The 10B and 11B nuclear quadrupole resonance spectra of boric acid
The 11B and 10B nuclear quadrupole resonance spectra of boric acid have been obtained at 77 K, by means of the technique of double resonance by level crossing. A 92% 10B-enriched material was examined in addition to one of normal isotopic composition. The quadrupole coupling constant and asymmetry parameter for 10B are 5344(2) kHz and 0.0163(5), respectively. The corresponding quadrupole coupling constant for 11B, assuming η = 0.0163, is 2576(8) kHz. The 10B spectrum is characterized by the appearance of transitions that may be classified as "multiple quantum," in addition to the more highly allowed "single-quantum" transitions. Certain of these, which lie at frequencies higher than that of the one allowed 11B transition, are useful in determining the field gradient parameters. In addition "double transitions," corresponding to simultaneous changes in spin states at two dipolar-coupled nuclei, have been observed; these involve both 10B and 11B. © 1981.
Publication Source (Journal or Book title)
Journal of Magnetic Resonance (1969)
Butler, L., & Brown, T. (1981). The 10B and 11B nuclear quadrupole resonance spectra of boric acid. Journal of Magnetic Resonance (1969), 42 (1), 120-131. https://doi.org/10.1016/0022-2364(81)90015-9