Cross-dimerization of nitrosobenzenes in solution and in solid state
摘要:
Cross-linking of nitrosobenzenes to heterodimers (azodioxides) when they are not sterically crowded with large groups in ortho-position was studied by NMR and FT-IR spectroscopy, X-ray crystallography as well as by cryogenic photolysis. It was found for the first time that cross-linked dimers (heterodimers) exist both in solution and in solid state and that they appear in the crystal together with homodimers. The system is used as a model for studying organic solid solution formation. The role of molecular packing in formation of a weak chemical bond is also discussed. (C) 2008 Elsevier B.V. All rights reserved.
Abstract Possibility of nitrosobenzenes to form dimeric molecular structures (azodioxides) is used as a model for intermolecular selectivity investigations in solution as well as in solidstate. Cross-dimerization of different combinations of p- and m-substituted nitrosobenzene pairs was studied by variable temperature 1H NMR, solid-stateNMR (CP MAS), IR, and ab initio calculations. It is evident that
摘要 亚硝基苯形成二聚分子结构(偶氮二氧化物)的可能性被用作溶液和固态分子间选择性研究的模型。通过变温 1H NMR、固态 NMR (CP MAS)、IR 和 ab initio 计算研究了对和间取代亚硝基苯对的不同组合的交叉二聚。很明显,对亚硝基苯具有非选择性,因为它与所有研究的亚硝基苯伙伴形成二聚体。相反,对甲氧基亚硝基苯在大多数情况下不会形成二聚体。可以通过晶格中分子排列的影响来解释溶液中形成二聚体的能力与固态不同的证据。
Sakaue Sigeki, Tsubakino Takashi, Nishiyama Yutaka, Ishii Yasutaka, J. Org. Chem., 58 (1993) N 14, S 3633-3638