Density functional calculations have been performed on molecular models of silica defects and their C2H4 adducts. The results are consistent with a previous experimental infrared characterization that was interpreted in terms of C2H4 addition to the SiO2 skeleton at both the oxygen-bridge and silicon-link vacancy defects produced by argon bombardment. The geometries and thermodynamical stabilities of the proposed species and other possible adducts have been evaluated. The calculated C = C, C = O and C-H stretching frequencies are in good agreement with the experimental values and confirm the validity of the previous interpretation, helping to clarify some unclear details. (C) 1998 Elsevier Science B.V.
Theoretical analysis of ethylene adducts to ion-bombarded porous silica
RE, Nazzareno;
1998-01-01
Abstract
Density functional calculations have been performed on molecular models of silica defects and their C2H4 adducts. The results are consistent with a previous experimental infrared characterization that was interpreted in terms of C2H4 addition to the SiO2 skeleton at both the oxygen-bridge and silicon-link vacancy defects produced by argon bombardment. The geometries and thermodynamical stabilities of the proposed species and other possible adducts have been evaluated. The calculated C = C, C = O and C-H stretching frequencies are in good agreement with the experimental values and confirm the validity of the previous interpretation, helping to clarify some unclear details. (C) 1998 Elsevier Science B.V.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
