Gold(I)-catalyzed addition of carbon nucleophiles to 1,6-enynes gives two different type of products by reaction at the cyclopropane or at the carbene carbons of the intermediate cyclopropyl gold carbenes. The 5-exo-dig cyclization is followed by most 1,6-enynes, although those bearing internal alkynes and alkenes react by the 6-endo-dig pathway. The cyclopropane versus carbene site-selectivity can be controlled in some cases by the ligand on the gold catalyst. In addition to electron-rich arenes and heteroarenes, allylsilanes and 1,3-dicarbonyl compounds can be used as the nucleophiles. In the reaction of 1,5-enynes with carbon nucleophiles, the 5-endo-dig pathway is preferred.

Indoles react intramolecularly with alkynes in the presence of gold catalysts to give from six- to eight-membered-ring annulated compounds. The cationic Au(I) complex [Au(P{C(6)H(4)(o-Ph)}(tBu)(2))(NCMe)]SbF(6) is the best catalyst for the formation of six- and seven-membered rings by 6-endo-dig, 6-exo-dig, and 7-exo-dig cyclizations. Indoloazocines are selectively obtained with AuCl(3) as catalyst in a rare 8-endo-dig process. In this process allenes or tetracyclic annulated derivatives are also formed as a result of an initial fragmentation reaction. The intermolecular reaction of indoles with alkynes proceeds to form 3-alkenylated intermediates that react with a second equivalent of indole to give bisindolyl derivatives. Indoles that are substituted at the 3-position react intermolecularly with alkynes to give 2-alkenylated intermediates that can be trapped intramolecularly with the appropriate nucleophiles.

Gold(I)-catalysed addition of electron-rich arenes and heteroarenes to 1,6-enynes gives two different types of products by reaction of the intermediate cyclopropyl gold carbenes at the cyclopropane or at the carbene.

In this work, we have studied the adsorption and diffusion of large functionalized organic molecules on an insulating ionic surface at room temperature using a noncontact atomic force microscope (NC-AFM) and theoretical modeling. Custom designed syn-5,10,15-tris(4-cyanophenylmethyl)truxene molecules are adsorbed onto the nanoscale structured KBr(001) surface at low coverages and imaged with atomic and molecular resolution with the NC-AFM. The molecules are observed rapidly diffusing along the perfect monolayer step edges and immobilized at monolayer kink sites. Extensive atomistic simulations elucidate the mechanisms of adsorption and diffusion of the molecule on the different surface features. The results of this study suggest methods of controlling the diffusion of adsorbates on insulating and nanostructured surfaces.

The synthesis of metallasupramolecular architectures, such as two-dimensional squares, triangles and polygons, and three-dimensional cages and polyhedra, has attracted much interest in the past decade. These structures are designed to have novel specific shapes and dimensions with interesting functional properties. In this overview the functional properties of metallasupramolecular architectures are highlighted with emphasis on potential applications such as catalysis, cavity-directed synthesis and sensing, that can be performed with these materials.

The dinuclear complex [(tpy)RuII(PCP-PCP)RuII(tpy)]Cl2 (bridging PCP-PCP = 3,3',5,5'-tetrakis(diphenylphosphinomethyl)biphenyl, [C6H2(CH2PPh2)2-3,5]22-) was prepared via a transcyclometalation reaction of the bis-pincer ligand [PC(H)P-PC(H)P] and the Ru(II) precursor [Ru(NCN)(tpy)]Cl (NCN = [C6H3(CH2NMe2)2-2,6]-) followed by a reaction with 2,2':6',2' '-terpyridine (tpy). Electrochemical and spectroscopic properties of [(tpy)RuII(PCP-PCP)RuII(tpy)]Cl2 are compared with those of the closely related [(tpy)RuII(NCN-NCN)RuII(tpy)](PF6)2 (NCN-NCN = [C6H2(CH2NMe2)2-3,5]22-) obtained by two-electron reduction of [(tpy)RuIII(NCN-NCN)RuIII(tpy)](PF6)4. The molecular structure of the latter complex has been determined by single-crystal X-ray structure determination. One-electron reduction of [(tpy)RuIII(NCN-NCN)RuIII(tpy)](PF6)4 and one-electron oxidation of [(tpy)RuII(PCP-PCP)RuII(tpy)]Cl2 yielded the mixed-valence species [(tpy)RuIII(NCN-NCN)RuII(tpy)]3+ and [(tpy)RuIII(PCP-PCP)RuII(tpy)]3+, respectively. The comproportionation equilibrium constants Kc (900 and 748 for [(tpy)RuIII(NCN-NCN)RuIII(tpy)]4+ and [(tpy)RuII(PCP-PCP)RuII(tpy)]2+, respectively) determined from cyclic voltammetric data reveal comparable stability of the [RuIII-RuII] state of both complexes. Spectroelectrochemical measurements and near-infrared (NIR) spectroscopy were employed to further characterize the different redox states with special focus on the mixed-valence species and their NIR bands. Analysis of these bands in the framework of Hush theory indicates that the mixed-valence complexes [(tpy)RuIII(PCP-PCP)RuII(tpy)]3+ and [(tpy)RuIII(NCN-NCN)RuII(tpy)]3+ belong to strongly coupled borderline Class II/Class III and intrinsically coupled Class III systems, respectively. Preliminary DFT calculations suggest that extensive delocalization of the spin density over the metal centers and the bridging ligand exists. TD-DFT calculations then suggested a substantial MLCT character of the NIR electronic transitions. The results obtained in this study point to a decreased metal-metal electronic interaction accommodated by the double-cyclometalated bis-pincer bridge when strong sigma-donor NMe2 groups are replaced by weak sigma-donor, pi-acceptor PPh2 groups.

A series of mono-and dimethyl aryl halides was a-brominated with NBS using either light-induction or microwave-assistance. Instead of the commonly used CCl 4 or other chlorinated solvents, MeOAc was used as an environmentally more benign solvent for these side-chain bromination reactions. Moreover, in MeOAc the use of initiator was not required, while the product yields were comparable. With microwave-assistance various benzylic bromides became accessible in short reaction times via direct a-bromination of the corresponding arenes. Finally, aryl halides that were unreactive in CCl 4 could be brominated in moderate to good yields in MeOAc under microwave conditions.

For the synthesis of corner building blocks with a 90°angle, to be used for the construction of larger structures, several homoleptic platinum(II) complexes [Pt(η 2 -C,N) 2 ] (10-14), as both cis-and trans-isomers, have been prepared starting from newly synthesized ortholithiated (dimethylamino)methyl arene ligands. The aryl groups of these arylplatinum(II) complexes contain additional substituents such as halides or methyl, naphthyl, or (dimethylamino)methyl groups. With these functionalities on the aryl rings the cis/trans ratio could be tuned. The presence of steric groups ortho to the metal center (methyl or naphthyl) favors the formation of planar-chiral cis-isomers. The trans-isomers isomerize irreversibly to the thermodynamically favored cis-isomers upon heating. The arylplatinum(II) complexes were used in various substitution reactions. Addition of a stronger coordinating ligand changes the denticity of the C,N-attached ligands. The halide functionalities were exploited for chemoselective lithiation and subsequent transmetalation reactions in order to synthesize the SnMe 3 -functionalized [Pt(C,N) 2 ] complexes. A Suzuki-Miyaura C-C coupling reaction on one of these complexes was also performed, resulting in the preparation of a mixed trinuclear palladium/platinum complex (25). The crystal structure determinations of four functionalized cis- [Pt(C,N) 2 ] complexes, cis-12‚Et 2 O, cis-14‚xC 6 H 6 , 19, and 25‚xCH 2 Cl 2 , are reported. With these structures it is shown that depending on the substituents, the degree of planarity around the platinum center can be tuned.