Halogen NQR and Crystal Structure of Ammonium Halides (R-NH3)+X- and (X–) (+H3NR´­NH3+) (X–). R = (HOCH2)3C, R´ = CH2C(CH3)2CH2; X = I,Br

1994 ◽  
Vol 49 (1-2) ◽  
pp. 174-184
Author(s):  
Shi-qi Dou ◽  
Hartmut Fuess ◽  
Helmut Paulus ◽  
Alarich Weiss
Keyword(s):  
Crystal Structure ◽  
Hydrogen Bonds ◽  
Crystal Structures ◽  
Unit Cell ◽  
Space Group ◽  
Temperature Range ◽  
Ammonium Halides

AbstractThe 127I-NQR of(HOCH2)3CNH3+ I- was determined in the range 77 ≤ T/K ≤ 310. At T = 310 K the NQR signal fades out (Tm = 463 K). The 127I spectrum ( T =77 K.): v1 =29.195 MHz, v2 = 14.597 MHz, η(121l)=0, e QΦzz h-1 (127I) = 97.315 MHz, is in agreement with the crystal structure. The 127I NQR spectrum of 1,3-diammonium-2,2-dimethylpropane diiodide, (H3NCH2C(CH3)2CH2NH3)2+ ·2I- , is a quartet within the whole temperature range investigated, and the lines correspond to two crystallographically independent iodines: Space group P21/c, Z = 4, a = 731.2(3) pm, b = 689.0(3) pm, c = 2255.1(8) pm, β = 104.90(1)°. At 7 = 7 7 K the 127I NQR quartet is (MHz): v1 = 34.145, v2 = 32.805, v3 = 22.113, v4 = 16.787; at 295 K (same order, MHz): 30.559, 29.729, 19.810, 15.651. There are two combinations of the NQR frequencies. Considering the coordination of I-, the hydrogen bonds N -H ··· I, eQΦzzQ h-1 and η, we choose for I(1) v1 and v3, for I(2) v2 and v4. At 77 K eQΦzzQ h-1 (I(1))= 118.86 MHz,η (127I(1)) = 0.498, eQΦzzQ h-1 (I(2)) = 109.75 MHz, η(127I(2)) = 0.135 follow for the two iodine atoms. Both, eQΦzzQ h-1 (I(1)) and e eΦzzQ h-1(I(2)) decrease smoothly with increasing T: η I(2)) increases with increasing T whereas η(127I(1)) is almost constant within 77 ≤ T /K ≤ 4 0 6 . The 79,81Br NQR spectrum of l,3-diamino-2,2-dimethylpropane dihydrobromide is also a quartet, showing two crystallographic inequivalent Br atoms in the unit cell. The frequencies are (T =273 K, MHz): v1 (79Br)= 14.303, v2 (79Br)= 12.884, (81Br)= 11.951, v2(81Br) = 10.781; space group C2/c, Z = 8 , a = 2136.4(6) pm, b = 854.6(3) pm, c = 1125.8(3) pm, β = 93.23(1)°. Crystal structures and NQR results are discussed.

79Br, 127I NQR of Diammoniumalkyl Halides and Piperazinium Halides. Crystal Structure of Piperazinium Dibromide Monohydrate and Piperazinium Monoiodide

1989 ◽  
Vol 44 (1) ◽  
pp. 41-55 ◽  
Author(s):  
Jutta Hartmann ◽  
Shi-Qi Dou ◽  
Alarich Weiss
Keyword(s):  
Crystal Structure ◽  
Phase Transitions ◽  
Hydrogen Bonds ◽  
Crystal Structures ◽  
Monoclinic Space Group ◽  
Orthorhombic Space Group ◽  
Space Group ◽  
Temperature Range

Abstract The 79Br and 127I NQR spectra were investigated for 1,2-diammoniumethane dibromide, -diiodide, 1,3-diammoniumpropane dibromide, -diiodide, piperazinium dibromide monohydrate, and piperazinium monoiodide in the temperature range 77 ≦ T/K ≦ 420. Phase transitions could be observed for the three iodides. The temperatures for the phase transitions are: 400 K and 404 K for 1,2-diammoniumethane diiodide, 366 K for 1,3-diammoniumpropane diiodide, and 196 K for piperazinium monoiodide.The crystal structures were determined for the piperazinium compounds. Piperazinium dibromide monohydrate crystallizes monoclinic, space group C2/c, with a= 1148.7 pm, 0 = 590.5 pm, c= 1501.6pm, β = 118.18°, and Z = 4. For piperazinium monoiodide the orthorhombic space group Pmn 21 was found with a = 958.1 pm, b = 776.9 pm, c = 989.3 pm, Z = 4. Hydrogen bonds N - H ... X with X = Br, I were compared with literature data.

Addukte Aromat/Chlorwasserstoff bei tiefen Temperaturen: Beiträge zu Bildung und Kristallstruktur [1] / Adducts Arene/Hydrogen Chloride at Low Temperatures: Contributions to Formation and Crystal Structure [1]

1993 ◽  
Vol 48 (5) ◽  
pp. 571-576 ◽  
Author(s):  
Axel Deeg ◽  
Dietrich Mootz
Keyword(s):  
Crystal Structure ◽  
Hydrogen Bonds ◽  
Crystal Structures ◽  
Hydrogen Chloride ◽  
Low Temperatures ◽  
Unit Cell ◽  
Aromatic System ◽  
Space Group ◽  
Weak Hydrogen Bonds

The melting diagrams of the systems benzene-HCl, toluene-HCl and mesitylene-HCl have been established and the crystal structures of two adducts determined. The adduct toluene · 2 HCl, melting incongruently at -115°C, is monoclinic with space group C2/c and Ζ = 4 formula units per unit cell; the adduct mesitylene · HCl, m. p. -64°C, is orthorhombic with space group Pbca and Ζ = 8. The HCl molecules are situated on both sides and one side, respectively, of the plane of the aromatic system and are linked to it by weak hydrogen bonds of the type Cl-H···π.

NQR and Crystal Structure of 4,5-Dichloroimidazole, C3H2N2Cl2

1992 ◽  
Vol 47 (1-2) ◽  
pp. 177-181 ◽  
Author(s):  
Shi-Qi Dou ◽  
Alarich Weiss
Keyword(s):  
Crystal Structure ◽  
Phase Transition ◽  
Temperature Dependence ◽  
Room Temperature ◽  
Unit Cell ◽  
Space Group ◽  
Temperature Range ◽  
Temperature Coefficients ◽  
Group D

AbstractThe two line 35Cl NQR spectrum of 4,5-dichloroimidazole was measured in the temperature range 77≦ T/K ≦ 389. The temperature dependence of the NQR frequencies conforms with the Bayer model and no phase transition is indicated in the curves v ( 35Cl)= f(T). Also the temperature coefficients of the 35Cl NQR frequencies are "normal". At 77 K the 35Cl NQR frequencies are 37.409 MHz and 36.172 MHz and at 389 K 35.758 MHz and 34.565 MHz. The compound crystallizes at room temperature with the tetragonal space group D44-P41212, Z = 8 molecules per unit cell; at 295 K : a = 684.2(5) pm, c = 2414.0(20) pm. The relations between the crystal structure and the NQR spectrum are discussed.

Synthese und Kristallstrukturen von N-[ω-(Dimethylammonio)alkyl]- N´,N´,N´´,N´´-tetramethylguanidinium-chlorid-tetraphenylboraten / Synthesis and Crystal Structures of N-[ω-(Dimethylammonio)alkyl]-N´,N´,N´´,N´´- tetramethylguanidinium Chloride Tetraphenylborates

2010 ◽  
Vol 65 (7) ◽  
pp. 907-916 ◽  
Author(s):  
Ioannis Tiritiris ◽  
Falk Lissner ◽  
Thomas Schleid ◽  
Willi Kantlehner
Keyword(s):  
Crystal Structure ◽  
Low Temperature ◽  
Hydrogen Bonds ◽  
Crystal Structures ◽  
Room Temperature ◽  
Chloride Ions ◽  
Monoclinic Space Group ◽  
Temperature Structure ◽  
Space Group ◽  
Temperature Modification

Dicationic N,N´,N´,N´´,N´´-pentasubstituted guanidinium dichlorides 4a, b are obtained from the chloroformamidinium salt 2 and diamines 3a, b. N-[2-(Dimethylammonio)ethyl]-N´,N´,N´´,N´´-tetramethylguanidinium chloride tetraphenylborate (5a) and N-[3-(dimethylammonio)propyl]-N´,N´,N´´,N´´-tetramethylguanidinium chloride tetraphenylborate (5b) were synthesized from 4a, b by anion metathesis with one equivalent of sodium tetraphenylborate. The thermal properties of the salts 5a, b were studied by means of DSC methods, and their crystal structures were determined by single-crystal X-ray diffraction analysis. For 5a a solid-solid phase transition is observed at −156 ◦C to a low-temperature structure. The room-temperature modification (α-5a) crystallizes in the centrosymmetric orthorhombic space group Pbca (a = 13.1844(4), b = 13.8007(4), c = 34.7537(11) A° ).The guanidinium ions are interconnected via chloride ions through bridging N-H· · ·Cl hydrogen bonds, providing isolated units. The tetraphenylborate ions show some dynamic disordering in the crystal structure. The low-temperature modification (β -5a) also crystallizes orthorhombically, but in the non-centrosymmetric space group Pna21 (a = 13.1099(4), b = 69.1810(11), c = 13.5847(5) A° ) and consists of four crystallographically independent cations and anions in the unit cell. Compared with the room-temperature structure, a similar N-H· · ·Cl hydrogen bond pattern is observed in the β -phase, but the tetraphenylborate ions are now completely ordered. 5b crystallizes in the monoclinic space group P21/c (a = 10.8010(3), b = 14.1502(5), c = 20.9867(9) A° , β = 94.322(1)◦). In the crystal structure the guanidinium ions are linked via chloride ions through N-H· · ·Cl hydrogen bonds, but in contrast to 5a two infinite strands are formed along the a axis with the tetraphenylborate ions interspersed between them for charge compensation.

Synthesis and Crystal Structure of M([12]crown-4)2O3 · 1.5 NH3 with M = K, Rb

2009 ◽  
Vol 64 (11-12) ◽  
pp. 1325-1328 ◽  
Author(s):  
Hanne Nuss ◽  
Martin Jansen
Keyword(s):  
Crystal Structure ◽  
Hydrogen Bonds ◽  
Alkali Metal ◽  
Liquid Ammonia ◽  
Unit Cell ◽  
Temperature Sensitive ◽  
Synthesis And Crystal Structure ◽  
Space Group ◽  
M 12 ◽  
K 12

The two new ozonide compounds K([12]crown-4)2O3 ・ 1.5 NH3 (1) and Rb([12]crown-4)2O3 ・ 1.5 NH3 (2) were synthesized from the binary alkali metal ozonides and [12]crown-4 in liquid ammonia. The air- and temperature-sensitive red, needle-shaped compounds crystallize isostructurally in the non-centrosymmetric space group Fdd2 (no. 43) with 16 formula units per unit cell. The lattice parameters are a = 26.917(8), b = 43.25(1), c = 7.823(2) Å, V = 9108(5) Å3; and a = 26.730(6), b = 44.70(1), c = 7.739(2) Å, V = 9245(4) Å3 for 1 and 2, respectively. The structure comprises rod-like [([M([12]crown-4)2(NH3)]O3)2(NH3)] supramolecular units, forming a fishbone pattern parallel to (001). The ozonide anions are separated from the metal cations and interact only weakly with two ammonia molecules via N-H・ ・ ・O hydrogen bonds

scholarly journals Crystal structures of two (±)-exo-N-isobornylacetamides

2015 ◽  
Vol 71 (10) ◽  
pp. 1117-1120 ◽  
Author(s):  
Dmitrijs Stepanovs ◽  
Daniels Posevins ◽  
Maris Turks
Keyword(s):  
Crystal Structure ◽  
Hydrogen Bonds ◽  
Crystal Structures ◽  
Asymmetric Unit ◽  
Double Chain ◽  
Space Group ◽  
Axis Direction ◽  
Independent Molecules

The title compounds consist of a bornane skeleton with attached acetamide, C12H21NO (±)-(1) {systematic name: (±)-N-[(1RS,2RS,4RS)-1,7,7-trimethylbicyclo[2.2.1]heptan-2-yl]acetamide}, and chloroacetamide, C12H20ClNO (±)-(2) {systematic name: (±)-2-chloro-N-[(1RS,2RS,4RS)-1,7,7-trimethylbicyclo[2.2.1]heptan-2-yl]acetamide}, functionalities to the 2-exo-position. The crystal structure of the first monoclinic polymorph of (±)-(1) has been reported previously [Unget al.(2014).Monatsh. Chem.145, 983–992]. Compound (±)-(1) crystallizes in the space groupP21/nwith two independent molecules in the asymmetric unit, in contrast to the above-mentioned polymorph which crystallized in the space groupC2/cwith one molecule in the asymmetric unit. In the title compounds, the bicyclic bornane moieties have normal geometries. In the crystals of both compounds, molecules are linked by N—H...O hydrogen bonds, reinforced by C—H...O contacts, formingtrans-amide chains propagating along thea-axis direction. In the case of compound (±)-(1), neighbouring chains are linked by further C—H...O contacts, forming double-chain ribbons along [100].

Molecular and Crystal Structure of Sildenafil Base

2012 ◽  
Vol 67 (5) ◽  
pp. 491-494 ◽  
Author(s):  
Dmitrijs Stepanovs ◽  
Anatoly Mishnev
Keyword(s):  
Crystal Structure ◽  
Erectile Dysfunction ◽  
Crystal Structures ◽  
Unit Cell ◽  
Sildenafil Citrate ◽  
Unit Cell Parameters ◽  
Monoclinic System ◽  
Space Group ◽  
X Ray ◽  
Cell Parameters

Sildenafil citrate monohydrate, well known as Viagra®, is a drug for the treatment of erectile dysfunction. Here we present the X-ray crystal structure of the sildenafil base, C22H30N6O4S. The compound crystallizes in the monoclinic system, space group P21/c with the unit cell parameters a = 17:273(1), b=17:0710(8), c=8:3171(4) Å , b =99:326(2), Z = 4, V = 2420:0(3) Å3. A comparison with the known crystal structures of sildenafil citrate monohydrate and sildenafil saccharinate is also presented.

scholarly journals Crystal structure of 1-methylimidazole 3-oxide monohydrate

2017 ◽  
Vol 73 (3) ◽  
pp. 372-374
Author(s):  
Christopher S. Frampton ◽  
James I. Murray ◽  
Alan C. Spivey
Keyword(s):  
Crystal Structure ◽  
Hydrogen Bonds ◽  
Unit Cell ◽  
Planar Geometry ◽  
Monoclinic Space Group ◽  
Space Group ◽  
Axis Direction

1-Methylimidazole 3-N-oxide (NMI-O) crystallizes as a monohydrate, C4H6N2O·H2O, in the monoclinic space groupP21withZ′ = 2 (moleculesAandB). The imidazole rings display a planar geometry (r.m.s. deviations = 0.0008 and 0.0002 Å) and are linked in the crystal structure into infinite zigzag strands of ...NMI-O(A)...OH2...NMI-O(B)...OH2... units by O—H...O hydrogen bonds. These chains propagate along theb-axis direction of the unit cell.

Oxotetrafluoro-vanadate(V): Die Kristallstruktur von [enH2] [VOF4(H2O)]2.

1976 ◽  
Vol 31 (5) ◽  
pp. 541-543 ◽  
Author(s):  
Helmut Rieskamp ◽  
Rainer Mattes
Keyword(s):  
Crystal Structure ◽  
Hydrogen Bonds ◽  
Least Squares ◽  
Unit Cell ◽  
Monoclinic Space Group ◽  
Trans Position ◽  
Space Group ◽  
X Ray ◽  
In Trans ◽  
Oxygen Atoms

The crystal structure of [enH2][VOF4(H2O)]2 has been determined from X-ray diffractometer data. Crystals are monoclinic, space group C2/c with Z = 4 in a unit cell of dimensions a = 16.576(13), b = 7.781(4), c = 10.338(8) Å, β = 120.0(1)°.The structure was refined by least-squares methods to R 0.053 for 1436 reflections. The structure contains monomeric [VOF4(H2O)]⁻-ions with the oxygen atoms in trans position. The bond distances are 1.577 Å (terminal oxygen) and 2.333 Å (H2O molecule), resp. The V–F distances vary between 1.769(2) and 1.858(2) Å for fluorine atoms involved in strong hydrogen bonds.

scholarly journals Crystal structure of anagyrine perchlorate

2015 ◽  
Vol 71 (5) ◽  
pp. o343-o344 ◽  
Author(s):  
Kambarali K. Turgunov ◽  
Shukhrat B. Rakhimov ◽  
Valentina I. Vinogradova ◽  
Bakhodir Tashkhodjaev
Keyword(s):  
Crystal Structure ◽  
Hydrogen Bonds ◽  
Unit Cell ◽  
Stacking Interactions ◽  
Space Group ◽  
Aerial Parts ◽  
Π Stacking ◽  
Ring Junction ◽  
Methylene Group ◽  
Molecular Salt

The title molecular salt, C15H21N2O+·ClO4−, crystallizes with four cations (A,B,CandD) and four anions in the chiral unit cell (space groupP21). The alkaloid was isolated from the aerial parts ofGenista Hispanicacollected in the Samarkand region of Uzbekistan. Each cation is protonated at the N atom that bridges the alkaloid ringsCandD. In each cation, ringAis almost planar and ringBadops a sofa conformation with the methylene group bridging to theCring as the flap. RingsCandDadopt chair conformations with acisring junction in all four cations. In the crystal,A+BandC+Ddimeric pairs linked by pairs of N—H...O hydrogen bonds are observed, which generateR22(16) loops in each case. The dimers are consolidated by weak aromatic π–π stacking interactions between theArings [centroid–centroid distances = 3.913 (3) and 3.915 (3) Å].

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