화학공학소재연구정보센터
Polymer, Vol.35, No.11, 2265-2271, 1994
Single-Crystal X-Ray Studies of Aromatic Oligomers - Structural Models for Polyimides Derived from Hexafluoroisopropylidene-Bridged and Sulfone-Bridged Dianhydrides
The crystal and molecular structures of two oligomeric aromatic ether-imides PhOArN(OC)2Ar’-X-Ar’(CO)2NArOPh [X=-SO2- (4) or -C(CF3)2- (5); Ar=a 1,4- and Ar’=a 1,3,4-substituted aromatic residue] have been determined by single crystal X-ray diffraction. Crystal data for 4, C40H24N2O8S.0.25 H2O : orthorhombic, Pbnm; a = 5.628(1), b = 24.903(8), c = 47.175(17) angstrom. Crystal data for 5, C43H24F6N2O6 : monoclinic, P2(1)/c, a = 6.919(1), b = 11.977(2), c = 43.203(9) angstrom; beta = 94.23(2)-degrees. Molecules of the sulfone-bridged oligomer 4 pack in discrete chevron-like lamellae, within which complementary, parallel ring-stacking (approximately 3.5 angstrom interplanar separation) occurs between aminophenol (-NC6H4O-) and arene-imide [-Ar(CO)2NAr’-] residues. In contrast, the hexafluoroisopropylidene-bridged oligomer 5 packs in a linearly displaced, non-lamellar fashion in the crystal, the structure showing no evidence for adjacent stacking of electronically complementary molecular sub-units.