Chiral molecules in the ISM: the best candidates

Details Chiral molecules in the ISM: the best candidates Chiral molecules in the ISM: the best candidates

May 2011

adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2011iaus..280p.303p&link_type=abstract

The Molecular Universe, Posters from the proceedings of the 280th Symposium of the International Astronomical Union held in Tole

Statistics

Computation

Scientific paper

In this report we address the question of whether some chiral molecules have a probability of being detected in the interstellar medium (ISM). It is a crucial question since life on Earth, as we know it today, is inseparable from homochirality. Under these conditions, the identification of any chiral species in the interstellar medium (ISM) would be a considerable breakthrough in the pursuit of the origin of life. To this end we rely on the Minimum Energy Principle that states that the most abundant isomer of a given generic formula should be that of lowest energy (Lattelais et al. 2009). We present here computations of the relative stability of complex organic molecules (COMs) believed to be potentially able to exist in the ISM under a chiral isomeric form. Such a search is submitted to a number of constraints. The molecules we are looking for should present precise characteristics, namely: i) have no improper axis of rotation Sn; possess at least one asymmetric center ; ii) satisfy the Minimum Energy Principle; iii) be small with a large enough dipole moment to be possibly identified through their radio millimeter rotational spectra. The energies and dipole moments are calculated by means of quantum simulations based on density functional theory (DFT). The result is that no chiral isomer in the C3H6O (acetone), C2H5ON, C3H7ON (amides), C2H5O2N, C3H7O2N (amino acid) families is the most stable species. This is also true of the C2(H2O)2 and C3(H2O)3 species when restricted to the sugar families, but another chiral molecule of the same chemical formula, i.e. lactic acid HOCH(CH3)COOH is found to be the most stable of all structures. Two other molecules with an NH2 group, namely, NH2CH(CH3)CN, the precursor of α-alanine and NH2CH(CH3)OH, the simplest chiral molecule (beyond halogen or isotopically substituted methane curiosities) are also the most stable species in their respective families. These three molecules satisfy the conditions for being detected according to the Minimum Energy Principle. With dipoles moments of 2.3, 2.7 and 1.6 Debye respectively, they make appealing targets. The present study should encourage laboratory experiments to determine rotational constants of higher precision prior to submission of observation proposals.

Affiliated with

Also associated with

No associations

Rating

Chiral molecules in the ISM: the best candidates does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.

If you have personal experience with Chiral molecules in the ISM: the best candidates, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Chiral molecules in the ISM: the best candidates will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-930576