title: A tripodal [2]rotaxane on the surface of gold.
abstract: Tripodal [2]rotaxane, 3, and the structurally related axle, 2, incorporating a viologen moiety, a crown ether, and three thiol anchoring groups have been synthesized. Analogous monopodal derivatives, 1, have also been prepared. Self-assembled monolayers of the above tripodal and monopodal systems on gold have been studied by cyclic voltammetry. It has been shown that a thiol anchoring group is required to attach the monopodal viologen 1 to the surface of gold and that the maximum surface coverage of 1 corresponds to 2.7 x 10(-10) mol.cm(-2). The adsorbed monopodal viologen 1 does not thread bis-p-phenylene-34-crown-10 ether, 6. However, the tripodal axle 2 adsorbed on the surface of gold threads the crown ether 6 to form a hetero [2]rotaxane. In the case of the tripodal axle 2, the surface coverage is 7 x 10(-11) mol.cm(-2), while for the tripodal [2]rotaxane 3 the surface coverage reaches 1.1 x 10(-10) mol.cm(-2).
authors.affiliation: School of Chemistry and Chemical Biology, University College Dublin, Belfield, Dublin 4, Ireland. kirill.nitikin@ucd.ie
authors.forename: Kirill
authors.initials: K
authors.lastname: Nikitin
authors.forename: Elena
authors.initials: E
authors.lastname: Lestini
authors.forename: Mariachiara
authors.initials: M
authors.lastname: Lazzari
authors.forename: Silvano
authors.initials: S
authors.lastname: Altobello
authors.forename: Donald
authors.initials: D
authors.lastname: Fitzmaurice