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The addition reaction of samarium enolates and 2-haloenolates derived from esters and amides to imines takes place in an efficient manner. A novel protocol to perform the addition reaction of samarium enolates derived from esters or amides to chiral 2-aminoimines, with total stereoselectivity and without racemization, is also reported. The use of samarium enolates in place of other classic metallic enolates (lithium, magnesium, etc.) could be a valuable alternative to obtain enantiopure 3,4-diamino esters or amides, when enolates of low basicity are necessary.

The chemical preparation and stereoselective enzymatic desymmetrization of a series of prochiral 2-substituted-1,3-propanediamines have been carried out using Pseudomonas cepacia lipase as biocatalyst. Syntheses of novel optically active orthogonally protected di- or triamines have been achieved for the first time with different grade of enantiodiscrimination depending on the C-2 substitution of the propane-1,3-diamine fragment. Final monoselective deprotection reactions of (S)-3-allyl-2-tert-butyl-1-(9-fluorenylmethyl)propane-1,2,3-triyltriscarbamate have allowed us to obtain a panel of novel enantiomerically enriched disubstituted triamines, compounds of difficult access by conventional synthetic methods.

We report on the synthesis of organic-inorganic hybrid nanotubes based on the γ -titanium phosphate, Ti (H2PO4)(PO4)·2H2O, layered crystal structure spaced with trioctylamine. These materials have been prepared by using microemulsion-mediated solvothermal and microwave-assisted methods. The interlayer distance in the inorganic sheets of the nanotube can be controlled by both the alkyl chain length and the amount of the amine template. All nanotubes obtained are made up of concentric openended cylinders. The possible reason for having this morphology is discussed combining X-ray diffraction and transmission electron microscopy data. This simple synthesis-route will be used to prepare other nanotubes with controlled geometries (© 2009 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)

A convenient highly stereoselective synthesis of chloro- and bromocyclopropanamides from di- tri- or tetrasubstituted (E)- or (Z)-α,β-unsaturated amides with total or high stereoselectivity promoted by chromium dichloride or dibromide is described. The transformation of chlorocyclopropanamides into the corresponding ketones or amines is also reported. A mechanism to explain these transformations is proposed.

A straightforward method of synthesizing cycloaurated gold(III) phosphinamide-based molecules starting from their ortho-tin(IV) derivatives in excellent yields is described. The structure of the tin and gold complexes has been investigated by multinuclear magnetic resonance (1H, 13C, 15N,31P, 119Sn) and single-crystal X-ray diffraction. In solution and in the solid state the ortho-functionalized phosphinamide moiety acts as a new C−C−P−O pincer ligand with formation of asymmetric five-membered ring metallocycles. Intramolecular P═O coordination to tin(IV) leads to a distorted trigonal-bipyramid configuration for the metal, while in the gold(III) metallocyclic complex the metal shows a square-planar geometry. The new Au(III) complex has been applied in multicomponent (A3) coupling processes, providing a variety of propargylamines in quantitative yields under very mild conditions without the use of any activator or additive. Diffusion NMR studies showed that the catalyst is present as a monomer in acetonitr...

Copper(II) and cobalt(II) complexes of salicylaldimine obtained by the condensation of N,N-diethyl-2-methyl-1,4-phenylenediamine with 3,5-di-tert-butyl-2-hydroxybenzaldehyde have been synthesized and characterized by elemental analyses, magnetic susceptibility measurements, cyclic voltammetry, and FT-IR and UV-Vis spectroscopy. The molecular structure of the title copper(II) complex was determined by the single crystal X-ray diffraction technique. The Cu(II) center is coordinated by four atoms of the donor set in a compressed tetrahedral trans-[N 2 O 2 ] environment, which can be essentially ascribed to the presence of bulky fragments of the ligand. The computed bond valences of the copper verify +2 oxidation state and indicate that the copper bonds, in particular Cu-N bonds, are elongated due to steric effects from bulky substituents in the ligands, N-(4-diethylamino-2-methylphenyl). Intermolecular C-H?? interactions leading to centrosymmetric synthons serve to stabilize periodic organization of the molecules. © 2008 Springer Science+Business Media, LLC.

Pop-directed asymmetric deprotonation of benzylic amines using [n-BuLi/(-)-sparteine] provides an efficient method for the synthesis of chiral NC alpha and NC alpha,alpha' derivatives with total selectivity with respect to competing allylic and ortho lithiation. The method described herein offers a straightforward route of accessing chiral N-Pop-protected nitrogen heterocycles.

The interaction of arsenate-bearing aqueous solutions with gypsum at a starting pH of 9 and 25 °C results in surface precipitation of guerinite, Ca5(HAsO4)2(AsO4)2·9H2O, sainfeldite, Ca5(HAsO4)2(AsO4)2·4H2O, and occasionally Ca2Na(HAsO4)(AsO4)·6H2O, a new arsenate. These three solid phases are characterized by the simultaneous presence of HAsO42− and AsO43− groups in their structure, which is explainable since crystallization occurs within a pH range in which both HAsO42− and AsO43− are available in the aqueous solution. The interaction leads to a decrease in the As(V) concentration in the aqueous phase to reach values controlled by the solubility of these solid phases. The study combines several macroscopic experiments, in which changes in the solution chemistry are monitored as a function of time, with the characterization of solid phases by SEM-EDS and XRD. The crystal morphologies of the precipitating phases are interpreted on the basis of their respective structures. The thermodynamic solubility products of both guerinite and the new arsenate have been determined, being 10−31.17±0.05 and 10−13.83±0.03, respectively. The reaction paths followed by the system and the equilibrium endpoints have been modeled using the geochemical code PHREEQC.

The synthesis of the C 2 -symmetrical (2R,5R)- and (2S,5S)-2,5-bis-[(S)-1-(dibenzylaminoalkyl)]-1,4-dioxanes 1 or 2 in enantiopure form is reported. Compounds 1 and 2 were obtained by a completely selective and unusual cyclodimerization of chiral (2R,1'S)- or (2S,1'S)-2-(1-aminoalkyl)epoxides 3 or 4 promoted by a mixture of diisopropylamine and boron trifluoride·diethyl etherate complex. The structure of the obtained dioxane was established by single-crystal X-ray diffraction analysis. A mechanism has been proposed to explain this transformation.

The synthesis of a set of 1-aryl-2-aryl(3-pyridyl)ethanones 1-5 and thecorresponding ketoximes 6-9 is reported. Structural studies of oximes 6, 7 and 9 wereperformed in solution using 1H-NMR and in the solid state by X-ray crystallography,providing evidence of H-bonding networks. The crystal packing was controlled byhomomeric intermolecular oxime···oxime H-bond interactions for 6 and cooperativeoxime···N(pyridyl) and CH/π interactions for 7 and 9. Keywords: Oximes; ethanones; hydrogen bonds; self-assembly; X-ray diffraction crystalography

N-benzyldiphenylphosphinamides are deprotonated at the NCalpha position diastereospecifically upon treatment with t-BuLi in diethyl ether at low temperature. The reaction of the anions with alkyl, acyl, and tin halides, aliphatic and aromatic aldehydes, and Michael acceptors allowed installation of a variety of functional groups into the benzylic arm in excellent yields. Cleavage of the P-N linkage affords 1,2-amino alcohols and alpha-, beta-, and gamma-amino acids.

A novel chromium-promoted alkyl- and silyl cyclopropanation of (E)- or (Z)-alpha,beta-unsaturated amides in which the C-C double bond is di-, or trisubstituted is described. This process takes place with total stereospecificity, and the new stereogenic center is generated with high or total stereoselectivity. A mechanism is proposed to explain the cyclopropanation reaction.

A Pd(II) complex of a new N-heterocyclic carbene (NHC) ligand with bulky substituents and functionalized methoxy-donor side arms has been synthesized and characterized by elemental analyses, 1H and 13C NMR, and IR spectroscopy. Molecular and crystal structures of the title complex have been determined by single crystal X-ray diffraction. The compound crystallizes in the monoclinic space group P21/c, with a = 15.927(2), b = 8.489(2), c = 20.309(5) Å, ß = 99.213(2)°, Z = 2, Dx = 1.253 g cm-3. The palladium atom is situated on an inversion center. There are several weak intramolecular C-H?N/O interactions. © 2007 Verlag der Zeitschrift für Naturforschung., Ministerio de Ciencia y Tecnología, MICYT: MAT2006-01997 Dokuz Eylül Üniversitesi, This work was financially supported by the Dokuz Eylül University Research Fund (Project No: 04.KB.FEN.100). Also, financial support from the Spanish Ministerio de Edu-cacion y Ciencia (MAT2006-01997 and ’Factoría de Cristal-ización’ Consolider Ingenio 2010) is acknowledged.

The first single-crystal X-ray crystallographic diffraction analysis of a dicationic heterophane showed a non-classic (C–H)+···Cl− hydrogen bond between the imidazolium rings and halide anions and the formation of unconventional charged assisted hydrogen bonds, which were the non-covalent forces driving the anion interactions shown by the dications 4·2X. Here is reported the halide-templated controlled synthesis and chemical response in basic media of 4·2X. Their structural properties were examined at the gas phase by electrospray ionization mass spectrometry in the negative-ion mode and in the solid-state by X-ray crystallography. Thus, the negative-ion ESI-MS response showed that the formation of non-covalent self-aggregates of macrocyclic dications is a consequence of hydrogen-bonded complexes with halide anions. Notably, X-ray diffraction of dication 4a·2Cl·2H2O provides evidence for the H-bonding network, which has a crucial role in crystal packing. The solid-state aggregates showed that chloride an...

The chemical synthesis and enzymatic desymmetrization of a panel of prochiral diamines have been successfully described for the first time using lipases in organic solvents. A family of 2-aryl-1,3-propanediamines has been obtained with high enantiopurity and good yields in the PSL-catalyzed reaction using diallyl carbonate in 1,4-dioxane.

The crystal and molecular structure of the N,N′-bis(2-methoxyethyl)-4,5-bis(2,4,6-trimethylphenyl)- imidazolinium hexafluorophosphate, which is the first example of 1,3- and 4,5-disubstituted imidazolinium salts, have been determined and characterized by X-ray single crystal diffraction technique,1H, 13C, 31P and 19F NMR spectroscopy. The compound, C27H39N2O2 +·PF6 −, crystallizes in the orthorhombic space group Pba2 with a = 15.8139(4) A, b = 22.9346(7) A, c = 8.069(3) A. Two charge-assisted C–H $$\cdots$$ F type crystal packing interactions between the imidazolinium C–H bonds and the F atoms of hexafluorophosphate counteranions build up zigzag chains along a-axis of the unit cell and indicate that the C–H bonds of the imidazolinium ring are also polarized. In addition, the title salt was modeled by DFT calculations in order to verify charge transfer mechanism observed in its imidazolinium ring.

The structure of a new semihydrate solvated form of the antibiotic azithromycin is reported. The new form was obtained by partial dehydration of the crystal of the monohydrate-i-PrOH, when the sample was left in laboratory conditions (22–25 °C, 55–65% relative humidity) over a long period of time (about 40 months). The new semihydrate solvate form retains the crystalline structure of the monohydrate (unit cell parameters and space group) but shows changes in the position of the hydrogen atoms of some OH groups of the azithromycin molecules, leading to a new and different hydrogen bonding network. Moreover, in one of the two azithromycin molecules in the asymmetric unit (the one labelled as “b”), the dimethyl amine group (in the desosamine sugar) shows a significant positional change. This fact provides information about the role of the solvent in the building of the solvated forms of the azithromycin drug, and allows the mobility of this group to be associated with an inversion operation and not a rotation.

Mayenite inorganic electrides are antizeolite nanoporous materials with variable electron concentration [Ca12Al14O32]2+ square5-deltaO1-delta2-e2delta- (0deltaor = 1), where square stands for empty sites. The oxymayenite crystal structure contains positively charged cages where loosely bounded oxide anions are located. These oxygens can be removed to yield electron-loaded materials in which the electrons behave like anions (electrides). Here, a new preparation method, which allows synthesizing powder mayenite electrides easily, is reported. Accurate structural data for the white (delta = 0) and green electride (delta approximately 0.5) are reported from joint Rietveld refinements of neutron and synchrotron X-ray powder diffraction data and also from single-crystal diffraction. The electride formation at high temperature under vacuum has been followed in-situ by neutron powder diffraction. The evolution of mayenite crystal structure, including the changes in the key occupation factor of the intracage oxide anions, is reported. Furthermore, the stability of mayenite framework in very low oxygen partial pressure conditions is also studied. It has been found that C12A7 decomposes, at 1373 K in reducing conditions, to give Ca5Al6O14 (C5A3) and Ca3Al2O6 (C3A). The kinetics of this transformation has also been studied. The fit of the transformed fraction to the classic Avrami-Erofe'ev equation gave an "Avrami exponent", n = 2, which indicates that nucleation is fast and the two-dimensional linear growth of the new phases is likely to be the limiting factor.

The complex fac-[Mn(CNtBu)(CO)3{(PPh2)2C−SCN}] (2) reacts with thiocyanogen, affording the unstable derivative fac-[Mn(CNtBu)(CO)3{(PPh2)C(SCN)C(SSCN)N(PPh2)}] (3), as a result of the insertion of ...

High enantioselection is obtained in Michael additions of cyclic beta-ketoesters in the presence of lanthanium triflates and (S,S)-ip-pybox. Intermediates based on simultaneous coordination of the lanthanide to both (S,S)-ip-box and beta-ketoester (in keto and enolate forms) are detected by means of ESI mass spectrometry and NMR experiments, and a possible mechanism is proposed through theoretical calculations.

Diphenylphosphinamides have been regioselectively ortho-lithiated under mild conditions providing a simple access to ortho-functionalized derivatives in good yields. The application of the methodology to the diastereoselective desymmetrization of the phosphorus atom is described for the first time.

Complexes [Re(ONCMe2)(CO)3(bipy)] (1) and [Re(ONCMe2)(CO)3(phen)] (2), synthesized by reaction of the respective triflato precursors [Re(OTf)(CO)3(N-N)] (N-N = bipy, phen) with KONCMe2, feature O-bonded monodentate oximato ligands. Compound [Re(CO)3(phen)(HONCMe2)]BAr'4 (3), with a monodentate N-bonded oxime ligand, was prepared by reaction of [Re(OTf)(CO)3(phen)], HONCMe2, and NaBAr'4. Deprotonation of 3 afforded 2. The oximato complexes reacted with p-tolylisocyanate, p-tolylisothiocyanate, maleic anhydride, and tetracyanoethylene, affording the products of the insertion of the electrophile into the Re-O bond, compounds 4-7. One representative of each type of compound was fully characterized, including single-crystal X-ray diffraction. The reactions of 1 and 2 with dimethylacetylenedicarboxylate were found to involve first an insertion as the ones mentioned above but followed by incorporation of water, loss of acetone, and formation of the charge-separated neutral amido complexes 9 and 10. The structure of 9 and 10 was determined by X-ray diffraction, and key features of their electronic distribution were studied using a topological analysis of the electron density as obtained from the Fourier map.

The crystal structure of the K6.4Nb28.2Ta8.1O94 pseudo-tetragonal tungsten bronze-type oxide was determined using a combination of X-ray powder diffraction, neutron diffraction and transmission electron microscopy techniques, including electron diffraction, high angle annular dark field scanning transmission electron microscopy (HAADF-STEM), annular bright field STEM (ABF-STEM) and energy-dispersive X-ray compositional mapping (STEM-EDX). The compound crystallizes in the space group Pbam with unit cell parameters a = 37.468(9) Å, b = 12.493(3) Å, c = 3.95333(15) Å. The structure consists of corner sharing (Nb,Ta)O6 octahedra forming trigonal, tetragonal and pentagonal tunnels. All tetragonal tunnels are occupied by K(+) ions, while 1/3 of the pentagonal tunnels are preferentially occupied by Nb(5+)/Ta(5+) and 2/3 are occupied by K(+) in a regular pattern. A fractional substitution of K(+) in the pentagonal tunnels by Nb(5+)/Ta(5+) is suggested by the analysis of the HAADF-STEM images. In contrast to similar structures, such as K2Nb8O21, also parts of the trigonal tunnels are fractionally occupied by K(+) cations.

The layered piperazinium cobalt-zinc phosphate, (pipH2)1.5 (Co0.6Zn0.4)2(HPO4)2 (PO4)·H2O, is prepared under hydrothermal conditions from a mixture of CoCl2, ZnCl2, H3PO4 (85 wt%), and piperazine (pip) hexahydrate (autoclave, 180 °C, 6 d).

Three new zinc(II) coordination polymers, [Zn(HO3PCH2CH2COO)(C12H8N2)(H2O)] (1), [Zn3(O3PCH2CH2COO)2(C12H8N2)](H2O)3.40 (2) and [Zn5(HO3PCH2CH2COO)2(O3PCH2CH2COO)2(C12H8N2)4](H2O)0.32 (3), with different structural dimensionality (0D, 2D and 3D, respectively) have been prepared by hydrothermal synthesis, and their structures were determined by single-crystal X-ray diffraction. Compound 1 crystallizes in the monoclinic system (P21/c) forming discrete dimeric units bonded through H-bonds, while compounds 2 and 3 crystallize in the triclinic (P−1) and the monoclinic (C2/c) systems, respectively. Compound 3, showing three different coordination numbers (4, 5 and 6) for the zinc atoms, has also been obtained by thermal treatment of 1 (probed by high-temperature XRPD experiments). The crystalline features of these compounds, related to the coordination environments for the zinc atoms in each structure, provoke the increase of the relative fluorescence for 2 and 3, compared to the free phenanthroline. Thermal analysis (TG and DSC) and XPS studies have been also carried out for all compounds., We thank financial support from Spanish Ministerio de Economía y Competitividad (MAT2010-15094, MAT2013-40950-R, Factoría de Cristalización Consolider Ingenio 2010) and ERDF. E.F-Z. thanks the Programa Severo Ochoa—FICyT for her pre-doctoral grant (BP 11-142).

This is an open-access article distributed under the terms of the Creative Commons Attribution Licence., The title compound, C19H17NO, has an E conformation about the N=C bond. The mol­ecule is relatively planar, with the benzene ring and naphthalene ring plane being inclined to one another by 4.28 (10)°. There is an intra­molecular O—H⋯N hydrogen bond generating an S(6) ring motif. In the crystal, mol­ecules are linked via C—H⋯O hydrogen bonds, forming chains propagating along [100]. Within the chains there are π–π inter­actions involving the benzene ring and the naphthalene ring system of an adjacent mol­ecule [inter-centroid distance = 3.6405 (14) Å]., We thank the Spanish Ministerio de Economía y Competitividad (MAT2013-40950-R and FPI grants: BES-2011-046948 to author MSMA) and the ERDF for financial support.

The one-pot eight-component reaction between Meldrum's acid, an aromatic aldehyde, and an aryl amine was achieved in the presence of citric acid catalyst. The corresponding dispirohydroquinolines were obtained in good yields with excellent diastereoselectivity. This method is a combination of the Knoevenagel and Michael reactions., We gratefully acknowledge the funding support received for this project from the Research Council of the University of Sistan and Baluchestan. This work was partially supported by FEDER funding, the Spanish Ministerio de Economía y Competitividad MAT2006–01997, MAT2010-15094 and the Factoría de Cristalización (Consolider Ingenio 2010).

Conformational analysis, X-ray crystallographic, FT-IR, FT-Raman, DFT, MEP and molecular docking studies on 1-(1-(3-methoxyphenyl) ethylidene) thiosemicarbazide (MPET) are investigated. From conformational analysis the examination of the positions of a molecule taken and the energy changes is observed. The docking studies of the ligand MPET with target protein showed that this is a good molecule which docks well with target related to HMG-CoA. Hence MPET can be considered for developing into a potent anti-cholesterol drug. MEP assists in optimization of electrostatic interactions between the protein and the ligand. The MEP surface displays the molecular shape, size and electrostatic potential values. The optimized geometry of the compound was calculated from the DFT–B3LYP gradient calculations employing 6-31G (d, p) basis set and calculated vibrational frequencies are evaluated via comparison with experimental values., The authors thank Misrimal Navajee Munoth Jain Engineering College Management, Thoraipakkam, Chennai 600 097, India for their support. We thank financial support from Spanish Ministerio de Economía y Competitividad (MAT2010-15094, Factoría de Cristalización – Consolider Ingenio 2010, FEDER funds.

New crystal of FeF4(2,2′-bipyridine)(H2O)2 was prepared by hydrothermal synthesis. Crystalline structure determination is performed from single crystal X-ray diffraction data. The unit cell is monoclinic space group P21/n, with cell parameters a=0.9046(5) nm, b=0.7502(5) nm, c=1.9539(5) nm, β=93.307(5)°, V=1.3238(12) nm3 and Z=4. The structure of FeF4(2,2′-bipyridine)(H2O)2 is built up from FeF4N2 octahedra coordinated by two nitrogen atoms of the 2,2′-bipyridine molecules, and four fluorine atoms as well as uncoordinated H2O molecules. Thermal analysis of the title compound showed that the decomposition introduced four steps. IR spectra confirmed the presence of 2,2′-bipyridine molecules. The optical absorption was measured at the corresponding λmax using UV-Vis diffuse reflectance spectrum., Supported by the Project from the Ministry of Superior Education and the Research of Tunisia and Spanish MINECO (No. MAT2006-150AM).

Lanthanide–organic frameworks based on 2,5-pyridinedicaboxylate (25p) ligand, formulated as [Yb4(OH)4(25p)4(H2O)3]·H2O (25pYb), [Y4(OH)4(25p)4(H2O)3]·H2O (25pY-1) and [Y6(OH)8(25p)5(H2O)2] (25pY-2), have been obtained as single phases under hydrothermal conditions. 25pYb and 25pY-1 are isostructural, and crystallize in the triclinic space group, P-1, with a=8.6075(5) Å, b=14.8478(7) Å, c=15.9164(9) Å, α=86.277(4)°, β=80.196(5)°, γ=81.785(4)°, and a=8.7166(6) Å, b=14.966(1) Å, c=15.966(1) Å, α=86.260(6)°, β=80.036(6)°, γ=81.599(6)°, respectively. 25pY-2 crystallizes in the monoclinic space group, P21/c, with a=24.9117(17) Å, b=13.7340(8) Å, c=14.3385(10) Å, β=100.551(7)°. 25pYb and 25pY-2 have been structurally characterized by single-crystal X-ray diffraction. The 25pYb structure is based on tetranuclear cubane-like [Yb4(OH)4]8+ clusters, which are interconnected to eight neighbouring clusters through teen surrounding 25p ligands leading to neutral 3D framework, while the structure of 25pY-2 is based on two independent cuban-like [Y4(OH)4]8+ clusters, which are joined together through Y1 cation leading to the formation of hexanuclear [Y6(OH)8]10+ clusters, which in turn are joined via Y2 cation resulting in infinite inorganic chain extending along c-axis, and each chain is interconnected to six adjacent chains through 25p ligands leading finally to 3D framework. The luminescence properties of Eu3+ and Tb3+ doped 25pY-1 and 25pY-2 compounds have also been investigated. All materials has been characterized by powder X-ray diffraction, thermal analyses (TG–SDTA–MS), FTIR spectroscopy, C–H–N elemental analysis, scanning electron microscopy (SEM-EDX), and powder X-ray thermodiffraction., Financial support from Spanish Ministerio de Economía y Competitividad (MAT2013-40950-R, and FPI grant BES-2011-046948 to MSM.A.) and Gobierno del Principado de Asturias (GRUPIN14-060), and FEDER funding are acknowledged.

A protocol has been developed for the diastereoselective synthesis of dispiro[tetrahydroquinoline-bis(2,2-dimethyl[1,3] dioxane-4,6-dione)] derivatives via a one-pot domino multicomponent reaction of arylamines, aromatic aldehydes, and Meldrum's acid for the first time. The products, with remarkable diastereoselectivity, were successfully synthesized in acetic acid media in ambient temperature along with the suggested mechanism through combination of domino Knoevenagel, Michael, and Diels–Alder reactions. The products have been characterized by IR, mass, 1H NMR, 13C NMR spectroscopy, and elemental analyses. The stereoselectivity of compounds was established with crystallography and NMR spectroscopy., Funded by: Research Council of the University of Sistan and Baluchestan; FEDER; Spanish Ministerio de Economía y Competitividad Grant Number: MAT2006-01997, MAT2010-15094; Factoría de Cristalización (Consolider Ingenio 2010).

The structure of photocatalytic and photoluminescent binary vanadate of the general formula “CaZnV2O7” has been investigated using X-ray powder diffraction. The compound is built up of isolated [V3O10], and [VO4] being this complex trivanadate–vanadate, in opposition to previous suggestions on isostructurality “CaMV2O7”, M – Mg or Co (Murashova et al., 1991, 36, 617–621). The present model has been confirmed by theoretical calculations. Thermal analysis and scanning electron microscopy have been performed, and the electronic structure analysis has been found to be in agreement with the experimental observations., Financial support from the Spanish Ministerio de Economía y Competitividad (MAT2013-40950-R), the Gobierno del Principado de Asturias (GRUPIN14-060) and the FEDER funding is acknowledged by AAB, SK and SGG. AAB and IVO acknowledge the JSPDS ICDD Grant-in-Aid program (12-02).

The crystal structure of (NH4)2(SO4)0.92H(AsO4)0.08⋅Te(OH)6 [NSAsTe] crystallizes in the monoclinic system P21/c with the following parameters: a = 11.382(5) Å, b = 6.615(5) Å, c = 13.707(5) Å, β = 106.731(5)° and Z = 4. The structure is formed by a set of anions (View the MathML source, SView the MathML source and HAsView the MathML source) and NH4+ groups connected by two types of hydrogen bonds Osingle bondH⋯O and Nsingle bondH⋯O which make the building of the crystal. The differential scanning calorimetry (DSC) analysis has shown three-phase transitions before the decomposition at 399 K, 466 K and 471 K. The thermal analyses (DTA) and (TG) of the title compound has proven that the decomposition of this material starts at a temperature equal to 475 K. The Raman spectroscopy at various temperatures, it has confirmed the presence of the phase transitions shown in DSC and DTA. The vibrational study at room temperature shows the presence and the independence of anionic groups, ammonium groups and gives more importance to the strong hydrogen bonds., This work is supported by the Ministry of the Higher Education and Research of Tunisia.

This is an open-access article distributed under the terms of the Creative Commons Attribution Licence., The crystal structure of the β-polymorph of ZnMoO4 was re-determined on the basis of single-crystal X-ray diffraction data. In comparison with previous powder X-ray diffraction studies [Katikaneani & Arunachalam (2005 ▸). Eur. J. Inorg. Chem. pp. 3080–3087; Cavalcante et al. (2013 ▸). Polyhedron, 54, 13–25], all atoms were refined with anisotropic displacement parameters, leading to a higher precision with respect to bond lengths and angles. β-ZnMoO4 adopts the wolframite structure type and is composed of distorted ZnO6 and MoO6 octa­hedra, both with point group symmetry 2. The distortion of the octa­hedra is reflected by variation of bond lengths and angles from 2.002 (3)–2.274 (4) Å, 80.63 (11)–108.8 (2)° for equatorial and 158.4 (2)– 162.81 (14)° for axial angles (ZnO6), and of 1.769 (3)–2.171 (3) Å, 73.39 (16)–104.7 (2), 150.8 (2)–164.89 (15)° (MoO6), respectively. In the crystal structure, the same type of MO6 octa­hedra share edges to built up zigzag chains extending parallel to [001]. The two types of chains are condensed by common vertices into a framework structure. The crystal structure can alternatively be described as derived from a distorted hexa­gonally closed packed arrangement of the O atoms, with Zn and Mo in half of the octa­hedral voids., We acknowledge financial support from the Spanish Ministerio de Economía y Competitividad (MAT2013–40950-R), Gobierno del Principado de Asturias (GRUPIN14–060) and ERDF.

A high efficient and convenient one-pot three-component diastreoselective synthesis of polysubstituted cyclohexenones in excellent yields has been developed through Michael addition and Claisen–Schmidt condensation of aldehydes and acetophenone with 3-oxo-N-phenylbutanamide using piperidine as an effective reagent under mild conditions within sort reaction time without using any previous activation.

A two-dimensional piperazinium cobalt–zinc phosphate, formulated as (C4N2H12)1.5(Co0.6Zn0.4)2(HPO4)2(PO4)·H2O (2D), was synthesized under hydrothermal conditions. The crystal structure was determined using single-crystal X-ray diffraction data (monoclinic P21/c, a=8.1165(3) Å, b=26.2301(10) Å, c=8.3595(4) Å, and β=110.930(5)°) and the hydrogen atom positions were optimized by DFT calculations. A single-crystal corresponding to one-dimensional metastable phase, (C4N2H12)Co0.3Zn0.7(HPO4)2·H2O (1D), was also isolated and the crystal structure was determined (monoclinic P21/c, a=8.9120(6) Å, b=14.0290(1) Å, c=12.2494(5) Å, and β=130.884(6)°). The bulk was characterized by chemical (C–H–N) analysis, powder X-ray diffraction (PXRD), powder X-ray thermodiffractometry (HT-XRD), transmission electron microscopy (STEM(DF)-EDX and EFTEM), and thermal analysis (TG/SDTA-MS), including activation energy data of its thermal decomposition. The magnetic susceptibility and magnetization measurements show no magnetic ordering down to 4 K., Financial support from Spanish Ministerio de Economía y Competitividad (MAT2010-15094, MAT2011-27573-C04, MAT2013-40950-R , Factoría de Cristalización—Consolider Ingenio 2010, and Técnicos de Infraestructuras Científico-Tecnológicas grants PTA2011-4903-I to ZA and PTA2011-4950-I to SAK) and FEDER funding is acknowledged.

A simple and efficient pseudo eight-component synthesis of 1′,5′,7′,8′-tetrahydro-2′H,4′H-dispiro[[1,3]dioxane-5,3′-quinoline-6′,5″-[1″,3″]dioxane]-4,4″,6,6″-tetrone derivatives is described. This reaction between, aromatic aldehydes, aromatic amines and Meldrum's acid in the presence of benzoic acid as an efficient catalyst at ambient temperature affords the product in good yields.

WOS: 000370762300147, PubMed ID: 26870396, In the molecule of title compound, C15H20O6, also known as cynarinin A, the cyclopentane ring having twist conformation and a gamma-lactone ring assuming an envelope conformation are trans-and cis-fused, respectively, to a cycloheptane ring adopting a twist-chair conformation. In the crystal, O-H center dot center dot center dot O hydrogen bonds link neighbouring molecules, forming a three-dimensional network. Theoretical calculations of the molecular structure using the CNDO approximation and MOPAC PM3 geometry optimization are in satisfactory agreement with the results of the X-ray structure analysis., Cumhuriyet University [F-436], This work was supported by the Scientific Research Project Fund of Cumhuriyet University under Project number F-436.

New complexes with guanazole (3,5-diamino-1,2,4-triazole = Hdatrz), [Cu 2 (Hdatrz) 2 (μ-OH 2 )(H 2 O) 4 (SO 4 )](SO 4 )·3.5H 2 O (1) and [Cu 3 (Hdatrz) 4 (μ-Cl) 2 (H 2 O) 4 (SO 4 ) 2 ]·11.4H 2 O (2), have been prepared and structurally characterized. Complex 1 is a noncentrosymmetric dinuclear compound in which the cop-per(II) ions are bridged by two triazole ligands and one μ-OH 2 molecule, with a Cu(1)···Cu(2) distance of 3.4945(8) A. The chromophores are Cu(1)N 2 O 2 O' (square pyramidal), and Cu(2)N 2 O 2 O'O" (octahedral). Complex 2 has a linear trinuclear copper(II) structure, with two crystallographically independent copper(II) atoms. Neighboring copper(II) ions are linked by two triazole ligands and one slightly asymmetric chlorido bridge. The intratrimeric Cu(1)···Cu(2) distance is 3.5602 (4) A. Cu(2), the central copper, is coordinated to N 4 Cl 2 (octahedral) while Cu(1), the terminal copper, is coordinated to N 2 O 2 ClO' (also octahedral). Magnetic susceptibility measurements (2-300 K) are in accordance with the dinuclear (1) and trinuclear (2) nature of these compounds. The best-fit parameters, obtained with the Hamiltonian H = -JΣ i

The monohydrate form of azithromycin (an antibiotic semisynthetic derivative of erythromycin A) is difficult to manipulate due to its great propensity to stick to metallic surfaces (during crystallization, drying, grinding,etc.). In this paper, this behaviour is explained on the basis of the conformation and packing of the azithromycin molecules in this crystal form. In particular, the crystal habit favours interaction between the N and O atoms with the metal through one particular crystal face.

The reaction of chiral (2R,1'S)- or (2S,1'S)-2-(1-aminoalkyl)epoxides, 1 or 2 with a variety of organolithium compounds to obtain the corresponding (alphaS,betaS)- or (alphaR,betaS)- beta-amino alcohols in enantiopure form is reported. In both cases, the opening of the oxirane ring at C-3 proceeded with total regioselectivity. Moreover, the ring opening of aminoepoxides 1 or 2 by hydride (utilizing LiAlH4) to obtain the corresponding (2S,3S)- or (2R,3S)-3-aminoalkan-2-ols is also described. The reaction of 1 or 2 with LiAlD4 in place of LiAlH4 gave the corresponding (2S,3S)- or (2R,3S)-3-amino-1-deuterioalkan-2-ols.

An analysis on what is known as the interpretation of Fourier maps has been done from the information theory point of view: determining the nature of the peaks in the map (in order to assign them a suitable scattering factor) and allocating bonds between some of the possible peak pairs. Before interpreting the map, a quantitatively measurable entropy (uncertainty, unknowingness) relating to the molecular structure is known. After the interpretation, this entropy becomes amount of information. This analysis allows us, for the first time in crystallography, to quantify these parameters and analyse the contributions of the different information sources.

Treatment of fac-[Mn(CNR)(CO)3{(PMe2)2CH2}]ClO4 (1a R = Ph, 1b R = tBu) with KOH produced the cleavage of one of the P–C bonds of the coordinated dmpm ligand, resulting in the formation of phosphine–phosphinite complexes fac-[Mn(PMe2O)(CNR)(CO)3(PMe3)] (2a,b). Alkoxides such as NaOMe and NaOEt promoted similar processes in 1a,b, yielding fac-[Mn(CNR)(CO)3(PMe3)(PMe2OR′)]ClO4 (3a R = tBu, R′ = Me; 3b R = Ph, R′ = Me; 4a R = tBu, R′ = Et; 4b R = Ph, R′ = Et) derivatives. The phosphinite ligand in 2a,b can be sequentially protonated by addition of 0.5 and 1 equivalent of HBF4 leading to fac-[{Mn(CNR)(CO)3(PMe3)(PMe2O)}2H]BF4 (6a,b) and fac-[Mn(CNR)(CO)3(PMe3)(PMe2OH)]BF4 (5a,b), respectively.

Copper(II) complexes of N-benzothiazolesulfonamides (HL1=N-2-(4-methylphenylsulfamoyl)-6-nitro-benzothiazole, HL2=N-2-(phenylsulfamoyl)-6-chloro-benzothiazole, and HL3=N-2-(4-methylphenylsulfamoyl)-6-chloro-benzothiazole) with ammonia have been synthesized and characterized. The crystal structures of the [Cu(L1)2(NH3)2].2MeOH, [Cu(L2)2(NH3)2], and [Cu(L3)2(NH3)2] compounds have been determined. Compounds and present a distorted square planar geometry. In both compounds the metal ion is coordinated by two benzothiazole N atoms from two sulfonamidate anions and two NH3 molecules. Complex is distorted square-pyramidal. The Cu(II) ion is linked to the benzothiazole N and sulfonamidate O atoms of one of the ligands, the benzothiazole N of another sulfonamidate anion, and two ammonia N atoms. We have tested the superoxide dismutase (SOD)-like activity of the compounds and compared it with that of two dinuclear compounds [Cu2(L4)2(OCH3)2(NH3)2] and [Cu2(L4)2(OCH3)2(dmso)2] (HL4=N-2-(phenylsulfamoyl)-4-methyl-benzothiazole). In vitro indirect assays show that the dimeric complexes are better SOD mimics than the monomeric ones. We have also assayed the protective action provided by the compounds against reactive oxygen species over Deltasod1 mutant of Saccharomyces cerevisiae. In contrast to the in vitro results, the mononuclear compounds were more protective to SOD-deficient S. cerevisiae strains than the dinuclear complexes.

The reactions of the hydrido-triruthenium cluster complex [Ru3(mu-H)(mu3-kappa(2)-HNNMe2)(CO)9] (1; H2NNMe2 = 1,1-dimethylhydrazine) with alkynes that have alpha-hydrogen atoms give trinuclear derivatives containing edge-bridging allyl or face-capping alkenyl ligands. Under mild conditions (THF, 70 degrees C) the isolated products are as follows: [Ru3(mu3-kappa(2)-HNNMe2)(mu-kappa(3)-1-syn-Me-3-anti-EtC3H3)(mu-CO)2(CO)6] (2) and [Ru3(mu3-kappa(2)-HNNMe2)(mu-kappa(3)-1-syn-Me-3-syn-EtC3H3)(mu-CO)2(CO)6] (3) from 3-hexyne; [Ru3(mu3-kappa(2)-HNNMe2)(mu-kappa(3)-3-anti-PhC3H4)(mu-CO)2(CO)6] (4), [Ru3(mu3-kappa(2)-HNNMe2)(mu-kappa(2)-MeCCHPh)(mu-CO)2(CO)6] (5) and [Ru3(mu3-kappa(2)-HNNMe2)(mu3-kappa(2)-PhCCHMe)(mu-CO)2(CO)6] (6) from 1-phenyl-1-propyne; [Ru3(mu3-kappa(2)-HNNMe2)(mu-kappa(2)-3-anti-PrC3H4)(mu-CO)2(CO)6] (7), [Ru3(mu3-kappa(2)-HNNMe2)(mu3-kappa(2)-BuCCH2)(mu-CO)2(CO)6] (8), and [Ru3(mu3-kappa(2)-HNNMe2)(mu3-kappa(2)-HCCHBu)(mu-CO)2(CO)6] (9) from 1-hexyne; [Ru3(mu3-kappa(2)-HNNMe2)(mu3-kappa(2)-HOH2CCCH2)(mu-CO)2(CO)6] (10) from propargyl alcohol; and [Ru3(mu3-kappa(2)-HNNMe2)(mu3-kappa(2)-MeOCH2CCH2)(mu-CO)2(CO)6] (11) from 3-methoxy-1-propyne. The regioselectivity of these reactions depends upon the nature of the alkyne reagent, which affects considerably the kinetic barriers of important reaction steps and the stability of the final products. It has been established that the face-capped alkenyl derivatives are not precursors to the allyl products, which are formed via edge-bridged alkenyl intermediates. At higher temperature (toluene, 110 degrees C), the complexes that have allyl ligands with an anti substituent are isomerized into allyl derivatives with that substituent in the syn position, for example, 4 into [Ru3(mu3-kappa(2)-HNNMe2)(mu-kappa(3)-3-syn-PhC3H4)(mu-CO)2(CO)6] (14). The diene complex [Ru3(mu-H)(mu3-kappa(2)-HNNMe2)(mu-kappa(4)-trans-EtC4H5)(CO)7] (13) has been obtained from the thermolysis of compounds 2 and 7 at 110 degrees C (3 and [Ru3(mu3-kappa(2)-HNNMe2)(mu-kappa(2)-3-syn-PrC3H4)(mu-CO)2(CO)6] (12) are also formed in these reactions). A DFT theoretical study has allowed a comparison of the thermodynamic stabilities of isomeric compounds and has helped rationalize the experimental results. Mechanistic proposals for the synthesis of the allyl complexes and their isomerization processes are also provided.

The experimental geometry obtained from single-crystal X-ray diffraction data for a metalladiphosphanyl carbene precursor is compared with the results of theoretical calculations made at the ab initio level by using Hartree–Fock (HF) and Density Functional Theory (DFT) methods over the carbene itself. Theoretical geometry optimizations for the singlet ground state of [ Mn(CO)4(PH2)2C: ]+ have been performed with several hybrid functionals and basis sets. Calculated geometries showed a perfect C 2v symmetry in the highest levels of calculation and were somewhat relaxed when compared with the experimental ones; for instance, with the largest basis set, the P–C–P angle found was 124.8°, whereas C–P bond distances were both 1.667 Å, compared to 103.5(3)° and 1.718(5) Å, respectively, from the experimental data. The absence of a ligand attached to the C : atom in the calculated structure, which is present in the form of iodine in the experimental complex, is probably responsible, to a certain extent, for the discrepancies. In addition to the structural computations, in order to theoretically quantify the highly electrophilic character expected for the carbene, electron affinities were calculated and found to be between 6.24 eV and 6.97 eV at different DFT levels of calculation, which confirmed the expectations. In this respect, a comparison with the analogous [Ru(CNH)4(PH2)2C:]2+ carbene is also made, showing the possibility of experimentally trapping the manganese carbene.

Nine coordination compounds of Cu(II) and Co(II) with Ciprofloxacin (HCp) and Enoxacin (HEx) as ligands have been prepared and characterized. Single crystal structural determinations of [Cu(HCp)2(ClO4)2].6H2O (1) and [Co(HEx)2(Ex)]Cl.2CH(3)OH.12H2O (4) are reported. The crystal of 1 is composed of [Cu(HCp)2(ClO4)2] units with the two perchlorate anions semicoordinated, and uncoordinated water molecules. The copper ion, at a crystallographic inversion centre, is in a tetragonally distorted octahedral environment. The structure of 4 consists of cationic monomeric [Co(HEx)2(Ex)]+ units, chloride anions, and uncoordinated methanol and water molecules. The complex is six-coordinate, with a slightly distorted octahedral environment around the metal centre. Some complexes of ciprofloxacin and enoxacin were screened for their activity against several bacteria, showing activity similar to that of the corresponding free ligands. All compounds tested were more active against Gram-negative bacteria than against Gram-positive bacteria. Ciprofloxacin hydrochloride and its complexes were more active than enoxacin and its complexes. In addition, the bactericidal studies against Staphylococcus aureus ATCC 25923 reveal that one complex exhibits the "paradoxical effect" (diminution in the number of bacteria killed at high drug concentration), which has been described and related to the mechanism of action of quinolones, but three other complexes do not, suggesting different mechanisms of bactericidal action. The ability of Cu(HCp)2(NO3)2.6H2O to cleave DNA has been determined. The results show that the complex behaves as an efficient chemical nuclease with ascorbate/hydrogen peroxide activation. Mechanistic studies using different inhibiting reagents reveal that hydroxyl radicals are involved in the DNA scission process mediated by this compound.