1,2-■■酮於有機凝相中的吸收光譜顯示, 在約363 nm及 395 nm左右有
兩帶主要之吸收峰, 吸收係數約在10～10之範圍 , 且具紅位移性質, 故
其最低激發單態為(π,π*)。在450 nm至650 nm間有螢光放射, 但無可測
得之磷光 利用做為比對劑, 於環己烷,四氯化碳、苯及甲醇中測得各螢
光量子產率值分別為0.15、0.02、0.019及0.0045,呈現出相當明顯之溶劑
效應。根據焠熄原理,利用Stern-Volmer理論式,求得螢光之生命期約
為9.8 ns。 1,2-■■酮與四甲基乙烯在去氧情況下於苯中照光, 約八小
時後,可生成兩種主要產物:一為黃色之1,2光加成產物oxetane２ , 產率
約為15%;另一則為紫黑色之1,4光加成產物dioxene３, 產率僅約3%。若以
二苯甲酮做為敏光劑,黃色化合物之產率可提升至約35%左右。經以上1,2-
■■酮的吸收光譜,光激發光光譜、焠熄效應及光敏化反應等結果之分
析, 兩主產物皆可能是由1,2-■■酮分子之T(ｎ,π*)能階參與反應所生
成。

The absorption spectrum of aceanthrenequinone,１, in non-polar
solvent shows a composition of two bands peaking at 363 nm and
395 nm with absorption coefficients 1000 ～ 10000. The red
shift of both bands in polar solvent re- veals that the lowest
excited singlet state of １ is (π,π*). The emission band
peaking at 450 nm to 650 nm was the fluorescence of compound １.
No phosphorescence could be measured even in the low
temperature matrix.The fluore- scence quantum yields of
compound １in cyclohexane, car- bon tetrachloride, benzene and
methanol, with referring to anthracene, were 0.15, 0.02, 0.019
and 0.0045, respective- ly. The lifetime of fluorescence of
compound １ was esti- mated as 9.8 ns by Stern-Volmer equation
in assuming the diffusion-limit rate of triethylamine quenching
study. The photoaddition of compound １ with triethylamine
proceeded in degassed benzene. The two major products were
obtained in 8 hours' irradiation. One is a 1,2-pho- toaddition
adduct, oxetane, ２, in 15% yield, and the o- ther is a
1,4-photoaddition adduct, dioxene, ３, in 3% yield. The yield
of compound ２ was raised to 35% in the presence of
photosensitizer, benzophenone. Both of these two products may
come from the second low excited triplet (ｎ,π*) state of
compound １ in the analysis of the ab- sorption and emission
spectrum as well as the quenching studies.
The absorption spectrum of aceanthrenequinone,１, in non-polar