TY - JOUR
T1 - Single and double carbon vacancies in pyrene as first models for graphene defects
T2 - A survey of the chemical reactivity toward hydrogen
AU - Nieman, Reed
AU - Das, Anita
AU - Aquino, Adélia J.A.
AU - Amorim, Rodrigo G.
AU - Machado, Francisco B.C.
AU - Lischka, Hans
N1 - Publisher Copyright:
© 2016 Elsevier B.V.
PY - 2017/1/12
Y1 - 2017/1/12
N2 - Graphene is regarded as one of the most promising materials for nanoelectronics applications. Defects play an important role in modulating its electronic properties and also enhance its chemical reactivity. In this work the reactivity of single vacancies (SV) and double vacancies (DV) in reaction with a hydrogen atom Hr is studied. Because of the complicated open shell electronic structures of these defects due to dangling bonds, multireference configuration interaction (MRCI) methods are being used in combination with a previously developed defect model based on pyrene. Comparison of the stability of products derived from C[sbnd]Hr bond formation with different carbon atoms of the different polyaromatic hydrocarbons is made. In the single vacancy case the most stable structure is the one where the incoming hydrogen is bound to the carbon atom carrying the dangling bond. However, stable C[sbnd]Hr bonded structures are also observed in the five-membered ring of the single vacancy. In the double vacancy, most stable bonding of the reactant Hr atom is found in the five-membered rings. In total, C[sbnd]Hr bonds, corresponding to local energy minimum structures, are formed with all carbon atoms in the different defect systems and the pyrene itself. Reaction profiles for the four lowest electronic states show in the case of a single vacancy a complex picture of curve crossings and avoided crossings which will give rise to a complex nonadiabatic reaction dynamics involving several electronic states.
AB - Graphene is regarded as one of the most promising materials for nanoelectronics applications. Defects play an important role in modulating its electronic properties and also enhance its chemical reactivity. In this work the reactivity of single vacancies (SV) and double vacancies (DV) in reaction with a hydrogen atom Hr is studied. Because of the complicated open shell electronic structures of these defects due to dangling bonds, multireference configuration interaction (MRCI) methods are being used in combination with a previously developed defect model based on pyrene. Comparison of the stability of products derived from C[sbnd]Hr bond formation with different carbon atoms of the different polyaromatic hydrocarbons is made. In the single vacancy case the most stable structure is the one where the incoming hydrogen is bound to the carbon atom carrying the dangling bond. However, stable C[sbnd]Hr bonded structures are also observed in the five-membered ring of the single vacancy. In the double vacancy, most stable bonding of the reactant Hr atom is found in the five-membered rings. In total, C[sbnd]Hr bonds, corresponding to local energy minimum structures, are formed with all carbon atoms in the different defect systems and the pyrene itself. Reaction profiles for the four lowest electronic states show in the case of a single vacancy a complex picture of curve crossings and avoided crossings which will give rise to a complex nonadiabatic reaction dynamics involving several electronic states.
KW - C[sbnd]H bond formation
KW - Graphene
KW - Hydrogenation
KW - Multireference configuration interaction
KW - Single and double vacancies
UR - http://www.scopus.com/inward/record.url?scp=84995616589&partnerID=8YFLogxK
U2 - 10.1016/j.chemphys.2016.08.007
DO - 10.1016/j.chemphys.2016.08.007
M3 - Article
AN - SCOPUS:84995616589
SN - 0301-0104
VL - 482
SP - 346
EP - 354
JO - Chemical Physics
JF - Chemical Physics
ER -