Orientation and bonding of biphenyldimethyldithiol

Abstract

Abstract:The molecular orbitals of 1, 1′-biphenyl-4,4′-dimethyldithiol (HS-CH 2 -C 6 H 4 -C 6 H 4 -CH 2 -SH) are identified from combined photoemission and inverse photoemission studies and compared with theory for several different surfaces, molecular conformations and molecular orientations. The preferential molecular orientations of biphenyldimethyldithiol, on both Au(111) and polycrystalline Co, are identified from polarization resolved photoemission studies. Two different molecular orientations are adopted by biphenyldimethyldithiol on gold depending on adsorption conditions. Biphenyldimethyldithiol is observed to bond more strongly to cobalt than gold surfaces.

Defect contributions to conductivity in poly(3‐hexylthiophene)?

“…As is typical [5,11,[15][16][17][18][19], except for the lowest unoccupied molecular orbitals of RR-P3HT, there is good qualitative agreement with experiment ( Figure 1).…”

“…Similar semiempirical molecular orbitals calculations have recovered much of the detail observed in large molecular systems using photoemission and inverse photoemission, including reproducing with reasonable agreement the highest occupied molecular orbital (HOMO) to lowest unoccupied molecular orbital (LUMO) gap for closo-carborane molecular fi lms [15], fl uorinated polymer fi lms [16], multilayer fi lms of biphenyldiisocyanide [17], biphenyldimethyldithiol [18], and tris(8-hydroxyquinoline) aluminum (Alq3) [19]. The model calculations were undertaken on short chain length polymers (from one to 16 repeat units) that were hydrogen terminated to prevent excessive folding as is typical of such calculations [5].…”

“…The difference between orbital energies for RR-P3HT obtained in theory (referenced to the vacuum level) and the experimental binding energies with respect to the Fermi level, obtained for RR-P3HT from the photoemission spectra is about 5.3 eV. This value is typical in comparing the calculated spectra with other conducting polymers [5,15] and molecular adsorbates [11,[16][17][18].…”

Photohole Screening Effects in Polythiophenes with Pendant Groups

“…19,20 Similar semiempirical molecular orbitals calculations have recovered much of the detail observed in large molecular systems using photoemission and inverse photoemission, including reproducing, with reasonable agreement, the highest occupied molecular orbital (HOMO) to lowest unoccupied molecular orbital (LUMO) gap for closo-carborane molecular films, 21 fluorinated polymer films, 22 multilayer films of biphenyldiisocyanide, 23 biphenyldimethyldithiol, 24 and tris(8-hydroxyquinoline) aluminum (Alq 3 ). 25 Hydrogen terminated (to prevent excessive folding) short chain length (from 1 to 16 repeat units for P3HT and 1 unit for PEDOT) polymers were used for our simplistic model calculations, as has been done elsewhere.…”

Cobaltocene adsorption and dissociation on Cu(111)

“…The light polarization dependent angle-resolved photoemission experiments were carried out using synchrotron radiation, dispersed by a 3 m toroidal monochromator, at the Center for Advanced Microstructure and Devices (CAMD) in Baton Rouge, LA, as described elsewhere [33][34][35]. The measurements were performed in an ultra high vacuum (UHV) chamber employing a hemispherical electron energy analyzer with an angular acceptance of ±1°, as described elsewhere [35].…”