ELECTRONIC AND MOLECULAR STRUCTURAL INVESTIGATIONS

电子和分子结构研究

• 批准号: 3940614
• 负责人: R MCDIARMID
• 金额: --
• 依托单位: NATIONAL INSTITUTE OF DIABETES AND DIGESTIVE AND KIDNEY DISEASES
• 依托单位国家: 美国
• 资助国家: 美国
• 起止时间: 至
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/3940614
• 关键词: Raman spectrometry; chemical structure; cis trans isomerization; diene; electronic spectra; infrared spectrometry; molecular energy level; polyenes; spectrometry; ultraviolet spectrometry

Preliminary experiments carried out the previous year suggest that 1,1,4,4- tetramethyl butadiene emits light at two different wavelengths when excited in the spectral region of the pi-pi* absorption. The excitation spectrum for each emission region is the same, but the excitation spectrum differs from the directly measured absorption spectrum. This is the first diene that has been observed to emit. To characterize (1) the symmetry of, (2) the lifetime of and (3) the wavelength of the emitting state two different types of experiments were either implemented or initiated. The 2 photon resonant multiphoton (RMPI) ionization spectrum was measured over the region of pi-pi* absorption and the adjacent 3p-Rydberg transition. The molecule was observed not to have a strict center of symmetry. The RMPI signal was observed not to correspond to the absorption spectrum. The latter suggests that two different states with significantly different physical properties are contained within the nominal pi-pi* absorption envelope. Instrumentation for time resolved emission measurements is being developed to enable the two emission wavelength regions to be identified, but these measurements have insufficiently progressed to be reported at this time.

去年进行的初步实验表明， 1，1，4，4-四甲基丁二烯在两种不同的温度下发光， 当在π-π * 的光谱区域中激发时的波长 吸收 每个发射区域的激发光谱是 相同，但激发光谱不同于直接 测量的吸收光谱。 这是第一个 被观察到排放。 为了表征（1）的对称性，（2）的寿命和（3） 发射状态的波长是两种不同类型的 实验要么被实施，要么被启动。 2光子 测量了共振多光子（RMPI）电离谱 在π-π * 吸收区和邻近的3 p-Rydberg区 过渡 观察到该分子没有严格的中心 对称性。 观察到RMPI信号不对应于 吸收光谱。 后者表明，两种不同的 具有显著不同物理性质的状态是 包含在标称π-π * 吸收包络内。 用于时间分辨排放测量的仪器正在 开发以使两个发射波长区域能够 已确定，但这些测量尚未取得充分进展 在这个时候报告。