Reduction of Nitroaromatic Compounds on the Surface of Metallic Iron: Quantum Chemical Study

International Journal of Molecular Sciences

Igor Zilberbergab³  Alexander Pelmenschikova³  Christian J. Mcgrathc²  William M. Davisc²  Danuta Leszczynskad¹ 

[1] Department of Civil Engineering, FAMU/FSU, College of Engineering, Tallahassee, FL 32310;U.S. Army Engineer Research and Development Center, Vicksburg, MS 39180;Computational Center for Molecular Structure and Interactions, Jackson State University, Jackson, MS 39217

关键词: Nitroaromatic compounds;    Semiempirical method NDDO/MC;    Nitrobenzene reduction;    Metallic iron;    Nitrosobenzene;   

DOI  :  10.3390/i3070801

来源: mdpi

【 摘 要 】

The initial reduction steps of nitroaromatic compounds on the surface of metallic iron have been studied theoretically using nitrobenzene (NB) as a representative of nitroaromatic compounds. The quantum chemical cluster approximation within the semiempirical Neglect of Diatomic Differential Overlap for Metal Compounds method was applied to model the Fe(110) crystallographic surface, taken as a representative reactive surface for granular iron. This surface was modeled as a 39-atom two-layer metal cluster with rigid geometry. The associative and dissociative adsorption of nitrobenzene was considered. Based on our quantum chemical analysis, we suggest that the direct electron donation from the metal surface into the π^* orbital of NB is a decisive factor responsible for subsequent transformation of the nitro group. Molecularly adsorbed NB interacts with metal iron exclusively through nitro moiety oxygens which occupy tri-coordinated positions on surface The charge transfer from metal to NB of approximately 2 atomic units destablizes the nitro group. As a result, the first dissociation of the N-O bond goes through a relatively low activation barrier. The adsorbed nitrosobenzene is predicted to be a stable surface species, though still quiet labile.

【 授权许可】

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