Complete multinuclear magnetic resonance analysis of heterophospholanes and their sulfur, selenium and borane adducts
✍ Scribed by Javier Peralta-Cruz; Vladimir I. Bakhmutov; Armando Ariza-Castolo
- Publisher
- John Wiley and Sons
- Year
- 2001
- Tongue
- English
- Weight
- 167 KB
- Volume
- 39
- Category
- Article
- ISSN
- 0749-1581
- DOI
- 10.1002/mrc.817
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✦ Synopsis
Abstract
^1^H, ^11^B, ^13^C, ^15^N, ^31^P and ^77^Se NMR spectra were obtained for 1,3‐(dioxa, oxaza or diaza)‐2‐phospholanes and their sulfur, selenium and borane adducts. The relative sign of the ^3^J(^1^H, ^31^P)/^2^J(^13^C, ^31^P) coupling constants was found to be positive in the sulfur and selenium adducts for the methylene and methyl groups. Conversely, for the compound with a phosphorus lone pair and in the borane adducts this sign changes for the methylene groups. It was shown that the ^31^P NMR spectra recorded by the CPMG or INEPT‐HEED pulse sequences can be used for observation of the ^15^N–^31^P coupling constants. In all the investigated compounds the spin–lattice relaxation of ^31^P is controlled by the spin‐rotation mechanism. The dipole–dipole ^31^P–^11^B interactions can provide less than 20% of the relaxation rate in compounds containing the BH~3~ group. The transverse ^31^P relaxation is dominated by the scalar contribution. Copyright © 2001 John Wiley & Sons, Ltd.