J. Weckesser et al., Binding and ordering of large organic molecules on an anisotropic metal surface: PVBA on Pd(110), SURF SCI, 431(1-3), 1999, pp. 168-173
The adsorption and ordering characteristics of 4-trans-2-(pyrid-4-yl-vinyl)
benzoic acid (PVBA) on a Pd(110) surface were investigated by variable tem
perature scanning tunneling microscopy, PVBA is a rigid organic molecule (m
= 225 amu) designed for nonlinear optics, The molecules adsorb flat on the
surface and bind diagonally to three neighbouring Pd-rows, which configura
tion is maintained at all submonolayer coverages, With the completion of th
e first monolayer a parquet pattern evolves, resulting from the fixed bondi
ng geometry and space limitations. Monte Carlo simulations of the film grow
th confirm that the monolayer ordering is stochastic in nature, even if an
extrinsic precursor mechanism is operative in the adsorption, The lateral i
nteractions between adsorbed molecules and Pd steps or adatoms at the surfa
ce are weak. (C) 1999 Elsevier Science B.V. All rights reserved.