scholarly journals Synthesis of a New Polyanion Possessing Dense 1,2,3-Triazole Backbone

Polymers ◽  
2021 ◽  
Vol 13 (10) ◽  
pp. 1614
Author(s):  
Linlin Xu ◽  
Yuri Kamon ◽  
Akihito Hashidzume
Keyword(s):  
Butyl Ester ◽  
Lattice Relaxation ◽  
Lattice Relaxation Time ◽  
Water Soluble ◽  
Spin Lattice Relaxation ◽  
Water Soluble Polymers ◽  
Spin Lattice ◽  
Wide Range ◽  
Titration Data ◽  
Novel Structures

Polyanions are an important class of water-soluble polymers because polyanions are utilized in a wide range of industrial fields. It is thus a great challenge to develop polyanions with novel structures to make their applications broader. In this study, a new polyanion with a dense 1,2,3-triazole backbone, poly(4-azido-5-hexanoic acid) (poly(AH)), was synthesized by copper(I)-catalyzed azide–alkyne cycloaddition (CuAAC) polymerization of t-butyl 4-azido-5-hexanoate followed by hydrolysis of the t-butyl ester groups. Turbidimetric and potentiometric titration data indicated that poly(AH) was well soluble in water under basic conditions (pH < 7) and a weaker polyanion (apparent pKa = 5.4) than polyacrylic acid (apparent pKa = 4.5). Adsorption tests exhibited that sodium salt of poly(AH) (poly(AH)Na) adsorbed most preferably Fe3+ among the four metal ions examined, i.e., Cu2+, Pb2+, Li+, and Fe3+. 1H spin-lattice relaxation time measurements indicated that Fe3+ ions were adsorbed favorably onto the 1,2,3-triazole residues.

NQR and Neutron Diffraction in Scheelites

1992 ◽  
Vol 47 (1-2) ◽  
pp. 308-312 ◽  
Author(s):  
R. Julian C. Brown ◽  
E. Shortreed ◽  
Andrew J. Szabo ◽  
Brian M. Powell ◽  
Stephen N. Stuart
Keyword(s):  
Neutron Diffraction ◽  
Temperature Dependence ◽  
Structural Parameters ◽  
Lattice Relaxation ◽  
Lattice Relaxation Time ◽  
Unit Cell ◽  
Spin Lattice Relaxation ◽  
Relaxation Rates ◽  
Spin Lattice ◽  
Wide Range

AbstractMeasurements of the spin-lattice relaxation time for rhenium in KReO4 and NH4ReO4 are reported; relaxation rates are extremely fast due to the large quadrupole moment of Re. Calculations of the electric field gradient in KReO4 show that the EFG is a very sensitive function of the orientation of the anion in the unit cell as well as of the unit cell dimensions, and that geometrical effects make a major contribution to the temperature dependence. Neutron diffraction in these two salts has been employed to determine the temperature dependence of structural parameters over a wide range of temperature, and preliminary results are reported.

Molecular Motion in Solid Tetraethyl-and Tetrabutylammonium Perchlorates

1994 ◽  
Vol 49 (3) ◽  
pp. 465-468 ◽  
Author(s):  
Barbara Szafrańska ◽  
Zdzisław Pająk
Keyword(s):  
Relaxation Time ◽  
Molecular Motion ◽  
Solid Phase ◽  
Lattice Relaxation ◽  
Lattice Relaxation Time ◽  
Spin Lattice Relaxation ◽  
Methyl Group ◽  
Alkyl Chains ◽  
Spin Lattice ◽  
Wide Range

Abstract The proton NMR second moment and spin-lattice relaxation time for polycrystalline tetraethyl-and tetrabutylammonium perchlorates have been measured over a wide range of temperatures. Solid-solid phase transitions related to the onset of cation tumbling were found for both compounds and confirmed by DSC. In the low temperature phases methyl-group reorientation was evidenced. For tetrabutylammonium cation a dynamic nonequivalence of one methyl group is found. The geared motion of the alkyl chains related with the onset of successive CH2-group reorientations is suggested.

An Effect of Deuteration on Ion Motions and Hydrogen Bondings in Guanidinium Tetrafluoroborate

1992 ◽  
Vol 47 (7-8) ◽  
pp. 803-806 ◽  
Author(s):  
J. Wąsicki ◽  
M. Grottel ◽  
A. Kozak ◽  
Z. Pająk
Keyword(s):  
Relaxation Time ◽  
Activation Parameters ◽  
Lattice Relaxation ◽  
Lattice Relaxation Time ◽  
Spin Systems ◽  
Spin Lattice Relaxation ◽  
Spin Lattice ◽  
Relaxation Effects ◽  
Wide Range ◽  
Hydrogen Bondings

Abstract The fluorine spin-lattice relaxation time as well as NMR second moment for perdeuterated guanidinium tetrafluoroborate were studied over a wide range of temperature. An analytical solution of a set of coupled differential equations describing the time variation of nuclear magnetisations for four unlike spin systems was applied to analyse all cross-relaxation effects in the compound. Activation parameters EFa = 19.3 kJ/mole and τFU= 9 • 10"14 s for the isotropic anion reorientation were derived. A coupling of rotational modes of cation and anion was found. Significant lowering of the melting point explained by a weakening of the hydrogen bonds involves diminishing of the ion activation energies due to the large positive isotope effect

CHAIN BEHAVIOR IN MODEL HOMOGENEOUS ER FLUIDS DEPENDING ON TEMPERATURE

2002 ◽  
Vol 16 (17n18) ◽  
pp. 2385-2391 ◽  
Author(s):  
HIROKAZU OKAMURA ◽  
KAORI SUZUKI ◽  
TAKESHI MORI ◽  
KEIJI MINAGAWA ◽  
SEIZO MASUDA ◽  
...  
Keyword(s):  
Conformational Stability ◽  
Lattice Relaxation ◽  
Lattice Relaxation Time ◽  
Water Soluble ◽  
Spin Lattice Relaxation ◽  
Solution Temperature ◽  
Spin Lattice ◽  
Chemical Structures ◽  
Responsive Polymers ◽  
Lower Temperature

Water-soluble urethane-modified polyethers were prepared by addition of poly(ethylene oxide)-co-poly(propylene oxide) and aromatic isocyanate compounds. These polymers were found to dissolve in water at lower temperature and separate from solution upon heating. The temperature showing this unusual solubility change is called lower critical solution temperature (LCST). These chemical structures of thermo-responsive polymers were similar to those of urethane-modified ER active polymers containing poly(tetramethylene oxide) and aromatic urethane moiety. The thermo-responsive and ER polymers may have various intra- and intermolecular interactions through the urethane moiety. It is considered that both thermo-responsivility and ER effect are dependent on the conformational stability of the polymers under different conditions possibly related to these stimuli-responsivility through the molecular interactions. In order to clarify molecular motion of thermo-responsive polymers near the LCST, 1 H-NMR spin-lattice relaxation time ( T 1) was measured in D 2 O . The result indicated that hydrophobic interaction of terminal urethane moiety would strongly affect the LCST behavior.

NUCLEAR SPIN-LATTICE RELAXATION TIME IN TIN

1978 ◽  
Vol 39 (C6) ◽  
pp. C6-1215-C6-1216
Author(s):  
H. Ahola ◽  
G.J. Ehnholm ◽  
S.T. Islander ◽  
B. Rantala
Keyword(s):  
Relaxation Time ◽  
Nuclear Spin ◽  
Lattice Relaxation ◽  
Lattice Relaxation Time ◽  
Spin Lattice Relaxation ◽  
Spin Lattice Relaxation Time ◽  
Spin Lattice ◽  
Nuclear Spin Lattice Relaxation

Protron spin-lattice relaxation time of duchenne dystrophy skeletal muscle by magnetic resonance imaging

1988 ◽  
Vol 11 (2) ◽  
pp. 97-102 ◽  
Author(s):  
Kiichiro Matsumura ◽  
Imaharu Nakano ◽  
Nobuo Fukuda ◽  
Hiroo Ikehira ◽  
Yukio Tateno ◽  
...  
Keyword(s):  
Magnetic Resonance Imaging ◽  
Skeletal Muscle ◽  
Relaxation Time ◽  
Magnetic Resonance ◽  
Lattice Relaxation ◽  
Lattice Relaxation Time ◽  
Spin Lattice Relaxation ◽  
Resonance Imaging ◽  
Duchenne Dystrophy ◽  
Spin Lattice

Determination of chemical shift anisotropy tensor and molecular correlation time of proton pump inhibitor omeprazole by solid state NMR measurements

2020 ◽  
Vol 44 (44) ◽  
pp. 19393-19403
Author(s):  
Krishna Kishor Dey ◽  
Manasi Ghosh
Keyword(s):  
Correlation Time ◽  
Chemical Shift Anisotropy ◽  
Lattice Relaxation ◽  
Lattice Relaxation Time ◽  
Spin Lattice Relaxation ◽  
Spin Lattice ◽  
Structure And Dynamics ◽  
Molecular Correlation ◽  
Anisotropy Tensor

The correlation between the structure and dynamics of omeprazole is portrayed by extracting CSA parameters through the 13C 2DPASS CP-MAS SSNMR experiment, site specific spin–lattice relaxation time by Torchia CP experiment, and calculation of the molecular correlation time.

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