title: Formation of the -N(NO)N(NO)- polymer at high pressure and stabilization at ambient conditions.
abstract: A number of exotic structures have been formed through high-pressure chemistry, but applications have been hindered by difficulties in recovering the high-pressure phase to ambient conditions (i.e., one atmosphere and 300 K). Here we use dispersion-corrected density functional theory [PBE-ulg (Perdew-Burke-Ernzerhof flavor of DFT with the universal low gradient correction for long range London dispersion)] to predict that above 60 gigapascal (GPa) the most stable form of N2O (the laughing gas in its molecular form) is a one-dimensional polymer with an all-nitrogen backbone analogous to cis-polyacetylene in which alternate N are bonded (ionic covalent) to O. The analogous trans-polymer is only 0.03∼0.10 eV/molecular unit less stable. Upon relaxation to ambient conditions, both polymers relax below 14 GPa to the same stable nonplanar trans-polymer. The predicted phonon spectrum and dissociation kinetics validates the stability of this trans-poly-NNO at ambient conditions, which has potential applications as a type of conducting nonlinear optical polymer with all-nitrogen chains and as a high-energy oxidizer for rocket propulsion. This work illustrates in silico materials discovery particularly in the realm of extreme conditions (very high pressure or temperature).
authors.affiliation: Materials and Process Simulation Center, California Institute of Technology, Pasadena, CA 91125, USA.
authors.forename: Hai
authors.initials: H
authors.lastname: Xiao
authors.forename: Qi
authors.initials: Q
authors.lastname: An
authors.forename: William A
authors.initials: WA
authors.lastname: Goddard
authors.forename: Wei-Guang
authors.initials: WG
authors.lastname: Liu
authors.forename: Sergey V
authors.initials: SV
authors.lastname: Zybin
mesh_terms: D007700:Kinetics; D008956:Models, Chemical; D015394:Molecular Structure; D009609:Nitrous Oxide / Q000737:chemistry*; D060739:Phonons; D058105:Polymerization; D011312:Pressure
chemical_list: D009609:Nitrous Oxide