The valence and core electronic structure of three non-steroidal anti-inflammatory drugs (methyl salicylate, fenoprofen and ketoprofen) have been studied by photoelectron and soft X-ray absorption spectroscopy, supported by theoretical calculations of the molecular and electronic structure. The conformational landscape has been explored for sixteen low-energy conformers of fenoprofen and ketoprofen, and the energies of both compounds fall into two groups with steric similarities, separated by about 3 kJ mol⁻¹. Valence band photoelectron spectra agree with previous results, and the spectra have been calculated using two approaches. We find the outer valence Green's function method gives good results, but the P3+ method is a little better, particularly for outer valence ionic states. Carbon and oxygen 1s photoemission spectra are reported and are in acceptable agreement with the theory. The C and O K near-edge X-ray absorption fine structure spectra are reported and interpreted by comparison with reference compounds. We analyse the data to provide rough estimates of the energies of the unoccupied orbitals in methyl salicylate.

中文翻译：

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深入了解非甾体抗炎药的电子结构：气相中非诺洛芬、酮洛芬和水杨酸甲酯的软 X 射线研究


三种非甾体抗炎药（水杨酸甲酯、非诺洛芬和酮洛芬）的价态和核心电子结构已经通过光电子和软 X 射线吸收光谱进行了研究，并得到了分子和电子结构理论计算的支持。已经探索了 fenoprofen 和 ketoprofen 的 16 种低能构象异构体的构象图谱，两种化合物的能量分为两组，具有空间相似性，相隔约 3 kJ ^mol-1。价带光电子能谱与之前的结果一致，光谱是使用两种方法计算的。我们发现外价 Green 函数方法给出了很好的结果，但 P3+ 方法要好一些，特别是对于外价离子态。报告了碳和氧 1s 光电子发射光谱，并且与该理论一致。通过与参考化合物进行比较来报告和解释 C 和 O K 近边缘 X 射线吸收精细结构光谱。我们分析数据以粗略估计水杨酸甲酯中未占据轨道的能量。