Quadrupole coupling of deuterium bonded to carbon

14N and 2H quadrupole double resonance in substituted imidazoles

“…tensor in imidazole interchange on passing from the gas to the solid state. Figure 7 against q for all the compounds listed in Table I , together with additional points for gaseous imidazole ( 18)," 1benzylimidazole ( 19),' L-histidine (20),' sodium urocanate (22),9 1-acetylimidazole (24)," and the N(7) nuclei in the fivemembered rings of hypoxanthine (H), guanine (G), and adenine (A) taken from the following paper. 26 The reflection implied at the q = 0 axis when (e'qQ/hI -3.7 MHz suggests that q,, and qyy have interchanged directions so that substituted imidazoles with imino-quadrupole coupling constants less than this should in the solid state have the orientation shown in Figure 8, in which the x and y axes of the I4N quadrupole tensor have been interchanged with respect to those deduced from the analyses of the microwave spectrum of gaseous imidazole."…”

“…Additional points have been inserted for imidazolium hydrogen maleate (17),* gaseous (26) 30 and solid pyrrole (27),2s,3' gaseous imidazole (1 8),'l sodium urocanate (22),9 L-histidine hydrochloride monohydrate (2 1 ),9 urocanic acid monohydrate ( 23),9 and 1-acetylimidazole ( 24) '' and the NH groups in the five-membered rings of several solid nucleotide bases and their salts,'6 including hypoxanthine (H), adenine (A) and its dihydrobromide (AB), and guanine (G), and the data (closed squares) for twelve imidazole complexes ([3]- [14]),* l-benzylimidazole (19), L-histidine (20), and imidazolium nitrate [15], and iodide [16], taken from Ashby et d.'s paper.' Most of the results fall within a series of three bands which have been inserted in Figure 9, the bands themselves crossing near the region in which Ie2qyyQ/h[ = 1e2q,,Q/hl = ca.…”

On the Nature of the “Bleaching out” Process of the 35Cl NQR Signals in 1,2,3-Trichlorobenzene

“…The results for 1,2,3-C1 3 D 3 C 6 , however, can not directly be compared with the values given in Table 8 ( 2 H) for 1,2,3-C1 3 D 3 C 6 at 77 K. Librational motions, which increase with increasing temperature, lead to a decrease of the NQCC at the chlorine site of chlorobenzenes. For aliphatic compounds like CD 2 C1 2 and CDC1 3 , such a temperature dependence for e 2 q Q h ~1 of the deuteron has been observed, too [18]. The same should be valid for e 2 qQh~1 of D bound to the aromatic ring.…”

“…These values are unrealistic and were rejected. The other solution leads to »/-values in the range of 0.06 ^ rj ^ 0.073 (see Table 3, in which ^( 2 H) and e 2 qQh~l( 2 H) are given for room temperature), which are typical values for 2 H bound to the aromatic ring [17,18].…”

High-resolution studies of deuterium by time-domain zero-field NQR

“…DeuteriUm quadrupole coupling constants have been studied extensively by a variety of techniques and are reviewed in the literature (5,(20)(21)(22) (20,21,23,24) and cover a range of -165-195 kHz although the asymmetry parameter is often undetermined. Often only the average quadrupole coupling constant over all sites on the ring is reported.…”