The crystal and molecular structures of two oligomeric aromatic ether-imides PhOArN(OC)2Ar'-XAr'( 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, C4oH24N2OsS.0.25 H20: orthorhombic, Pbnm; a= 5.628(1), b = 24.903(8), c =47.175(17)A. Crystal data for 5, C43H24F6NaO6: monoclinic, P21/c; a = 6.919(1), b = 11.977(2), c =43.203(9)A; fl = 94.23(2) °. Molecules of the sulfone-bridged oligomer 4 pack in discrete chevron-like lamellae, within which complementary, parallel ring-stacking (~ 3.5 ~ interplanar separation) occurs ~tween aminophenol (-NC6H40-) 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.
Посилання на статтю:
Single crystal X-ray studies of aromatic oligomers: structural models for polyimides derived from hexafluoroisopropylideneand sulfone-bridged dianhydrides / Howard M. Colquhoun and Caroline A. O'Mahoney and David J. Williams // Polymer. – 1994. – Vol 35. – P. 2265-2271.