Isolation and X-ray Structures of Labile Benzoic- and Acetic-Acidium Carbocations

New carbocationic salts (via O-protonation of substituted benzoic acids) are prepared for the first time by controlled hydration of the corresponding benzoylium salts and isolated in pure crystalline form. Precise X-ray structural analyses reveal the rather unexpected (electronic) structure of the carboxylic-acidium functionality.本研究首次通过对应苯甲酰鎓盐（benzoylium salts）的可控水合反应，制备出经由取代苯甲酸O-质子化得到的新型碳正离子盐（carbocationic salts），并以纯结晶形式分离得到。精准的X射线结构分析揭示了羧酸鎓官能团（carboxylic-acidium functionality）颇为出人意料的（电子）结构。