A Study on the Intermolecular Hydrogen Bonds of α-Glycylglycine in Its Actual Crystalline Phase Using ab Initio Calculated14N and2H Nuclear Quadrupole Coupling Constants

2005 ◽  
Vol 109 (8) ◽  
pp. 1729-1733 ◽  
Author(s):  
Fatemeh Elmi ◽  
Nasser L. Hadipour
Keyword(s):  
Hydrogen Bonds ◽  
Ab Initio ◽  
Crystalline Phase ◽  
Coupling Constants ◽  
Intermolecular Hydrogen Bonds ◽  
Quadrupole Coupling ◽  
Nuclear Quadrupole

14N Nuclear Quadrupole Coupling in Glycyl-Glycine and Related Peptides

1984 ◽  
Vol 39 (11) ◽  
pp. 1108-1111 ◽  
Author(s):  
Michael Palmer
Keyword(s):  
Crystal Structure ◽  
Ab Initio ◽  
Ab Initio Calculation ◽  
Coupling Constants ◽  
Double Zeta ◽  
Quadrupole Coupling ◽  
Aromatic Systems ◽  
Nuclear Quadrupole ◽  
Glycyl Glycine

An ab initio calculation of double zeta quality on glycyl-glycine at the crystal structure yielded nuclear quadrupole coupling constants at the peptide centres very close to experiment; Xzz -3.03, Xyy +2.14, Xxx +0.89 MHz. The first two couplings lie in the local π-direction, and along the C-N bond, respectively. At the NH⊕3 centre the values were less satisfactory, but the (low) positive value of Xzz was obtained, and lies relatively close to the N-C bond. The results suggest that similar calculations may be successful for other H-bonded systems, provided that aromatic systems are not involved.

Ab Initio Study of 2H Nuclear Quadrupole Coupling Constants in Deuterated Crystalline Oxalic Acid Dehydrated Polymorphs

2013 ◽  
Vol 575 (1) ◽  
pp. 188-201 ◽  
Author(s):  
Cuauhtémoc Samaniego ◽  
J. G. Rodríguez-Zavala ◽  
F. J. Tenorio ◽  
R. Flores-Moreno
Keyword(s):  
Oxalic Acid ◽  
Ab Initio ◽  
Coupling Constants ◽  
Ab Initio Study ◽  
Quadrupole Coupling ◽  
Nuclear Quadrupole

High Pressure NQR Study of the Phase Transition in Anilinium Iodide

1986 ◽  
Vol 41 (1-2) ◽  
pp. 290-293
Author(s):  
Mariusz Maćkowiak ◽  
Maria Zdanowska-Fra̧zek ◽  
Piotr Kozioł ◽  
Jan Stankowski ◽  
Alarich Weiss
Keyword(s):  
Phase Transition ◽  
High Pressure ◽  
Transition Temperature ◽  
Hydrogen Bonds ◽  
Transition Point ◽  
Pressure Coefficient ◽  
Coupling Constants ◽  
Quadrupole Coupling ◽  
Nuclear Quadrupole ◽  
Asymmetry Parameters

The 127I NQR frequency in anilinium iodide C6H5NH3⊕I⊖ was studied at pressures up to 300 MPa and within the temperature range 77 K - 290 K. With increasing pressure the order-disorder transition point Tc is shifted to higher temperatures. The pressure coefficient of the phase transition temperature amounts to dTc/dp = 4.2 x 10-2 deg MPa-1. The pressure coefficient of the NQR frequency is negative. In addition, the 12'I nuclear quadrupole coupling constants and the respective asymmetry parameters η were evaluated as a function of pressure. The results confirm the close connection between the mechanism of the phase transition and the dynamics of the N - H⊕ ...I⊖ hydrogen bonds.

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