37 research outputs found
Convergent Fabrication of a Nanoporous Two-Dimensional Carbon Network from an Aldol Condensation on Metal Surfaces
We report a convergent surface polymerization reaction scheme on Au(111),
based on a triple aldol condensation, yielding a carbon-rich, covalent
nanoporous two-dimensional network. The reaction is not self-poisoning and
proceeds up to a full surface coverage. The deposited precursor molecules
1,3,5-tri(4'-acetylphenyl) first form supramolecular assemblies that are
converted to the porous covalent network upon heating. The formation and
structure of the network and of the intermediate steps are studied with
scanning tunneling microscopy, Raman spectroscopy and density functional
theory.Comment: 1 Scheme, 5 Figure
Room temperature electronic template effect of pre-structured SmSi(111)-8x2 interface yielding self-aligned organic molecules
International audienceThis work describes an innovative concept for the development of organized molecular systems thanks to the template effect of the pre-structured semi-conductive SmSi(111) interface. This substrate was selected because Sm deposition in the submonolayer range leads to a 8x2-reconstruction, which is a well-defined one-dimensional semi-metallic structure. Adsorption of aromatic molecules (1,4-di-(9-ethynyltriptycenyl)-benzene) on SmSi(111)-8x2 and Si(111)-7x7 interfaces has been investigated by scanning tunneling microscopy (STM) at room temperature. Density functional theory (DFT) and semi-empirical (ASED+) calculations have been performed to define the nature of the molecular adsorption sites of the target molecule on SmSi as well as their self-alignment on this interface. Experimental data and theoretical results are in good agreement
Remarkable Anticancer Activity of Triruthenium-Arene Clusters Compared to Tetraruthenium-Arene Clusters
The invitro activity of a series of ruthenium clusters, [(η6-C6H6)(η6-C6Me6)2Ru3(μ-H)3(μ3-O)][BF4], [(η6-C6H6)(η6-1,4-iPrC6H4Me)(η6-C6Me6)Ru3(μ-H)3(μ3-O)][BF4], [(η6-C6H6)4Ru4(μ-H)4][BF4]2, [(η6-C6H5Me)4Ru4(μ-H)4][BF4]2 and [(η6-C6H6)4Ru4(μ-H)3(μ-OH)][Cl]2, has been evaluated against A2780 and A2780cisR ovarian carcinoma cell lines. Both triruthenium clusters are very active compared to ruthenium compounds in general, whereas the tetraruthenium clusters do not display significant cytotoxicities. Since the triruthenium clusters are known to form supramolecular interactions with arenes and other functions, it is possible that such interactions are also important with respect to their mode of biological activity. The X-ray structure analysis of [(η6-C6H5Me)4Ru4(μ-H)4][PF6]2 is also reported. Graphical Abstract: The invitro activity of a series of ruthenium clusters has been evaluated against A2780 and A2780cisR ovarian carcinoma cell lines and their activity compared to cisplatin. The triruthenium clusters are very active, while the tetraruthenium clusters do not display significant cytotoxicitie