Ca2( C2O4)Cl4·7H4O solid is limited to the formation of two-dimensional Ca2( C2O4)(H4O)5 slabs parallel to (001), inter-layered with hydrated chloride anions. This layered structure accounts for (001) being both a perfect cleavage and a twin interface plane. The infrared and Raman spectra of both salts are also briefly discussed. [ABSTRACT FROM AUTHOR]

In spite of the apparent contradiction between ‘liquid crystals’ (LC, materials exhibiting some degree of disorder) and ‘crystallography’ (a paradigmatic ordered kingdom), X-ray diffraction (XRD) studies make a substantial contribution to the field of LC. Focusing this review on smectic (Sm, lamellar) LC, we first describe how extremely careful XRD studies performed on mono-domain samples in the LC phase helped to elucidate the molecular structure of ordered Sm phases. Then, we describe selected examples in which single-crystal (SC) XRD on the solid-state phase of the mesogens provided information about their supra-molecular organization in the Sm phase. Finally, we present a different approach to this problem in the case of a thermo-tropic Schiff base (SB) which undergoes crystal ↔ LC ↔ isotropic liquid phase transformations. By combined SC and variable-temperature powder XRD, we show that the SB LC is a hexatic smectic B phase that derives from the crystal phase by relatively small topological changes promoted by the set-in of thermal rotational disorder around the long SB molecular axis. [ABSTRACT FROM AUTHOR]

The intermolecular interactions in the solid state and the spectroscopic vibrational, electronic and NMR properties of new 3-methyl-substituted-2-trifluoromethylchromone derivatives with –CN (1), –NO2 (2), –OH (3) and –NH2 (4) groups were discussed with the assistance of DFT calculations. The crystal structures of compounds 1–3 were determined by X-ray diffraction showing molecular ribbons for compounds 1 and 2, and dimers via O–H…O=C hydrogen bonds for 3. Hirshfeld surfaces and the corresponding fingerprint plots, as well as the electrostatic potentials mapped on the surfaces revealed C–H…O and C–H…F hydrogen bonds, and π…π stacking as the main cooperative driving forces for building supramolecular architectures in all compounds. The C–H…π and C=O…π interactions also contribute to stabilizing the crystal structures of 1 and 2. A further analysis of Hirshfeld surfaces was performed using the enrichment ratio as a new descriptor to determine the likelihood of chemical species to establish specific interactions in the molecular packing. The lattice energies of the crystal structures and several intermolecular contacts present in different molecular pairs were also quantified. Molecular docking studies showed the interaction of the title compounds with the catalytic site of PLA2 (PDB code URL URL="HTTP://XLINK.RSC.ORG/?PDB=2QOG"2QOG/URL) from Crotalus durissus terrificus, and suggested that the investigated compounds could inhibit toxic effects of snake venom. [ABSTRACT FROM AUTHOR]

The crystal structure of aqua lithium 6-methyl-1,2,3,-oxathiazine-4(3H)-one, 2.2-dioxide, for short Li(ace)HO, was determined by X-ray diffraction methods. It crystallizes in the triclinic P $$\overline {1}$$ space group with a = 6.1750(9) Å, b = 7.3969(9) Å, c = 9.016(1) Å, α = 105.88(1)°, β = 94.59(1)°, γ = 97.80(1)°, and Z = 2 molecules per unit cell. The crystal structure of Li(ace)HO sharply departs from the other heavier alkaline-metal acesulfamates, namely the monoclinic isotypic M-ace (M from Na to Cs) family of salts. Lithium is in a distorted LiO tetrahedral coordination with acesulfamate carbonyl, sulfoxide and water oxygen atoms. The FTIR spectrum of the new compound was also recorded and is briefly discussed. Some comparisons with other simple acesulfamate salts are also made. Graphical Abstract: The synthesis of aqua lithium acesulfamate, Li(CHNOS)HO, and its structural characterization by single-crystal X-ray diffractometry are reported. The FTIR spectrum of the salt is analyzed by comparison with data of related compounds. [ABSTRACT FROM AUTHOR]

Cadmium and lead(II) acesulfamate, Cd(C4H4NO4S)2 · 2H2O and Pb(C4H4NO4S)2, were prepared by the reaction of acesulfamic acid and the respective metal carbonates in aqueous solution, and characterized by elemental analysis. Their crystal structures were determined by single crystal X-ray diffraction methods. The Cd(II) compound crystallizes in the monoclinic space group P21/c with Z = 4 and the corresponding Pb(II) salt in the triclinic space group P1 with Z = 2. In both salts, acesulfamate acts both as a bi-dentate ligand through its nitrogen and carbonyl oxygen atoms and also as a mono-dentate ligand through this same oxygen atom, giving rise to polymeric structures; in the Pb(II) salt the ligand also binds the cation through its sulfoxido oxygen atoms. The FTIR spectra of the compounds were recorded and are briefly discussed. Some comparisons with other related acesulfamate and saccharinate complexes are made. [ABSTRACT FROM AUTHOR]

4,7-Dimethyl-2H-chromen-2-one (1) and its novel sulfur analogue 4,7-dimethyl-2H-chromen-2-thione (2) were synthesized and fully characterized by spectroscopic methods and mass spectrometry. The crystal structure of compound 2 has been determined by X-ray diffraction methods, and it crystallizes in the monoclinic I2/m space group. The molecular skeleton lies in the crystallographic mirror plane, in agreement with the expected theoretical planarity enforced by extended π-bonding. The crystal packing of both compounds is characterized by the R22(8) motif formed by intermolecular C–H…X=C (X = O and S) hydrogen-bonding interactions involving the 1-benzopyran-2-one/thione moiety, as also identified by Hirshfeld surface analysis. The vibrational properties have been studied by infrared and Raman spectroscopy complemented by quantum chemical calculations and normal coordinate analysis of the potential energy distribution. The UV-Vis spectrum is interpreted in terms of TD-DFT quantum chemical calculations, showing a clear red-shift in the HOMO–LUMO electronic transition when the chromen-2-one ring is converted into chromen-2-thione. [ABSTRACT FROM AUTHOR]

A reference to the prior publication of one of the crystal structures reported by Tobón‐Zapata [Acta Cryst. (2022), B78, 490–498] is given. [ABSTRACT FROM AUTHOR]

A new general synthetic procedure for preparation of Na3[Fe(C2O4)3]·5H2O (1), Rb3[Fe(C2O4)3]·3H2O (2), and Cs3[Fe(C2O4)3]·2H2O (3) was developed. The crystal structures of these salts have been determined by single crystal X-ray diffraction. Salt1crystallizes in the monoclinic space group C2/cwithZ = 8, salt2in P21/cwithZ = 4, and salt3in P21/nwithZ = 4. The three new salts and K3[Fe(C2O4)3]·3H2O, prepared for comparative purposes, were further characterized by infrared and57Fe-Mössbauer spectroscopy. These spectra are discussed in comparison with those of related oxalato complexes. [ABSTRACT FROM AUTHOR]

In February 1912 in Munich, P. P Ewald, one of A. Sommerfeld's Ph.D. students, consulted M. Laue on matters related to crystal optics, his thesis subject. During the conversation, Laue conceived the idea that a crystal might act as a three-dimensional diffraction grating to the X-rays. Despite the idea having met with scepticism among his colleagues, Laue succeeded in getting the help of two of W. C. Roentgen's doctorands: F. Friedrich, Sommerfeld's laboratory assistant, and P. Knipping: to undertake the, by now, legendary experiments that originated a new branch of Physics. The results solved two fundamental questions of the time: namely are the X-rays electromagnetic radiation (light) of very short wavelength? And also, do the crystals have spatial periodic arrangements? The affirmative answer to both questions was immediately followed in 1913 by the instrumentation and re-interpretation of the phenomenon through the pioneering work by W. H. Bragg and his son W. L. Bragg, who paved the way to the portentous development of structural crystallography by X-ray diffraction that took place during the last hundred years. [ABSTRACT FROM PUBLISHER]

The crystal structure of synthetic stepanovite, Na[Mg(HO)][Fe(CO)]·3HO, and zhemchuzhnikovite, Na[Mg(HO)][AlFe(CO)]·3HO, has been determined by single-crystal X-ray diffraction methods. The compounds are isotypic to each other and to the previously reported Na[Mg(HO)][M(CO)]·3HO (M: Cr, Al). They crystallize in the trigonal P3 c1 space group with Z = 6 molecules per unit cell and (hexagonal axes) a = 17.0483(4), c = 12.4218(4) Å for the iron compound, and a = 16.8852(5), c = 12.5368(5) Å for the Al/Fe solid solution. Comparison of our crystallographic results with previous X-ray diffraction and chemical data of type stepanovite and zhemchuzhnikovite minerals provides compelling evidence that these natural materials possess the same crystal and molecular structure as their synthetic counterparts. It is shown that the originally reported unit cell for stepanovite represents a pronounced sub-cell and that the correct unit cell and space group are based on weak superstructure reflections. The infrared and Raman spectra of both synthetic analogs were also recorded and are briefly discussed. [ABSTRACT FROM AUTHOR]

The potassium salt of the Schiff base obtained by condensation of 2-hydroxy-3-methoxybenzaldehyde (o-vanillin) and 2-aminoethanesulfonic acid (taurine) in a methanol potassium hydroxide solution was characterized by crystallographic, spectroscopic and DFT methods. The compound crystallizes in the monoclinic C2/c space group with a = 37.539(4), b = 5.9129(4), c = 26.321(5) Å, β = 121.10(2)° and Z = 8 molecules per unit cell. The crystallographic data reveal that two different anionic molecules, which constitute a tautomeric pair, coexist in the crystal. This finding is supported by FTIR, Raman and electronic measurements in methanol solution. The main crystallographic differences between the bonding structures occur along the shortest chemical path linking the oxygen and the nitrogen atom of the OH and CN group. Both tautomeric forms are stabilized by strong O–H…N and N–H…O intramolecular hydrogen bonds. Optimized geometrical parameters and calculated spectroscopic features obtained by DFT calculations show a very good agreement with the experimental data. Moreover, 1H NMR, 13C NMR and electronic measurements in DMSO solution show the prevalence of the enol-imine tautomer in this solvent. [ABSTRACT FROM AUTHOR]

The crystal structure of sodium and magnesiumtris(oxalato)chromato(III) nona hydrate, NaMg[Cr(C2O4)3]·9H2O, has been determined by X-ray diffraction methods. It crystallizes in the trigonalP3c1 space group with (in the hexagonal setting)a = b = 16.9635(4),c = 12.5247(3) Å, andZ = 6 molecules per unit cell. The Cr(III) and sodium ions are in octahedral environments coordinated to three oxalate molecules and arranged in a honeycomb-like layered structure perpendicular to the crystalc-axis. There are three different octahedral [Mg(H2O)6]2+hydrated ions that fill the honeycomb holes giving rise to electrically neutral Na[Mg(H2O)6][Cr(oxalato)3] crystal slabs. Neighboring slabs are bridged by the remaining three water molecules through H-bonds and therefore the whole crystal can be more properly described as Na[Mg(H2O)6][Cr(oxalato)3]·3H2O. Also, the structure of isomorphous NaMg[Al(C2O4)3]·9H2O compound has been re-examined and compared with the chromium(III) complex. Infrared and Raman spectra of both complexes were also recorded and briefly discussed. [ABSTRACT FROM PUBLISHER]

Two novel Re(i) complexes with the general formula fac-[Re(CO)3(L)(nHo)]CF3SO3, where L = 2,2′-bipyridine (bpy) or 1,10 phenanthroline (phen) and nHo (9H-pyrido[3,4-b]indole; norharmane) have been synthesized. The Re(i)–nHo complexes were characterized by structural X-ray diffraction, 1H and 13C NMR, UV-vis absorption and FT-IR spectroscopy, and by a combination of two mass spectrometry techniques, namely ESI-MS and UV-MALDI-MS. All characterizations showed that nHo is coordinated to the metal atom by the pyridine nitrogen of the molecule. X-ray structural analysis revealed that the crystal lattices for both complexes are further stabilized by a strong ＞N–H…O bond between the pyrrole NH group of the pyridoindole ligand and one oxygen atom of the trifluoromethanesulfonate counter-ion. Ground state geometry optimization by DFT calculations showed that in fluid solution the nHo ligand may rotate freely. The nature of the electronic transitions of Re(CO)3(bpy)(nHo)+ were established by TD-DFT calculations. The set of the most important electronic transitions present in this complex are comprised of π→π* electronic transitions centered on bpy and nHo moieties, LLCTnHo→COs, MLLCTRe(CO)3→bpy and LLCTnHo→bpy transitions. Additionally, TD-DFT calculations predict the existence of another two intense MLLCTRe(CO)3→nHo electronic transitions. Calculated UV-vis absorption spectra are in good agreement with the corresponding experimental data for the bpy-containing complex. [ABSTRACT FROM AUTHOR]

In search of prospective agents against infectious diseases, 1,1′-bis(diphenylphosphino)ferrocene pyridine-2-thiolato-1-oxide M(ii) hexafluorophosphate compounds [M(mpo)(dppf)](PF6), where M = palladium or platinum, were synthesized and fully characterized in the solid state and in solution using experimental and DFT computational techniques. The compounds are isomorphous and the M(ii) transition metal ions are in a nearly planar trapezoidal cis-coordination bound to the pyridine-2-thiolato-1-oxide (mpo) and to the 1,1′-bis(diphenylphosphino)ferrocene molecules, both acting as bidentate ligands. Both compounds showed high cytotoxic activity on Trypanosoma cruzi and Mycobacterium tuberculosis (MTB) and acceptable selectivities towards MTB, but good to excellent selectivity index values as anti-T. cruzi compounds. The inclusion of the ferrocene moiety (dppf ligand) improved the selectivity towards the parasite when compared to the previously reported [M(mpo)2] complexes. Related to the probable mechanism of action of the complexes, molecular docking studies on modelled T. cruzi NADH-fumarate reductase (TcFR) predicted that both be very good inhibitors of the enzyme. The effect of the compounds on the enzyme activity was experimentally confirmed using T. cruzi protein extracts. According to all obtained results, both [M(mpo)(dppf)](PF6) compounds could be considered prospective anti-trypanosomal agents that deserve further research. [ABSTRACT FROM AUTHOR]

The ammonium, barium hexacyanoferrate(II) trihydrate, Ba(NH)[Fe(CN)]·3HO, has been synthesized for the first time, was characterized by thermogravimetric and differential thermal analysis (TG-DTA), infrared (IR) and Raman spectroscopy and chemical analysis, and its crystal and molecular structures were determined by X-ray diffraction methods. The chemical composition was determined by assaying Ba(II) with EDTA, ammonia nitrogen with Nessler's reagent as indicator and Fe(II) using spectrophotometry with ortho-phenanthroline method. The hydration number was estimated by thermogravimetric analysis. The compound crystallizes in the trigonal R-3 c space group. The ferrocyanide anion has an almost perfect octahedral shape with its Fe(II) ion in a crystallographic special position of point symmetry S [d(Fe-C) = 1.912(2) Å, d(C-N) = 1.153(3) Å]. The barium, ammonium nitrogen and water oxygen atoms are also at lattice special positions with site symmetries D, C and C, respectively. The thermal decomposition process was also studied using TG-DTA, and the products of decomposition were identified by IR spectroscopy. It proposes a mechanism of decomposition. [ABSTRACT FROM AUTHOR]

Structural and conformational properties of two dixanthogen molecules, [CH3(CH2)2OC(S)S]2 and [(CH3)2CHOC(S)S]2, have been analyzed using a combined experimental and theoretical approach, with data obtained from structural X-ray diffraction methods, IR, Raman and UV-visible spectroscopies, and DFT calculations. [(CH3)2CHOC(S)S]2 crystallizes in the monoclinic P21/c space group with a = 9.735(1) Å, b = 12.588(3) Å, c = 12.131(2) Å, β = 112.65(1)°, and Z = 4 molecules per unit cell. The interactions in the crystal were modelled and interpreted by NBO analysis. [CH3(CH2)2OC(S)S]2 is liquid at room temperature, and the vibrational spectra were satisfactorily explained in terms of the equilibrium between three conformers, originating from the rotation of the two terminal CH3– groups, in agreement with the DFT predictions. The electronic spectra of both dixanthogens were assigned with the assistance of the TD-DFT calculations. [ABSTRACT FROM AUTHOR]

In the course of our studies on 3 $$H$$ -1,2-dithiole-3-thione synthesis, a serendipitous reactivity with $$\alpha $$ -haloketones, in the presence of excess of potassium iodide, has been observed. Instead of the expected reaction of the nucleophile in a remote point of the molecule, we have obtained a product resulted from the electrophile character of the thiocarbonyl moiety on the 3-position of the 1,2-dithiole. In order to obtain an efficient protocol in terms of energy efficiency, this methodology was studied under conventional and microwave heating with similar or better results in the latter conditions. Simplicity and great efficiency in this one-step transformation are some of the advantages of this reaction. Moreover, the results can be explained according to the Pearson's hard and soft acid base theory. [ABSTRACT FROM AUTHOR]

A new water-soluble complex, Re(CO)3(pterin)(H2O), was synthesized and characterized by 1H NMR and FTIR spectroscopy, and by a combination of three mass spectrometry techniques: MALDI, probe electrospray ionisation (PESI), and ESI. Because, unlike most metal-pterin complexes, the ReI complex is quite soluble in water, appropriate single crystals could be obtained for structural X-ray analysis. We report here the first solid state molecular structure containing a pterin ligand coordinated to the Re(CO)3 core. This determination revealed that strong H bonds between the hydrogen atom of the 2-amino group and crystallization water molecules give rise to a polymeric arrangement of Re(CO)3(pterin)(H2O) complexes in the lattice. Protonation studies in aqueous solutions of the ReI complex showed two acid-base equilibriums with p Ka1 = 3.9 and p Ka2 = 8.8. p Ka1 was assigned to the protonation equilibrium at N3 of the pterin ligand in the complex and p Ka2 could be ascribed to the deprotonation of a coordinated water molecule. [ABSTRACT FROM AUTHOR]

Salicylaldehyde 2-chlorobenzoyl hydrazone (H2LASSBio-466), salicylaldehyde 4-chlorobenzoyl hydrazone (H2LASSBio-1064) and their complexes [Zn(LASSBio-466)H2O]2 (1) and [Zn(HLASSBio-1064)Cl]2 (2) were evaluated in animal models of peripheral and central nociception, and acute inflammation. All studied compounds significantly inhibited acetic acid-induced writhing response. Upon coordination the antinociceptive activity was favored in the complex 1. H2LASSBio-466 inhibited only the first phase of the formalin test, while 1 was active in the second phase, like indomethacin, indicating its ability to inhibit nociception associated with the inflammatory response. Hence coordination to zinc(II) altered the pharmacological profile of H2LASSBio-466. H2LASSBio-1064 inhibited both phases but this effect was not improved by coordination. The studied compounds did not increase the latency of response in the hot plate model, indicating their lack of central anti-nociceptive activity. All compounds showed levels of inhibition of zymosan-induced peritonitis comparable or superior to indomethacin, indicating an expressive anti-inflammatory profile. [ABSTRACT FROM AUTHOR]

The crystal and molecular structure of dilapacholateaqua(dimethylformamide)nickel(II) was determined by X-ray diffraction. It crystallizes in the triclinic space group P1 with a = 9.8671(9) Å, b = 10.654(1) Å, c = 15.289(2) Å, α = 86.98(1)°, β = 79.32(1)°, γ = 87.031(8)°, and Z = two molecules per unit cell. The structure was solved from 5094 reflections with I>2σ(I) and refined by full matrix least-square to an agreement R1-factor of 0.0564. The nickel(II) is in a NiO6 octahedral environment, cis coordinated to two lapacholate anions through their adjacent carbonyl [Ni-O distances of 2.075(2) and 2.066(2) Å], and phenyl oxygens [Ni-O lengths of 2.011(2) and 2.021(2) Å], and to a water [d(Ni-Ow) = 2.073(2) Å] and a DMF [d(Ni-O) = 2.076(2) Å] at axial positions. Some physicochemical and spectroscopic properties of the complex are also reported. [ABSTRACT FROM AUTHOR]