Redox-active crown ethers derived from biphenyl. Electrochemical and spectroscopic study of binding processes with alkali, alkali-earth and mercury salts

Abstract Three new electroactive ligands, 3a, 3b and 3c, that contain the biphenyl frameworks in their structure were prepared. These new ligands presented three interesting characteristics: 1) they exhibited a reversible oxidation, 2) the oxidation induced a conformational change in the crown moiety and 3) they had two different coordination centers, the crown ether and the dimethylamino groups. Electrochemical and spectroscopic studies using alkali, alkali-earth and mercury salts were carried out.

BODIPY dyes functionalized with 2-(2-dimethylaminophenyl)ethanol moieties as selective OFF–ON fluorescent chemodosimeters for the nerve agent mimics DCNP and DFP

[EN] Two OFF-ON fluorescent chemodosimeters based on a BODIPY core for the detection of nerve agent mimics have been synthesized. Their reactivity towards diethylcyanophosphonate (DCNP) and diisopropylfluorophosphate (DFP) has been tested in organic and aqueous phase. These chemodosimeters selectively detect the nerve agent mimics with good LODs. The chemodosimeters hold their sensing properties on solid supports, allowing the preparation of a hand held sensing kit. The sensing in solid-liquid phase has been demonstrated. The X-ray structure of compound 2 has been resolved.

Experimental evidence for the homochiral aggregation of ammonium salts in solution

NMR and X-ray evidence for the homochiral aggregation of chiral ammonium picrates from racemic solutions is presented.

Synthesis, solution and electrochemical behaviour of new aza-crown ethers derived from biphenyl

Macrocyclic ligands L1–L4 containing biphenyl units have been synthesized. Potentiometric and voltametric studies in the presence and the absence of transition metal cations have been carried out. The relationship between the conformation of the ligand and oxidation states has been also considered. The crystal structure of [HgL2(CN)2]·2Hg(CN)2 has been elucidated by X-ray diffraction techniques.

Bis-cyclic Crown Ether Derived from Biphenyl. Different Behaviour in Complexing Hg(SCN)2 and Hg(CN)2

Abstract A new bis-cyclic crown ether containing a biphenyl unit in its structure has been prepared. This compound shows unexpected behaviour in complexing Hg(CN)2. The new ligand transports this mercury salt across liquid membranes with great efficiency. Clear differences have been observed in the complexation of Hg(CN)2 and Hg(SCN)2. The X-ray structure of a 1:2 mercury complex with Hg(SCN)2 is also reported.

Quantitative X-Ray Powder Diffraction Analysis of Some Feldspars Used as Raw Material in Ceramics

Crystal Data for Metal Cimetidine Isotiocionates: M(CM)2(NCS)2 (M = Co(II), Ni(II), Cu(II))

AbstractMetal cimetidine isothiocyanates, M(C10H16SN6)2(NCS)2, where M = Co(II), Ni(II) and Cu(II), have been investigated by means of X-ray powder diffraction. Unit cell dimensions were determined from powder diffractometer data. Refined cell parameters (monoclinic with a primitive cell), powder data, calculated densities and Z value are presented.

X-ray powder diffraction phase analysis and thermomechanical properties of silica and alumina porcelains

Chemical and mineralogical characterization, using the Rietveld method, of some silica and alumina rich porcelains and its relationship with thermomechanical properties have been studied in this work. X-ray powder diffraction analysis allows to differ clearly between silica and alumina porcelains. X-ray study shows that both porcelains have a content of vitreous phase. This vitreous phase is higher in the silica than in the alumina porcelain. Dilatometric studies combined with powder diffraction methods shows a strong relationship between silica content and a lower expansion coefficients and between alumina content and a higher crash resistance. Lower contents in vitreous phase in porcelain…

Powder diffraction analysis of gemstone inclusions

Gemstones are pieces of materials that once cut and polished are used as jewels or adornments. Gemstones may be single crystal (such as diamonds), polycrystalline (such as lapis lazuli), or amorphous (such as amber). In any case, gems may have inclusions that may yield a variety of optic effects. It is also important to unravel the crystal structure of the inclusion(s) in order to determine the origin of the gem and to help to understand their formation mechanism. Here, we expand the use of powder diffraction to identify crystalline inclusions in bulk gemstones highlighting Mo Kα radiation to penetrate within compact gems. Initially, rock crystal quartz with rutile needles was investigated …

Structure and Conformational Studies of Aza-Crown 8-Amino-BODIPY Derivatives: Influence of Steric Hindrance on Their Photophysical Properties

Herein, we report the synthesis, X-ray crystal structure and photophysical studies of six new 8-amino-BODIPY derivatives containing crown or azo-crown ether moieties. The influence of steric hindrance, caused by the crown ether, on the planarity of the BODIPY core and its relationship with the fluorescent properties has been established. 1H NMR spectroscopic studies were undertaken to clarify the changes in fluorescence observed in the presence of ZnII.

Cation and anion fluorescent and electrochemical sensors derived from 4,4′-substituted biphenyl

Five new fluorescent macrocyclic ligands derived from biphenyl are described. These new compounds can be used in cation and anion recognition and sensing. Their fluorescent and electrochemical properties are studied and the influence of the biphenyl conformation on these properties is considered. The X-ray single crystal structure of one of the described ligands has been determined.

Quantitative Phase Analysis of Mixtures of Three Components using Rietveld and Rius Standardless Methods. Comparative Results

Eight samples, supplied by the Commission on Powder Diffraction of the International Union of Crystallography, through the Round Robin on quantitative phase analysis, were analized using standardless methods. Samples were mixtures of corundum, zincite and fluorite in different ratios. The Rietveld method, using the DBW 3.2 and FULLPROF software, and the Rius method, using MENGE-PC software, were used. Results obtained agree well with the real composition supplied (a posteriori) by the IUCr.

Crystal Data for Nickel Cimetidine Chloride: Ni (CM)2 CL2·2H2O

AbstractNickel Cimetidine Chloride, Ni(C10H16SN6)2Cl2·2H2O has been investigated by means of X-ray powder diffraction. Unit cell dimensions were determined by indexing programs, from diffractometer data obtained with copper radiation. A primitive monoclinic cell was found: a = 11.836(3)Å, b = 13.322(5)Å, c = 10.487(2)Å, β = 113.08 (2)°, Z = 2, Dx = 1.462 g/cm3, M.W. = 670.32. These data are consistent with values reported in the literature for other cimetidine complexes.

Halogen-containing BODIPY derivatives for photodynamic therapy

Abstract Two iodinated (1 and 2) and two brominated (3 and 4) BODIPY-based photosensitizers are prepared and characterized using slightly modified synthetic procedures previously described. 1–4 present intense absorption bands in the 510–540 nm interval and very weak emissions due to the presence of halogen atoms in their structure. Irradiation of aqueous solutions of 1–4 with visible light (wavelength > 475 nm) induce the generation of singlet oxygen with quantum yields of ca. 0.62–0.66 for the photosensitizers containing iodine atoms (1 and 2) and of ca. 0.16–0.21 for the brominated counterparts (3 and 4). In vitro studies carried out with HeLa, SCC-13 and HaCaT cell lines and the four ph…

The crystal structure of 3,5-diisopropyl-4-nitropyrazole from X-ray powder diffraction data

The crystal structure of 3,5-diisopropyl-4-nitropyrazole, 3c, has been determined by a Patterson Search method from laboratory X-ray powder diffraction data. The crystal data are: monoclinic symmetry with the unit-cell parameters aa 19:530O5U; ba 6:485O1U and ca 17:937O3U A; ba 100:32O1U8; space group I2/a ,C 9H15N3O2, Za 8, 293 K. After indexing the powder pattern by two methods, the unit-cell parameters found were refined by a least-squares technique. A whole pattern- fitting program was used to extract the integrated intensities. The structure was solved taking a related compound as a search model and the final Rietveld refinement converged to Rwpa 0.1971 and Rpa 0.1437. The structure pr…

Crystal Data for Complexes of Co(II) and Ni(II) Perchlorates with Mepirizole

AbstractMetal mepirizole perchlorates, M(C11H14N4O2)3 (C104)2 where M = Co(II) and Ni(II) have been investigated by means of X-ray powder diffraction. Unit cell dimensions were determined by indexing programs from diffractometer data. Refined cell parameters (monoclinic with a C-centered cell), calculated density and Z values are presented.

Crystal structure of 4-{2-[4-(di­methyl­amino)­phen­yl]diazen-1-yl}-1-methyl­pyridinium iodide

The molecular geometry of the ionic title compound, C14H17N4+·I−or DAZOP+·I−, is essentially featureless. Regarding the crystal structure, in addition to the obvious cation–anion Coulombic interactions, the packing is mostly directed by non-covalent interactions involving both ring systems, as well as the iodide anion. It consists of cationic molecules aligned along [101] and disposed in an antiparallel fashion while linked into π-bonded dimeric entities by a stacking contact involving symmetry-related phenyl rings, with a centroid–centroid distance of 3.468 (3) Å and a slippage of 0.951 Å. The dimers are, in addition, sustained by a number of C—H...I and I...π (I...centroid = 3.876 Å) inte…

Quantitative x-ray diffraction phase analysis of coarse airborne particulate collected by cascade impactor sampling

Mineralogical composition of Castellon (Spanish Mediterranean coast) atmospheric aerosol was studied by X-ray diffraction by sampling with a cascade impactor without filters. Quantitative phase analysis of natural phases present in the atmospheric coarse aerosol was performed using a modified version of the computer program MENGE, that uses the standardless X-ray method developed by Rius for the quantitative analysis of multiphase mixtures, adapted for PC running. Presence of quartz, calcite and gypsum was identified in the atmospheric aerosol and we have quantified their amounts using the standardless method.

Structure Determination from Powder X-Ray Diffraction Data of a Hydrogen-Bonded Molecular Solid with Competing Ferromagnetic and Antiferromagnetic Interactions: The 2-(3,4-Dihydroxyphenyl)-α-Nitronyl Nitroxide Radical

Von den Pulver-Röntgenbeugungsdaten zur Struktur eines Molekülkristalls mit Wasserstoffbrückenbindungen und konkurrierenden ferromagnetischen und antiferromagnetischen Wechselwirkungen – das 2-(3,4-Dihydroxy-phenyl)-α-nitronylnitroxid-Radikal

A tangent formula derived from Patterson-function arguments. VII. Solution of inorganic structures from powder data with accidental overlap

Accidental overlap constitutes one of the principal limitations for the solution of crystal structures from powder diffraction data, since it reduces the number of available intensities for direct-methods application. In this work, the field of application of the direct-methods sum function is extended to cope with powder patterns with relatively large amounts of accidental overlap. This is achieved by refining not only the phases of the structure factors but also the estimated intensities of the severely overlapped peaks during the structure solution process. This procedure has been specifically devised for inorganic compounds with uncertain cell contents and with probable severe atomic di…

Determination of Molecular Crystal Structures from X-Ray Powder Diffraction Data

Concentration depending fluorescence of 8-(di-(2-picolyl)) aminoBODIPY in solution

[EN] An 8-dipicolylBODIPY derivative has been prepared and its photophysical properties evaluated under different conditions. Two different structures, hemicyanine and cyanine, are observed (depending on the solvent or the solution concentration). The hemicyanine form is not emissive whereas the cyanine form is fluorescent. This behavior is related with the planarity degree of the BODIPY core. The X-ray structure of the compound is reported and it shows that in solid state the hemicyanine form is present. The hemicyanine form seems to be stabilized by aggregation and is the main compound in concentrated solutions whereas the cyanine form is present in diluted solutions that are photochemica…

CCDC 1549738: Experimental Crystal Structure Determination

Related Article: Ana M. Costero, María L. Betancourt-Mendiola, Pablo Gaviña, Luis E. Ochando, Salvador Gil, Katherine Chulvi and Eduardo Peña-Cabrera|2017|Eur.J.Org.Chem.|2017|6283|doi:10.1002/ejoc.201701016

CCDC 966420: Experimental Crystal Structure Determination

Related Article: María de Lourdes Betancourt-Mendiola, Eduardo Peña-Cabrera, Salvador Gil, Katherine Chulvi, Luis E. Ochando, Ana M. Costero|2014|Tetrahedron|70|3735|doi:10.1016/j.tet.2014.03.095

CCDC 1549735: Experimental Crystal Structure Determination

Related Article: Ana M. Costero, María L. Betancourt-Mendiola, Pablo Gaviña, Luis E. Ochando, Salvador Gil, Katherine Chulvi and Eduardo Peña-Cabrera|2017|Eur.J.Org.Chem.|2017|6283|doi:10.1002/ejoc.201701016

CCDC 1549736: Experimental Crystal Structure Determination

Related Article: Ana M. Costero, María L. Betancourt-Mendiola, Pablo Gaviña, Luis E. Ochando, Salvador Gil, Katherine Chulvi and Eduardo Peña-Cabrera|2017|Eur.J.Org.Chem.|2017|6283|doi:10.1002/ejoc.201701016

CCDC 1549739: Experimental Crystal Structure Determination

Related Article: Ana M. Costero, María L. Betancourt-Mendiola, Pablo Gaviña, Luis E. Ochando, Salvador Gil, Katherine Chulvi and Eduardo Peña-Cabrera|2017|Eur.J.Org.Chem.|2017|6283|doi:10.1002/ejoc.201701016

CCDC 1549737: Experimental Crystal Structure Determination

Related Article: Ana M. Costero, María L. Betancourt-Mendiola, Pablo Gaviña, Luis E. Ochando, Salvador Gil, Katherine Chulvi and Eduardo Peña-Cabrera|2017|Eur.J.Org.Chem.|2017|6283|doi:10.1002/ejoc.201701016

CCDC 982038: Experimental Crystal Structure Determination

Related Article: Raúl Gotor, Pablo Gaviña, Luis E. Ochando, Katherine Chulvi, Alejandro Lorente, Ramón Martínez-Máñez, Ana M. Costero|2014|RSC Advances|4|15975|doi:10.1039/C4RA00710G

CCDC 1549734: Experimental Crystal Structure Determination

Related Article: Ana M. Costero, María L. Betancourt-Mendiola, Pablo Gaviña, Luis E. Ochando, Salvador Gil, Katherine Chulvi and Eduardo Peña-Cabrera|2017|Eur.J.Org.Chem.|2017|6283|doi:10.1002/ejoc.201701016