A pair of 8-shaped poly(tetrahydrofuran)s, poly(THF)s, having a metathesis-cleavable olefinic unit of isomeric forms at the focal position, IIaand IIb, has been synthesized through an electrostatic self-assembly and covalent fixation(ESA-CF) process using a telechelic poly(THF) having N-phenylpyrrolidinium salt groups carrying a tetracarboxylate counteranion containing a trans-3-hexenyl group, as equilibrated isomeric forms of Iaand Ib. The subsequent metathesis cleavage reaction of the olefinic group in IIaand IIbhas been conducted with a second generation Grubbs catalyst in the presence of ethyl vinyl ether. The polymer topology was thus converted from a dicyclic 8-shape into two simple loops having the two distinctive sizes consisting of one and two prepolymer units, IIIaand IIIb, respectively, corresponding to the linking mode of the two prepolymer segments on the pair of carboxylate groups at either the neighboring or the remote sites of the tetracarboxylate. Moreover, MALDI−TOF mass analysis has been performed for a series of the SEC-fractionated metathesis cleavage products. The absence of any fraction corresponding to polymeric [2]catenane products implies that the entanglement of the two prepolymer segments does not occur even though they are placed spatially close to each other. [ABSTRACT FROM AUTHOR]