Metal Template Synthesis of a Tripodal Tris(bipyridyl) Receptor that Encapsulates a Proton and an Iron(II) Centre in a Pseudo Cage

2012 ◽  
Vol 65 (10) ◽  
pp. 1371 ◽  
Author(s):  
Christopher R. K. Glasson ◽  
George V. Meehan ◽  
Cherie A. Motti ◽  
Jack K. Clegg ◽  
Murray S. Davies ◽  
...  
Keyword(s):  
1H Nmr ◽  
Template Synthesis ◽  
Fold Axis ◽  
Acid Base ◽  
X Ray ◽  
Counter Ion ◽  
Nmr Study ◽  
Hydrogen Bonded

The Fe(ii) template synthesis of the first member of a new category of tripodal tris-bipyridine ligands incorporating a nitrogen bridgehead is reported. The X-ray structure of the reaction product shows that the ligand adopts a pseudo cage-like structure that encapsulates both a proton and an Fe(ii) ion in its cavity. The complex shows an extended helical arrangement that is effectively ‘capped’ at its open end by a hydrogen bonded PF6– counter ion that is symmetrically aligned with the 3-fold axis of the helix. A 1H NMR study demonstrated that the encapsulated proton can be reversibly exchanged under acid/base conditions in CD3CN.

1H NMR study of the solvolysis of the paramagnetic tetrachloro-bis(imidazole)ruthenium(III) anion in water, methanol, and dimethyl sulfoxide

1995 ◽  
Vol 73 (4) ◽  
pp. 471-482 ◽  
Author(s):  
Craig Anderson ◽  
André L. Beauchamp
Keyword(s):  
Dimethyl Sulfoxide ◽  
1H Nmr ◽  
Room Temperature ◽  
Single Species ◽  
X Ray Diffraction ◽  
Chloro Complexes ◽  
X Ray ◽  
H Nmr ◽  
Nmr Study ◽  
Nmr Signals

The 1H NMR signals of the Ru(III) species present in solution are considerably broadened and shifted by paramagnetism, but they can be used to follow chloride displacement in the trans-[RuCl4Im2]− ion. This anion remains predominant for several hours at room temperature in D2O, but its signals are progressively replaced by those of a monoaqua [RuCl3(D2O)Im2] complex. Over a period of days, two new sets of peaks appear, corresponding to two isomers of [RuCl2(D2O)2Im2]+. The same behaviour is observed for the 1-methyl-and 4-methylimidazole analogues. These reactions can be driven backwards by addition of KCl, but [RuCl4Im2]− is not quantitatively regenerated in solution even for 6 M NaCl. Within several months, the [RuCl2(D2O)2Im2]+ isomers further aquate to a single species [RuCl(D2O)3Im2]2+. In CD3OD, displacement of the first chloride of [RuCl4Im2]− takes place faster, over several hours, but substitution stops at the [RuCl3(CD3OD)Im2] stage. In DMSO, substitution occurs very slowly. The [RuCl3(DMSO)Im2]:[RuCl4Im2]−mixture (1:2) obtained after 12 days starts to show very slow reduction to two Ru(II) species, one of which precipitates as yellow crystals. From X-ray diffraction work (monoclinic, P21/n, a = 9.951, b = 8.564, c = 10.527 Å, β = 92.95°, R = 0.033), the compound was identified as [RuCl2(DMSO-d6)2Im2], where the metal has a trans-trans-trans coordination and the DMSO ligands are S-bonded. Keywords: paramagnetic ruthenium anion, solvolysis, chloro complexes.

scholarly journals 1H NMR Study of the HCa2Nb3O10 Photocatalyst with Different Hydration Levels

Molecules ◽  
2021 ◽  
Vol 26 (19) ◽  
pp. 5943
Author(s):  
Marina G. Shelyapina ◽  
Oleg I. Silyukov ◽  
Elizaveta A. Andronova ◽  
Denis Y. Nefedov ◽  
Anastasiia O. Antonenko ◽  
...  
Keyword(s):  
1H Nmr ◽  
Nmr Spectra ◽  
Magic Angle Spinning ◽  
Spin Lattice Relaxation ◽  
Layered Perovskite ◽  
Magic Angle ◽  
1H Mas Nmr ◽  
Hydration Level ◽  
Nmr Study ◽  
Hydrogen Bonded

The photocatalytic activity of layered perovskite-like oxides in water splitting reaction is dependent on the hydration level and species located in the interlayer slab: simple or complex cations as well as hydrogen-bonded or non-hydrogen-bonded H2O. To study proton localization and dynamics in the HCa2Nb3O10·yH2O photocatalyst with different hydration levels (hydrated—α-form, dehydrated—γ-form, and intermediate—β-form), complementary Nuclear Magnetic Resonance (NMR) techniques were applied. 1H Magic Angle Spinning NMR evidences the presence of different proton containing species in the interlayer slab depending on the hydration level. For α-form, HCa2Nb3O10·1.6H2O, 1H MAS NMR spectra reveal H3O+. Its molecular motion parameters were determined from 1H spin-lattice relaxation time in the rotating frame (T1ρ) using the Kohlrausch-Williams-Watts (KWW) correlation function with stretching exponent β = 0.28: Ea=0.2102 eV, τ0=9.01 × 10−12 s. For the β-form, HCa2Nb3O10·0.8H2O, the only 1H NMR line is the result of an exchange between lattice and non-hydrogen-bonded water protons. T1ρ(1/T) indicates the presence of two characteristic points (224 and 176 K), at which proton dynamics change. The γ-form, HCa2Nb3O10·0.1H2O, contains bulk water and interlayer H+ in regular sites. 1H NMR spectra suggest two inequivalent cation positions. The parameters of the proton motion, found within the KWW model, are as follows: Ea=0.2178 eV, τ0=8.29 × 10−10 s.

scholarly journals Evidence for tautornerisrn in nucleic acid base pairs.1H NMR study of15N labeled tRNA

1982 ◽  
Vol 10 (21) ◽  
pp. 7027-7039 ◽  
Author(s):  
H. Rüterjans ◽  
E. Kaun ◽  
W.E. Hull ◽  
H.H. Limbach
Keyword(s):  
Nucleic Acid ◽  
1H Nmr ◽  
Acid Base ◽  
Base Pairs ◽  
Nmr Study ◽  
Nucleic Acid Base

A qualitative 1H NMR study of CHCl3 adsorption on conjugated acid–base pairs in cation exchanged Y-zeolites

1999 ◽  
Vol 30 (2-3) ◽  
pp. 327-333 ◽  
Author(s):  
Juha T. Timonen ◽  
Tuula T. Pakkanen
Keyword(s):  
1H Nmr ◽  
Acid Base ◽  
Base Pairs ◽  
Y Zeolites ◽  
Nmr Study

Complex hydrogen bonded cations. The imdazole/imidazolium complex cation

1976 ◽  
Vol 54 (15) ◽  
pp. 2458-2464 ◽  
Author(s):  
D. H. Bonsor ◽  
B. Borah ◽  
R. L. Dean ◽  
J. L. Wood
Keyword(s):  
Infrared Spectra ◽  
Association Constant ◽  
Complex Cation ◽  
Single Band ◽  
X Ray ◽  
Counter Ion ◽  
Proton Potential ◽  
Job's Method ◽  
Perchlorate Salt ◽  
Hydrogen Bonded

The salts (ImH+)X−, Im = imidazole, X− = PF6−, BF4−, or ClO4− have been prepared in solution, and the perchlorate salt has been crystallised. The molecularity implied by the formula is confirmed in solution by Job's method, and for the crystals gravimetrically. In MeCN the association constant is ∼8 M−1. Infrared spectra of solution and crystals are similar, independent of counter ion, and indicate an asymmetric single minimum proton potential. The pronounced doublet in the NH stretching band of the H bridged complex, and replaced by a single band in the D bridged analogue, is not indicative of proton tunnelling. The X-ray structure is compatible with this interpretation of the spectra.

An 1H NMR Study on the Cationic Motion in Solid tert-Butylammonium Chloride and Bromide

1991 ◽  
Vol 46 (3) ◽  
pp. 265-268 ◽  
Author(s):  
Hiroyuki Ishida ◽  
Syuichi Inada ◽  
Naomi Hayama ◽  
Daiyu Nakamura ◽  
Ryuichi Ikeda
Keyword(s):  
Relaxation Time ◽  
1H Nmr ◽  
Room Temperature ◽  
Lattice Relaxation ◽  
Lattice Relaxation Time ◽  
Spin Lattice Relaxation ◽  
X Ray ◽  
Spin Lattice ◽  
H Nmr ◽  
Nmr Study

AbstractThe 1H spin-lattice relaxation time (T1) in solid (CD3)3CNH3Cl and (CD3)3CNH3Br was measured above room temperature and the motional parameters for the reorientation of the NH3+ groups were determined. The 1H NMR absorptions measured in the same temperature range for (CH3)3CNH3Cl and (CH3)3CNH3Br indicate the presence of superimposed several cationic motions commonly taking place in both compounds. From X-ray powder patterns taken at room temperature, the bromide was found to be isomorphous with the chloride

Mechanochemical Preparation of Hydrogen-Bonded Adducts Between the Diamine 1,4-Diazabicyclo[2.2.2]octane and Dicarboxylic Acids of Variable Chain Length: An X-ray Diffraction and Solid-State NMR Study

2003 ◽  
Vol 9 (22) ◽  
pp. 5538-5548 ◽  
Author(s):  
Dario Braga ◽  
Lucia Maini ◽  
Giorgiana de Sanctis ◽  
Katia Rubini ◽  
Fabrizia Grepioni ◽  
...  
Keyword(s):  
Solid State ◽  
Chain Length ◽  
Solid State Nmr ◽  
Dicarboxylic Acids ◽  
X Ray Diffraction ◽  
X Ray ◽  
Nmr Study ◽  
Hydrogen Bonded

scholarly journals X-ray Crystallography at 170 K of Racemic 2,2'-Dimethoxy-9,9'-biacridine and 1H NMR Study of 2,2'-Diacetoxy-9,9'-biacridine

Molecules ◽  
1999 ◽  
Vol 4 (12) ◽  
pp. 104-121 ◽  
Author(s):  
Gérard Boyer ◽  
Tuan Lormier ◽  
Jean-Pierre Galy ◽  
Antonio Llamas-Saiz ◽  
Concepción Foces- Foces ◽  
...  
Keyword(s):  
1H Nmr ◽  
X Ray ◽  
X Ray Crystallography ◽  
Nmr Study

ChemInform Abstract: Diastereoselective Formation of 2-Aryl-3-arenesulfonyl-4-ethyl-1,3- oxazolidines: An X-Ray Crystallographic and 1H NMR Study.

ChemInform ◽  
2010 ◽  
Vol 28 (14) ◽  
pp. no-no
Author(s):  
G. B. KUMAR ◽  
H. V. PATEL ◽  
A. C. SHAH ◽  
M. TRENKLE ◽  
C. J. CARDIN
Keyword(s):  
1H Nmr ◽  
X Ray ◽  
Nmr Study

Low temperature X-ray diffraction analysis of 4,5,10,11-tetramethyl-heptacyclo[8.2.1.12,5.14,7.18,11.01,8.02,7]hexadecane: DSC, MM2 and 1H NMR study of its [2 + 2]retrocycloaddition to an isomeric diene

1996 ◽  
Vol 37 (47) ◽  
pp. 8601-8604 ◽  
Author(s):  
Pelayo Camps ◽  
Mercè Font-Bardia ◽  
Francesc Pérez ◽  
Lluis Solà ◽  
Xavier Solans ◽  
...  
Keyword(s):  
Low Temperature ◽  
Diffraction Analysis ◽  
1H Nmr ◽  
X Ray Diffraction ◽  
X Ray ◽  
Nmr Study
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