IR and UV matrix photochemistry and solvent effects: the isomerization of diazocyclohexadienones (ortho quinone diazides) — detection of molecules with the 1,2,3-benzoxadjazole structure. A UV/Vis and IR absorption and UV photoelectron spectroscopic investigation
作者:Arinin Schweig、Horst Baumgartl、Reinhard Schulz
DOI:10.1016/0022-2860(91)87070-x
日期:1991.7
disproving current textbook opinions. The 1,2,3-benzoxadiazole structure is derived from the agreement of observed and calculated vertical ionization energies, characteristic IR and UV/Vis absorption bands as well as selective IR and UV photochemical transformations. The relative concentration of the respective l,2,3-benzoxadiazole in equilibrium with the diazoketone isomer strongly depends on the substituents
摘要 6-重氮-2,4-环己二烯酮及其具有氟、氯、甲基、叔丁基和甲氧基取代基的衍生物已通过紫外/可见吸收、红外吸收和紫外光电子能谱进行了研究。在气相、10 K 的氩气基质和室温下的正己烷溶液中获得的光谱结果揭示了与相应的 1,2,3-苯并恶-二唑异构体的平衡,从而反驳了当前教科书的观点。1,2,3-苯并恶二唑结构源自观察和计算的垂直电离能、特征红外和紫外/可见吸收带以及选择性红外和紫外光化学转化的一致性。与重氮酮异构体平衡的相应 1,2,3-苯并恶二唑的相对浓度很大程度上取决于取代基和溶剂效应。重氮酮结构通过氢键和极性相互作用稳定。本研究中最稳定的 1,2,3- 苯并恶二唑,即 5,7-二叔丁基衍生物,比其重氮环己二烯酮价异构体至少稳定 6.3 kJ mol -1,而 2,3,4,5 -四氟-6-重氮-2,4-环己二烯酮和3-甲氧基-6-重氮-2,4-环己二烯酮没有显着异构化。讨论了稳定 1