X-ray and NQR studies of bromoindate(III) complexes: [C2H5NH3]4InBr7, [C(NH2)3]3InBr6, and [H3NCH2C(CH3)2CH2NH3]InBr5

2017 ◽  
Vol 72 (2) ◽  
pp. 141-151 ◽  
Author(s):  
Takeharu Iwakiri ◽  
Hiromitsu Terao ◽  
Enno Lork ◽  
Thorsten M. Gesing ◽  
Hideta Ishihara
Keyword(s):  
Thermal Analysis ◽  
Hydrogen Bond ◽  
Differential Thermal Analysis ◽  
Crystal Structures ◽  
The Other ◽  
Positive Temperature ◽  
X Ray ◽  
Hydrogen Bond Networks ◽  
Quadrupole Resonance ◽  
Nuclear Quadrupole

AbstractThe crystal structures of [C2H5NH3]4InBr7(1), [C(NH2)3]3InBr6(2), and [H3NCH2C(CH3)2CH2NH3]InBr5(3) were determined at 100(2) K: monoclinic, P21/n, a=1061.94(3), b=1186.40(4), c=2007.88(7) pm, β= 104.575(1)°, Z=4 for 1; monoclinic, C2/c, a=3128.81(12), b=878.42(3), c=2816.50(10) pm, β=92.1320(10)°, Z=16 for 2; orthorhombic, P212121, a=1250.33(5), b=1391.46(6), c=2503.22(9) pm, Z=4 for 3. The structure of 1 contains an isolated octahedral [InBr6]3− ion and a Br− ion. The structure of 2 contains three different isolated octahedral [InBr6]3− ions. The structure of 3 has a corner-shared double-octahedral [In2Br11]5− ion and an isolated tetrahedral [InBr4]− ion. The 81Br nuclear quadrupole resonance (NQR) lines of the terminal Br atoms of the compounds are widely spread in frequency, and some of them show unusual positive temperature dependence. These observations manifest the N−H···Br−In hydrogen bond networks developed between the cations and anions to stabilize the crystal structures. The 81Br NQR and differential thermal analysis (DTA) measurements have revealed the occurrence of unique phase transitions in 1 and 3. When the bond angles were estimated from the electric field gradient (EFG) directions calculated by the molecular orbital (MO) methods, accurate values were obtained for [InBr6]3− of 1 and for [In2Br11]5− and [InBr4]− of 3, except for several exceptions in those for the latter two ions. On the other hand, the calculations of 81Br NQR frequencies have produced up to 1.4 times higher values than the observed ones.

Adamantane derivatives of sulfonamide molecular crystals: structure, sublimation thermodynamic characteristics, molecular packing, and hydrogen bond networks

CrystEngComm ◽  
2015 ◽  
Vol 17 (4) ◽  
pp. 753-763 ◽  
Author(s):  
German L. Perlovich ◽  
Alex M. Ryzhakov ◽  
Valery V. Tkachev ◽  
Alexey N. Proshin
Keyword(s):  
Hydrogen Bond ◽  
Crystal Structures ◽  
Molecular Crystals ◽  
Thermodynamic Characteristics ◽  
Molecular Packing ◽  
Adamantane Derivatives ◽  
X Ray Diffraction ◽  
X Ray ◽  
Hydrogen Bond Networks ◽  
Derivatives Of

The crystal structures of six adamantane derivatives of sulfonamides have been determined by X-ray diffraction and their sublimation and fusion processes have been studied.

scholarly journals Disordered sodium alkoxides from powder data: crystal structures of sodium ethoxide, propoxide, butoxide and pentoxide, and some of their solvates

2021 ◽  
Vol 77 (1) ◽  
pp. 68-82
Author(s):  
Maurice Beske ◽  
Stephanie Cronje ◽  
Martin U. Schmidt ◽  
Lukas Tapmeyer
Keyword(s):  
Hydrogen Bond ◽  
Crystal Structures ◽  
Sodium Ethoxide ◽  
Amyl Alcohol ◽  
X Ray Diffraction ◽  
Oh Groups ◽  
Space Group ◽  
X Ray ◽  
Alkyl Groups ◽  
Hydrogen Bond Networks

The crystal structures of sodium ethoxide (sodium ethanolate, NaOEt), sodium n-propoxide (sodium n-propanolate, NaO n Pr), sodium n-butoxide (sodium n-butanolate, NaO n Bu) and sodium n-pentoxide (sodium n-amylate, NaO n Am) were determined from powder X-ray diffraction data. NaOEt crystallizes in space group P 421 m, with Z = 2, and the other alkoxides crystallize in P4/nmm, with Z = 2. To resolve space-group ambiguities, a Bärnighausen tree was set up, and Rietveld refinements were performed with different models. In all structures, the Na and O atoms form a quadratic net, with the alkyl groups pointing outwards on both sides (anti-PbO type). The alkyl groups are disordered. The disorder becomes even more pronounced with increasing chain length. Recrystallization from the corresponding alcohols yielded four sodium alkoxide solvates: sodium ethoxide ethanol disolvate (NaOEt·2EtOH), sodium n-propoxide n-propanol disolvate (NaO n Pr·2 n PrOH), sodium isopropoxide isopropanol pentasolvate (NaO i Pr·5 i PrOH) and sodium tert-amylate tert-amyl alcohol monosolvate (NaO t Am· t AmOH, t Am = 2-methyl-2-butyl). Their crystal structures were determined by single-crystal X-ray diffraction. All these solvates form chain structures consisting of Na+, –O− and –OH groups, encased by alkyl groups. The hydrogen-bond networks diverge widely among the solvate structures. The hydrogen-bond topology of the i PrOH network in NaO i Pr·5 i PrOH shows branched hydrogen bonds and differs considerably from the networks in pure crystalline i PrOH.

Synthesis, Crystal Structures and Properties of the Polychalcogenides Manganese-tris(1,2-ethanediamine)-triselenide [Mn(en)3]Se3 and Manganese-tris(1,2-ethanediamine)-monotellurodiselenide [Mn(en)3 ]TeSe2

2000 ◽  
Vol 55 (9) ◽  
pp. 871-876 ◽  
Author(s):  
Frank Wendland ◽  
Christian Näther ◽  
Wolfgang Bensch
Keyword(s):  
Thermal Analysis ◽  
Weight Loss ◽  
Differential Thermal Analysis ◽  
Crystal Structures ◽  
Elemental Selenium ◽  
Orthorhombic Space Group ◽  
X Ray ◽  
Structures And Properties ◽  
Two Samples ◽  
Solvothermal Conditions

The reaction of manganese(II)-chloride-tetrahydrate, caesium triselenide and elemental selenium or tellurium in 1,2-ethanediamine (en) under solvothermal conditions leads to the formation of two new isostructural compounds [Mn(en)3]Se3 (1) and [Mn(en)3]TeSe2 (2). The compounds crystallize in the orthorhombic space group Pbcn with the lattice parameters a = 1149.39(9), b = 1506.83(11), c = 935.96(6) pm for 1 and a = 1184.1(2), b = 1495.3(2), c = 949.8(1) pm for 2. Their crystal structures are built up of [Mn(en)3]2+ cations and Se32- or TeSe22- anions, respectively. Each cation is surrounded by six next neighbouring anions, and vice versa. Between the cations and the anions hydrogen bonding is observed. The thermal behaviour was investigated using differential thermal analysis, thermogravimetry as well as X-ray powder diffraction. Completely different properties were found. Compound 1 decomposes in two distinct endothermic steps, while compound 2 shows only one endothermic peak. The weight loss for 1 corresponds roughly to the emission of all en molecules, whereas the weight loss for 2 is significantly lower. The final products are composed of MnSe2 and elemental Se or Te, respectively, and an unknown crystalline phase which is different for the two samples

Composés d'addition de SbF5 avec H2O et HF. Formation d'ions hydronium

1974 ◽  
Vol 52 (11) ◽  
pp. 2077-2084 ◽  
Author(s):  
B. Bonnet ◽  
J. Roziere ◽  
R. Fourcade ◽  
G. Mascherpa
Keyword(s):  
Thermal Analysis ◽  
Differential Thermal Analysis ◽  
Water Molecule ◽  
The Other ◽  
Thermal Treatments ◽  
Analysis Study ◽  
X Ray ◽  
Donor Acceptor ◽  
Thermal Analysis Study ◽  
Coordinated Water

A differential thermal analysis study of solutions of SbF5 in H2O and HF has enabled us to determine the thermal treatments required to obtain the stable crystalline phases: SbF5•2H2O, 4SbF5•5H2O, SbF5•H2O, 3SbF5•2H2O, and SbF5•HF•2H2O.The SbF5 adducts were characterized by X-ray powder diagrams.The vibrational spectra of SbF5•2H2O and SbF5•HF•2H2O are consistent with the ionic structures H3O+SbF5OH− and H5O2+SbF6−.The other hydrates are simple donor-acceptor complexes with the structure H2O → SbF5, in which one water molecule is coordinated to the SbF5 and the others are bound by hydrogen bonds to the coordinated water molecule.

PENINGKATAN LAJU DISOLUSI ACYCLOVIR DENGAN METODE SISTEM DISPERSI PADAT MENGGUNAKAN POLOXAMER 188

2016 ◽  
Vol 5 (1) ◽  
pp. 6
Author(s):  
Budi Setiawan ◽  
Erizal Zaini ◽  
Salman Umar
Keyword(s):  
Electron Microscopy ◽  
Thermal Analysis ◽  
Scanning Electron Microscopy ◽  
Fourier Transform ◽  
Differential Thermal Analysis ◽  
Fourier Transform Infrared ◽  
X Ray Diffraction ◽  
Poloxamer 188 ◽  
X Ray ◽  
Scanning Electron

Sebuah penelitian tentang sistem dispersi padat dari asiklovir dengan poloxamer 188 telah dilakukan formulasi dengan pencampuran secara fisika dengan rasio 1 : 1, 1 : 3, 1 : 5 dan dispersi padat 1 : 1, 1 : 3, 1 : 5 dan penggilingan 1:1 sebagai pembanding. Dispersi padat dibuat menggunakan metode pencairan (fusi), yang digabung dengan poloxamer 188 pada hotplate kemudian asiklovir dimasukkan ke dalam hasil poloxamer 188 lalu di kocok hingga membentuk masa homogen. Semua formula yang terbentuk termasuk asiklovir poloxamer 188 murni dianalisis karakterisasinya dengan Differential Thermal Analysis (DTA), X-ray Diffraction, Scanning Electron Microscopy (SEM), dan Fourier Transform Infrared (FTIR), kemudian pengambilan dilakukan  (penentuan kadar) mengunakan spektrofotometer UV pada panjang gelombang 257,08 nm dan uji laju disolusi dengan aquadest bebas CO2 menggunakan metode dayung. Hasil pengambilan  (penentuan kadar) menunjukkan bahwa semua formula memenuhi persyaratan farmakope Amerika edisi 30 dan farmakope Indonesia edisi 4 yaitu 95-110%. Sedangkan hasil uji laju disolusi untuk campuran fisik 1: 1, dan dispersi padat 1: 1, dan penggilingan 1: 1 menunjukkan peningkatan yang nyata dibandingkan asiklovir murni. Hal ini juga dapat dilihat dari hasil perhitungan statistik  menggunakan analisis varian satu arah  SPSS 17.

scholarly journals The Potential for Natural Stones from Northeastern Brazil to Be Used in Civil Construction

Minerals ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 440
Author(s):  
Fabiana Pereira da Costa ◽  
Jucielle Veras Fernandes ◽  
Luiz Ronaldo Lisboa de Melo ◽  
Alisson Mendes Rodrigues ◽  
Romualdo Rodrigues Menezes ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Thermal Analysis ◽  
Differential Thermal Analysis ◽  
Chemical Resistance ◽  
Mechanical Analysis ◽  
Northeastern Brazil ◽  
X Ray Diffraction ◽  
X Ray ◽  
Chemical Agents ◽  
Natural Stones

Natural stones (limestones, granites, and marble) from mines located in northeastern Brazil were investigated to discover their potential for use in civil construction. The natural stones were characterized by chemical analysis, X-ray diffraction, differential thermal analysis, and optical microscopy. The physical-mechanical properties (apparent density, porosity, water absorption, compressive and flexural strength, impact, and abrasion) and chemical resistance properties were also evaluated. The results of the physical-mechanical analysis indicated that the natural stones investigated have the potential to be used in different environments (interior, exterior), taking into account factors such as people’s circulation and exposure to chemical agents.

scholarly journals X-Ray Investigations of the Low-Temperature Phases of the Organic Metals α- and β-(BEDT-TTF)2I3

1986 ◽  
Vol 41 (11) ◽  
pp. 1319-1324 ◽  
Author(s):  
H. Endres ◽  
H. J. Keller ◽  
R. Swietlik ◽  
D. Schweitzer ◽  
K. Angermund ◽  
...  
Keyword(s):  
Thermal Analysis ◽  
Differential Thermal Analysis ◽  
Room Temperature ◽  
Unit Cell Volume ◽  
Unit Cell ◽  
Slight Variation ◽  
X Ray ◽  
Organic Metals ◽  
Β Phase ◽  
Α Phase

The structure of single crystals of the organic metals α- and β-(BEDT-TTF)2I3* was determined at 100 K, well below the phase transitions indicated by resistivity and thermopower measurements as well as by differential thermal analysis. In the α-phase no unusual change of the room temperature unit cell but a slight variation in the triiodide network and especially a more pronounced dimerization in one of the two donor stacks have been found. The β-phase develops a superstructure with a unit cell volume three times as large as that at room temperature and with pronounced distortions of the I3--ions.

The Roman Ceramics of Salobrena (Granada-Spain) and their Raw Materials

1992 ◽  
Vol 267 ◽  
Author(s):  
Ana M De Andres ◽  
Isabel MuÑOZ
Keyword(s):  
Thermal Analysis ◽  
Differential Thermal Analysis ◽  
Raw Materials ◽  
Third Century ◽  
Western Coast ◽  
X Ray Diffraction ◽  
X Ray ◽  
The Third ◽  
Good Number ◽  
Scanning Electron

ABSTRACTNineteen roman ceramic sherds found near Salobreña (Granada, Spain), in the western coast of the Mediterranean Sea, as well as different ceramic clays from the surroundingsare studied. Both clays and ceramic sherds are characterizad by X-ray diffraction and spectrometry, differential thermal analysis, and scanning electron and optical microscopies. A good number of the ceramic pieces, among which some “Terrae Sigillatae”, have a composition similar to that of the local clays and, thus, have been probably manufactured at Salobreña. Only a few of them have a foreign origin. For most of them, the firing temperature was about 800-850 °C, although some have been produced at 900-1000 °C, and some others at 1000-1100 °C. It is concluded that Salobreña appearsto have been an important settlement just in the third century of the Christian era.

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