title: Structure and layer interaction in carbon monofluoride and graphane: a comparative computational study.
abstract: Carbon monofluoride (CF)(n) and graphane are two very different materials from the practical point of view, but the basic chemical motifs of these materials are closely related: both can be described as two-dimensional polycyclic (fluoro-/hydro-)carbons. However, the actual experimental data on the structure of these materials is ambiguous ((CF)(n)) or scarce (graphane). Herein, we report a detailed computational study of structure of (CF)(n) and graphane, both in a monolayer configuration and in three-dimensional stacked arrangements. A crucial point in achieving a proper description of layer interactions is the use of a nonlocal density functional to describe long-range dispersion attraction from first principles. We find strong qualitative and quantitative similarities between the two materials in both conformational energetics (including a "gauche-chair" conformational motif not considered in previous studies) and layer stacking arrangements. A molecular mechanics force field is derived for (CF)(n) that performs exceptionally well at reproducing our quantum chemical results and fits into a very general OPLS/AA molecular mechanics framework. The combined results of quantum chemical calculations and classical molecular dynamics simulations using the new force field suggest a pathway to explain the too-small experimental in-plane lattice constant values observed in these materials, as well as the variation of interlayer distance in (CF)(n), on the common basis of conformational disorder.
authors.affiliation: Institute of Biochemical Physics, Russian Academy of Sciences, Kosygin st. 4, Moscow, 119334 Russia.
authors.forename: Vasilii I
authors.initials: VI
authors.lastname: Artyukhov
authors.forename: Leonid A
authors.initials: LA
authors.lastname: Chernozatonskii
mesh_terms: D003198:Computer Simulation; D005465:Fluorocarbon Polymers / Q000737:chemistry*; D006108:Graphite / Q000737:chemistry*; D008956:Models, Chemical; D015394:Molecular Structure; D011789:Quantum Theory
chemical_list: D005465:Fluorocarbon Polymers; C017647:polycarbon monofluoride; D006108:Graphite