Crystal X-ray Diffraction (crystal + x-ray_diffraction)

Distribution by Scientific Domains
Distribution within Chemistry

Kinds of Crystal X-ray Diffraction

  • single crystal x-ray diffraction

  • Terms modified by Crystal X-ray Diffraction

  • crystal x-ray diffraction analysis
  • crystal x-ray diffraction studies

  • Selected Abstracts

    ChemInform Abstract: Crystal Structures of RPt3-xSi1-y (R: Y, Tb, Dy, Ho, Er, Tm, Yb) Studied by Single Crystal X-Ray Diffraction.

    CHEMINFORM, Issue 41 2009
    Alexander Gribanov
    Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a "Full Text" option. The original article is trackable via the "References" option. [source]

    Optical properties of 2-aminopyridinium nitrato silver

    K. P. Bhuvana
    Abstract Crystals of 2-aminopyridinium nitrato silver have been synthesized by slow evaporation method. Grown crystals have been subjected to FTIR, Single crystal X-Ray diffraction and UV-Visible studies in order to investigate the structural and optical properties of the crystal. The FTIR spectrum reveals the presence of the functional group that corresponds to both 2-aminopyridine and silver nitrate, suggesting the formation of the compound, 2-aminopyridinium nitrato silver. From XRD it is observed that the crystal crystallizes in the structure of monoclinic with the space group of P21/c. The optical transmittance spectrum shows the maximum transparency of about 95% in the visible region is in consistent with the wide band gap, estimated as 4.738 eV. The optical constants n and k has also been determined from the transmittance data. The static dielectric constant is found to be 0.851. The wide band gap and the less dielectric constant suggest the suitability of this compound material for photoconductive applications. (© 2010 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source]

    Vibrational, optical and microhardness studies of trimethoprim DL -malate

    S. Franklin
    Abstract Trimethoprim malate, an organic crystal, has been synthesized using slow evaporation method from its aqueous solution. Structural, optical and the mechanical properties of the grown crystal have been investigated by various characterization techniques which include FTIR spectra, single crystal XRD, UV-Vis spectra and Vickers microhardness testing. The structure of the compound predicted by analysing the recorded FTIR spectrum compliments the structure determined using single crystal X-ray diffraction. Single crystal X-ray diffraction study reveals that the crystals are monoclinic [P21/c, a=12.9850 Å, b=9.3038 Å, c=15.6815 Å and ,=111.065°]. The UV-Vis spectrum exhibits maximum transparency (98%) for a wide range suggesting the suitability of the title compound for optical applications. The optical constants have been calculated and illustrated graphically. Microhardness tests have been performed on the cystal under study and the Vicker hardness number has been calculated. The work hardening coefficient is found to be 2.85 which suggest that the crystal belongs to the family of soft materials. (© 2009 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source]

    Rh(I) and Pd(II) complexes of methoxy functionalized heterocyclic carbene: Synthesis and characterization

    M. E. Günay
    Abstract A new methoxy functionalized 2-(trichloromethyl)-1,3-diarylimidazolidin (6) was synthesized as the precursor for N-heterocyclic carbene complexes of Pd(II) and Rh(I) by the condensation of N,N'-bis(2,4-dimethoxyphenyl)-1,2-diaminoethane with chloral. The structures of all compounds have been elucidated by a combination of multinuclear NMR spectroscopy, elemental analysis and in one instance, by single crystal X-ray diffraction. Compound 8, C27H34N2O4ClRh, crystallizes in the triclinic space group P-1 with cell dimensions a = 9.7642(12)Å, b = 11.1914(11)Å, c = 13.0102(14)Å, , = 104.034(9)°, , = 106.658(9)°, , = 99.658(9)° with Z = 2. The molecular structure of 8 shows the geometry around the Rh metal to be a slightly distorted square planar. The crystal structure shows the formation of centrosymmetric dimers via intermolecular C-H...Cl hydrogen bonds. (© 2006 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source]

    Gel growth and characterization of , -DL-methionine

    E. Ramachandran
    Abstract DL-Methionine [C5H11NO2S] is one of the essential amino acids in humans. It has two crystalline forms, viz., ,- and ,- methionine. In the present study, , - form is crystallized in silica gel; under suitable pH conditions by single diffusion method. The grown crystals were characterized by density measurement and single crystal X-ray diffraction. Fourier transform infrared (FTIR) spectroscopic studies, thermal analysis and scanning electron microscopic (SEM) studies were also made as part of the structural studies. (© 2006 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source]

    Synthesis and X-ray structure of two conformational isomers of [Zn(medpt)(SCN)2], medpt = bis (3 , aminopropyl)methylamine

    S. Guha
    Abstract Two conformational isomers of [Zn (medpt)(NCS)2], medpt=bis(3-aminopropyl) methylamine, (1) and (2) have been synthesised and the crystal structures are determined using single crystal X-ray diffraction. The structures of the complexes have been solved by Patterson method and refined by full-matrix least- squares techniques to R1 = 0.0524 for (1) and R1 = 0.0506 for (2), respectively. The geometry around the Zn(II) centre in both isomers is distorted trigonal bipyramidal. The two pendent thiocyanate moieties in (1), with Zn,N,C angles 167.9(4),173.9(4)º, coordinate the mental centre almost linearly while the corresponding coordinations in (2) are significantly bent [Zn,N,C angles 150.8(3),153.1(2)°]. Intermolecular N,H,S hydrogen bonds stabilise the crystal packing in the complexes forming infinite chains parallel to the [100] direction. The combinations of molecular chains generate three/two dimensional supramolecular framework in complexes (1) and (2). (© 2006 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source]

    One-Dimensional CdII Coordination Polymers: Solid Solutions with NiII, Thermal Stabilities and Structures

    Dejana Vujovic
    Abstract Reactions of Cd(NCS)2 with 2-, 3- and 4-aminobenzonitrile ligands (2ABN, 3ABN and 4ABN respectively) have produced one-dimensional chain polymers of the general formula [M(NCS)2(ABN)2]n with the metal centres linked by double NCS, bridges. The three cadmium polymers [Cd(NCS)2(3ABN)2]n (1), [Cd(NCS)2(2ABN)2]n (2) and [Cd(NCS)2(4ABN)2]n (3) all differ in their hydrogen-bonding patterns. In terms of ABN coordination, both 1 and 2 exhibit terminal amine coordination while in 3 the ABNs are coordinated through the cyano groups. Crystalline solid solutions of 1 of general formula [Cd1,xNix(NCS)2(3ABN)2]n, containing nickel and cadmium in varying proportions, have also been prepared in order to establish the influence of the metal ratio on the thermal stability and bonding parameters of the polymers. The coordination polymers are not good candidates for forming clathrates while their thermal stability (ranging between 147 and 244 °C) depends on the position of functional groups on the ABN ligands and on the Cd:Ni ratio in the solid solutions. The new polymers have been characterised by single crystal X-ray diffraction, X-ray powder diffraction, electron microscopy, infrared spectroscopy, thermogravimetry and differential scanning calorimetry. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004) [source]

    The Orthogonal (e,e,e)-Tris-Adduct of 9,10-Dimethylanthracene with C60 -Fullerene: A Hidden Cornerstone of Fullerene Chemistry.

    Preliminary Communication
    Abstract Tris(9,,10,-dimethyl[9,10]ethanoanthracene[11,,12,:,1,9;11,,12,:,16,17;11,,,,12,,,:,30,31])[5,6]fullerene C60, the orthogonal (e,e,e)-tris-adduct of C60 and 9,10-dimethylanthracene, was obtained from [4+2]-cycloaddition (Diels,Alder reaction) at room temperature. The thermally unstable orange red (e,e,e)-tris-adduct was purified by chromatography and was isolated in the form of red monoclinic crystals. Its C3 -symmetric addition pattern was established spectroscopically. Its structure could be further investigated by single crystal X-ray diffraction. The (e,e,e)-tris-adduct of C60 and 9,10-dimethylanthracene has earlier been suggested as intermediate and reversibly formed critical component in ,template directed' addition reactions of C60. This previously elusive compound has now been isolated and structurally characterized. [source]

    N -substituted bis(tetrazol-5-yl)diazenes: Synthesis, spectra, X-ray molecular and crystal structures, and quantum-chemical DFT calculations

    Tatiyana V. Serebryanskaya
    N -Substituted bis(tetrazol-5-yl)diazenes (substituents are 1-CH3 (3a), 1-Ph (3b), 2-CH3 (3c), and 2- tBu (3d)) were synthesized by oxidative coupling of corresponding 5-aminotetrazoles. All compounds were characterized with 1H and 13C NMR, IR- and UV-spectroscopy, and thermal analysis. Crystal and molecular structures of bis(1-phenyltetra- zol-5-yl)diazene (3b) and bis(2- tert -butyltetrazol-5-yl)diazene (3d) were determined by single crystal X-ray diffraction. Molecules of these compounds are trans-isomers in solid. According to X-Ray data, 3b molecule is S-trans-S-trans conformer, however 3d is S-cis-S-cis one. Quantum-chemical investigation of geometry and relative stability of cis- and trans-isomers and stable conformations of compounds 3a,d was carried out. © 2010 Wiley Periodicals, Inc. Heteroatom Chem 21:24,35, 2010; Published online in Wiley InterScience ( DOI 10.1002/hc.20574 [source]

    Solvent-free alkali and alkaline earth metal complexes of di-imine ligands,

    Igor L. Fedushkin
    Compound [(dph-BIAN)Mg(THF)]2(2) was prepared by reacting magnesium metal with 1,2- bis[(2-biphenyl)imino]acenaphthene (dph-BIAN) in THF, followed by crystallization from toluene. Reac- tion of CaI2 with (dpp-BIAN)Li2 in toluene afforded [(dpp-BIAN)Li]2Ca (3) (dpp-BIAN = 1,2-bis[(2,6-diisopropylphenyl)imino]acenaphthene). Both complexes 2 and 3 were characterized by single crystal X-ray diffraction. The 1H NMR spectroscopic data obtained for complex 3 in toluene solution indicated an agostic interaction between the methyl groups of the ligand and lithium atoms. © 2005 Wiley Periodicals, Inc. Heteroatom Chem 16:663,670, 2005; Published online in Wiley InterScience ( DOI 10.1002/hc.20277 [source]

    On the purity of 2-[ortho -anilinyl]-1,3-benzoxazole derived from 2H -3,1-benzoxazine-2,4(1H)dione (isatoic anhydride) [1,2],

    Karen M. Button
    The Lewis acid catalyzed synthesis and chromatographic purification of isatoic anhydride-derived 2-(2,-anilinyl)-1,3-benzoxazole (2) can result in the co-isolation of 2 and a light pink colored impurity (<5%). This latter species has been identified (NMR, single crystal X-ray diffraction, mp) as 2,-hydroxy-2-aminobenzanilide (3), which represents a predictable intermediate in the formation of 2. Compound 3 crystallizes in an orthorhombic crystal system of space group P212121 with four molecules in the unit cell (, = , = , = 90°; a = 6.715 (2) Å, b = 12.100 (4) Å, c = 13.321 (4) Å; V = 1082.2 (6) Å3). Pure 2 is characterized as a colorless, high-melting solid; unlike the dark colored oil that is isolated if 2 contains traces of 3. J. Heterocyclic Chem., (2010). [source]

    Synthesis and crystal structure of 5-pyrazol-4,5-dihydropyrazoles derivatives

    Zhengfeng Xie
    A series of 1-acetyl(or phenyl)-3-aryl-5-(1-phenyl-3-methyl-5-aryloxyl-pyrazol)-4,5-dihydropyrazole derivatives have been efficiently synthesized under refluxing in glacial acetic acid with two kinds of hydrazines and five kinds of chalcones of 1-phenyl-methyl-5-phenoxyl-pyrazol-4-aldehyde. The structures were confirmed on the basis of 1H NMR, IR, MS and element analysis, and the crystal structure of the compound 4c was determined by single crystal X-ray diffraction. The compound 4c belongs to monoclinic system with space group P2(1)/n, a = 11.8779(3) nm, b = 12.0901(2) nm, c = 17.7004(4) nm, , = 90°, , = 100.05(10)°, , = 90°, Formula weight: 549.46, Triclinic V = 2502.89(9) nm3, Dc = 1.458 Mg/m3, Z = 4, F (000) = 1128. [source]

    Synthesis and biological activity of 3-[(6-chloropyridin-3-yl)methyl]-6-substituted-6,7-dihydro-3H -1,2,3-triazolo[4,5- d]-pyrimidin-7-imines

    Xiao-Bao Chen
    A series of 3-[(6-chloropyridin-3-yl)methyl]-6-substituted-6,7-dihydro-3H -1,2,3-triazolo[4,5- d]pyrimidin-7-imines were designed and synthesized via a multi-step sequence using 2-chloro-5-(chloromethyl)-pyridine as the starting material. Various primary aliphatic amines, hydrazine and hydrazide reacted with 3 to obtain the cyclization products 4. Their structures were confirmed by 1H NMR and elemental analyses, some of them were also confirmed by IR, 13C NMR, MS and single crystal X-ray diffraction. The preliminary bioassay indicated that some of the target compounds 4 displayed moderate to weak fungicidal activity and insecticidal activity. [source]

    Synthesis and biological activities of novel 1,3-bis[substituted-pyridyl (thiazolyl)methyl]-2-substitutedmethylideneimidazolidines

    Man Yan
    A series of novel 1,3-dissubstitutedpyridyl(thiazolyl)methyl-2-substituted-methylideneimidazolidine derivatives 2 and 4 were designed and synthesized via the N -alkylation of the disubstituted heterocyclic ketene aminal derivative 1. When 1 (R = CN, R' = COOC2H5) was used as the starting materials, mono N -alkylated reaction can take place in good yields owing to the presence of the intramolecular hydrogen bond. However, as for 1 (R = R' = CN), it is difficult to obtain pure mono N -alkylated product. The structures of the target compounds were confirmed by IR, 1H NMR, EI-MS and elemental analyses, and, in the case of 2c, by single crystal X-ray diffraction. The preliminary bioassay indicated that some of the title compounds possess moderate fungicidal and insecticidal activity. [source]

    C, -hydroxymethyl methionine: synthesis, optical resolution and crystal structure of its (+)- N, -benzoyl derivative

    Renata Witkowska
    Abstract (R,S)-Methionine was transformed into C, -hydroxymethyl methionine by a route involving C, -hydroxymethylation of 2-phenyl-4-methylthioethyl-5-oxo-4,5-dihydro-1,3-oxazole. The absolute configuration of (,)- C, -hydroxymethyl methionine was elucidated to be (S) by chemical correlation with (S) (,)- C, -ethyl serine. Absolute structure determination (by single crystal X-ray diffraction) on N, -benzoyl- C, -hydroxymethyl methionine confirmed the (R)-configuration for the (+)-enantiomer. In addition, the X-ray diffraction analysis showed that the C,,, -disubstituted glycyl residue adopts the fully extended (C5) conformation. Copyright © 2001 European Peptide Society and John Wiley & Sons, Ltd. [source]

    Salt or co-crystal? determination of protonation state by X-ray photoelectron spectroscopy (XPS)

    Joanna S. Stevens
    Combined 15N ssNMR and X-ray photoelectron spectroscopy (XPS) investigations for theophylline, a theophylline co-crystal, and a theophyllinium salt demonstrate that XPS allows direct observation of the degree of proton transfer, and thus identification of whether a salt or a co-crystal has been formed. The presence of a strongly binding-energy-shifted N 1s XPS peak with protonation indicates a salt (CNH+), while this peak is unmistakably absent in the co-crystal. XPS should be considered as an alternative and complementary technique to single crystal X-ray diffraction and solid-state nuclear magnetic resonance spectroscopy (ssNMR). © 2010 Wiley-Liss, Inc. and the American Pharmacists Association J Pharm Sci 99:4453,4457, 2010 [source]

    Structural, spectroscopic, and theoretical studies of a very short OHO hydrogen bond in bis(4-(N -methylpiperidinium)-butyrate) hydrobromide

    bieta Bartoszak-Adamska
    Abstract The molecular structure of bis(4-(N -methylpiperidinium)-butyrate) hydrobromide, (MPBu)2HBr, has been characterized by single crystal X-ray diffraction, infrared and NMR spectroscopies, and by DFT calculations. The crystals of the title compound at 140,K are monoclinic, space group C2/c, with a,=,11.7118(4), b,=,7.8737(2), c,=,23.9240(8),Å3,, ,,=,90.431(3)°, V,=,2206.1(1),Å3, and Z,=,4. Two 4-(N -methylpiperidinium)-butyrate moieties are joined by a very short and centrosymmetric O.H.O hydrogen bond of 2.436(2),Å3,. The piperidine ring adopts a chair conformation with the methyl group in the equatorial and the bulky (CH2)3COO substituent in the axial position. The broad absorption band below 1500,cm,1 in the FTIR spectrum confirms the existence of a very short O,H,O hydrogen bond. The 1H and 13C NMR spectra are interpreted on the basis of 2D experiments and the calculated GIAO/B3LYP/6-31G(d,p) magnetic isotropic shielding tensors. In the optimized structure of the complex, a 4-(N -methylpiperidinium)-butyrate zwitterion interacts with a 4-(N -methylpiperidinium)-butyric acid cation forming an O,. HO hydrogen bond of 2.580,Å3,. Copyright © 2008 John Wiley & Sons, Ltd. [source]

    Structure elucidation of thermal degradation products of amlodipine

    A. Siva Lakshmi Devi
    Abstract Thermal degradation of amlodipine base causes intramolecular reactions affording three cyclic products, referred to as AMLDEG-I, AMLDEG-II, and AMLDEG-III, respectively. AMLDEG-I is a cyclized product formed by intramolecular elimination of ammonia from amlodipine. AMLDEG-II is a positional isomer of AMLDEG-I. AMLDEG-III is also intramolecular cyclisation product. The three degradation products were isolated by column chromatography and characterized by FT-IR and 1H and 13C NMR spectroscopy data. The AMLDEG-III was crystallized and its structure was solved by single crystal X-ray diffraction (SXRD). Copyright © 2007 John Wiley & Sons, Ltd. [source]

    Synthesis and Characterization of a New Class of Energetic Compounds , Ammonium Nitriminotetrazolates

    Abstract 1-Methyl-5-nitriminotetrazole (1) and 2-methyl-5-nitraminotetrazole (2) obtained by nitration of 1-methyl-5-aminotetrazole (3) and 2-methyl-5-aminotetrazole (4) were deprotonated using aqueous ammonia solution yielding the energetic compounds, ammonium 1-methyl-5-nitriminotetrazolate (5) and ammonium 2-methyl-5-nitriminotetrazolate (6). The nitrogen-rich salts were tested and characterized comprehensively using vibrational spectroscopy (Infrared (IR) and Raman), multinuclear (1H, 13C, 14N, and 15N) NMR spectroscopy, and elemental analysis. The molecular structures in the crystalline state were determined using low temperature single crystal X-ray diffraction. The thermal behavior and the decompositions were investigated using differential scanning calorimetry (DSC) and gas IR spectroscopy. The heats of formation were calculated using bomb calorimetric measurements. In addition, the relevant detonation parameters, like the detonation pressure and velocity of detonation were calculated using the software EXPLO5 outperforming the values of TNT. Last but not least the sensitivities were determined using BAM methods showing moderate values against impact and friction (drophammer and friction tester) and the long-term stabilities were tested using Flexy Thermal safety calorimetry (TSC). X-ray crystallography: 5: monoclinic, P21/c, a=370.06(2),pm, b=2079.06(9),pm, c=859.69(5),pm, ,=99.120(5)°, V=65306(6),pm3, Z=4, ,calc=1.639,g cm,3; 6: monoclinic, P21, a=365.39(2),pm, b=,788.82(5),pm, c=1124.95(7),pm, ,=91.818(6), V=32408(3),pm3, Z=2, ,calc=1.651,g cm,3. [source]

    Synthesis and Characterization of 1-Azido-2-Nitro-2-Azapropane and 1-Nitrotetrazolato-2-Nitro-2-Azapropane

    Roland Boese
    Abstract 1-Azido-2-nitro-2-azapropane (1) was synthesized in high yield from 1-chloro-2-nitro-2-azapropane and sodium azide. 1-Nitrotetrazolato-2-nitro-2-azapropane (2) was synthesized in high yield from 1-chloro-2-nitro-2-azapropane and silver nitrotetrazolate. The highly energetic new compounds (1 and 2) were characterized using vibrational (IR and Raman) and multinuclear NMR spectroscopy (1H, 13C, 14N), elemental analysis and low-temperature single crystal X-ray diffraction. 1-Azido-2-nitro-2-azapropane (1) represents a covalently bound liquid energetic material which contains both a nitramine unit and an azide group in the molecule. 1-Nitrotetrazolato-2-nitro-2-azapropane (2) is a covalently bound room-temperature stable solid which contains a nitramine group and a nitrotetrazolate ring unit in the molecule. Compounds 1 and 2 are hydrolytically stable at ambient conditions. The impact sensitivity of compound 1 is very high (<1,J) whereas compound 2 is less sensitive (<6,J). [source]

    Organotin(IV) tryptophanylglycinates: potential non-steroidal antiinflammatory agents; crystal structure of dibutyltin(IV) tryptophanylglycinate

    Mala Nath
    Abstract Diorganotin(IV) derivatives of tryptophanylglycine (H2Trp,Gly) with general formula R2Sn(Trp,Gly), where R = Me, n -Bu, Ph and n -Oct, and triorganotin(IV) derivatives R,3 Sn(HTrp,Gly) where R, = Me, n -Bu and Ph, have been synthesized and structurally characterized in the ,solid state as well as in solution on the basis of various spectroscopic techniques, viz. FT-IR, multinuclear 1H, 13C and 119Sn NMR, 119Sn Mössbauer and single crystal X-ray diffraction. These investigations suggest that tryptophanylglycine in R2Sn(Trp,Gly) acts as dianionic tridentate coordinating through carboxylate oxygen [C(O)O,], amino nitrogen (NH2) and N,peptide, while in the case of R,3 Sn(HTrp,Gly), the ligand acts as monoanionic bidentate coordinating through C(O)O, and NH2. This is further confirmed by the single-crystal X-ray structure of n -Bu2Sn(Trp,Gly) which shows that two butyl groups and peptide nitrogen (N,peptide) are in the equatorial positions, while the two axial positions are occupied by the carboxylic oxygen [C(O)O,] and the amino nitrogen (NH2) atom from the same ligand molecule in the distorted trigonal,bipyramidal geometry around tin. The anti-inflammatory (using the carrageenan-induced paw edema bioassay in rats), cardiovascular activities and acute toxicity (LD50) of some of these compounds have been examined. All of the studied R2Sn(Trp,Gly) and Ph3Sn(HTrp,Gly) exhibit very high anti-inflammatory activities comparable to that of phenylbutazone along with high safety margin (LD50 > 400 mg kg,1) with no side effects on the cardiovascular system. Copyright © 2009 John Wiley & Sons, Ltd. [source]

    Synthesis, structure and reactivity of cationic base-stabilized gallyleneiron complexes,

    Keiji Ueno
    Abstract Addition of 2,2,-bipyridine (bpy) to an acetonitrile solution of dichlorogallyliron complex FpGaCl2 (1: Fp = (,-C5H5)Fe(CO)2) afforded almost quantitatively a salt consisting of a cationic base-stabilized gallylene complex [FpGaCl·bpy]+ ([3a]+) and an anionic complex [FpGaCl3], ([4],). Reaction of Fp,GaCl2 (Fp, = Fp (1), Fp* (2); Fp* = (,-C5Me5)Fe(CO)2) with NaBPh4 in the presence of a bidentate donor (Do2) gave [Fp,GaCl·Do2]BPh4 where Do2 was bpy or 1,10-phenanthroline (phen). These cationic complexes may be useful precursors for the synthesis of gallyleneiron complexes with various substituents on the gallium atom. Indeed, reaction of [Fp*GaCl·phen]BPh4 ([5b]BPh4) with NaSpTol or Me3SiSpTol afforded the gallyleneiron complex [Fp*GaSpTol·phen]BPh4 ([6]BPh4), the first example of a gallium,transition metal complex having a thiolate group on the gallium atom. The molecular structures of [5b]BPh4 and [6]BPh4 were determined by single crystal X-ray diffraction. Copyright © 2003 John Wiley & Sons, Ltd. [source]

    Mouse testis,brain RNA-binding protein (TB-RBP): expression, purification and crystal X-ray diffraction

    John M. Pascal
    TB-RBP (testis,brain RNA-binding protein) is a mouse RNA-binding protein that controls the temporal and spatial expression of mRNA. Found most abundantly in brain and male germ cells in the testis, TB-RBP is known to suppress the translation of specific testicular and brain mRNAs as part of cell development. TB-RBP,mRNA complexes can bind microtubules and thereby facilitate RNA translocation. Translin is the human orthologue of TB-RBP which binds to single-stranded ends of DNA sequences in breakpoint regions of chromosomal translocations. TB-RBP/translin has been crystallized in space group P21212. The expression, purification, and crystallization of TB-RBP are described as well as preliminary X-ray diffraction data. The multimeric state of TB-RBP is addressed using dynamic light-scattering results. [source]

    Phosphino-Aminothiazoline Platinum(II) and Platinum(II)/Gold(I) Complexes: Structural, Chemical and Vapoluminescent Properties

    Roberto Pattacini Dr.
    Abstract Phosphino-amino-thiazolines and -thiazoles can exist in solution in two tautomeric forms, in which the NH proton involves the endo-cyclic or exo-cyclic nitrogen atom. The two tautomers show different reactivities toward alcoholysis; the imino form degrades more rapidly. Their bischelated platinum complexes were studied in the solid state by single crystal X-ray diffraction. Thus, the unique stereoelectronic features of the [Pt(PNth)] (PNth=diphenylposphino-aminothiazoline) moiety were revealed. The complex cis -[Pt(PNth)2] reacts with gold(I) salts to yield dimetallic compounds, the molecular structures of which have been determined by X-ray diffraction. Solid cis -[Pt(PNth)2] shows vapoluminescent properties if exposed to alcohol vapors. A combined photophysical and crystallographic investigation has been carried out to clarify the unprecedented rigidochromic role of the alcohol in this phenomenon. [source]

    Guaiane Sesquiterpene Lactones from Salvia nubicola (Lamiaceae)

    Abstract A new sesquiterpene lactone, nubiol (1), belonging to the guaiane class, along with a dimer, bisnubidiol (2), has been isolated from Salvia nubicola collected from Quetta, Pakistan. The structures of both metabolites were elucidated with the aid of spectroscopic techniques including 2D-NMR. Additionally, the structure of nubiol (1) was finally confirmed via the single crystal X-ray diffraction. Nubiol (1) was found moderately active against Pseudomonas aeruginosa. [source]

    Photophysical Properties of Heteroleptic Iridium Complexes Containing Carbazole-Functionalized ,-Diketonates

    CHEMPHYSCHEM, Issue 4 2008
    Zhiwei Liu
    Abstract Twelve iridium complexes with general formula of Ir(C^N)2(LX) [C^N represents the cyclometalated ligand, i.e. 2-(2,4-difluorophenyl) pyridine (dfppy), 2-phenylpyridine (ppy), dibenzo{f, h}quinoxaline (DBQ); LX stands for ,-diketonate, i.e. acetyl acetonate (acac), 1-(carbazol-9-yl)-5,5-dimethylhexane-2,4-diketonate (CBDK), 1-(carbazol-9-yl)-5,5,6,6,7,7,7-heptafluoroheptane-2,4-diketonate (CHFDK), 1-(N-ethyl-carbazol-3-yl)-4,4,5,5,6,6,6-heptafluorohexane-1,3-diketonate (ECHFDK)] are synthesized, characterized and their photophysical properties are systemically studied. In addition, crystals of Ir(DBQ)2(CHFDK) and Ir(DBQ)2(acac) are obtained and characterized by single crystal X-ray diffraction. The choice of these iridium complexes provides an opportunity for tracing the effect of the triplet energy level of ancillary ligands on the photophysical and electrochemical behaviors. Data show that if the triplet energy level of the ,-diketonate is higher than that of the Ir(C^N)2 fragment and there is no superposition on the state density map, strong 3LC or 3MLCT-based phosphorescence can be obtained. Alternatively, if the state density map of the two parts are in superposition, the 3LC or 3MLCT-based transition will be quenched at room temperature. Density functional theory calculations show that these complexes can be divided into two categories. The lowest excited state is mainly determined by C^N but not ,-diketonate when the difference between the triplet energy levels of the two parts is large. However, when this difference is very small, the lowest excited state will be determined by both sides. This provides a satisfactory explanation for the experimental observations. [source]

    Hydrothermal Syntheses, Crystal Structure and Thermal Behavior of [(CH3)2NH2]2[B5O6(OH)4]2·[HCON(CH3)2] and [NH3CH2CH2NH3]2[B14O20(OH)6]

    Ping Li
    Abstract Two novel organic base templated nonmetal borates [(CH3)2NH2]2[B5O6(OH)4]2·[HCON(CH3)2] (?) and [NH3CH2CH2NH3]2[B14O20(OH)6] (II) have been synthesized under hydrothermal conditions, and characterized by elemental analyses, FT-IR spectroscopy, X-ray diffraction, and TG-DTA. Their crystal structures were determined from single crystal X-ray diffraction. The crystal structure of compound I is characterized by forming a 3D supramolecular structure with large channels along axes b and c through OH···O hydrogen-bonding among the [B5O6(OH)4], anions. The crystal structure of compound II is characterized by forming a 3D supramolecular structure with large channels along axis a and direction [111] through OH···O hydrogen-bonding among the [B14O20(OH)6]4, anions. The templating organic amine cations in I and II are both obtained through in situ hydrothermal reactions, and are both located in the channels of the 3D supramolecular structure, respectively. Their thermal behavior has been also investigated. [source]

    Crystal Structure of , -Cyclodextrin-Felbinac Inclusion Complex

    Enju Wang
    Abstract The crystal structure of the inclusion complex of , -cyclodextrin (, -CD) synthesized with felbinac (4-biphenylacetic acid) was determined by single crystal X-ray diffraction at 150 K. The complex contains two , -CDs, two felbinac molecules, twenty-two water molecules in the asymmetric unit, and could be formulated as (C42H70O35)2·(C14H12O2)2·22(H2O). In the crystal lattice, the two , -CD moieties form a head-to-head dimer jointed through hydrogen bonds, and the felbinacs that interact by face-to-face ,-, stacking are included in the , -CD dimer cavity with their carboxyl groups protruding out from cavity opening. In crystals the dimer units of , -CD are stacked in an intermediate type (IM) that consists of closely packed , -CD dimer layers. [source]

    Supramolecular Complexes Self-assembled by Copper(II) Carboxylate and Monohelical Pyridylamino Ligand

    Li-Jun Zhou
    Abstract Two novel supramolecular complexes [Cu(bpapa)(dhbd)]·CH3OH (1) and [Cu(bpapa)(ma)]·ma (2) (bpapa=bis[6-(2-pyridylamino)pyrid-2-yl]amine, dhbd=2,3-dihydroxybutanedioate dianion, ma=, -methacrylate) were rationally designed, synthesized and characterized by single crystal X-ray diffraction, IR, electronic spectroscopy and thermogravimetric analyses. Complex 1 was the first oligo- , -pyridylamino complex based on hydroxypolycarboxylate and self-assembled into a 3D honeycomb configuration network with open channels and tubes containing 1D ladder-shaped double chains formed by hydrogen bonds and aromatic ,-, stacking interactions. Complex 2 constructed a 2D supramolecular network extended by 1D chains from dimeric supramolecular synthon through noncovalent supramolecular interactions. In the two complexes, the chelating monohelical ligand adopted all- anti configuration. Density functional theory calculations were applied to 1 and 2. [source]

    Synthesis and Crystal Structure of a Two-dimensional Silver(I)-Iron(III) Heteronuclear Coordination Polymer: {[Ag,Fe2(SCN)12(H2O)2] [(inaH)2(H2O)2]}n

    Xiu-Ling Li
    Abstract The 2-D heteronuclear coordination polymer {[Ag4Fe2(SCN)12(H2O)2] (inaH)2(H2O)2}n (1) (inaH is the abbreviation of protonated isonicotinic acid) with chemical formula C24Ag4Fe2N14O8S12 has been synthesized and characterized by single crystal X-ray diffraction, elemental analysis and IR spectroscopy. The Ag2S2 rings connect two kinds of octahedral geometries of Fe(III) ions, [Fe(NCS)6]3, and Fe(H2O)2(NCS)4], units with bridging thiocyanate ions leading to 2-D [Ag4Fe2(SCN)12(H2O)22, anion framework. Four kinds of rings including the unprecedented thirty-two membered Ag4Fe4(SCN)8 rings share comers or edges in the 2-D anion layer structure. All thiocyanates coordinate to the metal ions according to the HSAB principle with N atoms binding to the Fe(III) ions and with S atoms binding to Ag(I) ions. Pronoated ina cations stabilize the layer structure as counter ions and hydrogen bonds were formed within the pronoated in a cations dimer and between the dimers and the lattice waters. Crystal data: Mr= 1560.44, triclinic, P1, a=0.76082(1) nm, b=0.9234 nm, c= 1.85611(4) nm, a= 103.0170(10)°, ,=93.7780(10)°, y=97.4080(10)°, V= 1.25385(3) nm3, Z=1, ,(Mo K,)=2.650 mm,1, Dc,=2.067 g · cm,3, F(000)=758, R1=0.0412. wR2=0.1003. [source]