1.3-Dithienium-and 1.3-Dithiolenium Salts, VI ,13C NMR Spectroscopic Investigations on 2-Substituted 1,3-Dithian-2-ylium Cations. Unusual γ-Effects
1997 ◽
Vol 52
(6)
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pp. 757-761
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Keyword(s):
13C Nmr
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Abstract The 13C NMR chemical shifts of 19 2-substituted 1,3-dithian-2-ylium-tetrafluorborates 1a-1s are discussed in comparison to known analogous 1,3-dithianes and 2-lithio-1,3-dithianes. The unusual γ-effects (up to 9 ppm), which can also observed in other six-membered ring systems, are explained by the electric field effect (σ-polarisation effect). The electron density distribution can be estimated qualitatively by comparison with the 1,3-dioxan-2-ylium-and cyclohexylcations.
1971 ◽
pp. 1218
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Keyword(s):
1968 ◽
Vol 46
(24)
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pp. 3813-3820
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1999 ◽
pp. 441-448
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Keyword(s):
1983 ◽
Vol 21
(12)
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pp. 727-729
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2021 ◽
Vol 1719
(1)
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pp. 012064
Keyword(s):