ELECTRONIC AND MOLECULAR STRUCTURAL INVESTIGATIONS

前一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 在pi-pi*的光谱区域激发时的波长 吸收。每个发射区的激发光谱为 相同，但激发光谱不同于直接 测量的吸收光谱。这是第一个具有 被观察到会散发出。 刻画(1)对称性，(2)寿命和(3) 发射状态的波长有两种不同类型 实验要么已经实施，要么已经启动。2个光子 测量了共振多光子(RMPI)电离光谱 在pi-pi*吸收区域和邻近的3p-里德堡 过渡。观察到该分子没有严格的中心。 对称的。观察到RMPI信号不对应于 吸收光谱。后者表明，两种不同的 具有显著不同物理特性的状态为 包含在标称pi-pi*吸收包络内。 用于时间分辨排放测量的仪器正在开发中 开发成使两个发射波长区域能够 已确定，但这些测量进展不够 在这个时候被报道。

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.