THE NATURE OF FORMALDEHYDE IN ITS LOW-LYING EXCITED STATES
THE NATURE OF FORMALDEHYDE IN ITS LOW-LYING EXCITED STATES
复制标题
甲醛在低位激发态下的性质
DOI：
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发表时间：
1958
期刊：
影响因子：
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通讯作者：
V. DiGiorgio
中科院分区：
文献类型：
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作者：
G. Robinson;V. DiGiorgio
−78 °C下H2 CO和D2CO的近紫外长光程、高分辨率光谱。已经获得，并提出了进一步的强有力的证据，支持非平面激发态。单重态-单重态系统长波长一侧的双头带属于单重态-三重态跃迁。振动分析和部分转动分析表明，激发三重态是非常相似的激发单重态。三重态中较大的C-O伸缩频率可能是简单脂肪族醛和酮中这些态的多重性的特征。发现两种状态下的C-O键级非常接近1.5，并指出这些状态下的成键与甲酸中的C-O键具有惊人的相似性。由于自旋相关规则，单重态和三重态激发态之间的相似性可能不会扩展到化学行为，但是没有一般的理由说明为什么三重态应该更具反应性。
Long path length, high resolution spectra in the near ultraviolet of H2CO and D2CO at −78 °C. have been obtained, and further strong evidence in support of a non-planar excited state is presented. The double-headed bands to the long wavelength side of the singlet–singlet system are shown to belong to the singlet–triplet transition. A vibrational analysis and partial rotational analysis shows the excited triplet state to be very similar to the excited singlet state. The larger C—O stretching frequency in the triplet state may characterize the multiplicity of these states in the simple aliphatic aldehydes and ketones. It is found that the C—O bond order in both states is very nearly 1.5, and striking similarities between the bonding in these states and the C—O bonding in formic acid are pointed out. The similarity between the singlet and triplet excited states may not extend to chemical behavior because of spin correlation rules, but there are no general reasons why the triplet state should be more reactive...