Deuterium NMR and ab initio studies of strongly hydrogen-bonded molecules.
Two newly synthesized alkylated cyanomalonaldehyde derivatives possess very short intramolecular hydrogen bonds, which are studied by deuterium NMR. Both the dimethyl and di-tert-butyl derivatives have small deuterium quadrupole coupling constants and large asymmetry parameters. In addition, the di-tert-butyl compound, which has one of the shortest O D...O hydrogen bonds yet measured, has a quadrupole coupling which anomalously increases with temperature. The significance of these phenomena is explored using a theoretical model which employs vibrationally averaged ab initio electric field gradient tensors calculated with large basis sets and electron correlation via the multiconfigurational self-consistent field method.
Zhao
Xingang
X
Department of Chemistry, University of Nebraska at Lincoln, Lincoln, Nebraska, USA.
Dvorak
Matt
M
Silvernail
Carter
C
Belot
John
J
Harbison
Gerard S
GS
D003198:Computer Simulation; D003903:Deuterium; D004574:Electromagnetic Fields; D006859:Hydrogen / Q000737:chemistry*; D007659:Ketones / Q000737:chemistry*; D009682:Magnetic Resonance Spectroscopy; D008958:Models, Molecular; D008962:Models, Theoretical; D008968:Molecular Conformation; D009570:Nitriles / Q000737:chemistry*; D012680:Sensitivity and Specificity; D013696:Temperature
C470749:3-cyano-2,4-pentanedione; C470750:4-cyano-2,2,6,6-tetramethyl-3,5-heptanedione; D007659:Ketones; D009570:Nitriles; D006859:Hydrogen; D003903:Deuterium