Grafting cavitands on the Si(100) surface.

Cavitand molecules having double bond terminated alkyl chains and different bridging groups at the upper rim have been grafted on H-terminated Si(100) surface via photochemical hydrosilylation of the double bonds. Pure and mixed monolayers have been obtained from mesitylene solutions of either pure cavitand or cavitand/1-octene mixtures. Angle resolved high-resolution X-ray photoelectron spectroscopy has been used as the main tool for the monolayer characterization.

Metal-directed self-assembly of cavitand frameworks.

The self-assembly between bidentate cavitand ligands and mono/dinuclear metal precursors to give cavitand frameworks has been explored. For this purpose, two new cavitands bearing AB and AC phenylpyridyl moieties at the upper rim have been synthesized. A series of self-assembled molecular dimers featuring fac-Re(CO)(3)Br as metal corners have been prepared and characterized.

Metal directed assembly of ditopic containers and their complexes with alkylammonium salts.

A new self-folding cavitand has been assembled through metal coordination to give a thermodynamically stable ditopic receptor of nanosize dimensions which has been used in the reversible binding of di-alkylammonium and n-alkylammonium salts.

Design and self-assembly of ditopic and tetratopic cavitand complexes.

The self-assembly of open ditopic and tetratopic cavitand complexes has been investigated by using monofunctionalized cavitand ligands and suitable metal precursors. In the case of ditopic complexes, self-assembly protocols, leading exclusively to the formation of both thermodynamically stable cis-Pt square-planar complexes 8 and 9 and the kinetically inert fac-Re octahedral complex 14, have been elaborated. The use of cis-[Pt(CH3)CN)2Cl2] as metal precursor led to the formation of monotopic trans-10 and ditopic trans-11 cavitand complexes, while cis-[Pt(dmso)2Cl2] afforded both cis-13 and trans-11 isomers.

Surface-confined single molecules: assembly and disassembly of nanosize coordination cages on gold (111).

A cavitand functionalized with four alkylthioether groups at the lower rim, and four tolylpyridine groups on the upper rim is able to bind to a gold surface by its thioether groups, and forms a coordination cage with [Pd(dppp)(CF(3)SO(3))(2)] by its pyridine groups. The cavitand or the cage complex can be inserted from solution into a self-assembled monolayer (SAM) of 11-mercaptoundecanol on gold. The inserted molecules can be individually detected as they protrude from the SAM by atomic force microscopy (AFM).