MAGNETIC RESONANCE IN CHEMISTRY
Magn. Reson. Chem. 37, 359–364 (1999)
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NMR spectroscopy in environmental chemistry: H and C
NMR parameters of tricyclic polychlorinated C10
hydrocarbons and their oxy derivatives based on
two-dimensional NMR techniques
Erkki Kolehmainen,* Jari Koivisto, Katri Laihia, Reijo Kauppinen and Jaakko Paasivirta
Department of Chemistry, University of Jyv a¨ skyl a¨ , P.O.B. 35, FIN-40351 Jyv a¨ skyl a¨ , Finland
Received 23 September 1998; revised 3 December 1998; accepted 7 December 1998
ABSTRACT: Two-dimensional homo- and heteronuclear NMR chemical shift correlation techniques were applied in
the characterization of five tricyclic polychlorinated C10 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.
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Approximate and partly contradictory H and 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.
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In addition, an INADEQUATE experiment was needed to ascertain the C chemical shifts assignment of 2. The
n
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J(H,H)s of 1–5 were solved by computer-assisted spectral analyses. Further, complete H and 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
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HMBC experiments, 1–5 can be reliably characterized at submilligram levels by their H and C NMR parameters
with a 500 MHz (11.8 T) spectrometer and a 5 mm diameter standard probehead. Copyright 1999 John Wiley &
Sons, Ltd.
KEYWORDS: NMR; H NMR; 13C NMR; two-dimensional NMR; tricyclic polychlorinated C10 hydrocarbons; oxy
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derivatives; computer-assisted spectral analysis; solvent susceptibility matched micro-NMR tubes
INTRODUCTION
heteronuclear chemical shift correlation techniques,
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3,14
15
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HMQC
and HMBC, to ascertain the H and
C
Tricyclic polychlorinated C10 hydrocarbons are globally
widespread environmental toxicants owing to their use as
NMR chemical shift assignments of 1–5 and their oxygen-
containing derivatives. J(H,H)s of these rigid tricyclic
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1
,2
insecticides and their chemical persistence. The iden-
tification of the components of chlordane (formerly one
of the most widely used pesticides) and their metabo-
lites and/or environmental degradation products is most
often based on gas chromatographic–mass spectrometric
structures can be further utilized in refining the struc-
tural vs NMR spectral relationships. Solvent susceptibility
matched micro-NMR tubes were tested for some of these
compounds especially to determine their detection limits
and to clarify the effect of resonance lineshape on their
computer-assisted spectral analysis.
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techniques. However, for their configuration and isomer-
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specific structure elucidation, H NMR parameters are of
predominant importance, as demonstrated in the case of
endo- and exo-epoxides of heptachlor (2). Further, the
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EXPERIMENTAL
Compounds
biological transformation of isomers, diasteremers and
even enantiomers of toxicants can be (stereo)selective,
and their uptake, metabolism and excretion can be very
3
,4
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Chlordene (1) (4,5,6,7,8,8-hexachloro-3a,4,7,7a-tetrahy-
dro-4,7-methano-1H-indene), heptachlor (2) (1-exo,4,5,6,
different. In the literature there are some H and
C
NMR data on polychlorinated tricyclic C10 hydrocar-
bons with more or less incomplete spectral analyses
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,8,8-heptachloro-3a,4,7,7a-tetrahydro-4,7-methano-1H-
indene), trans-nonachlor (3) (1-exo,2-endo,3-exo,4,5,6,7,
,8-nonachloro-3a,4,7,7a-tetrahydro-4,7-methanoindane),
-chlordene (4) (1,2,3,5,7,8-hexachloro-1,3a,4,5,6,6a-
hexahydro-1,4-ethanopentalene), ꢀ-chlordene (5) (2,3,3a,
,5,8-hexachloro-3a,6,7,7a-tetrahydro-1,6-methano-1H-
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–8
and/or contradictory chemical shift assignments.
The
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˛
aim of this study was to apply two-dimensional homonu-
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clear NMR techniques, DQF COSY , NOESY
and
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2
INADEQUATE, and proton detected, two-dimensional
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indene) and heptachlor epoxide (6) (1-exo-4,5,6,7,8,8-
heptachloro-2,3-exo-epoxy-3a,4,7,7a-tetrahydro-4,7-me-
thano-1H-indene) were commercial products: 1 (100%)
*
Correspondence to: E. Kolehmainen, Department of Chemistry, Uni-
versity of Jyv a¨ skyl a¨ , P.O.B. 35, FIN-40351 Jyv a¨ skyl a¨ , Finland.
E-mail: ekolehma@cc.jyu.fi
Copyright 1999 John Wiley & Sons, Ltd.
CCC 0749–1581/99/050359–06 $17.50