Dihydrophenanthrene-Type Intermediates during Photoreaction of <i>trans</i>-4‘-Benzyl-5-styrylfuran
作者:Shingo Samori、Michihiro Hara、Tong-Ing Ho、Sachiko Tojo、Kiyohiko Kawai、Masayuki Endo、Mamoru Fujitsuka、Tetsuro Majima
DOI:10.1021/jo047977x
日期:2005.4.1
using a Nd3+:YAG laser (30 ps, 5 mJ pulse-1 or 5 ns, 30 mJ pulse-1). Transient fluorescence and absorption spectra assigned to the singlet excited trans-BSF were observed during the 30-ps LFP, whereas a transient absorption spectrum with two peaks at 400 and 510 nm, assigned to the trans-fused dihydrophenanthrene (DHP)-type intermediate (DP1), was observed during the 5-ns LFP. It is clearly suggested that
的光反应的反式-4'-苄基-5-苯乙烯基呋喃(反式- BSF)已经研究了通过在CH 355-nm激光闪光光解(LFP)2氯2使用的Nd 3+:YAG激光(30个PS,5毫焦耳脉冲- 1或5纳秒,为30mJ脉冲-1)。分配给单重激发荧光瞬态和吸收光谱反式- BSF 30-PS LFP过程中观察到,而瞬态吸收光谱在400的两个峰和510nm的,分配给所述反式-融合二氢菲(DHP)型中间体(DP1)在5 ns LFP期间被观察到。清楚地表明,双光子吸收过程涉及DP1的形成。第一个光反应的光致异构反式- BSF,发生给顺- BSF。第二光反应过程是photocyclization顺- BSF,其发生以得到DP1与半衰寿命衰减(τ 1/ 2)2.8-4.0的微秒以产生另一个DHP型中间(DP2在400纳米的吸收峰)通过[1,9]-氢转移不存在O 2。DP2随τ1 /2 > 500μs衰减,通过芳构化得到产物。在O