关键词: 紫外分光光度法, 硫酸, 分子结构, 碳13核磁共振谱法, 氯仿, 弛豫时间, 极化, 亚砜 P, 聚芳醚酮

This paper studies the structure and polarization of model compounds of poly (aryl ether ketone) in solution of H2SO4 and CDCl3 or CDCl3+DMSO-d6. Results show that these compounds are greatly polarized in H2SO4, that is, their carbonyl carbons have shorter spin-lattice relaxation time (T1) and greater chemical shifts while their quaternary carbons connected to the carbonyl group have short T1 but smaller chemical shifts. This polarization produces new maximum absorption at about 400nm (λmax in UV spectrum). The average dihedral angle of these model compounds relative to the molecular Zig-Zag plane are 36° to 39°, based on which the Mulliken charges of different polarization models are calculated. All of these support the polarization mechanism that the bridge-bonds are protonated and/or effected by dipole-dipole interaction of H2SO4, which unlocalizes the changes on aryl-rings.

Key words: ULTRAVIOLET SPECTROPHOTOMETRY, SULFURIC ACID, MOLECULAR STRUCTURE, C13 NMR SPECTROMETRY, CHLOROFORM, RELAXATION TIME, POLARIZATION, SULFOXIDE P, POLYETHERKETONE