Kinetic Stabilization and Reactivity of π Single-Bonded Species: Effect of the Alkoxy Group on the Lifetime of Singlet 2,2-Dialkoxy-1,3-diphenyloctahydropentalene-1,3-diyls
作者:Tomoyuki Nakagaki、Tomoko Sakai、Tsutomu Mizuta、Yoshihisa Fujiwara、Manabu Abe
DOI:10.1002/chem.201300038
日期:2013.7.29
Kinetic stabilization and reactivity of π single‐bonded species have been investigated in detail by generating a series of singlet 2,2‐dialkoxy‐1,3‐diphenyloctahydropentalene‐1,3‐diyls (DRs). The lifetime at 293 K in benzene was found to increase when the carbon chain length of the alkoxy groups was increased; 292 ns (DRb; OR=OR′=OCH3) <880 ns (DRc; OR=OR′=OC2H5) <1899 ns (DRd; OR=OR′=OC3H7) ≈2292 ns
通过生成一系列单重态2,2-二烷氧基-1,3-二苯基八氢戊烯-1,3-二基(DR s),对π单键物质的动力学稳定性和反应性进行了详细研究。发现当烷氧基的碳链长度增加时,在苯酚中293 K的寿命增加。292 ns(DRb ; OR = OR'= OCH 3)<880 ns(DRc ; OR = OR'= OC 2 H 5)<1899 ns(DRd ; OR = OR'= OC 3 H 7)≈2292ns(DRe ; OR = OR'= OC 6 H 13)≈2146ns(DRf ; OR = OR'= OC 10 H 21)。具有混合乙缩醛部分的DRh(OR = OC 3 H 7,OR'= OCH 3; 935 ns)是寿命更长的物种,比另一种非对映体DRg(OR = OCH 3,OR'= OC 3 H 7); 516 ns)。为一阶衰变过程确定的激活参数表明,焓因子在决定闭环反应的能垒(即