Abstract
Isotopic fractionation in interstellar clouds can occur by ion-molecule reactions at low temperatures. The major effect is not kinetic but thermodynamic in origin in that it arises from the difference in rate coefficients between forward and backward directions in reactions which exchange isotopic atoms. In this article, we concentrate on deuterium fractionation in interstellar clouds; this effect enhances the relative abundances of deuterated isotopomers to their normal counterparts by up to four orders of magnitude as compared with the basic D/H elemental abundance ratio. We also discuss the fractionation of 15N and 13C.
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Aikawa, Y., and Herbst, E.:1999, ‘Deuterium Fractionation in Protoplanetary Disks’ Astrophys. J. 526, 314–326.
Caselli, P., Stantcheva, T., Shalabiea, O., Shematovich, V.I., and Herbst, E.:2002, ‘Deuterium Fractionation on Interstellar Grains Studied with Modified Rate Equations and a Monte Carlo Approach’ Plan. Space Sci. in press.
Charnley, S.B., Tielens, A.G.G.M., and Rodgers, S.D.: 1997, ‘Deuterated Methanol in the Orion Compact Ridge’ Astrophys. J 482, L203–L206.
Clary, D.C.: 1988, ‘Theory of Reactive Collisions at Low Temperatures’, in T.J. Millar and D.A. Williams (eds.) Rate Coefficients in Astrochemistry Kluwer, Dordrecht, pp. 1–16.
Cordonnier, M., Uly, D., Dickman, R.M., Kerr, K.E., Zhang, Y., and Oka, T.: 2000, ‘Selection Rule fo Nuclear Spin Modifications in Ion-Neutral Reactions Involving H. V, J. Chem. Phys. 113, 3181–3193.
Federman, S.R., Lambert, D.L., Sheffer, Y., Cardelli, J.A., Andersson, B.-G., van Dishoeck, E.F., and Zsargo, J.: 2002, ‘Further Evidence for Chemical Fractionation from Ultraviolet Observations of Carbon Monoxide’ Astrophys. J. in press.
Gerlich, D., Herbst, E., and Roueff, E.:2002, ‘H3 + HD • H2D+ + H2: Low-temperature Laboratory Measurements and Interstellar Implications’ Plan. Space Sci. in press.
Henchman, M.J., Paulson, J.F., Smith, D., Adams, N.G., and Lindinger, W.: 1988, ‘Chemical Pathways for Deuterium Fractionation in Interstellar Molecules’ in T.J. Millar and D.A. Williams (eds.) Rate Coefficients in Astrochemistry, Kluwer, Dordrecht, pp. 201–208.
Herbst, E.: 1982, ‘The Temperature Dependence of the HCO+/DCO+ Abundance Ratio in Dense Interstellar Clouds’ Astron. Astrophys. 111 76–80S.
Herbst, E.: 1996, ‘Gas Phase Reactions’, in G.W.F. Drake (ed.) Atomic Molecular and Optical Physics Handbook Amer. Inst. of Physics, Woodbury, NY, pp. 429–440.
Herbst, E.: 2001, ‘The Chemistry of Interstellar Space’ Chem. Soc. Rev. 30 168–176.
Herbst, E., and Klemperer, W.: 1973, ‘The Formation and Depletion of Molecules in Dense Interstellar Clouds’ Astrophys. J 185 505–533.
Kallenbach, R. etal.: 1998, ‘Isotopic Composition of Solar Wind Nitrogen: First In Situ Determina-tion With The CELIAS/MTOF Spectrometer Aboard SOHO’ Astrophys. J 507, L185–L188.
Lambert, D.L., Sheffer, Y., Gilliland, R.L., and Federman, S.R.: 1994, ‘Interstellar Carbon Monoxide Toward Zeta Ophiuchi’ Astrophys. J 420 756–771.
Langer, W.D., Graedel, T.E., Frerking, M.A., and Armentrout, P.B.: 1984, ‘Carbon and Oxygen Isotope Fractionation in Dense Interstellar Clouds’ Astrophys. J. 277 581–604.
Le Bourlot, J.: 1991, ‘Ammonia Formation and the Ortho-to-Para Ratio of H2 in Dark Clouds’ Astron. Astrophys. 242 235–240.
Le Teuff, Y.H., Millar, T.J., and Markwick, A.J.: 2000, ‘The UMIST Database for Astrochemistry 1999’ Astron. Astrophys. Suppl. Ser. 146 157–168.
Millar, T.J., Bennett, A., and Herbst, E.: 1989, ‘Deuterium Fractionation in Dense Interstellar Clouds’ Astrophys. J. 340 906–920.
Millar, T.J., Roberts, H., Markwick, A.J., and Charnley, S.B.: 2000, ‘The Role of H2D+ in the Deuteration of Interstellar Molecules’ Phil. Trans. Roy. Soc. Lond. A 358 2535–2547.
Owen, T., Mahaffy, P.R., Niemann H.B. Atreya, S., and Wong, M.: 2001, ‘Protosolar Nitrogen’ Astrophys. J. 553 L77–L79.
Roberts, H., and Millar, T.J.: 2000a, ‘Modelling of Deuterium Chemistry and its Application to Molecular Clouds’ Astron. Astrophys. 361 388–398.
Roberts, H., and Millar, T.J.: 2000b, ‘Gas-phase Formation of Doubly Deuterated Species’ Astron. Astrophys. 364 780–784.
Roberts H. Herbst, E., and Millar, T.J.: 2002, ‘The Importance of new Rate Coefficients for Deuterium Fractionation Reactions on Interstellar Chemistry’ Month. Not. Roy. Astron. Soc. 336 283–290.
Roueff, E., Tiné, S., Pineau des Forêts, G., Falgarone, E., and Gerin, M.: 2000, ‘Detection of Doubly Deuterated Ammonia in L134N’ Astron. Astrophys. 354 L63–L66.
Rowe, B.R.: 1988, ‘Studies of Ion-Molecule Reactions at T < 80 K’, in T.J. Millar and D.A. Williams (eds.) Rate Coefficients in Astrochemistry Kluwer, Dordrecht, pp. 135–152.
Sidhu, K.S., Miller, S., and Tennyson, J.: 1992, ‘Partition Functions and Equilibrium Constants for H3 and H2D+’ Astron. Astrophys. 255 453–456.
Terzieva, R., and Herbst, E.: 2000, ‘The Possibility of Nitrogen Isotopic Fractionation in Interstellar Clouds’ Month. Not. Roy. Astron. Soc. 317 563–568.
Williams, D.A., and Herbst, E.: 2002, ‘It’s a Dusty Universe: Surface Science in Space’ Surface Science 500 823–837.
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Herbst, E. (2003). Isotopic Fractionation by Ion-Molecule Reactions. In: Kallenbach, R., Encrenaz, T., Geiss, J., Mauersberger, K., Owen, T.C., Robert, F. (eds) Solar System History from Isotopic Signatures of Volatile Elements. Space Sciences Series of ISSI, vol 16. Springer, Dordrecht. https://doi.org/10.1007/978-94-010-0145-8_19
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DOI: https://doi.org/10.1007/978-94-010-0145-8_19
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