Crystal structures, infrared-spectra, and thermal behavior of calcium hydrogenselenite monohydrate, Ca(HSeO3)2 · H2O, and dicalcium diselenite bis(hy…

1986

Abstract Calcium hydrogenselenite monohydrate and dicalcium diselenite bis(hydrogenselenite) were synthesized and their crystal structures determined. Crystal data for Ca(HSeO3)2 · H2O: a = 6.911(2), b = 7.369(2), c = 6.739(2) A, α = 90.51(3)°, β = 90.93(3)°, γ = 107.46(2)°, V = 327.3(2) A3, space group P 1 (No. 2), dcalcd = 3.19 M gm−3, Z = 2, and R = 0.036 for 1503 reflections. Data for Ca2(HSeO3)2(Se2O5): a = 14.719(4), b = 7.059(2), c = 11.793(2) A, β = 117.96(2)°, V = 1082.3(4) A3, space group C2 c (No. 15), dcalcd = 3.52 Mg m−3, Z = 4, and R = 0.047 for 1251 reflections. Both structures form a three-dimensional network. The coordination polyhedron around calcium is a monocapped trigon…

Electronic Structures and Molecular Properties of Chalcogen Nitrides Se2N2 and SeSN2

2006

The electronic structures and molecular properties of S2N2 as well as the currently unknown chalcogen nitrides Se2N2 and SeSN2 have been studied using various ab initio and density functional methods. All molecules share a qualitatively similar electronic structure and can be primarily described as 2π-electron aromatics having minor singlet diradical character of 6−8% that can be attributed solely to the nitrogen atoms. This diradical character is manifested in the prediction of their molecular properties, in which coupled cluster and multiconfigurational approaches, as well as density functional methods, show the best performance. The conventional ab initio methods RHF and MP2 completely f…

Synthesis, characterization and thermal properties of small R2R′2N+X−-type quaternary ammonium halides

2005

Twenty-one R {sub 2} R {sup '} {sub 2}N{sup +} X {sup -} -type (R=methyl or ethyl, R {sup '}=alkyl, X=Br or I) quaternary ammonium (QA) halides have been prepared by using a novel one-pot synthetic route in which a formamide (dimethyl-, diethylformamide, etc.) is treated with alkyl halide in the presence of sodium or potassium carbonate. The formation of QA halides was verified with {sup 1}H-NMR, {sup 13}C-NMR, MS and elemental analysis. The crystal structures of four QA halides (two bromide and two iodide) were determined using X-ray single crystal diffraction, and the powder diffraction method was used to study the structural similarities between the single crystal and microcrystalline bu…

Experimental and Theoretical Investigations of Structural Trends for Selenium(IV) Imides and Oxides: X-ray Structure of Se3(NAd) 2

2004

The thermal decomposition of Se(NAd)(2) (Ad = 1-adamantyl) in THF was monitored by (77)Se NMR and shown to give the novel cyclic selenium imide Se(3)(NAd)(2) as one of the products. An X-ray structural determination showed that Se(3)(NAd)(2) is a puckered five-membered ring with d(Se-Se) = 2.404(1) A and |d(Se-N)| = 1.873(4) A. On the basis of (77)Se NMR data, other decomposition products include the six-membered ring Se(3)(NAd)(3), and the four-membered rings AdNSe(micro-NAd)(2)SeO and OSe(micro-NAd)(2)SeO. The energies for the cyclodimerization of E(NR)(2) and RNEO (E = S, Se; R = H, Me, (t)Bu, SiMe(3)), and the cycloaddition reactions of RNSeO with E(NR)(2), RNSO(2) with Se(NR)(2), and S…

Conformations and Energetics of Sulfur and Selenium Diimides

2003

The geometries and energetics of different conformations of sulfur and selenium diimides E(NR) 2 (E = S, Se; R = H, Me, 'Bu, C 6 H 3 Me 2 -2,6, SiMe 3 ) have been studied by using various ab initio and DFT molecular orbital techniques. The syn,syn conformation is found to be most stable for parent E(NH) 2 , but in general, the preferred molecular conformation for substituted chalcogen diimides is syn,anti. In the case of E(NH) 2 the present calculations further confirm that syn,syn and syn,anti conformations lie energetically close to each other. From the three different theoretical methods used, B3PW91/6.31G * proved to be the most suitable method for predicting the geometries of chalcogen…

The tris(hexasulphido)platinate(IV) ion: Seven-membered chelate rings

1988

Le sel complexe [[(C 6 H 5 ) 4 P] 2 Pt(S 6 ) 3 ] a l'etat cristallin est prepare a partir de [N(C 2 H 5 ) 4 ] 2 PtS 17 ou (NH 4 ) 2 PtS 17 •H 2 O en solution dans l'acetone. Caracterisation structurale et configuration geometrique de l'anion Pt(S 6 ) 3 2−

1,1,4,4-Tetramethylpiperazinediium dibromide

2009

A small quantity of the title compound, C8H20N22+·2Br−, was formed as a by-product in a reaction between a diamine and an alkyl bromide. The asymmetric unit contains half of a centrosymmetric dication and a bromide anion. In the crystal, weak intermolecular C—H...Br hydrogen bonds consolidate the crystal packing.

Properties of new asymmetrically quaternized dicationic ammonium based room-temperature ionic liquids with ether functionality

2013

Eleven asymmetrically quaternized dicationic ammonium-based room-temperature ionic liquids (DRTILs) with bis(trifluoromethanesulfonyl)imide (TFSI) were synthesized and characterized, along with 11 analogous dibromide precursors. Two-step synthesis was used to diquaternize tetramethyl-1,3-propanediamine and 2-(dimethylamino)-ethyl ether amines with a variety of alkyl and ether functionalized side chain groups (R1 ≠ R2). Each salt contain 1 to 3 ether groups located either in a linkage or in a side chain moieties. Structural and thermoanalytical properties, water content, and viscosity have been characterized using, for example, NMR, mass spectrometry (MS), X-ray diffraction, and thermal anal…

N,N-Dimethyl-N-propylpropan-1-aminium chloride monohydrate

2008

The title compound, C8H20N+·Cl−·H2O, has been prepared by a simple one-pot synthesis route followed by anion exchange using resin. In the crystal structure, the cations are packed in such a way that channels exist parallel to the b axis. These channels are filled by the anions and water molecules, which interact via O—H...Cl hydrogen bonds [O...Cl = 3.285 (3) and 3.239 (3) Å] to form helical chains. The cations are involved in weak intermolecular C—H...Cl and C—H...O hydrogen bonds. The title compound is not isomorphous with the bromo or iodo analogues.

Characterization of the non-stoichiometry in lanthanum oxyfluoride by FT-IR absorption, Raman scattering, X-ray powder diffraction and thermal analys…

1997

Abstract The FT-IR absorption, FT-Raman scattering, X-ray powder diffraction (XPD), and thermogravimetry were used to explore the non-stoichiometry in LaOF. The TGA-DTA analyses between 30 and 1500°C showed that the LaO1 − xF1 + 2x phases yielded the stoichiometric LaOF as an intermediate product. The temperature of formation of the LaOF and La2O3 increased with increasing excess of fluoride. The room temperature XPD data in 6.5 ⩽ 2θ ⩽ 121° range were analyzed by the Rietveld profile refinement method and subsequently by the bond valence calculations. All LaO1 − xF1 + 2x phases possess the tetragonal PbFCl-type structure (space group: P4/nmm; Z = 2) while the stoichiometric LaOF has the hex…

X-ray powder diffraction pattern for lactitol and lactitol monohydrate

1994

Diffraction patterns were recorded, and unit cell dimensions refined by the least-squares method, for lactitol and lactitol monohydrate. Refined unit cell parameters for lactitol are: a =7.622(1) Å, b = 10.764(2) Å, c = 9.375(1) Å, β= 108.25(1)° in space group P21, and those for lactitol monohydrate a =7.844(1) Å, b = 12.673(2) Å, c = 15.942(2) Å in space group P212121.

Experimental and Theoretical Investigations of Structural Trends for Selenium(IV) Imides and Oxides: X-ray Structure of Se3(NAd)2

2004

The thermal decomposition of Se(NAd)2 (Ad = 1-adamantyl) in THF was monitored by 77Se NMR and shown to give the novel cyclic selenium imide Se3(NAd)2 as one of the products. An X-ray structural determination showed that Se3(NAd)2 is a puckered five-membered ring with d(Se−Se) = 2.404(1) Å and |d(Se−N)| = 1.873(4) Å. On the basis of 77Se NMR data, other decomposition products include the six-membered ring Se3(NAd)3, and the four-membered rings AdNSe(μ-NAd)2SeO and OSe(μ-NAd)2SeO. The energies for the cyclodimerization of E(NR)2 and RNEO (E = S, Se; R = H, Me, tBu, SiMe3), and the cycloaddition reactions of RNSeO with E(NR)2, RNSO2 with Se(NR)2, and S(NR)2 with Se(NR)2 have been calculated at…

Thermal and spectroscopic investigation of europium and samarium sulphates hydrates by TG-FTIR and ICP-MS techniques.

2005

The investigation of europium(III) sulphate hydrate and samarium(III) sulphate hydrate was performed by thermal analysis (TG-DTG) and simultaneous infrared evolved gas analysis-Fourier transformed infrared (EGA-FTIR) spectroscopy. The TG, DTG and DTA curves were recorded at the 25-1400 degrees C in the dynamic air atmosphere by TG/DTA analyser. The infrared evolved gas analysis was obtained on the FTIR spectrometer. Eu(2)(SO(4))(3).nH(2)O (n=3.97) and Sm(2)(SO(4))(3).nH(2)O (n=8.11) were analysed, the dehydration and decomposition steps were investigated and the water content was calculated. The formation of different oxysulphates was studied. The trace rare earth elements in Eu and Sm sulp…

Electronic Structures and Spectroscopic Properties of 6π-Electron Ring Molecules and Ions E2N2 and E42+ (E = S, Se, Te)

2004

The electronic structures and molecular properties of square-planar 6π-electron ring molecules and ions E2N2 and E42+ (E = S, Se, Te) were studied using various ab initio methods and density functionals. All species were found to contain singlet diradical character in their electronic structures. Detailed analysis of the CAS wave function of S2N2 in terms of different valence bond structures gives the largest weight for a Lewis-type singlet diradical VB structure in which the two unpaired electrons reside on nitrogen atoms, though the relative importance of the different VB structures is highly dependent on the level of theory. The diradical character in both E2N2 and E42+ was found to incr…

Transition paths between phases IV, III and II of ammonium nitrate predicted from X-ray powder diffractometer and differential scanning calorimeter d…

1994

Abstract Ammonium nitrate solid phase transition paths between phases IV, III and II were explained and predicted on the basis of X-ray powder diffraction (XRD) and differential scanning calorimetry (DSC) data by applying partial least-squares regression (PLS) and principal component analysis (PCA). The samples were clustered according to their different transition paths with the PLS and PCA models, and the transition paths were predicted with PLS component clusters. The best PLS clusters were formed by a few first components. Prediction of the transition path with the PLS clusters made a semiquantitative prediction of the transition energy possible. In PCA, principal components 6 and 11, w…

Preparation and characterization of new low melting ammonium-based ionic liquids with ether functionality

2009

Abstract Eighteen new and three previously known but insufficiently characterized RR´3N+A− and R2R´2N+A− type (R = 2-ethoxyethyl or 4-methoxybenzyl, R´ = methyl, ethyl, n-propyl, n-butyl, n-pentyl or n-hexyl, A = Br, BF4 or PF6) quaternary ammonium (QA) salts were synthesized and characterized by using 1H and 13C NMR techniques, mass spectroscopy and elemental analysis. The bromide salts were synthesized either by treating dimethyl formamide with an ether functionalized alkyl bromide in the presence of potassium carbonate or by treating a tertiary amine with an ether functionalized alkyl bromide. The QA tetrafluoroborates and hexafluorophosphates were synthesized by metathesis reaction betw…

Preparation and structural characterization of (Me(3)SiNSN)(2)Se, a new synthon for sulfur-selenium nitrides.

2002

The reaction of (Me(3)SiN)(2)S with SeCl(2) (2:1 ratio) in CH(2)Cl(2) at -70 degrees C provides a route to the novel mixed selenium-sulfur-nitrogen compound (Me(3)SiNSN)(2)Se (1). Crystals of 1 are monoclinic and belong the space group P2(1)/c, with a = 7.236(1) A, b = 19.260(4) A, c = 11.436(2) A, beta = 92.05(3) degrees, V = 1592.7(5) A(3), Z = 4, and T = -155(2) degrees C. The NSNSeNSN chain in 1 consists of Se-N single bonds (1.844(3) A) and S=N double bonds (1.521(3)-1.548(3) A) with syn and anti geometry at the N=S=N units. The N-Se-N bond angle is 91.8(1) degrees. The EI mass spectrum shows a molecular ion with good agreement between the observed and calculated isotopic distributions…

Crystal and molecular structure of anhydrous betaine, (CH3)3NCH2CO2

1999

Abstract 1–Carboxy–N,N,N–trimethylmethanamanium inner salt or anhydrous betaine, (CH3)3NCH2CO2, FW=117.15 gmol −1 , crystallizes in the orthorhombic space group Pnma with a=14.544(2) A , b=6.859(3) A , c=6.131(1) A , V=611.7(3) A 3 , Z=4, D x =1.27 Mgm −3 , λ (MoK α )=0.71073 A , μ =0.091 mm −1 . The structure was resolved by direct methods and refined by least-square calculations to R=0.038 for 531 reflections. Observed changes in bond angles imply that there is a repulsion between nitrogen and oxygen. The melting point (measured at onset) is 570 K. FTIR spectra of anhydrous betaine and monohydrate were recorded. Clear differences were found between the two compounds based on infrared (i.r…

Ca[Ag2(SCN)4]·2H2O

2004

Calcium tetrathiocyanatodiargentate(I) dihydrate, Ca[Ag(2)(SCN)(4)].2H(2)O, contains eight-membered Ag(4)S(4) rings bonded together through shared atoms to form layers parallel to (100). The thiocyanate groups link the layers to Ca-O chains running parallel to the c axis. The Ca atom is located on a twofold rotation axis parallel to b and is surrounded by four water molecules of crystallization and four thiocyanate N atoms in a distorted square antiprism.

Potassium silver thiocyanate

2001

The structure of K[Ag(SCN)2] forms a three-dimensional network consisting of seven-coordinated K atoms and four-coordinated Ag atoms connected together by bridging thio­cyanate groups.

Structural Modifications of Rb<sub>3</sub>RE(PO<sub>4</sub>)<sub>2</sub> Phases (RE = La, Gd, Y)

2001

The Influence of User-Selected Models on the Results of the Rietveld Refinement of the LaOCl Structure

1998

Polymorphism in Cs[AgZn(NCS)4].

2002

The title compound, caesium silver zinc tetrathiocyanate, crystallizes in two polymorphic forms, in space groups P2(1)/n and C2/c. Both structures form a continuous three-dimensional network. The structure in C2/c contains a delocalized Ag atom in a binuclear-like anion, where two [Ag(NCS)(4)] units (delocalized Ag as an average) share two common NCS(-) ligands.

Simulataneous application of charge coupled device array-detected Raman spectroscopy and differential scanning calorimetry to in situ investigation o…

1992

The combination of differential scanning calorimetry (DSC) with charge coupled device (CCD) array-detected Raman spectroscopy for the in situ investigation of phase transition is illustrated using ammonium nitrate as an example. This method aids unambiguous characterization of different phases by providing a simultaneous probe of thermodynamic and vibrational data. The availability of real-time vibrational data, including both the internal and external mode regions, is unique to array-detected Raman spectroscopy. The intensity changes of the symmetric stretching mode ν1 of the nitrate ions and the lattice vibrations, that accompany the phase transition IV → II of ammonium nitrate, are ratio…

Physicochemical Properties of New Dicationic Ether-Functionalized Low Melting Point Ammonium Salts

2010

Eleven new and one previously known but insufficiently characterized dicationic quaternary ammonium (QA) salts were synthesized and characterized. They contain an ethoxy ethyl group either in a side chain and/or as spacer of the diammonium cation and have bromide, hexafluorophosphate (PF6–), bis(trifluoromethanesulfonyl)imide (TFSI), or trifluoromethanesulfonate (TFMS) as an anion. 1H and 13C techniques, mass spectrometry, and elemental analysis together with X-ray diffraction and thermoanalytical methods were used for their characterization both in the liquid and solid state. In addition, residual water content and viscosity measurements were made for the two room temperature ionic liquid…

Simultaneous application of Fourier transform Raman spectroscopy and differential scanning colorimetry for the in situ investigation of phase transit…

1991

Abstract The combination of Fourier transform Raman spectroscopy with differential scanning colorimetry for the in situ investigation of phase transitions is illustrated using ammonium nitrate as an example. This method helps unambiguous characterisation of different phases by providing a simultaneous probe of thermodynamic and vibrational data.

Dicaesium silver zinc thiocyanate, Cs2[AgZn(SCN)5]

2001

The title compound, dicaesium(I)-μ-thio­cyanato-κ2N:S-zinc(II)-tetra-μ-thio­cyanato-κ2S:N-argentate(I), crystallizes in the orthorhombic space group Pmn21 and contains units of composition AgZn(SCN)3 lying on a mirror plane and bonded together through Cs+ ions and thio­cyanate groups. The crystal studied contained equal numbers of inversion twins.

Cs[Ag4Zn2(SCN)9].

2002

Caesium tetrasilver dizinc nona­thio­cyanate, Cs[Ag4Zn2(SCN)9], forms a continuous structure, where the Ag atoms and the S atoms of the thio­cyanate groups form chains which run along [101]. These chains are bonded together through the Cs and Zn atoms. It is not possible to distinguish between space groups P1 and P\overline 1, but, if the latter space group is correct, the structure contains a thio­cyanate group disordered across a centre of inversion. The structure is described in space group P\overline 1, in which the Cs atom also lies on a centre of inversion.

[Bis(dimethylsulphoxide) protium][trans-bisdimethylsulphoxidetetrachloroiridate(III)]

1988

Abstract [(DMSO)2H]trans-[IrCl4(DMSO)2] (DMSO = dimethylsulphoxide) has been structurally characterized. The hydrogen bonded cation [DMSOHDMSO]+ has a very short OHO bond distance (2.405 A) which compares well with that in the known rhodium analogue. The two DMSO ligands are trans on iridium and coordinate via the sulphur atoms. Earlier work had assigned the cis structure to the anion in this compound.

Synthesis, characterization and thermal behavior of nine new -type quaternary ammonium tetrafluoroborate or hexafluorophosphate salts prepared by met…

2008

Abstract Nine new quaternary ammonium tetrafluoroborate or hexafluoroborate salts were prepared from analogous bromide or chloride salts using anion exchange reaction in which the corresponding bromide or chloride salt was treated with HBF4 or HPF6 acid in aqueous solutions. The characterizations were performed by 1H NMR and 13C NMR spectroscopy as well as by elemental analysis. The single crystals of three tetrafluoroborate and two hexafluorophosphate salts were obtained by slow evaporation from a methanol/ethyl acetate solution and the crystal structures were determined by X-ray single crystal diffraction. Four of the compounds crystallized in the orthorhombic and one in the monoclinic cr…

The conformational polymorphism and weak interactions in solid state structures of ten new monomeric and dimeric substituted dibenzyldimethylammonium…

2009

In this study, ten new dibenzyldimethyl/ethyl ammonium chloridopalladate(II) compounds with five different cations and two anions have been synthesized and a simple method for a synthesis, in which hydrochloric acid solutions are used, has been described. Furthermore, twelve structures including two polymorphs have been obtained from hydrochloric and methanol/acetonitrile solutions. The anion–cation and cation–cation interactions of the synthesized compounds have been studied mainly by means of single X-ray diffraction in order to study the effects of varying either the anion or the cations in these QA2PdCl4 and QA2Pd2Cl6 salts. The results indicate that the effects of intermolecular cation…

Electronic Structures and Spectroscopic Properties of 6π-Electron Ring Molecules and Ions E2N2 and E42+ (E = S, Se, Te)

2004

The electronic structures and molecular properties of square-planar 6π-electron ring molecules and ions E2N2 and E42+ (E = S, Se, Te) were studied using various ab initio methods and density functionals. All species were found to contain singlet diradical character in their electronic structures. Detailed analysis of the CAS wave function of S2N2 in terms of different valence bond structures gives the largest weight for a Lewis-type singlet diradical VB structure in which the two unpaired electrons reside on nitrogen atoms, though the relative importance of the different VB structures is highly dependent on the level of theory. The diradical character in both E2N2 and E42+ was found to incr…

Properties of new low melting point quaternary ammonium salts with bis(trifluoromethanesulfonyl)imide anion

2010

Eight new monocationic quaternary ammonium (QA) salts with the bis(trifluoromethanesulfonyl)imide (TFSI) anion were prepared by metathesis using our previously reported QA halides as precursors. New salts were characterized both in liquid and solid state using 1 H and 13 C NMR techniques, mass spectroscopy and elemental analysis together with X-ray diffraction and thermoanalytical methods. In addition, residual water content, viscosity and conductivity measurements were made for three of the roomtemperature ionic liquids (RTILs). The crystal structures of three compounds were determined by X-ray single crystal diffraction. Powder diffraction was used to study the crystallinity of the solid …

X-ray powder diffraction study of the stability of solid solutions in LaO(Cl1−xBrx)

1997

Abstract The formation of solid solutions in the LaO(Cl 1− x Br x ) series was studied by X-ray powder diffraction (XPD), Rietveld profile refinement and bond valence calculations. The LaO(Cl 1− x Br x ) (0 ≤ x ≤ 1, step 0.2, and x = 0.5) powder samples were prepared by the solid state reaction between La 2 O 3 and a mixture of ammonium chloride and bromide. The X-ray powder diffraction patterns were collected at room temperature between 5 and 125° in 2Θ using Cu K α 1 radiation (λ = 1.5406 A). The XPD data between 20 and 90° were analyzed with the DBWS-9006PC Rietveld profile refinement program. All the LaO(Cl 1− x Br x ) phases studied crystallize in the tetragonal PbFCl-type structure wi…

X-ray powder diffraction study of the stability of solid solutions in (La1−xGdx)OCl

1996

The formation of the solid solutions in the (La1−xGdx)OCl series was studied by X-ray powder diffraction (XPD) at room temperature in the 2θ region between 6.5 and 120°. The Rietveld profile refinement analyses of the XPD patterns were carried out with the background, unit cell, atomic position, isotropic temperature, and Gaussian profile form parameters refined freely. All (La1−xGdx)OCl samples possessed the tetragonal PbFCl-type structure with P4/nmm as the space group (Z=2). The unit cell parameters a and c evolve smoothly through the series and no clustering of the Gd3+ ions was observed according to Vegard's law. The solid solubility exists throughout the whole series. The valence bond…

Cyclopentadienyl derivatives of octahedral carbonylcarbide hexaruthenium clusters: synthesis, NMR, IR and X-ray characterization

1996

Abstract The reaction of hexanuclear carbonylcarbide cluster Ru6C(CO)17 (1) with pentamethylcyclopentadiene by reflux in heptane leads to a new chelate cluster Ru6C(μ-η1-η5-CH2C5Me4)(CO)14 (2). The compound 2 contains a CH2 group α-bonded to one of the Ru atoms in the Ru6 cluster and a C5Me4-ligand η5-coordinated by the adjacent Ru atom of the Ru6 cluster. Reflux of 1 in hexane with two molecular equivalents of nickelocene, Ni(C5H5)2  NiCp2, used as a source of cyclopentadiene yields the Ru6C(CO)12Cp2 (3) cluster. The compounds 2 and 3 have been characterized by NMR and IR spectroscopy and their crystal structures determined by X-ray diffraction studies.

ChemInform Abstract: X-Ray Powder Structure Determination and Thermal Behavior of a New Modification of Pb(II) Selenite.

2010

The crystal structure of a new polymorphic form of lead(II) selenite (PbSeO3) was solved directly from conventional X-ray powder diffraction data. Direct methods and Rietveld refinement techniques were used for the structure determination. The compound crystallizes in the monoclinic space group P21/c (no. 14) with cell dimensions a = 9.1587(1) A, b = 8.0902(1) A, c = 8.7932(1) A, β = 103.032(1)°, and V = 634.76(2) A3. The final refinement gave background excluded Rp = 6.22%, Rwp = 8.81%, and RB = 2.16% by using 45 structural and 15 profile parameters with 10 atoms in an asymmetric unit. The three-dimensional structure consists of 9-coordinated lead atoms, which are linked by three bidentate…

X-ray powder diffraction pattern for glucopyranosylsorbitol and glucopyranosylmannitol dihydrate

1997

X-ray powder data are given for glucopyranosylsorbitol, C12H24O11, and glucopyranosylmannitol dihydrate, C12H24O11 * 2H2O. Refined unit cell parameters for glucopyranosylsorbitol are: a=0.9124(4) nm, b=1.1336(5) nm, c=0.7232(3) nm, and β=91.23(4)° in space group P21 and those for glucopyranosylmannitol dihydrate are a=2.2579(15) nm, b=1.0016(5) nm, and c=0.7584(5) nm in space group P212121.

Crystal structure of lactitol (4-O-beta-D-galactopyranosyl-D-glucitol).

1992

Abstract Lacitol, C 12 H 24 O 11 , is monoclinic, space group P 2 1 with cell dimensions a = 7.614(1), b = 10.757(1), c = 9.370(1) A, β = 108.19(1)°, and V = 729.0(1) A 3 ; Z = 2, D x = 1.57 Mg.m −3 , λ(Cu- K α ) = 1.5406 A, μ = 1.166 mm −1 , F (000) = 368, and T = 23°. The structure was solved by direct methods and refined by least-squares calculations to R = 0.048 for 1510 unique observed reflections. There are one intra- and eight inter-molecular hydrogen bonds in the structure. Bond lengths and angles accord well with the mean values of related structures. The galactopyranosyl ring has a chair conformation.

X-ray powder diffraction data for five lanthanoid chromates [Ln2(CrO4)3(H2O)5]·2H2O (Ln=La,Pr,Nd,Sm,Eu)

1994

X-ray powder diffraction data are reported for a series of isomorphous compounds of [Ln2(CrO4)3(H2O)5]·2H2O, where Ln=La, Pr, Nd, Sm, or Eu. The compounds crystallize in monoclinic space group P21/c (No: 14) with Z=4. Refined unit cell parameters and indexed powder diffraction patterns are given.

Stability of non-stoichiometric laof phases: x-ray diffraction investigation

1998

Summary The X-ray diffraction patterns of the polycrystalline LaO 1−x F 1+2x (0.05≤x≤0.3) phases were measured at room temperature and analyzed by the Rietveld profile refinement method. All compounds crystallize in the tetragonal PbFCl-type structure with P4/nmm as the space group. No distortion to lower orthorhombic symmetry was observed. The tetragonal lattice parameters a and c increase with increasing excess of fluoride. The La-oxygen (La-fluorine) distances first decrease (increase) but then these trends are reversed. The Global Instability Index calculated from the bond valence model increases towards the higher fluoride content of the compounds indicating decreasing stability

Synthesis, characterization and thermal properties of new aromatic quaternary ammonium bromides

2004

Series of new aromatic R 2R′ 2N +Br - (R=benzyl, 4-methylbenzyl, 2-phenylethyl, 3-phenylpropyl; R′=ethyl, methyl, isopropyl) or RR′ 2NH +Br --type (R=benzyl, R′=isopropyl) quaternary ammonium bromides were prepared by using novel synthetic route in which a formamide (N,N-diethylformamide, N,N-dimethylformamide, N,N-diisopropylformamide) is treated with aralkyl halide in presence of a weak base. The compounds were characterized by 1H-NMR and 13C-NMR spectroscopy and mass spectrometry. Structures of the crystalline compounds were determined by X-ray single crystal diffraction, and in addition the powder diffraction method was used to study the structural similarities between the single crysta…

Luovuuden edistäminen liikuntakasvatuksessa

2004

Experimental and Theoretical Investigations of Tellurium(IV) Diimides and Imidotelluroxanes: X-ray Structures of B(C6F5)3 Adducts of OTe(μ-NtBu)2TeNt…

2005

The hydrolysis of tBuNTe(μ-NtBu)2TeNtBu (1) with 1 or 2 equiv of (C6F5)3B·H2O results in the successive replacement of terminal imido groups by oxo ligands to give the telluroxane-Lewis acid adducts (C6F5)3B·OTe(μ-NtBu)2TeNtBu (2) and [(C6F5)3B·OTe(μ-NtBu)2Te(μ-O)]2 (3), which were characterized by multinuclear NMR spectroscopy and X-ray crystallography. The TeO distance in 2 is 1.870(2) Å. The di-adduct 3 involves the association of four tBuNTeO monomers to give a tetramer in which both terminal TeO groups [d(TeO) = 1.866(3) Å] are coordinated to B(C6F5)3. The central Te2O2 ring in 3 is distinctly unsymmetrical [d(TeO) = 1.912(3) and 2.088(2) Å]. The X-ray structure of (C6F5)3B·NH2tBu (4),…

Synthesis, characterization and thermal properties of nine quaternary dialkyldiaralkylammonium chlorides

2006

Abstract Nine R 2 R 2 ′ N + Cl − (R=benzyl, 2-methylbenzyl, 3-methylbenzyl, 4-methylbenzyl, 2-phenylethyl or 3-phenylpropyl; R′=ethyl or methyl) quaternary dialkyldiaralkylammonium chlorides were synthesized by treating dimethylformamide or diethylformamide with non-substituted or substituted arylalkyl (aralkyl) halide in the presence of sodium carbonate. The 1H NMR, 13C NMR spectroscopy, mass spectroscopy and elemental analysis were used to characterize the synthesized products. The crystal structures of six compounds were determined by X-ray single crystal diffraction. Four of the compounds crystallized in monoclinic space groups C2/c and P21/c (or P21/n), one in triclinic space group P−1…

77Se NMR Spectroscopic, DFT MO, and VBT Investigations of the Reversible Dissociation of Solid (Se6I2)[AsF6]2•2SO2 in Liquid SO2 to Solutions Contain…

2009

The composition of a complex equilibrium mixture formed upon dissolution of (Se6I2)[AsF6]2·2SO2 in SO2(l) was studied by 77Se NMR spectroscopy at −70 °C with both natural-abundance and enriched 77Se-isotope samples (enrichment 92%). Both the natural-abundance and enriched NMR spectra showed the presence of previously known cations 1,4-Se6I22+, SeI3+, 1,1,4,4-Se4I42+, Se102+, Se82+, and Se42+. The structure and bonding in 1,4-Se6I22+ and 1,1,4,4-Se4I42+ were explored using DFT calculations. It was shown that the observed Se−Se bond alternation and presence of thermodynamically stable 4pπ−4pπ Se−Se and 4pπ−5pπ Se−I bonds arise from positive charge delocalization from the formally positively c…

Halogenation of tellurium by SO2Cl2. Formation and crystal structures of (H3O)[Te3Cl13]·1/2SO2, [(C4H8O)2H][TeCl5]·(C4H8O), [(Me2SO)2H]2[TeCl6], and …

2002

Abstract The halogenation of elemental tellurium with SO2Cl2 in various solvents has been investigated. (H3O)[Te3Cl13]·1/2SO2 (1) and [(C4H8O)2H][TeCl5]·(C4H8O) (2) were obtained in CS2 and THF, respectively. When DMSO is added into the THF solution of tellurium and SO2Cl2, [(Me2SO)2H]2[TeCl6] (3) is formed. In the acetonitrile solution tellurium and SO2Cl2 form [Ni(NCCH3)6][Te2Cl10] (4) in the presence of metallic nickel. All compounds 1–4 were characterized by 125Te NMR and by X-ray crystallography. The formation of the anions has been discussed.

The crystal structure of neodymium and europium chromate heptahydrate: Synthesis, infrared spectra, and thermal behavior of lanthanoid chromate hepta…

1991

Abstract The crystal structures of Nd2(CrO4)3 · 7H2O and Eu2(CrO4)3 · 7H2O were determined by the conventional single-crystal X-ray diffraction technique. In addition, unit cell dimensions were measured for La2 (CrO4)3 · 7H2O and Sm2(CrO4)3 · 7H2O. All these compounds are isostructural. Crystals are monoclinic, space group P2 1 c . For Nd2(CrO4)3 · 7H2O, a = 8.052(4) A, b = 19.143(4) A, c = 13.326(6) A, β = 128.15(4)°, Z = 4, Dx = 3.14 Mg · m−3, T = 296(1); and for Eu2(CrO4)3 · 7H2O, a = 7.965(3) A, b = 18.985(4) A, c = 13.185(4) A, β = 128.00(2)°, Z = 4, Dx = 3.29 Mg · m−3, T = 296(1). Ln atoms are nine-coordinated so that the coordination polyhedron is a tricapped trigonal prism for Ln1 a…

X-ray Powder Structure Determination and Thermal Behavior of a New Modification of Pb(II) Selenite

2002

The crystal structure of a new polymorphic form of lead(II) selenite (PbSeO3) was solved directly from conventional X-ray powder diffraction data. Direct methods and Rietveld refinement techniques were used for the structure determination. The compound crystallizes in the monoclinic space group P21/c (no. 14) with cell dimensions a = 9.1587(1) A, b = 8.0902(1) A, c = 8.7932(1) A, β = 103.032(1)°, and V = 634.76(2) A3. The final refinement gave background excluded Rp = 6.22%, Rwp = 8.81%, and RB = 2.16% by using 45 structural and 15 profile parameters with 10 atoms in an asymmetric unit. The three-dimensional structure consists of 9-coordinated lead atoms, which are linked by three bidentate…

The thermal decomposition, IR spectrum and crystal structure of ammonium manganese(II) tris(hydrogenselenite), NH4Mn(HSeO3)3

1985

Abstract The compound NH 4 Mn(HSeO 3 ) 3 has been prepared and its IR spectrum and thermal behaviour have been investigated. It crystallizes in the monoc

ChemInform Abstract: tris-Pentasulfidorhodates(III). X-Ray Structure of (NH4)3(Rh(S5)3)(H2O)2.

1987

Abstract The crystal structure of the racemic dihydrated ammonium salt of the tris -pentasulfidorhodate(III) anion is compared with those of salts of the tris -pentasulfidoplatinate(IV) ion.

Crystal Structures and Thermal Behavior of Isostructural Bis(dibenzyldimethylammonium) Tetrachlorometallate [M = Mn(II), Co(II), Ni(II) and Zn(II)] S…

2007

Five isostructural bis(dibenzyldimethylammonium) tetrachlorometallate solvate complexes [M = Mn(II), Co(II), Ni(II) or Zn(II)] were crystallized from acetonitrile and/or methanol solutions. The crystal structures are compared to those of the analogous, isostructural copper compounds (X = Cl or Br) reported earlier. The complexes crystallize in the monoclinic space group P21/n with Z = 4, and unit cell dimensions of a ≈ 14.1, b ≈ 16.1, c ≈ 15.7 °A and β ≈ 108 - 109°. The asymmetric unit of these compounds contains one MCl4 2− anion, two Bz2Me2N+ cations in theW-conformation and one half of a disordered solvent molecule (acetonitrile or methanol). The geometry of the MCl4 2− anion is close to…

Calcium dicaesium silver thiocyanate dihydrate.

2001

The title compound, CaCs2[Ag2(SCN)6]·2H2O, forms a continuous structure where the Ag atoms form chains with S atoms in the c-axis direction. The chains are bonded together through Cs and Ca atoms. The crystal water of the structure is bonded to the Ca atoms, which lie on centers of symmetry.

Powder X-ray diffraction data for potassium silver thiocyanate, AgK(SCN)2 and dipotassium silver thiocyanate, AgK2(SCN)3

2002

Previously unpublished powder X-ray diffraction data for potassium silver thiocyanate, AgK(SCN)2 and dipotassium silver thiocyanate, AgK2(SCN)3 are presented. F30 values for AgK(SCN)2 and AgK2(SCN)3 are 80(0.0075, 50) and 53(0.0089, 63), respectively. The Rietveld refinement of the patterns is also performed. For AgK(SCN)2Rp=6.98, Rwp=11.84, and RBragg=2.9. For AgK2(SCN)3Rp=7.22, Rwp=10.79, and RBragg=5.0.

Crystal structure of lactitol (4-O-beta-D-galactopyranosyl-D-glucitol) dihydrate.

1992

Abstract Lactitol dihydrate, C 12 H 24 O 11 ·2H 2 O, is tetragonal, space group P 4 3 2 1 2 with cell dimensions a and b = 8.762(1), c = 45.500(3) A, and V = 3493.2(3) A 3 ; Z = 8, D x = 1.45 Mg.m −3 , λ(Cu- K α ) = 1.54056 A, μ = 1.108 mm −1 , F (000) = 1632, and T = 23°. The structure was solved by direct methods and refined by least-squares calculations to R = 0.054 for 2037 unique observed reflections. There are three intra- and twelve inter-molecular hydrogen bonds in the structure. Bond lengths and angles accord quite well with the mean values of related structures. The galactopyranosyl ring has a chair of conformation.

Tris-pentasulfidorhodates(III). X-ray structure of (NH4)3[Rh(S5)3](H2O)2

1987

Abstract The crystal structure of the racemic dihydrated ammonium salt of the tris -pentasulfidorhodate(III) anion is compared with those of salts of the tris -pentasulfidoplatinate(IV) ion.

Sulphides of the platinum group elements—12. Bis(tetraphenylphosphonium) pentakaidekakissulphido platinates(IV)

1991

Abstract Synthetic routes to tetraphenylphosphonium salts of [PtSx]2− are outlined, where x = 15 or 18. Generally, (PPh4)2[Pt(S5)3] is formed most readily. The compound [(C6H5)4P]2[PtS15], always solvated, has been obtained by synthesis in acetonitrile (sulphur, triethylamine, H2S and [PPh4]2[PtCl6]) and by metathesis (in DMF) from the known hydrated ammonium compound (NH4)2[Pt(S5)3]2H2O+2[Ph4P]Br→(Ph4P)2[Pt(S5)3]· DMF+2NH4Br, and from the dismutation (in acetone) 3PtS172−→PtS152−+2PtS182−. X-ray diffraction shows that crystals obtained from DMF and acetone are the solvated salts [Ph4P]2· [Pt(S5)3]· S, with solvent molecules (S) uncoordinated. In both, the three platinopentathian rings rela…

Crystal structures and thermal behavior of bis[dibenzyldimethylammonium]CuBr4, bis[dibenzyldimethylammonium]CuCl4 and bis[dimethyldi(2-phenylethyl)am…

2006

Abstract Bis[dibenzyldimethylammonium]CuBr4, bis[dibenzyldimethylammonium]CuCl4 and bis[dimethyldi(2-phenylethyl)ammonium]CuBr4 were crystallized from acetonitrile and/or dilute HX solutions. Five different kinds of single crystals were obtained. In the case of bis[dibenzyldimethylammonium]CuX4 (X=Br or Cl), the acetonitrile molecules cocrystallized into the crystal structure when acetonitrile solution was used. As a result, the isomorphic structures of Bis[dibenzyldimethylammonium]CuX4·0.5 CH3CN (X=Br or Cl) in monoclinic space group P21/n were obtained. When a dilute HX solution was used, the bis[dibenzyldimethylammonium]CuX4 (X=Br or Cl) crystallized without solvent molecules. The formed…

Stability of Rare-Earth Oxychloride Phases: Bond Valence Study

2002

Abstract The crystal structures of the tetragonal rare earth ( RE ) oxychlorides, RE OCl ( RE =La–Nd, Sm–Ho, and Y) were studied by X-ray powder diffraction measurements, Rietveld analyses, and bond valence calculations. The tetragonal structure (space group P 4/ nmm , No. 129, Z =2) is stable for all but Er–Lu oxychlorides, which possess a hexagonal structure. The tetragonal structure consists of alternating layers of ( RE O) n n + complex cations and X n − anions, where the rare earth is coordinated to four oxygens and four plus one chlorines in a monocapped tetragonal antiprism arrangement. The Rietveld analyses yielded a coherent series of structural parameters. Preferred orientation an…

ChemInform Abstract: Preparation and Structural Characterization of (Me3SiNSN)2Se, a New Synthon for Sulfur-Selenium Nitrides.

2010

The reaction of (Me(3)SiN)(2)S with SeCl(2) (2:1 ratio) in CH(2)Cl(2) at -70 degrees C provides a route to the novel mixed selenium-sulfur-nitrogen compound (Me(3)SiNSN)(2)Se (1). Crystals of 1 are monoclinic and belong the space group P2(1)/c, with a = 7.236(1) A, b = 19.260(4) A, c = 11.436(2) A, beta = 92.05(3) degrees, V = 1592.7(5) A(3), Z = 4, and T = -155(2) degrees C. The NSNSeNSN chain in 1 consists of Se-N single bonds (1.844(3) A) and S=N double bonds (1.521(3)-1.548(3) A) with syn and anti geometry at the N=S=N units. The N-Se-N bond angle is 91.8(1) degrees. The EI mass spectrum shows a molecular ion with good agreement between the observed and calculated isotopic distributions…