Solution structures of [IrH2(1,5-cyclooctadiene) (bisphosphine)](CF3SO3) complexes. Homo- and heteronuclear long-range couplings from hydride and phosphorus spins to cyclooctadiene protons
✍ Scribed by Werner J. Hälg; Lars R. Öhrström; Heinz Rüegger; Luigi M. Venanzi
- Publisher
- John Wiley and Sons
- Year
- 1993
- Tongue
- English
- Weight
- 712 KB
- Volume
- 31
- Category
- Article
- ISSN
- 0749-1581
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✦ Synopsis
Abstract
The solution structures of the two all‐cis stereoisomers of IrH~2~(COD)((−)‐chiraphos) and the four all‐cis stereoisomers of IrH~2~(COD)((−)‐norphos) [COD = cycloocta‐1,5‐diene, (−)‐chiraphos = 2__S__,3__S__‐bis(diphenyl‐ phosphino)butane, (−)‐norphos = 2__R__,3__R__‐bis(diphenylphosphino)norbornene] were assigned on the basis of various one‐ and two‐dimensional correlation methods. The rationalization of a specifically observed scalar coupling interaction between one of the hydrides and a methylene proton of the cyclooctadiene moiety required an assignment of all the relevant protons including their stereochemical relationship. Analogous long‐range coupling pathways were also found for the heteronuclear interactions ^n^J(P,H) and an interpretation of the origin of these scalar couplings is provided in the form of an expansion of the known geometric dependence of allylic and homoallylic couplings.