Triptycene-terminated thiolate and selenolate monolayers on Au(111)
نویسندگان
چکیده
To study the implications of highly space-demanding organic moieties on the properties of self-assembled monolayers (SAMs), triptycyl thiolates and selenolates with and without methylene spacers on Au(111) surfaces were comprehensively studied using ultra-high vacuum infrared reflection absorption spectroscopy, X-ray photoelectron spectroscopy, near-edge X-ray absorption fine structure spectroscopy and thermal desorption spectroscopy. Due to packing effects, the molecules in all monolayers are substantially tilted. In the presence of a methylene spacer the tilt is slightly less pronounced. The selenolate monolayers exhibit smaller defect densities and therefore are more densely packed than their thiolate analogues. The Se-Au binding energy in the investigated SAMs was found to be higher than the S-Au binding energy.
منابع مشابه
Relative Stability of Thiolate and Selenolate SAMs on Ag(111) Substrate Studied by Static SIMS. Oscillation in Stability of Consecutive Chemical Bonds
The stability of chemical bonds at the molecule− metal interface is of fundamental importance for a majority of applications based on organic materials. It remains, however, extremely difficult to determine this stability using experimental and theoretical methods. A detailed analysis of the static SIMS (SSIMS) data obtained for the homologous series of thiolateand selenolate-based self-assembl...
متن کاملThe interface structure of n-alkylthiolate self-assembled monolayers on coinage metal surfaces.
The current state of understanding of the structure of the metal/thiolate interface of n-alkylthiolate 'self-assembled monolayers' (SAMs) on Cu(111), Ag(111) and Au(111) is reviewed. On Cu(111) and Ag(111) there is now clear evidence that adsorbate-induced reconstruction of the outermost metal layer occurs to a less atomically-dense structure, with the S head-group atom bonded to four-fold and ...
متن کاملSurface dipoles and work functions of alkylthiolates and fluorinated alkylthiolates on Au(111).
We study the dipole formation at the surface formed by -CH(3) and -CF(3) terminated short-chain alkylthiolate monolayers on Au(111). In particular, we monitor the change in work function upon chemisorption using density functional theory calculations. We separate the surface dipole into two contributions, resulting from the gold-adsorbate interaction and the intrinsic dipole of the adsorbate la...
متن کاملPreparation and characterization of 4'-donor substituted stilbene-4-thiolate monolayers and their influence on the work function of gold.
Self-assembled monolayers of E-stilbene-4-thiolate (SAM1), E-4'-(ethoxy)stilbene-4-thiolate (SAM2), and E-4'-(dimethylamino)stilbene-4-thiolate (SAM3) on Au(111) have been obtained from reaction of ethanol solutions of the corresponding S-acetyl derivatives with gold substrates. A combination of X-ray photoelectron spectroscopy, ellipsometry, and infrared reflection absorption spectroscopy indi...
متن کاملIs Due Principally to Electrons
This paper models damage induced by monochromatized Al Ka X-rays to organic thin films using self-assembled monolayers supported on Al, Ti, Cu, and Au. An X-ray photoelectron spectrometer is used both to conduct the X-ray irradiation and to analyze the damage. In all cases these monolayers comprised a trifluoroacetimido (CF3CONH-) group bound to the substrate through an undecyl tether to either...
متن کامل