光化学量子产率是光开关的关键特性之一,其调谐具有挑战性。为了在流行的基于二芳基乙烯的开关中解决这个问题,我们探索了使用内部电荷转移 (CT)(一种易于控制的参数)来有效调制光环化量子产率的可能性。为此,设计了具有不同CT特性但具有相同光致变色核的同质三芳基化合物家族,二芳基乙烯的一个子类,并对其光致变色性能进行了充分研究。在环化量子产率和开关的 CT 特性之间发现了明显的相关性。更准确地说,在闭环量子产率和 (i) 伴随 S 0的电子密度变化之间建立了几乎线性的关系→ S 1跃迁和 (ii) LUMO 在活性碳原子上的百分比。这种相关性通过基态和第一激发态的联合光谱分析和理论建模合理化,引入了“早期”或“晚期”光致变色的概念。令人鼓舞的是,当应用于文献中报道的其他一些基于二芳基乙烯的开关时,这种潜在的预测模型似乎也具有相关性。
A self-contained photoacid generator for super acid based on photochromic terarylene
作者:Ruiji Li、Takuya Nakashima、Tsuyoshi Kawai
DOI:10.1039/c7cc01635b
日期:——
Super acid is efficiently released from a self-containedphotoacidgeneratorbased on a triangle terarylene backbone upon photoinduced 6[small pi]-electrocyclization reactions.
在光诱导的6π-电环化反应中,过酸从基于三角亚芳基骨架的自包含的光酸产生剂中有效释放。
Self-Contained Photoacid Generator Triggered by Photocyclization of Triangle Terarylene Backbone
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。
A Systematic Study of Suzuki-Miyaura Cross-Coupling Reactions on Thiazoleboronic Esters in the 4- and 5-Position
reaction of thiazoleboronic esters under microwave conditions is presented. Boronic acid esters were prepared in the 4- and 5-position of the thiazole ring and subsequently cross-coupled with a number of different (hetero)aryl halides. Yields of the coupling process depended on the reactivity of the boronic acid at the particular position in the thiazole system, as hydrolysis and subsequent deboronation
A series of highly sensitive neutral photoacidgenerators (PAGs) based on photochromicterarylenes was prepared. Like the example presented herein, these compounds show a subsequent thermal elimination of a Brønsted acid after a light‐triggered 6π‐electrocyclization, concomitant with the hexatriene aromatization. A novel type of molecular systems was developed, in which one thiazolyl moiety was replaced
Systematic studies of structural variations in terarylene photohydride generators
作者:Colin J. Martin、Jan Patrick Calupitan、Miho Minamide、Ryosuke Asato、Yora Goto、Gwénaël Rapenne、Takuya Nakashima、Tsuyoshi Kawai
DOI:10.1016/j.jphotochem.2020.112594
日期:2020.6
systematic study of structural and conformational variations in a series of terarylene molecules designed for use as photohydride generators. This family of compounds have been shown to facilitate self-contained hydride release, without the need for external sources of hydrogen in a manner analogous to previously reported photoacidgenerators. A systematic analysis has been carried out on the effects of minor