Lukas J. Scherer

2,2′:6′,2″-Terpyridine-4′(1′H)-thione: a missing link in metallosupramolecular chemistry

The compound 2,2′:6′,2″-terpyridine-4′(1′H)-thione 1 has been prepared and structurally characterised; in both the solid state and in solution, the thione tautomer is dominant. Compound 1 is a key entry into 4′-sulfur-functionalised tpy ligands and a representative alkylation with an electrophilic Frechet dendrimer is presented and the structural characterisation of the new ligand 4 reported. Oxidation of 1 yields bis(2,2′:6′,2″-terpyridin-4′-yl)disulfide 2 which is a novel homoditopic tpy ligand and which forms a tetranuclear [4 + 4] iron(II) metallomacrocycle. Structural characterisation of 2 and preliminary data for the iron complex are presented.

Deprotection, Tethering, and Activation of a Catalytically Active Metalloporphyrin to a Chemically Active Metal Surface: [SAc](4)P-Mn(III)Cl on Ag(100)

The adsorption and subsequent thermal chemistry of the acetyl-protected manganese porphyrin, [SAc](4)P-Mn(III)Cl on Ag(100) have been studied by high resolution XPS and temperature-programmed desorption. The deprotection event, leading to formation of the covalently bound thioporphyrin, has been characterized and the conditions necessary for removal of the axial chlorine ligand have been determined, thus establishing a methodology for creating tethered activated species that could serve as catalytic sites for delicate oxidation reactions. Surface-mediated acetyl deprotection occurs at 298 K, at which temperature porphyrin diffusion is limited. At temperatures above approximately 425 K porphyrin desorption, diffusion and deprotection occur and at >470 K the axial chlorine is removed.

A Versatile Fréchet-Dendron Compound Unifies Host-Guest and Templated Heterogeneous Self-Assembly

To date, heterogeneous patterns on surfaces could assemble either in host guest or templated structures only. A Frechet-type dendron now shows both classes of ordering and thus connects both assembly types. Depending on the type of interaction with the guest molecule, saturated adamantane is included in an existing host structure, while aromatic coronene templates a new molecular ordering.

Self-assembled monolayers as two-dimensional crystals: relationship to three-dimensional crystals

A critical comparison of the two-dimensional and three-dimensional packing of Frechet-type dendrons in monolayers on HOPG and three-dimensional crystals, respectively, reveals a precise matching of the monolayer to sheets present in the bulk material.