Parent- and daughter-mediated halogenation reactions modeled for 1,2- and 1,4-dibromobenzene at Si(111)-7×7

Harikumar, K. R.; Petsalakis, Ioannis D.; Polanyi, J. C.; Theodorakopoulos, Giannoula

doi:10.1016/j.susc.2004.08.042

Cited by 21 publications

(38 citation statements)

References 26 publications

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“…Most of the present calculations have been carried out with the AM1 method, 17 embodied in the Gaussian 98 programs. 19 In previous work on benzene as well as 1,2-and 1,4-dibromobenzene adsorbed on Si(111), 8,14 the AM1 method was found to perform quite adequately, as compared with DFT-B3LYP calculations on smaller models, and also give reasonable rationalizations of experimental observations. While AM1 is not widely used for surface reactions, there have been previous studies of benzene at Si (100) with AM1 as well as with Hartree-Fock and with density functional methods, where it was found that the AM1 calculations were useful and led to new and unexpected configurations.…”

Section: Calculationsmentioning

confidence: 84%

“…Throughout the work, as was the case for our previous theoretical work 8,14 on similar systems, the experimental geometry has been retained for the models when they are calculated without any adsorbed molecules. For the systems consisting of the model plus the adsorbed molecule, geometry optimization was performed for the adsorbed molecule, for the two Si atoms (Si adatom and Si rest atom) directly involved in the attachment of the organic molecule to the surface, as well as for the three Si atoms directly bonded to each of the above two Si atoms.…”

Section: Calculationsmentioning

confidence: 99%

“…In this manner larger positive value for the calculated binding energy implies stronger binding. As mentioned above, the procedure followed in previous work on benzene 8 and 1,2-and 1,4-dibromobenzene on Si(111), 14 did not involve any geometry optimization on the Si cluster model when it was considered alone without any adsorbed molecule. Geometry optimization was carried out on the free organic molecule, while for the combined system, molecule-Si cluster, geometry optimization was carried out for the organic molecule, the Si rest atom, and the Si adatom involved in the C-Si bonds, as well as the three Si atoms attached to the particular Si rest atom and those attached to the Si adatom (i.e., the coordinates of a total of 8 Si atoms, as well as those of the organic molecule).…”

Section: Chemisorbed Structures In the 14-cyclohexadiene Type Of Attmentioning

confidence: 99%

“…The adsorption of benzene (and to a lesser extent halogen-substituted benzene) on silicon surfaces and in particular on Si(111)7×7 has been the subject of a large number of studies. [1][2][3][4][5][6][7][8][9][10][11][12] Beyond the determination of the geometry of physisorbed and chemisorbed benzene, subjects of investigation have been the modes of binding of chlorobenzene, 3,9-11 1,2-and 1,4-dichlorobenzene 12 and 1,2-, 1,3-, and 1,4-dibromobenzene on Si(111)7×7, 13,14 as well as the energetics for transfer of the halogen atom from the organic molecule to the surface. 10,14 Halogen-containing hydrocarbons are of interest because of their possible technological applications such as in photochemical etching as a means to device fabrication.…”

Section: Introductionmentioning

confidence: 99%

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Theoretical study of halogen‐substituted benzene at a Si(111)7×7 surface

Petsalakis

Theodorakopoulos

2005

Israel Journal of Chemistry

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The adsorption of halobenzene (for halogens F, Cl, Br, and I) on Si(111)7×7 was investigated using AM1 quantum mechanical calculations. First the 1,4‐cyclohexadiene type of chemisorbed structures with two C—Si bonds at C atoms 1 and 4 have been calculated. Generally, the calculated binding energy increases with the size of the halogen atom, in the series F, Cl, Br, and I. The sp2 carbon positions are the most favorable for the halogen atom, and for bromobenzene and iodobenzene there is significant additional stabilization for the geometry that allows interaction of the halogen atom with a nearby Si adatom. This stabilization hinders the transfer of the heavier halogen atoms, Br and I, to the surface. Other chemisorbed structures, involving formally divalent halogen atoms in a C‐X‐Si type of binding, have also been found to correspond to energy minima in the AM1 calculations. Furthermore, it was possible to calculate physisorbed structures for chlorobenzene and bromobenzene once the Si rest atoms were capped with H atoms. Two types of binding structures are suggested for chemisorption in excess of three molecules per half‐unit cell: one is a radical structure binding by a single C‐Si adatom bond, and the second one is binding by a single C‐X‐Si adatom interaction. Both of these singly‐bonded structures have been calculated to correspond to energy minima with binding energies smaller than the 1,4‐cyclohexadiene type of chemisorbed structure.

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Section: Calculationsmentioning

confidence: 84%

Section: Calculationsmentioning

confidence: 99%

Section: Chemisorbed Structures In the 14-cyclohexadiene Type Of Attmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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Theoretical study of halogen‐substituted benzene at a Si(111)7×7 surface

Petsalakis

Theodorakopoulos

2005

Israel Journal of Chemistry

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“…At issue are some of the key questions, including the number of benzene adstructures on Si(100)2×1 and the relative stabilities of these adstructures. 12,25 Furthermore, substituted derivatives of benzene that replace H atoms on the ring with chemically active functional groups (including amine 9 and the halogen atom [27][28][29][30][31][32][33][34] have attracted a lot of recent attention. Some of these studies examine the reaction mechanisms and the possibilities of generating an organo-silicon interface by manipulating the frontier orbitals and the energy gaps of the adstructures.…”

Section: Introductionmentioning

confidence: 99%

Surface Chemistry of Monochlorinated and Dichlorinated Benzenes on Si(100)2×1: Comparison Study of Chlorine Content and Isomeric Effects

2006

J. Phys. Chem. B

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Using X-ray photoelectron spectroscopy (XPS) and temperature-programmed desorption (TPD), the room temperature (RT) adsorption and thermal evolution of monochlorobenzene (MCB) and 1,3-dichlorobenzene (1,3-DCB) on Si(100)2×1 have been investigated and compared with that of 1,2-dichlorobenzene (1,2-DCB) reported previously. Like 1,2-DCB, the C 1s features observed at 284.6 (C 1 ) and 286.0 eV (C 2 ) for both MCB and 1,3-DCB could be attributed to the C-H and C-Cl bonds, respectively. The C 1 /C 2 intensity ratios for MCB (5.0) and 1,3-DCB (2.0) are found to follow the stoichiometric ratios of the C-H to C-Cl bonds for MCB and 1,3-DCB, respectively, indicating that both MCB and 1,3-DCB adsorb on Si(100)2×1 molecularly with negligible C-Cl dissociation at RT, in marked contrast to the partial C-Cl dissociation found for 1,2-DCB. Unlike 1,2-DCB with two discernible Cl 2s features at 270.3 and 271.2 eV, a single Cl 2s feature at 271.2 eV is observed for MCB and 1,3-DCB, in accord with the single local chemical environment for Cl. The TPD results show that MCB undergoes molecular desorption exclusively, similar to that found for benzene. Both molecular desorption and recombinative HCl desorption are found for 1,3-DCB, similar to that for 1,2-DCB. Despite the different Cl contents and relative Cl locations on the benzene ring, both MCB and 1,3-DCB exhibit RT adsorption behavior remarkably similar to that of benzene. To explain the C-Cl dissociation observed for 1,2-DCB, we propose a possible transition state involving the Cl atoms located at more physically compatible positions with the surface Si dimers in order to facilitate the conversion of 1,2-DCB (preferentially over 1,3-DCB) to dissociated products at RT. However, the thermal evolution of 1,3-DCB is closer to that of 1,2-DCB than that of MCB and benzene. The breakage of C-Cl bonds is found to occur at a relatively low temperature of 425 K, which suggests a relatively low activation barrier for the dechlorination of 1,3-DCB adspecies. Calculated energetics for 1,4-DCB on Si(100)2×1 shows that double dechlorination is not as favorable a process as those for 1,2-DCB and 1,3-DCB.

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Influence of Functional Groups in Substituted Aromatic Molecules on the Selection of Reaction Channel in Semiconductor Surface Functionalization

Teplyakov

2012

Functionalization of Semiconductor Surfaces

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Parent- and daughter-mediated halogenation reactions modeled for 1,2- and 1,4-dibromobenzene at Si(111)-7×7

Cited by 21 publications

References 26 publications

Theoretical study of halogen‐substituted benzene at a Si(111)7×7 surface

Theoretical study of halogen‐substituted benzene at a Si(111)7×7 surface

Surface Chemistry of Monochlorinated and Dichlorinated Benzenes on Si(100)2×1: Comparison Study of Chlorine Content and Isomeric Effects

Influence of Functional Groups in Substituted Aromatic Molecules on the Selection of Reaction Channel in Semiconductor Surface Functionalization

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