One- and two-dimensional 15N NMR spectroscopy of tris(trimethylsilyl)-, tris(trimethylstannyl)-, tris(trimethylplumbyl)-amine and tetrakis(trimethyistannyl)hydrazine: Sign determination of various scalar coupling constants
✍ Scribed by Bernd Wrackmeyer; Hong Zhou
- Book ID
- 102528534
- Publisher
- John Wiley and Sons
- Year
- 1990
- Tongue
- English
- Weight
- 342 KB
- Volume
- 28
- Category
- Article
- ISSN
- 0749-1581
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✦ Synopsis
Abstract
The signs of the coupling constants ^1^J(^29^Si^15^N) and ^1^J(^119^Sn^15^N) are positive and negative, respectively, in tris(trimethylsilyl)‐ and tris(trimethylstannyl)‐amine. This results from two‐dimensional (2D) ^15^N/^1^H heteronuclear shift correlations [at natural abundance of ^15^N, based on long‐range couplings ^3^J(^1^N ^1^H), with respect to the positive coupling constants ^2^J(^29^SiC ^1^H) and ^2^J(^119^SnC ^1^H)]. The same type of experiment proves the negative sign of ^1^J(^119^Sn^15^N) in tetrakis(trimethylstannyl)hydrazme and it allows the unambiguous assignment of ^1^J(^119^Sn^15^N) and ^2^J(^119^SnN ^15^N). In tris(trimethylplumbyl)‐amine, the largest value (335.7 Hz) reported so far for ^1^J(^207^Pb ^15^N) of plumbylamines is observed. In the case of tris(trimethylstannyl)amine, the 2D ^15^N/^1^H experiment also gave the sign of ^4^J(^119^SnNSnC^1^H) (positive), and this is used in the 2D ^119^Sn/^1^H experiment to prove a negative sign for ^2^J(^119^Sn ^117^Sn).