1,2-O-(Ethane-1,2-diyl)-α-D-glucofuranose. Crystal Structure, and the Stereochemistry of Related Bicyclic Acetal Analogues

1996 ◽  
Vol 49 (3) ◽  
pp. 299 ◽  
Author(s):  
AM Lebuis ◽  
DS Lee ◽  
AS Perlin
Keyword(s):  
Crystal Structure ◽  
Aqueous Solution ◽  
Hydrogen Bonding ◽  
Solid State ◽  
Intermolecular Hydrogen Bonding ◽  
Methyl Substituent ◽  
Spectroscopic Evidence

Crystalline 1,2-O-(ethane-1,2-diyl)-α-D- glucofuranose (9) is orthorhombic, P 21212, with a = 17.702(4), b = 8.892(2), c = 5.6400(9) Ǻ, Z = 4, R = 0.050, and Rw = 0.041. The conformation of the 1,4-dioxan ring in this bicyclic acetal is slightly distorted from 7C1, and that of the glucofuranose ring is intermediate between the 3E and 3T2 conformations. Extensive intermolecular hydrogen-bonding of exocyclic OH(5) and OH(6) dominates the solid state interactions. In aqueous solution, compound (9) retains close to the same stereochemical characteristics as in the crystal, including those of the exocyclic C(4)-C(5)-C(6) segment of the molecule, according to n.m.r. spectroscopic evidence. These findings provide support for the structures assigned to related bicyclic acetals (7) and (8), which differ from (9) in having a methyl substituent at C(8) on their 1,4-dioxan rings, notably in confirming that the configuration at C(8) is R in (7) and S in (8).

The Thermal Isomerization of Coordinated Thiocyanate in Crystalline trans-[Co(NH3)4(15NH3)SCN](N14CS)2

1993 ◽  
Vol 46 (4) ◽  
pp. 503 ◽  
Author(s):  
DA Buckingham ◽  
CR Clark ◽  
GF Liddell ◽  
J Simpson
Keyword(s):  
Crystal Structure ◽  
Aqueous Solution ◽  
Hydrogen Bonding ◽  
Solid State ◽  
Exchange Process ◽  
Thermal Isomerization ◽  
Asymmetric Unit ◽  
Open Structure ◽  
Solvent Cage ◽  
Intramolecular Exchange

Heating crystalline trans-[Co(NH3)4(15NH3)SCN](N14CS)2 in the dark at c. 60°C results in the following immediate products (partial formulae are shown): 39% trans-CoNCS2+ (without incorporation of ionic thiocyanate ), 31% cis-CoS14CN2+ and 30% cis-CoN14CS2+ (with incorporation of ionic thiocyanate ). A crystal structure of the unlabelled reactant [Co(NH3)5SCN](NCS)2 [a 14.001(5), b 14.176(5), c 14.774(5) Ǻ, β 117.12(3)°, P21/n, Z = 8, 2898 reflections with I > 2σ(I), R 3.85%, Rw 4.10%] identifies two independent cobalt(III) cations in the asymmetric unit, and a consideration of the four distinct lattice thiocyanates identifies one of these, S(4)C(4)N(4)-, as that most likely to be involved in replacing the originally coordinated SCN-; S(4) at Co(1), and N(4) at Co(2). Intramolecular (as distinct from intermolecular) isomerization of coordinated thiocyanate is suggested for the formation of trans-CoNCS2+. The solid-state incorporation of lattice N14CS- and S14CN- is compared to that found in aqueous solution where ion-paired N14CS- and S14CN- as well as H2O compete in a solvent-cage, intramolecular , exchange process. The structure of the coordination isomer [Co(NH3)5NCS]SO4.1.5H2O, containing the product CoNCS2+ cation [a 6.621(9), b 7.123(21), c 26.906(19) Ǻ, Pnma, Z = 4,524 reflections with I > 2σ(1), R 6.34%, Rw 7.67%], is reported. A reexamination of the crystal structure of [Co(NH3)5SCN]Cl2.H2O (ref. 1) suggests that hydrogen bonding to ammine ligands, rather than a more open structure or poorer positioning of lattice Cl-, is the reason for the non-incorporation of ionic Cl- on heating this material.

scholarly journals Exploring the Structural Chemistry of Pyrophosphoramides: N,N′,N″,N‴-Tetraisopropylpyrophosphoramide

Chemistry ◽  
2021 ◽  
Vol 3 (1) ◽  
pp. 149-163
Author(s):  
Duncan Micallef ◽  
Liana Vella-Zarb ◽  
Ulrich Baisch
Keyword(s):  
Crystal Structure ◽  
Mass Spectrometry ◽  
Nuclear Magnetic Resonance ◽  
Hydrogen Bonding ◽  
Nmr Spectroscopy ◽  
Ir Spectroscopy ◽  
Room Temperature ◽  
Intermolecular Hydrogen Bonding ◽  
X Ray Diffraction ◽  
X Ray

N,N′,N″,N‴-Tetraisopropylpyrophosphoramide 1 is a pyrophosphoramide with documented butyrylcholinesterase inhibition, a property shared with the more widely studied octamethylphosphoramide (Schradan). Unlike Schradan, 1 is a solid at room temperature making it one of a few known pyrophosphoramide solids. The crystal structure of 1 was determined by single-crystal X-ray diffraction and compared with that of other previously described solid pyrophosphoramides. The pyrophosphoramide discussed in this study was synthesised by reacting iso-propyl amine with pyrophosphoryl tetrachloride under anhydrous conditions. A unique supramolecular motif was observed when compared with previously published pyrophosphoramide structures having two different intermolecular hydrogen bonding synthons. Furthermore, the potential of a wider variety of supramolecular structures in which similar pyrophosphoramides can crystallise was recognised. Proton (1H) and Phosphorus 31 (31P) Nuclear Magnetic Resonance (NMR) spectroscopy, infrared (IR) spectroscopy, mass spectrometry (MS) were carried out to complete the analysis of the compound.

(Acetylacetonato-κ2O,O′)[1-(4-bromophenyl-κC2)-3-methylimidazol-2-ylidene-κC2]platinum(II)

2012 ◽  
Vol 68 (8) ◽  
pp. m203-m205 ◽  
Author(s):  
Mario Tenne ◽  
Yvonne Unger ◽  
Thomas Strassner
Keyword(s):  
Hydrogen Bonding ◽  
Solid State ◽  
Intermolecular Hydrogen Bonding ◽  
Coordination Environment ◽  
Π Interactions ◽  
New Class ◽  
Square Planar ◽  
Parallel Fashion

The title platinum(II) complex, [Pt(C10H8BrN2)(C5H7O2)], has a bidentate cyclometallated phenylimidazolylidene ligand and an acetylacetonate spectator ligand, which form a distorted square-planar coordination environment around the PtIIcentre. In the solid state, the molecules are oriented in a parallel fashion by intermolecular hydrogen bonding and π–π and C—H...π interactions, while close Pt...Pt contacts are not observed. The structure is only the second example for this new class of compounds.

Syntheses and vibrational spectra of some tris(alkanethiolato)mercurate(II) complexes, and crystal structure of the Hexakis(methanethiolato)dimercurate(II) dianion

1984 ◽  
Vol 37 (8) ◽  
pp. 1607 ◽  
Author(s):  
GA Bowmaker ◽  
IG Dance ◽  
BC Dobson ◽  
DA Rogers
Keyword(s):  
Crystal Structure ◽  
Solid State ◽  
Vibrational Spectra ◽  
Crystal Data ◽  
Tetrahedral Geometry ◽  
Space Group ◽  
Spectroscopic Evidence ◽  
Distorted Tetrahedral Geometry ◽  
Complex Anions

The complexes [cation] [Hg(SR)3](R = Me, cation = Et4N+; R = But, cation = Et4N+, Bu4N+, [N(Ph3P)2]+) have been prepared. The crystal structure of the methanethiolate complex shows that it contains centrosymmetric dinuclear anions [(MeS)2Hg(�-SMe)2Hg(SMe)2]2- with distorted tetrahedral geometry about the mercury atoms. Vibrational spectroscopic evidence suggests that this complex dissociates on dissolution in ethanol to give mononuclear [Hg(SMe)3]- species. The ButS- complexes appear to exist as mononuclear [Hg(SBut)3]- species both in the solid state and in solution. The metal-sulfur stretching frequencies are assigned for all of the complexes studied, and the vibrational spectra are discussed in terms of the structures of the complex anions involved. Crystal data for [(C2H5)4N]2Hg2(SCH3)6 : a 8.656(5), b gS130(6), c 12.368(8) �; α 102.16(4), β 105.51(4), γ 105.29(4)�; space group P1, Z 1, R 0.034, Rw 0.042.

scholarly journals Crystal structure of 2-cyano-1-methylpyridinium tetrafluoroborate

2015 ◽  
Vol 71 (10) ◽  
pp. o697-o698 ◽  
Author(s):  
Francesca A. Vaccaro ◽  
Lynn V. Koplitz ◽  
Joel T. Mague
Keyword(s):  
Crystal Structure ◽  
Hydrogen Bonding ◽  
Solid State ◽  
Three Dimensional ◽  
Asymmetric Unit ◽  
State Structure ◽  
Solid State Structure ◽  
Two Component

The asymmetric unit of the title salt, C7H7N2+·BF4−, comprises two independent but nearly identical formula units. The solid-state structure comprises corrugated layers of cations and anions, formed by C—H...F hydrogen bonding, that are approximately parallel to (010). Further C—H...F hydrogen bonding consolidates the three-dimensional architecture. The sample was refined as a two-component non-merohedral twin.

scholarly journals Crystal structure of a trigonal polymorph of aquadioxidobis(pentane-2,4-dionato-κ2 O,O′)uranium(VI)

2022 ◽  
Vol 78 (1) ◽  
Author(s):  
Alejandro Hernandez ◽  
Indranil Chakraborty ◽  
Gabriela Ortega ◽  
Christopher J. Dares
Keyword(s):  
Crystal Structure ◽  
Hydrogen Bonding ◽  
Water Molecule ◽  
Equatorial Plane ◽  
Title Compound ◽  
Uranium Atom ◽  
Intermolecular Hydrogen Bonding ◽  
Two Dimensional ◽  
Asymmetric Unit ◽  
Acta Cryst

The title compound, [UO2(acac)2(H2O)] consists of a uranyl(VI) unit ([O=U=O]2+) coordinated to two monoanionic acetylacetonate (acac, C5H7O2) ligands and one water molecule. The asymmetric unit includes a one-half of a uranium atom, one oxido ion, one-half of a water molecule and one acac ligand. The coordination about the uranium atom is distorted pentagonal–bipyramidal. The acac ligands and Ow atom comprise the equatorial plane, while the uranyl O atoms occupy the axial positions. Intermolecular hydrogen bonding between complexes results in the formation of two-dimensional hexagonal void channels along the c-axis direction with a diameter of 6.7 Å. The monoclinic (P21/c space group) polymorph was reported by Alcock & Flanders [(1987). Acta Cryst. C43, 1480–1483].

A comparison of the intramolecular and intermolecular hydrogen bonding of N,N′-ethylenebis(aminobenzylidene) in the solid state with its salen analogue

2005 ◽  
Vol 737 (1) ◽  
pp. 69-74 ◽  
Author(s):  
Samantha Gakias ◽  
Colin Rix ◽  
Alan Fowless ◽  
Graham Wills-Johnson ◽  
Kay Latham ◽  
...  
Keyword(s):  
Hydrogen Bonding ◽  
Solid State ◽  
Intermolecular Hydrogen Bonding
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