Characterization of a surface reaction by means of atomic force microscopy.

We study a thermally activated on-surface planarization reaction by a detailed analysis of the reactant and reaction products from atomically resolved atomic force microscopy (AFM) images and spectroscopy. The three-dimensional (3D) structure of the reactant, a helical diphenanthrene derivative, requires going beyond constant-height imaging. The characterization in three dimensions is enabled by acquisition and analysis of the AFM signal in a 3D data set.

Atomic force microscopy reveals bistable configurations of dibenzo[a,h]thianthrene and their interconversion pathway.

We investigated dibenzo[a,h]thianthrene molecules adsorbed on ultrathin layers of NaCl using a combined low-temperature scanning tunneling and atomic force microscope. Two stable configurations exist corresponding to different isomers of free nonplanar molecules. By means of excitations from inelastic electron tunneling we can switch between both configurations.

Copper curcuminoids containing anthracene groups: fluorescent molecules with cytotoxic activity.

The coordination chemistry of the new curcuminoid ligand, 1,7-(di-9-anthracene-1,6-heptadiene-3,5-dione), abbreviated 9Accm has been studied, resulting in two new copper-9Accm compounds. Compound 1, [Cu(phen)Cl(9Accm)], was synthesized by reacting 9Accm with [Cu(phen)Cl(2)] in a 1:1 ratio (M:L) and compound 2, [Cu(9Accm)(2)], was prepared from Cu(OAc)(2) and 9Accm (1:2). UV-vis, electron paramagnetic resonance (EPR), and superconducting quantum interference device (SQUID) measurements were some of the techniques employed to portray these species; studies on single crystals of free 9Accm, [Cu(phen)Cl(9Accm)] and [Cu(9Accm)(2)(py)] provided detailed structural information about compounds 1 and 2·py, being the first two copper-curcuminoids crystallographically described.