Sulfone-linked paracyclophanes via macrocyclic aromatic thioethers: Synthetic and structural investigations

• Published in: Chemistry : a European journal Vol. 6; no. 23; pp. 4285 - 4296
• Main Authors: Baxter, Ben-Haida, A, Colquhoun, HM, Hodge, P, Kohnke, FH, Williams, DJ
• Format: Journal Article
• Language: English
• Published: BERLIN Wiley 01.12.2000
• Subjects: Chemistry; Chemistry, Multidisciplinary; Physical Sciences; Science & Technology; oxidations; SQUARE; arenes; macrocycles; sulfur; POLYMERIZATION; CRYSTAL; nucleophilic aromatic substitution; OLIGOMERS
• ISSN: 0947-6539; 1521-3765
• DOI: 10.1002/1521-3765(20001201)6:23<4285::AID-CHEM4285>3.3.CO;2-4

Reaction of 4,4'-sulfonylbis(benzenethiol) with 4,4'-dichlorodiphenylsulfone under pseudo-high-dilution conditions leads to macrocyclic thioethersulfones [-S-Ar-SO2-Ar-](n) (Ar=1,4-phenylene). These include a highly strained [1+1] cyclodimer (n=2), a cyclotrimer resulting from thioetherexchange reactions, and a [2+2] cyclotetramer which can adopt two entirely different conformations in the crystalline state, one having molecular D-2d ("tennis-ball-seam") 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 thioethersulfones with hydrogen peroxide affords a series of sulfone-linked paracyclophanes, [-Ar-SO2-](4), [-Ar-SO2-](6), [-Ar-SO2-](8) and [-Ar-SO2-](12). Single crystal X-ray analysis reveals [Ar-SO2-](4) to be a near-perfect square box, whilst the cyclic hexamer [-Ar-SO2-](6) adopts a much more irregular conformation, and [-Ar-SO2-](8) displays a "double-box" structure clearly related to that of [Ar-SO2-](4).