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Simulating Low Temperature Photochemistry in Space - The Photoproduction of Organic Residues in Laboratory Interstellar Ice Analogs
New stars and planets form in dense interstellar molecular clouds. These clouds are sufficiently dense to screen out starlight from outside the cloud, so that the dust grains that are present in these dense clouds can get as cold as 10 K (-263 °C). At these temperatures, most gas-phase species other than hydrogen, helium, and neon will freeze out onto these cold dust grains, much as the water vapor in your breath freezes onto a cold window. As a result, most of the grains in dense clouds are coated with a mantle of ice that contains a variety of molecules. More...
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Hexamethylenetetramine (HMT) and HMT Variants: Major Photoproducts of the UV Irradiation of Interstellar Ices
Hexamethylenetetramine (HMT; chemical formula: C6H12N4, see image to the left was identified as a compound over 130 years ago. It was the first organic molecule on which X-ray crystallography was performed, and it was found to have tetrahedral symmetry. The infrared (IR) and Raman spectra of the solid and IR spectra More...
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Amino Acids and Their Production during the Photolysis of Astrophysically Relevant Ices
Amino acids are important biological molecules that serve as the basic molecular building blocks of proteins (including enzymes) used by all living things on Earth. All amino acids have a similar basic structure, with different amino acids differing only in the specific structure that lies in the chemical group or side carbon chain labeled “R”. More...
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Amphiphiles: A Major Photoproduct of the UV Irradiation of Interstellar Ices
Amphiphiles are long molecules that have a polar, hydrophilic (water-loving) ‘head’ group and a hydrophobic (water-fearing) ‘tail’. Molecules of this sort are common in detergents: in the presence of dirt they will orient themselves to surround the particles with their tails on the particle (away from the water) and their heads facing outward (into the water). This effectively couples the particle to the surrounding water and makes it easier to wash away. More...
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Nucleobases and Their Production during the Photolysis of Astrophysically Relevant Ices
DNA (deoxyribonucleic acid) and RNA (ribonucleic acid) play fundamental roles in carrying genetic information in all life on Earth. DNA is a macromolecule that has the structure of a double helix that looks like a twisted ladder in which the rungs of the ladder consist of matching pairs of nucleobases. RNA is similar to DNA, but has only one strand of the helix and uses a slightly different set of nucleobases. More...
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PAH-Related Photoproducts: Alcohols, Ketones, Hn-PAHs, Aromatic Heterocycles, and Other Substituted Aromatic Compounds
Polycyclic aromatic hydrocarbons (PAHs) represent one of the most abundant forms of carbon in the universe. They are seen in a wide variety of environments in space, and many varieties of these molecules are seen in meteorites as well as asteroidal and cometary dust. More...
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The Production of Sugars and Sugar Derivatives from the Photolysis of Astrophysically Relevant Ices
Sugars and sugar derivatives such as sugar alcohols, sugar acids, sugar diacids, and their corresponding deoxy variants (altogether sometimes referred to as ‘polyols’) are molecules that have a wide range of roles in modern biology. For example, the sugar glucose serves as the fuel source for cells, and it is also used More...
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