New soluble aromatic polyimides have been prepared from 4,4’-(hexafluoroisopropylidene)bis(phthalic anhydride)(6FDA) and 4,4’-(alkylenediyldioxy)dianilines. Their structures were determined by i.r., H-1 n.m.r. and C-13 n.m.r. spectroscopic measurements, based on model compounds prepared by reacting 6FDA with p-anisidine. These polymers show low glass transition temperatures and good solubility in various solvents, and are stable up to 440-degrees-C in a nitrogen atmosphere.