title: An experimental and theoretical investigation of the C(1D) + D2reaction.
abstract: In a previous joint experimental and theoretical study of the barrierless chemical reaction C(1D) + H2at low temperatures (300-50 K) [K. M. Hickson, J.-C. Loison, H. Guo and Y. V. Suleimanov, J. Phys. Chem. Lett., 2015, 6, 4194], excellent agreement was found between experimental thermal rate constants and theoretical estimates based on ring polymer molecular dynamics (RPMD) over the two lowest singlet potential energy surfaces (PESs). Here, we extend this work to one of its isotopologues, C(1D) + D2, over the same temperature range. Experimental and RPMD results are in good agreement when contributions from both PESs to this chemical reaction are included in the RPMD simulations. The deviation between experiment and the RPMD calculations does not exceed 25% and both results exhibit a slight negative temperature dependence. The first excited1A'' PES plays a more important role than the ground1A' PES as the temperature is decreased, similar to our previous studies of the C(1D) + H2reaction but with a more pronounced effect. The small differences in temperature dependence between the earlier and present experimental studies of C(1D) + H2/D2reactions are discussed in terms of the use of non-equilibrium populations of ortho/para-H2/D2. We argue that RPMD provides a very convenient and reliable tool to study low-temperature chemical reactions.
authors.affiliation: Université de Bordeaux, Institut des Sciences Moléculaires, F-33400 Talence, France. km.hickson@ism.u-bordeaux1.fr and CNRS, Institut des Sciences Moléculaires, F-33400 Talence, France.
authors.forename: Kevin M
authors.initials: KM
authors.lastname: Hickson
authors.affiliation: Computation-based Science and Technology Research Center, Cyprus Institute, 20 Kavafi Str., Nicosia 2121, Cyprus and Department of Chemical Engineering, Massachusetts Institute of Technology, 77 Massachusetts Ave., Cambridge, Massachusetts 02139, USA. ysuleyma@mit.edu.
authors.forename: Yury V
authors.initials: YV
authors.lastname: Suleimanov