5,5‘-Tetrahydroxy-3,3,3‘,3‘-tetramethyl spirobisindane (TTSBI) was deprotonated with potassium tert -butoxide and polycondensed with di(ethylene glycol) tosylate or tri(ethylene glycol) tosylate. Polycondensations in DMSO gave cleaner reaction products than in DMF. At concentrations of 0.1 or 0.2 mol/L no cross-linking was observed and multicyclic polyethers were isolated. The high yields (up to 99%), the 1 H NMR and the MALDI−TOF mass spectra proved almost complete conversion. The DSC measurements indicated an amorphous character with two glass-transition temperatures. The SEC measurements showed rather narrow mass distributions with polydispersities below 2. The multicyclic polyethers dissolved lithium, sodium, potassium, and cesium benzoate in tetrahydrofuran at weight ratios around 1/50 (salt/multicycle).
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Kricheldorf et al. (2007) studied this question.
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