We herein propose a new type of efficient neutral photoacidgenerator. A photoinduced 6π-electrocyclization reaction of photochromic triangle terarylenes triggers subsequent release of a Brønsted acid, which took place from the photocyclized form. A H-atom and its conjugate base were introduced at both sides of a 6π-system to form the self-containedphotoacidgenerator. UV irradiation to the 6π-system
我们在此提出了一种新型高效的中性光酸产生剂。光致变色三角四萘嵌苯的光诱导 6π-电环化反应触发了布朗斯台德酸的后续释放,该反应从光环化形式发生。在 6π 体系的两侧引入 H 原子及其共轭碱以形成自含的光酸产生剂。对 6π 系统的紫外线照射会产生一个带有 H 原子的环己-1,3-二烯部分和分别位于 sp(3) C-原子的 5 位和 6 位的共轭碱,这会自发地释放酸分子定量形成多环芳烃化合物。证明了在环境条件下光酸产生的净量子产率高达 0.52,并证明了环氧单体的光引发阳离子聚合。
Photon-Quantitative Reaction of a Dithiazolylarylene in Solution
作者:Sayo Fukumoto、Takuya Nakashima、Tsuyoshi Kawai
DOI:10.1002/anie.201006844
日期:2011.2.11
Ready for action: An excellent quantum yield was observed for a photocoloration reaction of a photochromic molecule based on a triangular terarylene structure. The molecule is brought into a conformation favorable for photocyclization by multiple intramolecular interactions, including CHN hydrogen bonding and SN and CHπ interactions (see picture).
Intramolecular Hydrogen Bonding in a Triangular Dithiazolyl-Azaindole for Efficient Photoreactivity in Polar and Nonpolar Solvents
作者:Sayo Fukumoto、Takuya Nakashima、Tsuyoshi Kawai
DOI:10.1002/ejoc.201100676
日期:2011.9
to a photoreactive state with C2-symmetry around the hexatriene reaction center. Temperature-dependent NMR studies and quantum chemical calculations indicated the contribution of intramolecular hydrogen-bonding between the central azaindole unit and the side thiazole units, which stabilizes the photoreactive C2-symmetric conformation and elevates the photoreactivity in both non-polar and polar solvents