Novel macrocyclic aryl thioether ester oligomers have been synthesized in h
igh yield from phthaloyl dichloride and 4,4'-thiodiphenol under pseudo high
dilution conditions. The cyclic nature was unambiguously confirmed by a co
mbination of MALDI-TOF MS, gel permeation chromatography and NMR analyses.
Single-crystal X-ray diffraction of cyclic ester dimer reveals no severe st
rain on the cyclic structure. The free-radical ring opening polymerization
(ROP) of the macrocyclic oligomers was achieved to give high molecular weig
ht polymers via a transthioetherification reaction. The molecular weight of
the polymer resulting from ROP decreases as the conversion of cyclic oligo
mers increases after a polymerization period of 30 min.