Formation of six-membered palladacycles from phenanthroline Pd(II) bisacetate precursors and phenylisocyanate

Synthesis and characterization of 5a-d. CCDC-221834 contains the supplementary crystallographic data for this paper. These data can be obtained free of charge from The Cambridge Crystallographic Data Centre via: www.ccdc.cam.ac.uk/data_request.cif.International audiencePhenylisocyanate reacts with palladium(II) bis-acetate phenanthroline complexes to give six-membered palladacycles in nearly quantitative yields. In this new reaction, the acetate ligands act as decarbonylating agents toward the isocyanate functionality by possibly forming the isolated palladacycles via an intramolecular rearrangement

Optical electron transfer through 2,7-diethynylfluorene spacers in mixed-valent complexes containing electron-rich "(η2-dppe)(η5-C5Me5)Fe" endgroups.

International audienceWe report in this communication the study of the intramolecular electron transfer through a 2,7-diethynylfluorenyl spacer in the Fe(II)/Fe(III) mixed-valent (MV) complex [(η(2)-dppe)(η(5)-C(5)Me(5))FeC≡C(2,7-C(21)H(24))C≡CFe(η(5)-C(5)Me(5))(η(2)-dppe)][PF(6)] (1[PF(6)]). The complex is generated in situ by comproportionation from its homovalent dinuclear Fe(II) and Fe(III) parents (1 and 1[PF(6)](2)). It is shown that electronic delocalization is much more effective through a 2,7-fluorenyl than through a 4,4'-biphenyl bridging unit

Stable Near-Infrared Anionic Polymethine Dyes: Structure, Photophysical, and Redox Properties

International audienceThe concept of cyanine has been successfully extended to anionic heptamethine dye featuring tricyanofuran (TCF) moieties in terms of structure, reactivity and photophysical properties. Importantly, absorption and emission are red-shifted compared to its classical cationic analog without any cost in term of thermal stability. In addition to its "cyanine" behavior, this molecule exhibits further redox properties: oxidation and reduction led to the reversible formation of radical species whose absorption is in marked contrast with that of cyanines

Enhanced two-photon absorption cross-sections of zinc(II) tetraphenylporphyrins peripherally substituted with d(6)-metal alkynyl complexes

International audienceThe syntheses of new Zn(II) tetraphenylporphyrin (ZnTPP) derivatives functionalized with electron-rich d6-transition metal alkynyl complexes at their periphery are reported. Z-scan measurements reveal remarkably large effective two-photon absorption (TPA) cross-sections in the visible range for these compounds

Modulating the luminescence of an iridium(III) complex incorporating a di(2-picolyl)anilino-appended bipyridine ligand with Zn2+ cations

International audienceA novel iridium complex incorporating a di(2-picolyl)anilino-appended bipyridine ligand was synthesized and its optical properties studied. The presence of Zn2+ ions specifically perturbs the excited state, giving rise to a blue-shifted absorption and emission, and a shorter luminescence lifetime

Photoinduced phenomena and structural analysis associated with the spin-state switching in the [FeII(DPEA)(NCS)2] complex

International audienceOut-of-equilibrium photoinduced switching from the low-spin to the high-spin state has been investigated on the iron(II) complex [Fe(II)(DPEA)(NCS)2] by both optical reflectivity and magnetic measurements under continuous light irradiation at low temperature. The photoinduced HS state can be observed up to 47 K and the relaxation process has been followed. Structural changes of both the temperature- and the photoinduced spin-state switching have been analyzed in detail by x-ray diffraction indicating no change of symmetry. Short intermolecular contacts and intramolecular deformations associated with the change of molecular spin state have been quantified. Actually a crossover behavior is observed at thermal equilibrium with however a quasiabrupt shape indicating significant cooperative effects. These aspects are compared between the temperature- and photoinduced spin crossovers

Syntheses and coordination chemistry of bis(4-pyridyl)- and mixed (4-pyridyl) (2-pyridyl)-phospholes

International audienceThe syntheses, spectroscopic characterizations, and X-ray structures of two new N,P,N-ligands 1 and 2 are described. These ligands are based on a central 2,5-substituted phosphole ring and have, respectively, two 4-pyridyl moieties, or one 4-pyridyl moiety and one 2-pyridyl moiety as substituents. The coordination chemistry of these ligands has been investigated. A Au(I)-complex 5 bearing ligand 1 as a P-donor and a Pt(II) complex 6 featuring ligand 2 as a P,N-chelate were obtained. Complex 6 spontaneously evolves to complex 7 bearing a 2-phospholene ring. Spectroscopic characterizations for complexes 5-7 as well as the X-ray crystal structure of 7 are described

Preparation of hexacoordinating benzimidazole containing ligand and hexakis(benzimidazole-ruthenium(II)) complex. Molecular structure of C6{CH2-(N-benzimidazole-RuCl2(p-cymene))}6.

International audienceA hexabenzimidazole ligand was synthesised and used to prepare a hexakis{benzimidazole-ruthenium(II)} complex containing six RuCl(2)(arene) units of which the X-ray structure analysis shows a helical arrangement with alternating up and down benzymidazole-ruthenium(II) branches attached to a central benzene ring. The reactivity of the prepared complex with phosphite and carbonate was investigated and revealed the weakness of (benzimidazole)N-Ru bonds and the release of the polydentate ligand