The equilibrium structure of alkanethiol monolayers self-assembled on metal
substrates is determined by a delicate interplay of the intermolecular cha
in-chain and chemisorptive substrate-head group interactions. To understand
the role of the individual constituents of this interplay, we studied the
structure of biphenyl and perfluoroalkyl terminated alkanethiol monolayers
self-assembled on Au and Ag. The structural characteristics of the monolaye
rs derived from NEXAFS, FTIRRAS and XPS measurements point to a decisive ro
le of the directional substrate-head group interactions.