Sulfone-Linked Paracyclophanes via Macrocyclic Aromatic Thioethers: Synthetic and Structural Investigations
✍ Scribed by Ian Baxter; Abderrazak Ben-Haida; Howard M. Colquhoun; Philip Hodge; Franz H. Kohnke; David J. Williams
- Publisher
- John Wiley and Sons
- Year
- 2000
- Tongue
- English
- Weight
- 309 KB
- Volume
- 6
- Category
- Article
- ISSN
- 0947-6539
No coin nor oath required. For personal study only.
✦ Synopsis
Reaction of 4,4'-sulfonylbis-(benzenethiol) with 4,4'-dichlorodiphenylsulfone under pseudo-high-dilution conditions leads to macrocyclic thioethersulfones [-S-Ar-SO 2 -Ar-] n (Ar 1,4phenylene). These include a highly strained [1 1] cyclodimer (n 2), a cyclotrimer resulting from thioetherexchange reactions, and a [22] cyclotetramer which can adopt two entirely different conformations in the crystalline state, one having molecular D 2d (ªtennis-ball-seamº) symmetry. The same type of reaction is successful using 4,4'-thiobis(benzenethiol) instead of 4,4'-sulfonylbis(benzenethiol) and affords macrocycles with a higher ratio of thioether to sulfone linkages. Exhaustive oxidation of macrocyclic thioether-sulfones with hydrogen peroxide affords a series of sulfone-linked paracyclophanes, [-Ar-SO 2 -] 4 , [-Ar-SO 2 -] 6 , [-Ar-SO 2 -] 8 and [-Ar-SO 2 -] 12 . Single crystal X-ray analysis reveals [Ar-SO 2 -] 4 to be a near-perfect square box, whilst the cyclic hexamer [-Ar-SO 2 -] 6 adopts a much more irregular conformation, and [-Ar-SO 2 -] 8 displays a ªdouble-boxº structure clearly related to that of [Ar-SO 2 -] 4 .