Nuclear magnetic resonance shift reagents: evidence for different mechanisms of contact contributions to C shifts induced by nickel and cobalt acetylacetonates with saturated amines and alcohols.
نویسندگان
چکیده
The pattern of (13)C and (1)H nuclear magnetic resonance (NMR) shift changes produced by complexation of cobalt and nickel acetylacetonates with amines and alcohols indicates that there is more than one mode of operation of the contact interaction. A large effect with alternating signs is important at the alpha and beta carbons, but this effect seems to be overlaid by another influence that appears to fall off monotonically as one proceeds away from the site of complexation.
منابع مشابه
Nuclear Magnetic Resonance Shift Reagents: Abnormal C Shifts Produced by Complexation of Lanthanide Chelates with Saturated Amines and n-Butyl Isocyanide.
Lanthanide-induced shfits of (13)C nuclear magnetic resonances are reported for several amines and n-butyl isocyanide. Contact contributions to such shifts, especially of beta carbons, are clearly important for the chelates of Eu(+3) and Pr(+3). The importance of contact terms is shown to change in a rather predictable manner with the structure of the amine.
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ورودعنوان ژورنال:
- Proceedings of the National Academy of Sciences of the United States of America
دوره 70 3 شماره
صفحات -
تاریخ انتشار 1973