The synthesis of three novel disulfone-based monomers from readily available hexafluorobenzene and thiols for the preparation of homopolymers and copolymers of intrinsic microporosity (PIMs) is described. The disulfonyl-based PIMs derived from 5,5',6,6'-tetrahydroxy-3,3,3',3'-tetramethylspirobisindane (TTSBI) with tetrafluoroterephthalonitrile (TFTPN) and disulfone-based monomers were prepared at high temperature (160 degrees C) within 1 h. Three new copolymers (monomer molar ratio of TTSBI and disulfone-based monomers = 3: 1) show a good combination of properties, such as excellent film-forming characteristics and gas transport properties. Compared with a previously reported microporous nitrile-based homopolymer, referred to as PIM-1, the present sulfone-based copolymers have higher gas selectivities for O-2/N-2 and CO2/N-2, while showing some reduction in pure-gas permeabilities. The relationship between the structure and gas permeation behavior of the copolymers is discussed.