THz Spectroscopy of Candidate Prebiotic Species: Exploring the Conformational Energy Landscape of Flexible Molecules and the Limits of Interstellar Molecular Complexity

在这个由化学部实验物理化学计划和天文科学部银河天文学计划资助的项目中，加州理工学院的杰弗里·布莱克教授将对益生菌物种进行太赫兹(THz)光谱研究，包括3C糖、氨基酸和二肽。特定的靶分子是甘油醛、1，3-二羟基-2-丙酮、甘氨酸(Gly)和丙氨酸(Ala)。同样要研究的还有结构上相关的3C化合物二甲基碳酸酯。这些研究形成了随后对最简单的二肽，即甘氨酸-甘氨酸、甘氨酸-丙氨酸、丙氨酸-甘氨酸和丙氨酸-丙氨酸的基础。实验室研究的结果将用于对这些物种进行天文搜索。量子化学计算的结果将被用来缩小太赫兹搜索窗口，也将被用来构建准确的分子内力场模型。现有太赫兹光谱仪的灵敏度将得到提高，以便能够观测到计划中要研究的最复杂物种的光谱特征。这项研究将在研究生和本科生的帮助下进行，其中包括妇女和代表性不足的少数群体成员。除了这些活动，布莱克教授领导的小组还积极参与加州理工学院的SEED和CAPSIK-12教育计划，并正在为各种年级开发新的光谱学和天文学教学模块。

In this project, funded by the Experimental Physical Chemistry Program of the Chemistry Division and the Galactic Astronomy Program of the Division of Astronomical Sciences, Prof. Geoffrey Blake of the California Institute of Technology will conduct a research program in Terahertz (THz) spectroscopy of prebiotic species, including 3C sugars, amino acids, and dipeptides. Specific target molecules are glyceraldehyde, 1,3-dihydroxy-2-propanone, glycine (gly), and alanine (ala). Also to be investigated is the structurally related 3C compound dimethylcarbonate. These investigations form the basis for subsequent studies of the simplest dipeptides namely gly-gly, gly-ala, ala-gly, and ala-ala. The results of the laboratory studies will be used to undertake astronomical searches for these species. The results of quantum chemical calculations will be used to narrow down the THz search windows and also to construct accurate models of intramolecular force fields. The sensitivity of the available THz spectrometers will be improved to enable the observation the spectral signatures of the most complex species to be studied in the program. This research will be conducted with the assistance of graduate and undergraduate students, including women and members of underrepresented minorities. In addition to these activities, the group headed by Prof. Blake is strongly involved in the Caltech SEED and CAPSIK-12 educational programs, and is developing new teaching modules in spectroscopy and astronomy for a variety of grade levels.