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dc.contributor.authorTao, Franklin Feng
dc.contributor.authorWang, Zhong Hai
dc.contributor.authorChen, Xian Feng
dc.contributor.authorXu, Guo Qin
dc.date.accessioned2015-11-20T20:03:54Z
dc.date.available2015-11-20T20:03:54Z
dc.date.issued2002-02-21
dc.identifier.citationTao, Feng, Zhong Hai Wang, Xian Feng Chen, and Guo Qin Xu. "Selective Attachment of Benzonitrile on Si(111)-7×7: Configuration, Selectivity, and Mechanism." Phys. Rev. B Physical Review B 65.11 (2002). http://dx.doi.org/10.1103/PhysRevB.65.115311en_US
dc.identifier.urihttp://hdl.handle.net/1808/18958
dc.descriptionThis is the published version. Copyright 2002 American Physical Societyen_US
dc.description.abstractThe cycloaddition of benzonitrile with Si(111)-7×7 has been investigated as a model system for understanding the interaction of conjugated π-electron systems with Si(111)-7×7 using high-resolution electron energy loss spectroscopy, x-ray photoelectron spectroscopy (XPS), ultraviolet photoelectron spectroscopy, scanning-tunneling microscopy (STM), and density-functional-theory calculation (perturbative Beck-Perdew functional in conjugation with a basis set of DN**). Vibrational features of chemisorbed benzonitrile unambiguously demonstrate that the cyano group directly interacts with Si surface dangling bonds, evidenced in the disappearance of C≡N stretching mode around 2256 cm−1 coupled with the appearance of C=N stretching mode at 1623 cm−1 and the retention of all vibrational signatures of phenyl ring. XPS shows that both C 1s and N 1s core levels of the cyano groups display large down-shifts by 2.5 and 1.5 eV, respectively, after chemisorption. A smaller down-shift of ∼0.8 eV is observed for the C 1s core level of phenyl group due to the weaker inductive effect of the formed C=N groups in chemisorbed benzonitrile than that of C≡N groups in physisorbed molecules. Compared with physisorbed molecules, the photoemission from πCN orbitals of chemisorbed benzonitrile is significantly reduced, suggesting the direct involvement of πCN in the surface binding. These experimental results show that the covalent attachment of benzonitrile on Si(111)-7×7 occurs in a selective manner through the (2+2) cycloaddition between the cyano group and the adjacent adatom-rest atom pair. The cycloadduct formed contains an intact phenyl ring protruding into vacuum, retaining aromaticity. This functionalized Si surface may serve as a substrate for further modification or act as an intermediate for fabrication of multilayer organic thin films or materials syntheses in vacuum.en_US
dc.publisherAmerican Physical Societyen_US
dc.titleSelective attachment of benzonitrile on Si 111 -7Ã7: Configuration, selectivity, and mechanismen_US
dc.typeArticle
kusw.kuauthorTao, Franklin Feng
kusw.kudepartmentChemical & Petroleum Engren_US
dc.identifier.doi10.1103/PhysRevB.65.115311
kusw.oaversionScholarly/refereed, publisher version
kusw.oapolicyThis item does not meet KU Open Access policy criteria.
dc.rights.accessrightsopenAccess


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