title: Nuclear quadrupole resonance of norephedrine.
abstract: Toward searching for illegal drugs, we investigated the pulsed nuclear quadrupole resonance (NQR) response of 14N in (1R,2S)-(-)-norephedrine, based on the predictions of quantum chemical calculations. Two pairs of spectral lines (ν+=3.089, 3.093 MHz and ν-=2.594, 2.608 MHz) were observed despite its molecule structure having only a single nitrogen atom. This indicates that the molecular crystal has two nonequivalent nitrogen atoms in the unit cell. The temperature dependence of the NQR frequencies and relaxation properties were investigated for the purpose of accurate remote sensing of the drugs. The NQR frequency shift was approximately 0.23 kHz/K around room temperature. The spin-lattice relaxation and spin-phase memory times were 5.2-10.2 ms and 0.6-1.5 ms, respectively.
authors.affiliation: Graduate School of Engineering Science, Osaka University, Machikaneyama 1-3, Toyonaka, Osaka 560-8531, Japan. sinohara@sup.ee.es.osaka-u.ac.jp
authors.forename: Junichiro
authors.initials: J
authors.lastname: Shinohara
authors.forename: Kazuhiko
authors.initials: K
authors.lastname: Kobayashi
authors.forename: Hideo
authors.initials: H
authors.lastname: Sato-Akaba
authors.forename: Hideo
authors.initials: H
authors.lastname: Itozaki
mesh_terms: D016208:Databases, Factual; D013287:Illicit Drugs / Q000138:chemical synthesis; D007536:Isomerism; D009682:Magnetic Resonance Spectroscopy / Q000379:methods*; D010665:Phenylpropanolamine / Q000737:chemistry*; D011789:Quantum Theory; D013696:Temperature; D013997:Time Factors
chemical_list: D013287:Illicit Drugs; D010665:Phenylpropanolamine