NMR spectroscopy in environmental chemistry: 1H and 13C NMR parameters of tricyclic polychlorinated C10 hydrocarbons and their oxy derivatives based on two-dimensional NMR techniques

✍ Scribed by Erkki Kolehmainen; Jari Koivisto; Katri Laihia; Reijo Kauppinen; Jaakko Paasivirta

• Publisher: John Wiley and Sons
• Year: 1999
• Tongue: English
• Weight: 78 KB
• Volume: 37
• Category: Article
• ISSN: 0749-1581
• DOI: 10.1002/(sici)1097-458x(199905)37:5<359::aid-mrc460>3.0.co;2-3

✦ Synopsis

Two-dimensional homo-and heteronuclear NMR chemical shift correlation techniques were applied in the characterization of five tricyclic polychlorinated C 10 hydrocarbons, chlordene (1), heptachlor (2), trans-nonachlor (3), ˛-chlordene (4) and -chlordene (5), which are spread globally in the environment owing to their use as insecticides. Approximate and partly contradictory 1 H and 13 C NMR chemical shifts reported in the literature were corrected in this work. The chemical shift assignments of 1-5 were based on DQF COSY, HMQC and HMBC experiments. In addition, an INADEQUATE experiment was needed to ascertain the 13 C chemical shifts assignment of 2. The n J(H,H)s of 1-5 were solved by computer-assisted spectral analyses. Further, complete 1 H and 13 C NMR parameter sets of three oxy derivatives, heptachlor exo-epoxide (6), 1-exo-hydroxychlordene ( 7) and its acetate (8), were also determined. Compounds 7 and 8 were synthesized to be used as model compounds, and their NMR parameters are reported for the first time. By using solvent susceptibility matched symmetrical micro-NMR tubes and HMQC and HMBC experiments, 1-5 can be reliably characterized at submilligram levels by their 1 H and 13 C NMR parameters with a 500 MHz (11.8 T) spectrometer and a 5 mm diameter standard probehead.