Synthesis of HCN and HNC in Ion-Irradiated N2-Rich Ices

Details Synthesis of HCN and HNC in Ion-Irradiated N2-Rich Ices Synthesis of HCN and HNC in Ion-Irradiated N2-Rich Ices

Nov 2002

adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2002nla..work..208m&link_type=abstract

NASA Laboratory Astrophysics Workshop, held May 1-3 2002 at NASA Ames Research Center, Moffett Field, CA 94035-1000. Publisher:

Astronomy and Astrophysics

Astrophysics

Scientific paper

Near-IR observations reveal that nitrogen-rich ice containing small amounts of methane, CH4, and carbon monoxide, CO, is abundant on the surfaces of Triton, a moon of Neptune, and Pluto (Cruikshank et al.. 1993; Owen et al., 1993). N2-rich apolar ices are also possible in some interstellar environments (Ehrenfreund et al., 1998). To investigate the radiation chemical behavior of N2-dominated ices we performed a systematic IR study of ion-irradiated N2-rich ices containing CH4 and CO. Experiments at 18 K, showed that HCN, HNC, and the reactive molecule diazomethane, CH2N2, formed along with several radicals. NH3 was also identified in irradiated N2 + CH4. Comparing results from similarly photolyzed ices (Bohn et al., 1994) shows that the significant difference between radiolysis and photolysis of these N2-dominated ices is that photolyzed ices do not form detectable HCN and HNC. Our experiments examined different N2/CH4 ratios, the half-life of CH4, possible HCN and HNC formation routes, and competing pathways in the presence of CO. Intrinsic band strengths (A(HCN) and A(HNC)) were measured and used to calculate nearly equal values of HCN and HNC yields in N2+CH4 irradiated ices. Low temperature results apply to interstellar ices. Reaction products that appear at 30-35 K are also expected to form and survive on the surfaces of Triton and Pluto and interstellar grains. We examined the evolution of ice features as species undergo acid-base (acids such as HCN, HNC, HNCO and a base NH3) reactions triggered by warming from 18 K to 30-35 K. We identified anions (OCN-, CN- and N3-) attributed to relatively stable salts in ices where NH4+ is the likely cation. These results also have an astrobiology implication since many of these products (HCN, HNC, HNCO, NH3, NH4OCN, and NH4CN) are reactants used in synthesis studies of bio- molecules such as amino acids and peptides.

Affiliated with

Also associated with

No associations

Rating

Synthesis of HCN and HNC in Ion-Irradiated N2-Rich Ices 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 Synthesis of HCN and HNC in Ion-Irradiated N2-Rich Ices, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Synthesis of HCN and HNC in Ion-Irradiated N2-Rich Ices will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-1192936