Investigation of the disorder of dibromo- and dichloromethane in their tri-ortho-thymotide clathrates using X-ray diffraction and solid-state 2H NMR spectroscopy

2011 ◽  
Vol 89 (7) ◽  
pp. 854-862
Author(s):  
Glenn A. Facey ◽  
Ilia Korobkov
Keyword(s):  
Solid State ◽  
Nmr Spectroscopy ◽  
Guest Molecule ◽  
Type B ◽  
X Ray Diffraction ◽  
Guest Molecules ◽  
X Ray ◽  
Twofold Axis ◽  
H Nmr ◽  
Heavy Atoms

The tri-ortho-thymotide (TOT) clathrates of dibromo- and dichloromethane were characterized by single crystal X-ray diffraction at 200 K and solid-state 2H NMR spectroscopy as a function of temperature. The host structure was found to be typical of other cage-type TOT clathrates. The X-ray results showed a substantial amount of disorder among the guest molecules. In both clathrates, multiple guest molecule positions could be modeled. The heavy atoms of all the guest molecule positions lie approximately in the same plane, with some out-of-plane distortion. The guest molecules were of two different types in positions symmetric about the crystallographic twofold rotation axis: type A guests, with carbon atoms well removed from the crystallographic twofold axis, and type B guests, with carbon atoms very close to the twofold axis. The 2H NMR spectra for the guests confirmed that the disorder was dynamic. The experimental results could be accounted for by the presence of three simultaneous types of molecular motion, all fast with respect to the 2H quadrupolar interaction: (i) twofold molecular flips about the molecular C2 symmetry axis, (ii) exchange between the type A and type B sites in a single plane, and (iii) a two-site libration of the plane containing the heavy atoms of the A and B guest sites with a temperature-dependent amplitude.

Sila-Pharmaka, 26. Mitt. [1]. Darstellung und Eigenschaften potentiell curarewirksamer Silicium-Verbindungen, III / Sila-Pharmaca, 26th Communication [1]. Preparation and Properties of Silicon Compounds with Potential Curare-Like Activity, III

1982 ◽  
Vol 37 (11) ◽  
pp. 1461-1471 ◽  
Author(s):  
Reinhold Tacke ◽  
Haryanto Linoh ◽  
Moayad T. Attar-Bashi ◽  
William S. Sheldrick ◽  
Ludger Ernst ◽  
...  
Keyword(s):  
Solid State ◽  
Nmr Spectroscopy ◽  
Neuromuscular Blocking ◽  
Neuromuscular Blocking Agents ◽  
X Ray Diffraction ◽  
Silicon Compounds ◽  
X Ray ◽  
Structure Activity Relationships ◽  
H Nmr ◽  
Structure Activity

The potentially curare-like silicon compounds 8a-8f wore synthesized and investigated with respect to their structure-activity relationships. The conformations of the com­pounds in the solid state and in solution were studied by X-ray diffraction analysis (8a-8e) and 1H NMR spectroscopy (8a-8f), respectively. The muscle relaxing properties of 8a-8f were investigated on the mouse. The observed structure-activity relationships are not in accordance with the classical “14 Å model” for neuromuscular blocking agents.

scholarly journals Construction of pillar[4]arene[1]quinone–1,10-dibromodecane pseudorotaxanes in solution and in the solid state

2020 ◽  
Vol 16 ◽  
pp. 2954-2959
Author(s):  
Xinru Sheng ◽  
Errui Li ◽  
Feihe Huang
Keyword(s):  
Solid State ◽  
Hydrogen Bonds ◽  
Single Crystal ◽  
Guest Molecule ◽  
X Ray Diffraction ◽  
Guest Molecules ◽  
X Ray ◽  
Π Interactions ◽  
Host Molecules ◽  
Complexation Stoichiometry

We report novel pseudorotaxanes based on the complexation between pillar[4]arene[1]quinone and 1,10-dibromodecane. The complexation is found to have a 1:1 host–guest complexation stoichiometry in chloroform but a 2:1 host–guest complexation stoichiometry in the solid state. From single crystal X-ray diffraction, the linear guest molecules thread into cyclic pillar[4]arene[1]quinone host molecules in the solid state, stabilized by CH∙∙∙π interactions and hydrogen bonds. The bromine atoms at the periphery of the guest molecule provide convenience for the further capping of the pseudorotaxanes to construct rotaxanes.

Chemistry of zwitterionic penta-coordinate silicon compounds of the (ammoniomethyl)bis[glycolato(2–)-O1,O2]silicate type in aqueous and nonaqueous solution

2003 ◽  
Vol 81 (11) ◽  
pp. 1315-1325 ◽  
Author(s):  
Reinhold Tacke ◽  
Rüdiger Bertermann ◽  
Andreas Biller ◽  
Christian Burschka ◽  
Martin Penka
Keyword(s):  
Solid State ◽  
Nmr Spectroscopy ◽  
Computational Chemistry ◽  
Experimental Investigations ◽  
Computational Studies ◽  
X Ray Diffraction ◽  
Model Species ◽  
Silicon Compounds ◽  
X Ray ◽  
H Nmr

The zwitterionic spirocyclic λ5Si-silicates bis[glycolato(2–)-O1,O2][(trimethylammonio)methyl]silicate ([OCH2C(O)O]2SiCH2NMe3, 3) and bis[2-methyllactato(2–)-O1,O2][(trimethylammonio)methyl]silicate ([OCMe2C(O)O]2SiCH2NMe3, 4) were synthesized by treatment of the zwitterionic λ5Si-silicate F4SiCH2NMe3 with 2 mol. equiv. of Me3SiOCR2C(O)OSiMe3 (R = H, Me) (formation of 4 mol. equiv. of Me3SiF). Compounds 3 (isolated as 3•2/3MeCN after drying in vacuo) and 4 were studied by solution 1H, 13C, and 29Si NMR spectroscopy and by solid-state VACP/MAS 13C, 15N, and 29Si NMR experiments, and the solvates 3•MeCN and 4•2MeCN were structurally characterized by single-crystal X-ray diffraction. These experimental investigations were complemented by computational studies of the zwitterions 3 and 4 and the anionic model species bis[2-methyllactato(2–)-O1,O2]hydridosilicate(1–) ([OCMe2C(O)O]2SiH–, 8). Compounds 3•2/3MeCN and 4 and their already known derivatives [OCH2C(O)O]2SiCH2NMe2H (1) and [OCMe2C(O)O]2SiCH2NMe2H (2) were studied for their dynamic behavior (Λ/Δ-enantiomerization) in solution by VT 1H NMR spectroscopy. In addition, compounds 1, 2, 3•2/3MeCN, and 4 were studied in CD3OD and D2O with 1H, 13C, and 29Si NMR experiments.Key words: penta-coordinate silicon, zwitterionic λ5Si-silicates, Λ/Δ-enantiomerism, NMR spectroscopy, computational chemistry.

scholarly journals Tautomerisation in 1-(4-Methylphenylazo)naphthalen-2-ol and 2-(4-Methylphenylazo)-4-methylphenol: A Crystallographic and 13C{1H}NMR Study

1999 ◽  
Vol 23 (3) ◽  
pp. 178-179
Author(s):  
Wendy I. Cross ◽  
Kevin R. Flower ◽  
Robin G. Pritchard
Keyword(s):  
Acetic Acid ◽  
Nmr Spectroscopy ◽  
Resonant Frequency ◽  
X Ray Diffraction ◽  
X Ray ◽  
H Nmr ◽  
Nmr Study ◽  
Acetic Acid Esters ◽  
Acid Esters ◽  
Equivalent Carbon

The acetic acid esters of 1-(4-methylphenylazo)naphthalen-2-ol 1 and 2-(4-methylphenylazo)-4-methylphenol 3 are prepared and characterised by single crystal X-ray diffraction studies and 13C{1H}NMR spectroscopy; the position of the C(2)13C resonance for the ester is used to predict the position of resonant frequency of the equivalent carbon in the parent alcohols and hence, calculate the position of the azo-hydrazone equilibrium in these compounds.

scholarly journals Synthesis, Structure, and Properties of a Dinuclear Cu(II) Coordination Polymer Based on Quinoxaline and 3,3-Thiodipropionic Acid Ligands

2021 ◽  
Author(s):  
Adedibu Clement Tella ◽  
Samson Owalude ◽  
Vincent Adimula ◽  
Adetola Oladipo ◽  
Victoria Olayemi ◽  
...  
Keyword(s):  
Nmr Spectroscopy ◽  
Nitrogen Atom ◽  
Coordination Polymer ◽  
Elemental Analysis ◽  
Catalytic Reduction ◽  
Copper Acetate ◽  
Structure And Properties ◽  
X Ray Diffraction ◽  
X Ray ◽  
H Nmr

Abstract The coordination polymer [Cu2(TDPH)4(QNX)].DMF, (QNX = Quinoxaline; TDPH = 3,3-thiodipropionic acid), has been prepared by reaction of copper acetate, TDPH, and quinoxaline. The compound was characterized by elemental analysis, FTIR spectroscopy, and single-crystal X-ray diffraction. The crystal is monoclinic with a P21/n space group and dimensions of a = 12.889(3) Å, b = 14.983(4) Å, c = 14.091(3) Å, α = 90 °, β = 90.200(11) °, γ = 90 °, V = 2721.18 (2) Å3, Z = 4. The ligands are hexagonally coordinated to the Cu(II) centre in the form of Cu2O4N with one nitrogen atom from the quinoxaline ligand, and four oxygen atoms from four TDPH molecules in a monodentate fashion. The Cu-Cu bond length was 2.642(1) and 2.629(1) Å for the Cu1----Cu1 and Cu2----Cu2 bonds. The QNX ligand bridged the two copper atoms. The catalytic reduction of 4-nitrophenol to 4-aminophenol using NaBH4 in the presence of [Cu2(TDPH)4(QNX)].DMF, as catalyst was completed within 11 minutes. The 4-aminophenol product was confirmed using 1H NMR spectroscopy.

Inclusion compounds of plant growth regulators in cyclodextrins. V. 4-Chlorophenoxyacetic acid encapsulated in β-cyclodextrin and heptakis(2,3,6-tri-O-methyl)-β-cyclodextrin

2005 ◽  
Vol 61 (2) ◽  
pp. 207-217 ◽  
Author(s):  
Frantzeska Tsorteki ◽  
Kostas Bethanis ◽  
Nikos Pinotsis ◽  
Petros Giastas ◽  
Dimitris Mentzafos
Keyword(s):  
Guest Molecule ◽  
Crystal Packing ◽  
Host Molecule ◽  
X Ray Diffraction ◽  
Guest Molecules ◽  
Space Group ◽  
X Ray ◽  
Dimeric Complexes ◽  
The Mean ◽  
Chlorophenoxyacetic Acid

The crystal structures of 4-chlorophenoxyacetic acid (4CPA) included in β-cyclodextrin (β-CD) and heptakis(2,3,6-tri-O-methyl)-β-cyclodextrin (TMβCD) have been studied by X-ray diffraction. The 4CPA/β-CD complex crystallizes as a head-to-head dimer in the space group C2 in the Tetrad packing mode. The packing modes of some β-CD dimeric complexes, having unique stackings, are also discussed. The 4CPA/TMβCD inclusion complex crystallizes in the space group P21 and its asymmetric unit contains two crystallographically independent complexes, complex A and complex B, exhibiting different conformations. The host molecule of complex A is significantly distorted, as a glucosidic residue rotated about the O4′—C1 and C4—O4 bonds forms an aperture where the guest molecule is accommodated. The phenyl moiety of the guest molecule of complex B is nearly perpendicular to the mean plane of the O4n atoms. The conformations of the guest molecules of the two complexes are similar. The crystal packing consists of antiparallel columns as in the majority of the TMβCD complexes published so far.

Adsorption behaviour of a CdII–triazole MOF for butan-2-one in a single-crystal-to-single-crystal (SCSC) fashion: the role of hydrogen bonding and C—H...π interactions

2019 ◽  
Vol 75 (6) ◽  
pp. 806-811
Author(s):  
Jia Wang ◽  
Tianchao You ◽  
Teng Wang ◽  
Qikui Liu ◽  
Jianping Ma ◽  
...  
Keyword(s):  
Hydrogen Bonding ◽  
Single Crystal ◽  
Specific Binding ◽  
Supramolecular Interactions ◽  
Adsorption Behaviour ◽  
X Ray Diffraction ◽  
Guest Molecules ◽  
X Ray ◽  
Π Interactions ◽  
H Nmr

The adsorption behaviour of the CdII–MOF {[Cd(L)2(ClO4)2]·H2O (1), where L is 4-amino-3,5-bis[3-(pyridin-4-yl)phenyl]-1,2,4-triazole, for butan-2-one was investigated in a single-crystal-to-single-crystal (SCSC) fashion. A new host–guest system that encapsulated butan-2-one molecules, namely poly[[bis{μ3-4-amino-3,5-bis[3-(pyridin-4-yl)phenyl]-1,2,4-triazole}cadmium(II)] bis(perchlorate) butanone sesquisolvate], {[Cd(C24H18N6)2](ClO4)2·1.5C4H8O} n , denoted C4H8O@Cd-MOF (2), was obtained via an SCSC transformation. MOF 2 crystallizes in the tetragonal space group P43212. The specific binding sites for butan-2-one in the host were determined by single-crystal X-ray diffraction studies. N—H...O and C—H...O hydrogen-bonding interactions and C—H...π interactions between the framework, ClO4 − anions and guest molecules co-operatively bind 1.5 butan-2-one molecules within the channels. The adsorption behaviour was further evidenced by 1H NMR, IR, TGA and powder X-ray diffraction experiments, which are consistent with the single-crystal X-ray analysis. A 1H NMR experiment demonstrates that the supramolecular interactions between the framework, ClO4 − anions and guest molecules in MOF 2 lead to a high butan-2-one uptake in the channel.

Imidazole-containing Bispidine Ligands: Synthesis, Structure and Cu(II) Complexation

2011 ◽  
Vol 66 (7) ◽  
pp. 721-728 ◽  
Author(s):  
Martin Walther ◽  
Madlen Matterna ◽  
Stefanie Juran ◽  
Silke Fähnemann ◽  
Holger Stephan ◽  
...  
Keyword(s):  
Solid State ◽  
Nmr Spectroscopy ◽  
Enol Form ◽  
Trans Configuration ◽  
X Ray Diffraction ◽  
X Ray ◽  
The Impact ◽  
Configurational Isomerism

The preparation and characterization of tris-pyridyl bispidine (3,7-diazabicyclo[3.3.1]nonane) derivatives with benzimidazole and imidazole donor groups at the N-3 position of the bispidine skeleton and their copper(II) complexes are reported. The impact of the hetaryl substituents on the configurational isomerism of piperidones and their corresponding bispidones has been studied by NMR spectroscopy, revealing the exclusive appearance in the enol form for the piperidones in solution and the trans-configuration regarding the two pyridyl substituents, as well as the sole formation of the unsymmetric exo-endo isomers for the corresponding bispidones. Thus, the bispidones are preorganized ligands for building pentacoordinated complexes, confirmed by the preparation and characterization of the corresponding Cu(II) complexes. Of the di-pyridyl piperidones with benzimidazole and imidazole substituents, and of the Cu(II) complex of the benzimidazole-containing bispidone, crystals have become available for the analysis by X-ray diffraction, showing that the piperidones form the enol tautomers also in the solid state.

Sign in / Sign up

Export Citation Format

Share Document