New Alkali Metal Primary Amide Ladder Structures Derived from tBuNH2: Building Cisoid and Transoid Ring Conformations into Ladder Frameworks
✍ Scribed by William Clegg; Kenneth W. Henderson; Lynne Horsburgh; Fiona M. Mackenzie; Robert E. Mulvey
- Book ID
- 101300175
- Publisher
- John Wiley and Sons
- Year
- 1998
- Tongue
- English
- Weight
- 97 KB
- Volume
- 4
- Category
- Article
- ISSN
- 0947-6539
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✦ Synopsis
Two novel alkali metal amide ladder complexes have been synthesised and crystallographically characterised. Derived from the same primary amine precursor (tBuNH 2 ), they represent important additions to the series of ladder arrangements previously established within secondary amide chemistry. Thus the sodium amide ´amine complex [{[tBuN(H)Na] 3 ´H2 NtBu} I ] forms an infinite wavelike ladder structure. Covering three nitrogen ± sodium rungs, its curved sections display a cisoid conformation of amide substituents; but where these curved sections fuse, a transoid conformation is found. Every third sodium cation along the ladder framework is ligated by a tert-butylamine solvent molecule. In contrast, the heterobime-
, adopts a finite oligomeric ladder structure limited to only four nitrogen ± metal rungs in length. The central rungs contain lithium, while the outer rungs contain sodium. As in the all-sodium structure, the ladder is curved; there is a mixture of cisoid and transoid ring conformations within its framework. TMEDA solvent molecules complete the structure by chelating the sodium cations at the ladder ends.