Organic acids, aminoalcohols, and amides are key ingredients for life as we know it on Earth. Organic acids are prevalent in plant and animal tissues. Aminoalcohols are the direct chemical precursors to amino acids, the fundamental building blocks of proteins. Amides provide the molecular linkages that dictate protein structure. While some of the simplest versions in each class of molecules have been characterized, there is generally a lack of laboratory rotational spectroscopic data for representative species in these important biomolecule classes. In terms of the organic acids, both formic acid (HCOOH) and acetic acid (CH₃COOH) have been extensively characterized in the laboratory and detected in space. However, the next most complex organic acids, carbonic acid (HOCOOH) and glycolic acid (HOCOCH₂OH), have only limited spectral data available in the literature. The story is similar for amino alcohols, where aminoethanol (NH₂CH₂CH₂OH) has been studied in the laboratory, but the simpler amino alcohol, aminomethanol (NH₂CH₂OH), is not stable under typical laboratory conditions and has not yet been characterized. For the amides, formamide (NH₂CHO), acetamide (NH₂COCH₃), and glycolamide (H₂NCOCH₂OH) are well-characterized through laboratory studies, and formamide and acetamide have been detected in space. But the next most complex amide, carbamic acid (H₂NCOOH) has not been studied spectroscopically. We are therefore conducting laboratory rotational spectroscopic investigations of aminomethanol, carbonic acid, glycolic acid, and carbamic acid so that the necessary spectral information needed to guide observational searches for these important biomolecules is obtained. Glycolic acid can be purchased commercially; we have recently collected its spectrum up to 1 THz using direct absorption spectroscopic techniques in a long-pathlength flow cell spectrometer. Aminomethanol, carbonic acid, and carbamic acid cannot be purchased. We are therefore using O(¹D) insertion reactions with the precursor molecules methyl amine, formic acid, and formamide, to produce aminomethanol, carbonic acid, and carbamic acid, respectively. In this talk, we will report on the results from these laboratory studies and associated reaction models used to interpret our results. We will also present comparisons between the laboratory spectra and our database of broadband line surveys of 32 molecule-rich interstellar sources.

Chase Schultz

Appearances