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In this work, the 2D Eu(III) coordination polymer {[Eu(HPDC)(PDC)]}n (PDC = 2,6-pyridinedicarboxylate) (1) was prepared in a fast manner via microwave-assisted hydrothermal synthesis. The same compound was obtained by a conventional hydrothermal route and had its structure determined through single crystal X-ray diffraction. In 1, the HPDC and PDC ligands exhibit terminal and chelating bridging modes, respectively, forming a coordination polymer through interconnected europium–carboxylate chains, leading to a highly ordered two-dimensional layer. The nanosheets in 1 self-organize in the solid-state by intermolecular interactions, producing a 3D supramolecular network. Solid-state photoluminescence studies have shown that the antenna effect is responsible for the red emission of the compound under ultraviolet excitation. In alcoholic solutions, it was possible to exfoliate the material by ultrasonication in a top-down approach, leading to single nanosheets of 1. In the chemical stability studies, there was observed a water-induced transformation of 1, leading to the compound {[Eu(PDC)(HPDC)(H2O)2]·4H2O}n (2). The aqueous suspension of this material shows strong red luminescence with the naked-eye. 2 demonstrates reversible behavior induced by heating under reduced pressure. Our work highlights the properties related to solvent-induced exfoliation and water-induced transformation. [ABSTRACT FROM AUTHOR]

The synthesis and structural characterization of three families of coordination complexes synthesized from 4′‐phenyl‐2,2′:6′,2′′‐terpyridine (8, Ph‐TPY), 4′‐(4‐chlorophenyl)‐2,2′:6′,2′′‐terpyridine (9, ClPh‐TPY) and 4′‐(4‐methoxyphenyl)‐2,2′:6′,2′′‐terpyridine (10, MeOPh‐TPY) ligands with the divalent metals Co2+, Fe2+, Mn2+ and Ni2+ are reported. The compounds were synthesized from a 1:2 mixture of the metal and ligand, resulting in a series of complexes with the general formula [M(R‐TPY)2](ClO4)2 (where M = Co2+, Fe2+, Mn2+ and Ni2+, and R‐TPY = Ph‐TPY, ClPh‐TPY and MeOPh‐TPY). The general formula and structural and supramolecular features were determinated by single‐crystal X‐ray diffraction for bis(4′‐phenyl‐2,2′:6′,2′′‐terpyridine)nickel(II) bis(perchlorate), [Ni(C21H15N3)2](ClO4)2 or [Ni(Ph‐TPY)2](ClO4)2, bis[4′‐(4‐methoxyphenyl)‐2,2′:6′,2′′‐terpyridine]manganese(II) bis(perchlorate), [Mn(C22H17N3O)2](ClO4)2 or [Mn(MeOPh‐TPY)2](ClO4)2, and bis(4′‐phenyl‐2,2′:6′,2′′‐terpyridine)manganese(II) bis(perchlorate), [Mn(C21H15N3)2](ClO4)2 or [Mn(Ph‐TPY)2](ClO4)2. In all three cases, the complexes present distorted octahedral coordination polyhedra and the crystal packing is determined mainly by weak C—H...π interactions. All the compounds (except for the Ni derivatives, for which FT–IR, UV–Vis and thermal analysis are reported) were fully characterized by spectroscopic (FT–IR, UV–Vis and NMR spectroscopy) and thermal (TGA–DSC, thermogravimetric analysis–differential scanning calorimetry) methods. [ABSTRACT FROM AUTHOR]

Polymorphism in racemic pharmaceutical compounds is relatively unexplored. However, this phenomenon may provide an additional tool to crystal engineering, opening the doors to rational design of chiral resolution, chiral enrichment, and chiral purification of pharmaceutical compounds. In this work we report two racemic polymorphs occurring for the nitrate salt of the antidepressant drug fluoxetine (FLX): a racemate (P21/n, Z = 4, Z' = 1) and a kryptoracemate (Pca21, Z = 4, Z' = 2). The relative stability of these polymorphs was established through a combination of techniques, namely, differential scanning calorimetric (DSC), thermogravimetric analysis (TGA), hot stage microscopy (HSM), and solubility measurements. Though the two polymorphs share some structural features, the N+-H…O- hydrogen bonds have created dissimilar racemic motifs in their packing, resulting in different enantiomer orientations. The racemate is more stable over the temperature ranges we studied and is monotropically related to kryptoracemate. In our experiments, the obtaining of non-centrosymmetric lattice of racemic fluoxetine nitrate was shown to be dependent on kinetic factors. The thermodynamic relationships between both polymorphs were further confirmed by measuring their water solubility at 20 and 37 °C. [ABSTRACT FROM AUTHOR]

Abstract: The solid state properties of deflazacort (1-(1β,16α)-21-(acetyloxy)-11-hydroxy-2′-methyl-5′H-pregna-1,4-dieno[17,16-d]oxazole-3,20-dione, 1) were investigated using differential scanning calorimetry (DSC), thermogravimetry (TG), single-crystal X-ray diffraction, solid and liquid nuclear magnetic resonance spectroscopy (13C NMR), Fourier transform infrared and Raman spectroscopy (FTIR and FT Raman). From the trends observed in the crystal structure and spectral data some conclusions can be made about hydrogen bonding, molecular conformation and crystal packing. Compound 1 crystallizes in an orthorhombic cell, space group P212121 and the following lattice parameters: a =11.2300(5), b =12.8161(8), c =16.171(1)Å, V: 2327.4(2)Å3, D c: 1.260g/cm3, R1=0.0479, =0.1012. The crystal structure is stabilized by intra and intermolecular interactions, which provides for a very closely packed form. The NMR data indicated that 1 shows a similar conformation in solid and liquid state; while, thermal data revealed that 1 follows a monophasic pattern with a DSC melting peak at 258.4°C (ΔH 99.7Jg−1, n =3), indicating that 1 is thermally stable as solid; but, as liquid is unstable to undergo a thermal decomposition reaction. The reactivity of 1 toward light and moisture was examined via DSC and TLC. The data indicated that 1 do not interact with water to give hydrated forms or decomposition products; however, light degrades 1. [Copyright &y& Elsevier]

Abstract: An X-ray and a theoretical study of the structure of the isoniazid derivatives, 2,4-difluoro-N′-isonicotinoylbenzohydrazide, 3, and 2,4-dichloro-N′-isonicotinoylbenzohydrazide hydrochloride, [4H+, Cl−, 2(H2O)], are reported. Quantum chemical calculations as well as conformational analysis are presented with the isolated cations [3H+] and [4H+], where the former was protonated in silico to allow direct comparison of results. Supermolecule calculations were also carried out with the asymmetric unit of [4H+, Cl−, 2(H2O)], which is comprised of two independent cations (4H+), two chloride ions and four water molecules. Our results indicate that the crystal structures, although clearly representing accessible conformations, are highly distorted in comparison to the predicted lower energy conformers in the gas-phase. These distortions are most probably imposed by polar and electrostatic interactions within the crystal packing. In general, the calculated potential energy surfaces (PES) for both isoniazid derivatives are fairly flat, a feature confirmed by the low energetic difference calculated for several conformers corresponding to local minima in PES. Noteworthy, the fluorinated compound [3H+] shows an important additional energy barrier for rotation around the bond connecting the halogenated ring to the proximate carbonyl due to a strong internal hydrogen bond involving the fluorine atom. [Copyright &y& Elsevier]

The UnitedNations declared 2014 to be the InternationalYear of Crystallography (IYCr2014) to commemorate the centennial ofX-ray crystallography since the first X-ray diffraction experimentwas performed on a crystal of copper sulfate pentahydrate. A Crystal Growth and Designvirtual special issue has beendedicated to celebrate IYCr2014. This is a perspective on the compilationof selected papers that appeared in the virtual special issue. [ABSTRACT FROM AUTHOR]

Reports on an appreciable degree of pyramidalization of the amine nitrogen (N) atom observed in 2-methyl-5-nitroaniline. Confirmation of the existence of polar chains; Description of the structure as non-polar layers with chains interlinked by centrosymmetric dimers; Implication that a relationship between molecular recognition patterns and crystal structures should not be assumed.

Three principal factors may influence the final structure of coordination polymers (CPs): (i) the nature of the ligand, (ii) the type and coordination number of the metal center, and (iii) the reaction conditions. Further, flexible carboxylate aliphatic ligands have been widely employed as building blocks for designing and synthesizing CPs, resulting in a diverse array of materials with exciting architectures, porosities, dimensionalities, and topologies as well as an increasing number of properties and applications. These ligands show different structural features, such as torsion angles, carbon backbone number, and coordination modes, which affect the desired products and so enable the generation of polymorphs or crystalline phases. Additionally, due to their large coordination numbers, using 4f and 5f metals as coordination centers combined with aliphatic ligands increases the possibility of obtaining different crystal phases. Additionally, by varying the synthetic conditions, we may control the production of a specific solid phase by understanding the thermodynamic and kinetic factors that influence the self-assembly process. This revision highlights the relationship between the structural variety of CPs based on flexible carboxylate aliphatic ligands and f-elements (lanthanide and actinides) and their outstanding luminescent properties such as solid-state emissions, sensing, and photocatalysis. In this sense, we present a structural analysis of the CPs reported with the oxalate ligand, as the one rigid ligand of the family, and other flexible dicarboxylate linkers with –CH2– spacers. Additionally, the nature of the luminescence properties of the 4f or 5f-CPs is analyzed, and finally, we present a novel set of CPs using a glutarate-derived ligand and samarium, with the formula [2,2′-bipyH][Sm(HFG)2 (2,2′-bipy) (H2O)2]•(2,2′-bipy) (α-Sm) and [2,2′-bipyH][Sm(HFG)2 (2,2′-bipy) (H2O)2] (β-Sm). [ABSTRACT FROM AUTHOR]

The water‐soluble compound [Ru3O(CH3COO)6(4‐ampy)3]Cl (1, 4‐ampy=4‐aminopyridine) was evaluated in terms of its biologically relevant properties. Compound 1 participates in a hydrogen bonding network which includes the NH2 substituents of the ancillary ligands, methanol molecules, the Cl− counter‐ion, and a non‐conventional hydrogen bond with the neighboring 4‐ampy molecules′ π‐cloud, as determined by X‐ray measurements. One protonation equilibrium was observed at pH values below 2.3. Additionally, the compound exhibited a partition coefficient value of −0.86 (±0.07), indicating that it is highly hydrophilic. At 37 0C and pH=7.4 (phosphate buffer), compound 1 shows moderate (Ksv=2.4 104 M−1) and spontaneous (ΔG=−26.4 kJ mol−1) binding to human serum albumin (HSA) through ground‐state association, which involves formation of hydrogen bonds (ΔH=−35.7 kJ mol−1 and, ΔS=−29.8 J mol−1 K−1). Molecular docking calculations support the formation of hydrogen bonds between 1 and HSA, and suggest subdomain IIA (site I), which contains the Trp‐214 residue, as the primary interactive pocket, in agreement with the experimental static fluorescence quenching mechanism. Furthermore, a preliminary assay reveals that 1 has low cytotoxicity towards human glioblastoma U87‐MG cells. [ABSTRACT FROM AUTHOR]

The chemical reaction of 4-bromo-benzoyl-chloride and 2-amino-thia-zole in the presence of potassium thio-cyanate yielded a white solid formulated as C15H10BrN3OS2, which consists of 4-bromo-benzamido and 2-benzo-thia-zolyl moieties connected by a thio-urea group. The 4-bromo-benzamido and 2-benzo-thia-zolyl moieties are in a trans conformtion (sometimes also called s-trans due to the single bond) with respect to the N-C bond. The dihedral angle between the mean planes of the 4-bromo-phenyl and the 2-benzo-thia-zolyl units is 10.45 (11)°. The thio-urea moiety, -C-NH-C(=S) -NH- fragment forms a dihedral angle of 8.64 (12)° with the 4-bromo-phenyl ring and is almost coplanar with the 2-benzo-thia-zolyl moiety, with a dihedral angle of 1.94 (11)°. The mol-ecular structure is stabilized by intra-molecular N-H⋯O hydrogen bonds, resulting in the formation of an S(6) ring. In the crystal, pairs of adjacent mol-ecules inter-act via inter-molecular hydrogen bonds of type C-H⋯N, C-H⋯S and N-H⋯S, resulting in mol-ecular layers parallel to the ac plane. [ABSTRACT FROM AUTHOR]

Lapachol (lap) is widely studied due to its biological application, as well as its importance in the coordination chemistry field. The structure of cis and trans isomers of new ruthenium(III) complex [RuCl2(PPh3)2(lap)] is reported here. The complexes present one molecule of the natural product lapachol, coordinated as bidentate by oxygen atoms, two monodentate triphenylphosphines and two chlorido ligands in a cis or trans configurations. All neutral complexes were characterized by single-crystal X-ray diffraction and these data were compared with Density Functional Theory (DFT) data results. This study highlights the stereochemistry and structural versatility of metal complexes containing lapachol as ligand. [ABSTRACT FROM AUTHOR]

A three-dimensional terbium(III) coordination polymer of formula [Tb(bttb)0.5(2,5-pzdc)0.5]n (1) [H4bttb = 1,2,4,5-tetrakis(4′-carboxyphenyl)benzene and H2-2,5-pzdc = 2,5-pyrazinedicarboxylic acid] was obtained under hydrothermal conditions. The bttb4− tetraanion in 1 adopts the bridging and chelating–bridging pseudo-oxo coordination modes while the 2,5-pzdc2− dianion exhibits a rather unusual bis-bidentate bridging pseudo-oxo coordination mode, both ligands being responsible for the stiffness of the resulting 3D structure. Solid-state photoluminescent measurements illustrate that 1 exhibits remarkable green luminescence emission, the most intense band occurring in the region of 550 nm (5D4 → 7F5) with lifetimes at the millisecond scale. Thermometric performances of 1 reveal a maximum relative sensitivity (Sm) of 0.76% K−1 at 295 K (δT = 0.05 K), constituting a TbIII ratiometric solid luminescent thermometer over the physiological temperature range. Variable-temperature static (dc) magnetic susceptibility measurements for 1 in the temperature range 2.0–300 K show the expected behavior for the depopulation of the splitted mJ levels of the 7F7 ground state of the magnetically anisotropic terbium(III) ion plus a weak antiferromagnetic interaction through the carboxylate bridges. No significant out-of-phase magnetic susceptibility signals were observed for 1 in the temperature range 2.0–10.0 K, either in the absence or presence of a static dc magnetic field. [ABSTRACT FROM AUTHOR]

This study addressed the formation of co‐crystals from Quercetin and Curcumin by mechanochemical treatment employing ball mill grinding. The binary system was initially studied using molecular complementarity and hydrogen bond propensity analysis structural tools available in Mercury software. This study was performed from CCDC reported structural data for Curcumin and Quercetin dihydrate used as starting reagents. Reaction conditions, such as Quercetin: Curcumin molar ratio, grinding time, and solvent‐assisted variables, were optimised to synthesise a new solid phase from the binary system. The synthesised product was characterised by differential scanning calorimetry, thermogravimetric analysis, Fourier transform infrared spectroscopy, scanning electron microscopy, and powder X‐ray diffraction techniques. Finally, to compare the anti‐oxidant capacities from the pure components, eutectic mixtures previously reported and the new crystalline phase was evaluated in vitro using the 1,1‐diphenyl‐2‐pycril‐hydrazylhydrate radical inhibition method. The co‐crystal phase and eutectic mixtures present higher anti‐oxidant activity with values around 5.0 mg/L compared to pure Quercetin (3,444 mg/L) and Curcumin (9,141 mg/L), using only half of the molecules. These results indicate Quercetin molecule is synergically active with the Curcumin molecule in the binary mixtures. [ABSTRACT FROM AUTHOR]

We employed (Z)‐N'‐[phenyl(pyrimidin‐2‐yl)methylene]nicotinohydrazide (2) and (Z)‐4‐(dimethylamino)‐N'‐[phenyl(pyrimidin‐2‐yl)methylene]benzohydrazide (3) as cores of dynamic chemical systems whose different states are modulated, in a reversible fashion, through specific physical and chemical stimuli. The structure of the compounds was determined by Nuclear Magnetic Resonance (NMR) techniques (1D and 2D) and confirmed by single‐crystal X‐ray diffraction. By Variable temperature (VT) 1H NMR experiments and DFT calculations, the conformational isomerism of 2 was studied and added as an additional input for the dynamic system. Additionally, 2 exhibits configurational E/Z isomerization mediated by pH variations and UV light. On the other hand, configurational isomerism locks an unlocks a tridentate pocket for metal cation coordination in both 2 and 3. All the different dynamic states configurational/conformational isomerism and locked and unlocked coordination constitute a development in the field of systems of multiple dynamics suitable for molecular machines. [ABSTRACT FROM AUTHOR]

Peptidomimetics containing an aziridine moiety have been reported as potent cysteine protease inhibitors. In this sense, the development of stereoselective and sustainable synthetic strategies to obtain three-membered N -heterocyclic compounds has gained importance in the last decades. In this work, an efficient method was designed to achieve highly functionalized aziridine peptidomimetics via a sequential reaction, which involves the organocatalytic aziridination of α,β-unsaturated aldehydes followed by the Passerini multicomponent reaction in an environmentally friendly solvent mixture (ethanol: water). [ABSTRACT FROM AUTHOR]

Coordination compounds of copper exhibit cytotoxic activity and are suitable for the search for novel drug candidates for cancer treatment. In this work, we synthesized three copper(II) carboxylate complexes, [Cu2(3-(4-hydroxyphenyl)propanoate)4(H2O)2]·2H2O (C1), [Cu2(phenylpropanoate)4(H2O)2] (C2) and [Cu2(phenylacetate)4] (C3), and characterized them by elemental analysis and spectroscopic methods. Single-crystal X-ray diffraction of C1 showed the dinuclear paddle-wheel arrangement typical of Cu–carboxylate complexes in the crystal structure. In an aqueous solution, the complexes remain as dimeric units, as studied by UV-visible spectroscopy. The lipophilicity (partition coefficient) and the DNA binding (UV visible and viscosity) studies evidence that the complexes bind the DNA with low Kb constants. In vitro cytotoxicity studies on human cancer cell lines of metastatic breast adenocarcinoma (MDA-MB-231, MCF-7), lung epithelial carcinoma (A549) and cisplatin-resistant ovarian carcinoma (A2780cis), as well as a nontumoral lung cell line (MRC-5), indicate that the complexes are cytotoxic in cisplatin-resistant cells. [ABSTRACT FROM AUTHOR]

[Display omitted] Famotidine (FMT) is an orally administered histamine H2-receptor blocker with limited bioavailability since it exhibits low solubility and low permeability. In addition, the recent withdrawal of ranitidine from the market, makes famotidine an interesting candidate to obtain solid forms with improved pharmacokinetic performance. In this work, crystal engineering concepts and the co-amorphous formation strategy were applied to obtain two novel solids. Crystalline famotidine malate (FMT-MT) and a vitreous phase (FMT-MTa) were prepared by solvent evaporation and mechanochemical synthesis, respectively. FMT-MT (monoclinic, S.G. P2 1 /n) crystallizes with one FMT and one co-former molecules in the asymmetric unit forming a (R 2 2 8) structural motif. FMT-MT resulted in a salt by proton transfer from one malic carboxylic group to the guanidine moiety of FMT. The three-dimensional packing is described as undulating layers of alternated FMT+ and MT- running along the a direction. FMT-MTa shows the inherent features of amorphous phases according to powder X-ray diffraction and DSC analysis. The higher physical stability was found for amorphous samples maintained at 4 °C up to 60 days. The solubility assays in water, indicate that FMT-MT and FMT-MTa are 2.02 and 2.68-fold more soluble than the marketed polymorph, whereas similar values were obtained in simulated gastric fluid. [ABSTRACT FROM AUTHOR]

Herein, we report on the synthesis and characterization of ruthenium compounds with the general formula [RuCl(AA-H)(NO)(dppb]PF6, where AA = glycine (1), L-alanine (2), L-phenylalanine (3) and L-valine (4), and dppb = 1,4-bis(diphenylphosphine)butane. The complexes were characterized using elemental analysis, UV/Vis and infrared spectroscopies, 1H, 13C, 31P NMR techniques, and cyclic voltammetry. Furthermore, the structures of the compounds (1) and (3) were determined using single-crystal X-ray diffraction. In vitro evaluation of the Ru(II)/nitrosyl/amino acid complexes revealed their cytotoxic activities against triple-negative MDA-MB-231 breast cancer cells, and against the non-tumor murine fibroblast cells. All the compounds decreased the percentage of viable cells, inducing cell death by apoptosis. Additionally, the Ru(II) complexes inhibited the migration of MDA-MB-231 cells at concentrations lower than 35 µM, after 48 h of exposure. Thus, these complexes may be promising agents for the treatment of triple-negative MDA-MB-231 breast cancer. [ABSTRACT FROM AUTHOR]

• Three new Ru(II) complexes were prepared. • Full characterization is reported. • Single-crystal X-ray diffraction confirm the molecular structures. • DFT are in agreement with experimental data. Reactions of cis -[RuCl 2 (P-P)(bipy)] precursors with the SpymMe 2 ligand (4,6-dimethyl-2-pyrimidinethiol) yielded complexes of the [Ru(SpymMe 2)(P-P)(bipy)]PF 6 type, where P-P = 1,2-bis(diphenylphosphino)ethane (dppe - for complex 1), 1,3-bis(diphenylphosphino)propane (dppp - for complex 2) and 1,1'-bis(diphenylphosphino)ferrocene (dppf - for complex 3) and bipy = 2,2'-bipyridine. The new compounds were obtained by displacing the chlorido ligands from the precursors and coordination of one monoanionic 4,6-dimethyl-2-pyrimidinethiol ligand. All complexes were characterized by spectroscopic, electrochemical and elemental analysis techniques, as well as single-crystal X-ray diffraction, where the structures of complexes 1, 2 and 3 showed that the SpymMe 2 ligand coordinates to the ruthenium(II) center as bidentated, yielding complexes with the sulfur atom trans positioned to the nitrogen atom from the bipy ligand. A theoretical study of the structures of the complexes was performed using the DFT/B3LYP method. Distances and angles of optimized structures agree with X-ray experimental data. Furthermore, the calculated IR and UV-Vis spectra are compatible with experimental data. Charge decomposition analysis (CDA) and NBO (natural bond orbitals) charges showed that there was an overall charge transfer from bipy and P-P ligands to the ruthenium centers. Higher electrochemical stability and 1H and 31P{1H} NMR shifts of 1, 2 and 3 compared with precursors could be explained by the lower values of calculated molecular orbital energies, NBO charge on atoms and CDA data. Finally, the structure of the isomers of complexes 1, 2 and 3, considering the sulfur atom trans positioned to the phosphorus atom, were optimized, showing that they are slightly less stable, presenting total energy higher, 10.4, 31.5 and 60.5 kJ/mol than 1, 2 and 3 , where nitrogen is trans to the phosphorus atom. [ABSTRACT FROM AUTHOR]

Coordination complexes may act as anticancer agents. Among others, the formation of the complex may facilitate the ligand uptake by the cell. Searching for new copper compounds with cytotoxic activity, the complex Cu-dipicolinate was studied as a neutral scaffold to form ternary complexes with diimines. A series of [Cu(dipicolinate)(diimine)] complexes (where diimine: Phenanthroline, phen, 5-NO2-phenanthroline, 4-methyl-phenanthroline, neocuproine, 3,4,7,8-tetramethyl-phenanthroline, tmp, bathophenanthroline, bipyridine, dimethyl-bipyridine, as well as the ligand 2,2-dipyridil-amine, bam) were synthesized and characterized both in the solid state, including a new crystal structure of [Cu2(dipicolinate)2(tmp)2]·7H2O. Their chemistry in aqueous solution was explored by UV/vis spectroscopy, conductivity, cyclic voltammetry, and electron paramagnetic resonance studies. Their DNA binding was analyzed by electronic spectroscopy (determining Kb values), circular dichroism, and viscosity methods. The cytotoxicity of the complexes was assessed on human cancer cell lines MDA-MB-231, MCF-7 (breast, the first triple negative), A549 (lung epithelial) and A2780cis (ovarian, Cisplatin-resistant), and non-tumor cell lines MRC-5 (lung) and MCF-10A (breast). The major species are ternary, in solution and solid state. Complexes are highly cytotoxic as compared to Cisplatin. Complexes containing bam and phen are interesting candidates to study their in vivo activity in triple-negative breast cancer treatment. [ABSTRACT FROM AUTHOR]

The ruthenium(II) compounds cis -[Ru(bpy) 2 (4-bzpy)(CO)](PF 6 ) 2 ( I ) and cis -[Ru(bpy) 2 (4-bzpy)(Cl)](PF 6 ) ( II ) (4-bzpy = 4-benzoylpyridine, bpy = 2,2′-bipyridine) were synthesized and characterized by spectroscopic and electrochemical techniques. The crystal structure of II was determined by X-ray diffraction. The photochemical behavior of I in aqueous solution shows that irradiation with ultraviolet light (365 nm) releases both CO and 4-bzpy leading to the formation of the cis -[Ru(bpy) 2 (H 2 O) 2 ] 2 + ion as identified by NMR and electronic spectroscopy. Carbon monoxide release was confirmed with the myoglobin method and by gas chromatographic analysis of the headspace. CO release was not observed when aqueous I was irradiated with blue light (453 nm). Changes in the electronic and 1 H NMR spectra indicate that I undergoes photoaquation of 4-bzpy to form cis -[Ru(bpy) 2 (CO)(H 2 O)] 2 + . Blue light irradiation of aqueous II released the coordinated 4-bzpy to give the cis -[Ru(bpy) 2 (H 2 O)(Cl)] 2 + ion. When the latter reaction was carried out in the presence of the nucleobase guanine, Ru-guanine adducts were formed, indicating that the metal containing photoproduct may also participate in biologically relevant reactions. The photochemical behavior of I indicates that it can release either CO or 4-bzpy depending on the wavelength chosen, a feature that may have therapeutic application. [ABSTRACT FROM AUTHOR]

In 2021, our research group published the prominent anticancer activity achieved through the successful combination of two redox centres (ortho-quinone/para-quinone or quinone/selenium-containing triazole) through a copper-catalyzed azide-alkyne cycloaddition (CuAAC) reaction. The combination of two naphthoquinoidal substrates towards a synergetic product was indicated, but not fully explored. Herein, we report the synthesis of 15 new quinone-based derivatives prepared from click chemistry reactions and their subsequent evaluation against nine cancer cell lines and the murine fibroblast line L929. Our strategy was based on the modification of the A-ring of para-naphthoquinones and subsequent conjugation with different ortho-quinoidal moieties. As anticipated, our study identified several compounds with IC50 values below 0.5 µM in tumour cell lines. Some of the compounds described here also exhibited an excellent selectivity index and low cytotoxicity on L929, the control cell line. The antitumour evaluation of the compounds separately and in their conjugated form proved that the activity is strongly enhanced in the derivatives containing two redox centres. Thus, our study confirms the efficiency of using A-ring functionalized para-quinones coupled with ortho-quinones to obtain a diverse range of two redox centre compounds with potential applications against cancer cell lines. Here as well, it literally takes two for an efficient tango! [ABSTRACT FROM AUTHOR]

Searching for new copper compounds which may be useful as antitumor drugs, a series of new [Cu(L-dipeptide)(batho)] (batho:4,7-diphenyl-1,10-phenanthroline, L-dipeptide: Gly-Val, Gly-Phe, Ala-Gly, Ala-Ala, Ala-Phe, Phe-Ala, Phe-Val and Phe-Phe) complexes were synthesized and characterized. To interpret the experimental IR spectra, [Cu(ala-gly)(batho)] was modelled in the gas phase using DFT at the B3LYP/LANL2DZ level of theory and the calculated vibrational frequencies were analyzed. Solid-state characterization is in agreement with pentacoordinate complexes of the general formula [Cu(L-dipeptide)(batho)]·x solvent, similar to other [Cu(L-dipeptide)(diimine)] complexes. In solution, the major species are heteroleptic, as in the solid state. The mode of binding to the DNA was evaluated by different techniques, to understand the role of the diimine and the dipeptide. To this end, studies were also performed with complexes [CuCl2(diimine)], [Cu(L-dipeptide)(diimine)] and free diimines, with phenanthroline, neocuproine and 3,4,7,8-tetramethyl-phenanthroline. The cytotoxicity of the complexes was determined on human cancer cell lines MDA-MB-231, MCF-7 (breast, the first triple negative), and A549 (lung epithelial) and non-tumor cell lines MRC-5 (lung) and MCF-10A (breast). [Cu(L-dipeptide)(batho)] complexes are highly cytotoxic as compared to cisplatin and [Cu(L-dipeptide)(phenanthroline)] complexes, being potential candidates to study their in vivo activity in the treatments of aggressive tumors for which there is no curative pharmacological treatment. [ABSTRACT FROM AUTHOR]

Single crystals of the phenyl­coumarin named mammeigin (or mammea A/AA cycle D) [systematic name: 5-hydroxy-8,8-dimethyl-6-(3-methyl­butanoyl)-4-phenyl-2 H,8 H-pyrano[2,3- f]chromen-2-one], C25H24O5, were obtained in the course of a chemotaxonomic study of the Guttiferae family. Mammeigin was extracted from the fruits of Kilmeyera pumila. The structure reveals an infinite three-dimensional network stabilized by non-classical inter­molecular hydrogen bonds. [ABSTRACT FROM AUTHOR]

In the centrosymmetric molecule of the title compound, [Hg(C12H10O2P)2(C5H5N)2(C12H11O2P)2], the approximately octa­hedral Hg atom is coordinated by two each of phenyl­phosphinate, phosphinic acid and pyridine ligands. Each pair of phosphinic acid and phosphinate ligands features an intra­molecular hydrogen bond, so forming an eight-membered ring. [ABSTRACT FROM AUTHOR]

Immunomodulatory agents are widely used for the treatment of immune-mediated diseases, but the range of side effects of the available drugs makes necessary the search for new immunomodulatory drugs. Here, we investigated the immunomodulatory activity of new ferrocenyl-N-acyl hydrazones derivatives (SintMed(141–156). The evaluated N-acyl hydrazones did not show cytotoxicity at the tested concentrations, presenting CC50 values greater than 50 µM. In addition, all ferrocenyl-N-acyl hydrazones modulated nitrite production in immortalized macrophages, showing inhibition values between 14.4% and 74.2%. By presenting a better activity profile, the ferrocenyl-N-acyl hydrazones SintMed149 and SintMed150 also had their cytotoxicity and anti-inflammatory effect evaluated in cultures of peritoneal macrophages. The molecules were not cytotoxic at any of the concentrations tested in peritoneal macrophages and were able to significantly reduce (p < 0.05) the production of nitrite, TNF-α, and IL-1β. Interestingly, both molecules significantly reduced the production of IL-2 and IFN-γ in cultured splenocytes activated with concanavalin A. Moreover, SintMed150 did not show signs of acute toxicity in animals treated with 50 or 100 mg/kg. Finally, we observed that ferrocenyl-N-acyl hydrazone SintMed150 at 100 mg/kg reduced the migration of neutrophils (44.6%) in an acute peritonitis model and increased animal survival by 20% in an LPS-induced endotoxic shock model. These findings suggest that such compounds have therapeutic potential to be used to treat diseases of inflammatory origin. [ABSTRACT FROM AUTHOR]

Palladium and nickel complexes featuring thiosemicarbazones derived from chalcones and benzalketone were synthesized and fully characterized. Palladium compounds demonstrated remarkable antitumor efficacy against prostate (DU-145), breast (MCF-7), and non-tumor prostate (PNT2) cell lines. In contrast, the Ni(II) compound was inactive. Highlight the role of the metallic center for anticancer activity. Notably, these compounds did not interact significantly with DNA and Topoisomerase. [Display omitted] In this study, we report the synthesis and characterization of eight new palladium complexes and a nickel complex containing thiosemicarbazone ligands derived from chalcones and benzalketones. The techniques of Infrared and UV–visible spectroscopy, Nuclear Magnetic Resonance, Mass Spectrometry, and Elemental Analysis fully characterized the compounds. Crystallography was successful for five complexes and two ligands, allowing for X-ray Diffraction analysis. Molecular docking studies and assays involving DNA interaction via agarose gel electrophoresis and UV–Vis titration revealed no DNA interaction or inhibition of topoisomerase IIα enzyme activity. However, these compounds demonstrated potent cytotoxic effects (IC 50) against breast tumor (MCF-7) and prostate (DU-145) cell lines, as well as non-tumor prostate (PNT2) cell lines. These findings highlight the relevance of structural variations and the metallic center's nature in achieving cytotoxic effects, offering insights into the development of bioactive compounds. [ABSTRACT FROM AUTHOR]

The synthesis and XRD characterization at 295 K of three isomers, X-fluoro-N-(2-hydroxy-5-methyl phenyl) benzamide: (o-FPhB), (m-FPhB), and (p-FPhB), are presented. o-FPhB and m-FPhB show high structural affinity concerning molecular and packing structures. The planarity of the C1-C7(O1)-N1-C8 peptide bond in o-FPhB, and m-FPhB confers high stability, favoring its tendency to acquire a resonant structure in the peptide segment and in the molecule. For p-FPhB, a stereochemical gate opens, leading to the activation of N-H∙∙∙∙O interpeptide bonds, defining its supramolecular properties. Active participation of the halogen in the assembly of the structures is observed, forming intramolecular rings and molecule chains during crystal growth. The o-FPhB and m-FPhB form parallel sheets that develop hydrogen C-H···Cg, halogen C-F···Cg, or C=O···Cg interactions. Theoretical evaluations of the properties performed by the DFT/B3LYP/(6-311G(d,p) showed good agreement with the experimental values. The IR analysis reaffirms the presence of N-H, C=O, O-H, C-F, and C-H. In the UV-Vis, an increase in the energetic stability, O···H interactions, and electrostatic potential in the NH region reaffirm the disposition of p-FPhB for the formation of the N-H···O interpeptide bond. A molecular docking on the benzamides involving protein receptors showed similar behavior for all three isomers. [ABSTRACT FROM AUTHOR]

New compounds to fight cancer are needed due to cancer high incidence and lack of curative treatments for several classes of this disease. Metal-based coordination compounds offer a variety of molecules that can turn into drugs. Among them, coordination copper complexes are emerging as an attractive class of compounds for cancer treatment. A series of [Cu(l-dipeptide)(tmp)] (tmp = 3,4,7,8-tetramethyl-1,10-phenanthroline) complexes were synthesized and characterized in the solid state, including the determination of the crystalline structure of [Cu(Gly-Gly)(tmp)]·3.5 H2O and [Cu2Cl4(tmp)2]. The complexes were studied in solution, where the major species are also ternary ones. The lipophilicity of the complexes was determined and the binding to the DNA was evaluated, suggesting that it occurs in the DNA's major groove. The cytotoxicity of the complexes was evaluated on different cancer cell lines: human metastatic breast adenocarcinoma MDA-MB-231 (triple negative, ATCC: HTB-26), MCF-7 (ATCC: HTB-22), SK-BR-3 (ATCC: HTB-30), human lung epithelial carcinoma A549 (ATCC: CCL-185), cisplatin resistant-human ovarian carcinoma A2780cis (SIGMA) and nontumoral cell lines: MRC-5 (lung; ATCC: CCL-171) and MCF-10A (breast, ATCC: CRL-10317). [Cu(l-dipeptide)(tmp)] complexes are highly cytotoxic as compared to [Cu(l-dipeptide)(phenanthroline)] and cisplatin. Therefore, [Cu(l-dipeptide)(tmp)] complexes are promising candidates to have their in vivo activity further studied toward new treatments for triple negative breast cancer and other aggressive tumors for which there is no curative pharmacological treatment to the date. [ABSTRACT FROM AUTHOR]

Crystal engineering of the anti-HIV drug lamivudine has currently provided improvement in its pharmaceutical performance besides getting insights into several branches of nucleoside structural chemistry. Here, we demonstrated the synthon robustness and the role of the five-membered ring conformation in the diversity of lamivudine crystal forms even with supramolecular isomerism. Oxathiolane conformation defines the ability of lamivudine to assemble into different multicomponent molecular crystal forms. This was observed in a polymorph of lamivudine hydrochloride, which is related to the previously reported lamivudine hydrochloride monohydrate. The absence of water molecules has little effect on their supramolecular organization. If water is not present, just one conformational change from C3′-endo puckering in the monohydrate form to the C2′-endo one in the anhydrate form reported here is enough to cause a hydrogen bonding reorganization involving the 5′-OH group. DFT calculations reveal a low energy gap for this change in the oxathiolane conformation. Therefore, lamivudine can variably forward its 5′-OH group through changing oxathiolane conformations of similar energies. In addition, the isostructurality and robustness of the supramolecular synthons were illustrated in two halide salts of lamivudine with hydrobromic and hydrofluoric acids. While the previously reported lamivudine hydrochloride is strictly isostructural to the hydrobromide salt, the lamivudine hydrofluoride crystallized as a hydrofluoric acid cocrystal. HF cocrystallization appears to be primarily related to further stabilization between sheets rather than a major size effect. [ABSTRACT FROM AUTHOR]

Famotidine ( FMT), a histamine H2-receptor antagonist, is a drug commonly used in treatments of gastroesophageal diseases that presents solid-state polymorphism ( A and B forms), the marketed form being the metastable polymorph B. A new stable salt was obtained by combination of FMT and maleic acid as coformer. FMT maleate ( FMT- MLT) was prepared either by solvent evaporation or comilling methods. Single-crystal X-ray diffraction reveals that ( FMT)+ in FMT- MLT adopts an extended conformation that is stabilized by classical and nonclassical H-bonds. The three-dimensional packing consists of tapes along the axis b that further develop a columnar array based on H-bonds involving ( FMT)+ side chain. Nonconventional π-stacking interactions between adjacent tapes were also identified. Fourier transform infrared, differential scanning calorimetry, thermogravimetric analysis, polarized light thermal microscopy, and scanning electron microscopy were employed to characterize the multicomponent complex. According to the solubility values in water and simulated gastric fluid, FMT- MLT exhibits such a performance that improves on the solubility of the commercially available polymorph. Finally, the higher stability of FMT- MLT regarding both FMT forms, as well as its easy preparation from either A or B forms or a mixture of them, also allows to consider this salt as a valuable alternative to avoid the polymorphism issue in marketed formulations containing FMT. © 2014 Wiley Periodicals, Inc. and the American Pharmacists Association J Pharm Sci 103:3754-3763, 2014 [ABSTRACT FROM AUTHOR]

Highlights: [•] New polymorph of the 9,10-dichloroanthracene is reported. [•] Halogen contacts define the packing motif of the crystal structure of the new polymorph. [•] DFT-D and MP2 calculations estimates properly the intermolecular interactions present in the system. [Copyright &y& Elsevier]

• Polybromination by NBS and IR activation of potential antileishmanial guanidine. • Conformational study is performed by Nuclear Magnetic Resonance and SCXRD. • Hirshfeld surface and fingerprint plots of compounds showed a high Br—C contact. • XRPD and SCXRD X-ray patterns agree. • Conformational changes from Z to E promoted by polybromination. Leishmaniasis is a neglected disease that affects regions such as South Asia, South Africa, and Latin America, less developed regions. The research proposed the conformational study of brominated guanidine compounds with potential antileishmanial activity using Nuclear Magnetic Resonance (NMR) and X-ray diffraction (XRD) techniques. The present study involves the brominated molecules LQOF-G2, LQOF-G30, LQOF-G35 and LQOF-G35-Br. The latter was synthesized by the reaction of LQOF-G35 with NBS under IR irradiation at 120 Watts of potency and dichloromethane as solvent by 12 h of exposition. The obtained results demonstrated the efficiency of the bromination method, since two bromine atoms entered the molecule. Furthermore, NMR analysis showed a conformational change from Z to E when compound LQOF-G35 was brominated to LQOF-G35-Br. This behavior was confirmed by a comparative XRD study of the LQOF-G35 and LQOF-G35-Br compounds. The antileishmanial activity of LQOF-G2 e LQOF-G35 motivated the synthesis of new brominated compounds LQOF-G30 e LQOF-G35-Br. [Display omitted] [ABSTRACT FROM AUTHOR]

The success of a classic inorganic coordination compound, Cisplatin, cis -[Pt(NH 3) 2 Cl 2 ], as the first anticancer metallodrug started a field of research dedicated to discovering coordination compounds with antitumor activity, encompassing various metals. Among these, copper complexes have emerged as interesting candidates to develop drugs to treat cancer. In this work, mixed ligand complexes of Cu(II) with diimines (phenanthroline or 4-methylphenanthroline) and 3-(4-hydroxyphenyl)propanoate, phenylcarboxylate or phenylacetate were synthesized. They were characterized in the solid state, including a new crystal structure of [Cu 2 (3-(4-hydroxyphenyl)propanoate) 3 (phenanthroline) 2 ]Cl·H 2 O. The obtained complexes presented a variety of stoichiometries. In solution, complexes were partially dissociated in the corresponding Cu-diimine complex. The complexes bound to the DNA by partial intercalation and groove binding, as assessed by Circular Dichroism, relative viscosity change and UV–Vis titration. The cytotoxicity of the complexes was determined in vitro on MDA-MB-231, MCF-7 (human metastatic breast adenocarcinomas, the first triple negative), MCF-10A (breast nontumoral), A549 (human lung epithelial carcinoma), and MRC-5 (human nontumoral lung epithelial cells), finding an activity higher than that of Cisplatin, although with less selectivity. Six copper complexes with diimines and phenylcarboxylates as ligands were characterized. Their DNA binding and cytotoxic activity were assessed, and they were found to present high cytotoxic activity. [Display omitted] • Six copper complexes with diimines and phenylcarboxylates as ligands were characterized. • The crystal structure of [Cu 2 (3-(4-hydroxyphenyl)propanoate) 3 (phen) 2 ]Cl·H 2 O is reported. • Cu-diimine-phenylcarboxylate complexes are highly cytotoxic to cancer cells. [ABSTRACT FROM AUTHOR]

Highlights: [•] The potential metal–protein attenuating compound INHHQ was synthesized. [•] Its crystal structure is described here for the first time. [•] DFT calculations allowed to obtain reliable theoretical vibrational frequencies. [•] Based on this, an attempt of total FT-IR and Raman assignment was performed. [ABSTRACT FROM AUTHOR]

Copper can be opportunely complexed to modulate oncogenic pathways, being a promising strategy for cancer treatment. Herein, three new copper(II) complexes containing long-chain aliphatic hydrazides and 1,10-phenanthroline (1,10-phen), namely, [Cu(octh)(1,10-phen)(H 2 O)](NO 3) 2 1 , [Cu(dech)(1,10-phen)(H 2 O)](NO 3) 2 2 and [Cu(dodh)(1,10-phen)(H 2 O)](NO 3) 2.H 2 O 3 (where octh = octanoic hydrazide, dech = decanoic hydrazide, dodh = dodecanoic hydrazide) were successfully prepared and characterized by several physical-chemical methods. Furthermore, X-ray structural analysis of complex 2 indicated that the geometry around the copper(II) ion is distorted square-pyramidal, in which hydrazide and 1,10-phenanthroline act as bidentate ligands. A water molecule in the apical position completes the coordination sphere of the metal ion. All new copper(II) complexes were cytotoxic to breast cancer cell lines (MCF7, MDA-MB-453, MDA-MB-231, and MDA-MB-157) and selective when compared to the non tumor lineage MCF-10A. In particular, complex 2 showed half-maximal inhibitory concentration (IC 50) values ranging between 2.7 and 13.4 μM in MDA-MB231 cells after 24 and 48 h of treatment, respectively. Furthermore, this complex proved to be more selective for tumor cell lines when compared to doxorubicin and docetaxel. Complex 2 inhibited the clonogenicity of MDA-MB231 cells, increasing adenosine diphosphate (ADP) hydrolysis and upregulating ecto-nucleoside triphosphate diphosphohydrolase 1 (ENTPD1) transcriptional levels. In this sense, we suggest that the inhibitory effect on cell proliferation may be related to the modulation of adenosine monophosphate (AMP) levels. Thus, a novel copper(II) complex with increased cytotoxic effects and selectivity against breast cancer cells was obtained, contributing to medicinal chemistry efforts toward the development of new chemotherapeutic agents. Three new copper(II) complexes containing long-chain aliphatic hydrazides and 1,10-phenanthroline were synthesized and characterized. Complex 2 was the most promising, exhibiting cytotoxicity and selectivity against triple-negative breast cancer cells. This compound also impaired the clonogenicity, increasing adenosine diphosphate (ADP) hydrolysis and upregulating ecto-nucleoside triphosphate diphosphohydrolase 1 (ENTPD1) transcriptional level. [Display omitted] • New Cu(II) complexes were prepared and characterized by physical-chemical methods. • New Cu(II) complexes are selectively cytotoxic to mammary tumor cells. • Complex 2 impairs proliferation of breast cancer cells. • Complex 2 alters purinergic signaling increasing adenosine tri-phosphate hydrolisis. [ABSTRACT FROM AUTHOR]

Abstract: Vanadosilicates with the structures of ETS-10 and AM-6 microporous materials have been hydrothermally synthesized using organic directing structures agent (SDAs) derivatives of decahydroquinoline, 3,5-dimethyl-piperidine, 2,6-dimethyl-piperidine and (S)-Sparteine. Derivatives of these chiral amines have not been explored before in the sol gel chemistry of vanadosilicates. Physicochemical characterization of the obtained vanadosilicate materials with these different chiral templates was carried out by X-ray diffraction (XRD), scanning electron microscopy (SEM), Raman and infrared (IR) spectroscopy, solid-state NMR spectroscopy, and differential thermogravimetric analysis (DTA)/thermogravimetric analysis (TGA). The results suggest that the presence of the chiral organic templates have different effects in terms of the final phase of the synthesized materials and their morphology. The products obtained using chiral template derivatives of decahydroquinoline reveal that certain products might be very enriched with chiral polymorph A while others present structures which are similar to other large-porous vanadosilicate such as AM-6 and AM-13. Derivatives of 2,6-dimethyl-piperidine and 3,5-dimethyl-piperidine have not favored any structure that resembles a chiral polymorph A, but only known vanadosilicates such as AM-6, AM-13. Derivatives of (S)-Sparteine, on the other hand, have not only favored the formation of structures enriched with a large amount of chiral polymorph A, but also their use has resulted in other unknown vanadosilicate structures whose physicochemical characterizations are in progress. [Copyright &y& Elsevier]

Two coordination octahedral Sn(IV) complexes [Sn(L)] and cis-[SnCl(L)(dmso)], where HL is 2-hydroxyacetophenone ( S-benzydithiocarbazate), were prepared and characterized by elemental analysis, IR, NMR (H, C), Sn Mössbauer spectroscopies and X-ray diffraction techniques to investigate their structural properties. Both crystallize in the Monoclinic system, with parameters: a = 8.1905(3), b = 30.8811(15), c = 12.8959(7) Å, β = 94.465(3)° and Z = 4 for [Sn(L)] and a = 8.5247(2), b = 21.5445(7), c = 12.3706(3) Å, β = 96.932(2)° and Z = 4 for cis-[SnCl(L)(dmso)]. In both complexes, the Sn(IV) central atom is coordinated in a distorted octahedral geometry with the thiolate ligand (L) coordinated via O, N and S atoms. The Sn Mössbauer spectroscopy of the complexes were studied and the results revealed that both complexes posses isomer shift ( δ) and quadrupole splitting (Δ), which are almost the same. Graphical Abstract: [Figure not available: see fulltext.] [ABSTRACT FROM AUTHOR]

The article provides information on a study which examined the X-ray and density functional theory (DFT)-calculated structure of 4-(2,5-Dioxo-2,5-dihydro-1H-pyrrol-1-yl)benzoic acid. The study particularly carried out structural, spectroscopic and theoretical studies. The DFT optimized structures at the B3LYP/6-311 G(d,p) and 6-31++G(d,p) while levels were compared with the experimentally determined molecular structure in the solid state.

Abstract: Complexes [RuCl(H4NO2Fo4M)(bipy)(dppb)]PF6 (1), [RuCl(H4NO2Fo4M)(Mebipy)(dppb)]PF6 (2), [RuCl(H4NO2Fo4M)(phen)(dppb)]PF6 (3), [RuCl(H4NO2Ac4M)(bipy)(dppb)]PF6 (4), [RuCl(H4NO2Ac4M)(Mebipy)(dppb)]PF6 (5) and [RuCl(H4NO2Ac4M)(phen)(dppb)]PF6 (6) with N4 -methyl-4-nitrobenzaldehyde thiosemicarbazone (H4NO2Fo4M) and N4 -methyl-4-nitroacetophenone thiosemicarbazone (H4NO2Ac4M) were obtained from [RuCl2(bipy)(dppb)], [RuCl2(Mebipy)(dppb)], and [RuCl2(phen)(dppb)], (dppb = 1,4-bis(diphenylphospine)butane; bipy = 2,2′-bipyridine; Mebipy = 4,4′-dimethyl-2,2′-bipyridine; phen = 1,10-phenanthroline). In all cases the thiosemicarbazone is attached to the metal center through the sulfur atom. Complexes (1–6), together with the corresponding ligands and the Ru precursors were evaluated for their ability to in vitro suppress the growth of Trypanosoma cruzi. All complexes were more active than their corresponding ligands and precursors. Complexes (1–3) and (5) revealed to be the most active among all studied compounds with ID50 = 0.6–0.8 μM. In all cases the association of the thiosemicarbazone with ruthenium, dppb and bipyridine or phenanthroline in one same complex proved to be an excellent strategy for activity improvement. [Copyright &y& Elsevier]

A DNA-like duplex of nucleosides is probable to exist even without the 5′-phosphate groups needed to assemble the chain backbone. However, double-stranded helical structures of nucleosides are unknown. Here, we report a duplex of nucleoside analogs that is spontaneously assembled due to stacking of the neutral and protonated molecules of lamivudine, a nucleoside reverse transcriptase inhibitor (NTRI) widely used in anti-HIV drug combinatory medication. The left-handed lamivudine duplex has features similar to those of i-motif DNA, as the face-to-face base stacking and the helix rise per base pair. Furthermore, the protonation pattern on alternate bases expected for a DNA-like duplex stabilized by pairing of neutral and protonated cytosine fragments was observed for the first time in the lamivudine double-stranded helix. This structure demonstrates that hydrogen bonds can substitute for covalent phosphodiester linkage in the stabilization of the duplex backbone. This interesting example of spontaneous molecular self-organization indicates that the 5′-phosphate group could not be a requirement for duplex assembly. Helical stacking of the hydrogen-bonded 3TC−3TC+ pairs gives rise to lamivudine duplex. This structure reveals that nucleosides have the least structural requisites to self-assemble DNA duplexes. [ABSTRACT FROM AUTHOR]

Mebendazole (MBZ) is a common benzimidazole anthelmintic that exists in three different polymorphic forms, A, B, and C. Polymorph C is the pharmaceutically preferred form due to its adequated aqueous solubility. No single crystal structure determinations depicting the nature of the crystal packing and molecular conformation and geometry have been performed on this compound. The crystal structure of mebendazole form C is resolved for the first time. Mebendazole form C crystallizes in the triclinic centrosymmetric space group and this drug is practically planar, since the least-squares methyl benzimidazolylcarbamate plane is much fitted on the forming atoms. However, the benzoyl group is twisted by 31(1)° from the benzimidazole ring, likewise the torsional angle between the benzene and carbonyl moieties is 27(1)°. The formerly described bends and other interesting intramolecular geometry features were viewed as consequence of the intermolecular contacts occurring within mebendazole C structure. Among these features, a conjugation decreasing through the imine nitrogen atom of the benzimidazole core and a further resonance path crossing the carbamate one were described. At last, the X-ray powder diffractogram of a form C rich mebendazole mixture was overlaid to the calculated one with the mebendazole crystal structure. © 2008 Wiley-Liss, Inc. and the American Pharmacists Association J Pharm Sci 98:2336–2344, 2009 [ABSTRACT FROM AUTHOR]

Abstract: Cyclization of thiosemicarbazones derived from β-keto esters and β-keto amides (HTSC) in the presence of diphenyllead(IV) acetate was explored in methanol solution at room temperature and under reflux. All β-keto ester TSCs underwent cyclization to give the corresponding pyrazolone (HL), which, except in one case, deprotonated and coordinated the PbPh2 2+ moiety to form homoleptic [PbPh2(L)2] or heteroleptic [PbPh2(OAc)(L)] derivatives. Cyclization did not occur with β-keto amide TSCs and only [PbPh2(TSC)2] or [PbPh2(OAc)(TSC)] thiosemicarbazonates were isolated. The complexes were characterized by IR spectroscopy in the solid state and by 1H, 13C and 207Pb NMR spectroscopy in DMSO–d 6 solution, in which they evolve and decompose with time. Additionally, crystals of p-acetoacetanisidide thiosemicarbazone (HTSC10), [PbPh2(OAc)(L5)]·MeOH (HL5 =2,5-dihydro-3,4-dimethyl-5-oxo-1H-pyrazolone-1-carbothioamide), [PbPh2Cl(L2)] (HL2 =2,5-dihydro-5-oxo-3-phenyl-1H-pyrazolone-1-carbothioamide), [PbPh2(OAc)(TSC8)]·2MeOH (HTSC8 =acetoacetanilide thiosemicarbazone), [PbPh2(OAc)(TSC10)]·H2O and [PbPh2(OAc)(TSC11)]·0.75MeOH (HTSC11 = o-acetoacetotoluidide) were studied by X-ray crystallography. The complexes, monomers or dimers with almost linear C–Pb–C moieties, are compared with the corresponding derivatives of Pb(II). [Copyright &y& Elsevier]

The roméite-group is part of the pyrochlore-supergroup and comprises cubic oxides of A2B2X6Y formula in which Sb5+ predominates in the B-site. The A and Y main occupants determine different minerals in the group and are important for the discovery of new mineral species. Two different roméite-group mineral samples were analysed by electron microprobe analysis (EMPA), Raman spectroscopy and single-crystal X-ray diffraction (XRD). The first sample is from Prabornaz Mine (locality of the original roméite), Saint Marcel, Valle d'Aosta, Italy, whereas the other one occurs in Kalugeri Hill, Babuna Valley, Jakupica Mountains, Nezilovo, Veles, Macedonia. Sample 1 was identified as fluorcalcioroméite, and sample 2 as hydroxycalcioroméite. Both samples belong to the cubic crystal system, space group Fd 3 ¯ m, Z = 8, where a = 10.2881(13) Å, V = 1088.9(4) Å3 for sample 1, and a = 10.2970(13) Å, V = 1091.8(4) Å3 for sample 2. The crystal structure refinements converged to (1) R1 = 0.016, wR2 = 0.042; and (2) R1 = 0.023, wR2 = 0.049. Bond-valence calculations validated the crystal structure refinements determining the correct valences at each crystallographic site. Discrepancies observed in the Sb5+ bond-valence calculations were solved with the use of the proper bond valence parameters. The resulting structural formulas are (Ca1.29Na0.55□0.11Pb0.05)Σ=2.00(Sb1.71Ti0.29)Σ=2.00[O5.73(OH)0.27]Σ=6.00[F0.77O0.21(OH)0.02]Σ=1.00 for sample 1, and (Ca1.30Ce0.51□0.19)Σ=2.00(Sb1.08Ti0.92)Σ=2.00O6.00[(OH)0.61O0.21F0.18]Σ=1.00 for sample 2. The Raman spectra of the samples exhibited the characteristic bands of roméite-group minerals, the most evident corresponding to the Sb-O stretching at around 510 cm−1. [ABSTRACT FROM AUTHOR]

Abstract: Cyclization of n butyl glyoxylate thiosemicarbazone (HBuTSC) under reflux in the presence of Pb(OAc)2 led to the formation of the complex [Pb(HTz)2] (H2Tz=3,4-dihydro-3-thioxo-1,2,4-triazin-5(2H)-one), which after recrystallization from DMSO afforded the polymer [Pb(Tz)] n , the first example of a Tz2− metal complex. [Copyright &y& Elsevier]

Abstract: The reaction of dimethylthallium(III) hydroxide with picolinic acid (Hpic), 3-hydroxypicolinic acid (H23hpic) and 6-hydroxypicolinic acid (H26hpic) in an aqueous/methanol mixture afforded the complexes [TlMe2(pic)] (1), [TlMe2(H3hpic)] (2) and [TlMe2(H6hpic)] (3), respectively. Complex 3′, [NaTlMe2(6hpic)2] n , was obtained as a minor product from a methanolic solution of 3. Compounds 1–3 were characterized by IR and Raman spectroscopy and, in the cases of 1, 2 and 3′, by single-crystal X-ray diffraction. Complex 3′ is the first example of an H6hpic− heterobimetallic compound to be isolated. The 1H and 13C NMR spectra of 1 and 2 are also discussed. [Copyright &y& Elsevier]

Abstract: [Ru(HL)(PPh3)2Cl]Cl complexes have been obtained in which HL= N(4)-ortho (complex 1), N(4)-meta (complex 2) and N(4)-para-tolyl 2-acetylpyridine thiosemicarbazone (complex 3). NMR and electrochemical studies indicate that both cis and trans isomers exist in solution, and that the cis isomers are converted into the trans isomers with time. Crystal structure determination of (1) reveals that the trans isomer is formed in the solid state. [Copyright &y& Elsevier]

Abstract: The reactions of PbPh2(OAc)2 with alkylglyoxylate thiosemicarbazones (HRGTSC, R=Et, Bu) afforded complexes of the type [PbPh2(GTSC)]·H2O, [PbPh2(RGTSC)2] and [PbPh2Cl(BuGTSC)]. The structures of HRGTSC (R=Me, Et, Bu), [PbPh2(OAc)(RGTSC)](R=Me, Et, Bu), [PbPh2Cl(BuGTSC)] and [PbPh2(GTSC)]·H2O have been studied by X-ray diffraction. [PbPh2(OAc)(RGTSC)] and [PbPh2(GTSC)]·H2O have [PbC2NO3S] kernels and the coordination sphere of the metal is pentagonal bipyramidal. [PbPh2Cl(BuGTSC)] has a [PbC2NOSCl] kernel and the coordination geometry around lead is pentagonal bipyramidal with one vacant site. Analysis of the bond distances in [PbPh2(GTSC)]·H2O suggests a significant affinity between diphenyllead(IV) and carboxylate donor groups, supporting a borderline acidic character for this organometallic cation. 1H and 13C NMR spectra in DMSO-d 6 suggest the partial dissociation of the acetate in [PbPh2(OAc)(RGTSC)] solutions and indicate some differences in the coordination mode of the two RGTSC− ligands in [PbPh2(RGTSC)2] complexes. [Copyright &y& Elsevier]

Abstract: New Pd(II) and Pt(II) complexes [ML2] (HL=a substituted 2,5-dihydro-5-oxo-1H-pyrazolone-1-carbothioamide) have been synthesized by reacting K2MCl4 (M=Pd, Pt) or Pd(OAc)2 with β-ketoester thiosemicarbazones. The structures of seven of these complexes were determined by X-ray diffraction. Although all exhibit a distorted square-planar coordination with trans- or (in one case) cis-[MN2S2] kernels, their supramolecular arrangements vary widely from isolated molecules to 3D-networks. The in vitro antitumoral assays performed with two HL ligands and their metal complexes showed significant cytostatic activity for the latter, with the most active [ML2] derivative (a palladium complex) being about sixteen times more active than cis-DDP against the cisplatinum-resistant cell line A2780cisR. [Copyright &y& Elsevier]