Isoindole and isomeric heterocyclic donating substituents in ruthenium(II)nitrosyl complexes with large first hyperpolarizabilities and potential two-photon absorption capabilities: a computational approach

A set of 22 ruthenium nitrosyl complexes of general formula [RuII(L)Cl2(NO)]+ is investigated computationally by the density functional theory. L is a terpyridine ligand substituted by different R isomers of formula C12H8N, either indole, isoindole, or carbazole, proposed as alternative donors to the electron-rich fluorene substituent. The computed resulting nonlinear optical (NLO) properties are found to strongly depend on the isomer. While the ruthenium complexes exhibit modest efficiencies at the second-order (two-photon absorption) level, some of the R isomers lead to complexes of enhanced capabilities in first order (b) nonlinear optics. The synthetic feasibility of these ligands is discussed

Fuzzy species limits in Mediterranean gorgonians (Cnidaria, Octocorallia): inferences on speciation processes

The study of the interplay between speciation and hybridization is of primary importance in evolutionary biology. Octocorals are ecologically important species whose shallow phylogenetic relationships often remain to be studied. In the Mediterranean Sea, three congeneric octocorals can be observed in sympatry: Eunicella verrucosa, Eunicella cavolini and Eunicella singularis. They display morphological differences and E.singularis hosts photosynthetic Symbiodinium, contrary to the two other species. Two nuclear sequence markers were used to study speciation and gene flow between these species, through network analysis and Approximate Bayesian Computation (ABC). Shared sequences indicated the possibility of hybridization or incomplete lineage sorting. According to ABC, a scenario of gene flow through secondary contact was the best model to explain these results. At the intraspecific level, neither geographical nor ecological isolation corresponded to distinct genetic lineages in E.cavolini. These results are discussed in the light of the potential role of ecology and genetic incompatibilities in the persistence of species limits.French National Research Agency (ANR) program Adacni (ANR) [ANR-12-ADAP-0016]CNRSHubert Curien 'Tassili' program [12MDU853]CCMAR Strategic Plan from Fundacao para a Ciencia e a Tecnologia-FCT [PEst-C/MAR/LA0015/2011,FEDERinfo:eu-repo/semantics/publishedVersio

Photocommutation à l'état solide dans les complexes de ruthénium à ligand nitrosyle (vers la réalisation de matériaux composites photochromes)

TOULOUSE3-BU Sciences (315552104) / SudocSudocFranceF

Nitric oxide (NO) photo-release in a series of ruthenium–nitrosyl complexes: new experimental insights in the search for a comprehensive mechanism

International audienceA series of four ruthenium(ii) complexes built from the [Ru(terpy)(bipy)(NO)](3+) core (terpy is 2,2:6,2-terpyridine and bipy is 2,2-bipyridine) are investigated. They differ by the presence of zero, one, two, or three 4-(4-methoxyphenyl) (MP) electron donor substituents introduced at different positions on the pyridine fragments to increase the intramolecular charge transfer capabilities towards the strongly withdrawing nitrosyl (NO) ligand. The UV-visible spectra reflect the presence and position of the MP substituents on the complexes. In the case of species containing the 4-(MP)-terpy ligand, a low-lying transition is identified as arising from 4-(MP)-terpy to Ru(NO) intramolecular charge transfer, which is further confirmed by TD-DFT analysis. Irradiation performed at = 436 nm on this isolated transition for different complexes leads to quantum yields of NO photo-release equal to 0.002 and 0.011, in a ratio of 6 (instead of 1), which allows concluding non-ambiguously that a single electron transition cannot account for the NO release mechanism

The three-dimensional intermolecular network formed via water molecules in trans-bis(nitrito-κN)tetrakis(pyridine-κN)ruthenium(II) dihydrate.

International audienceThe molecular geometry of the tetragonal crystal structure of the title compound, [Ru(NO(2))(2)(C(5)H(5)N)(4)]*2H(2)O, differs from that previously determined by powder diffraction [Schaniel et al. (2010). Phys. Chem. Chem. Phys. 12, 6171-6178]. In the [Ru(NO(2))(C(5)H(5)N)(4)] molecule, the Ru atom lies at the intersection of three twofold axes (Wyckoff position 8b). It is coordinated by four N atoms of the pyridine rings, as well as by two N atoms of N-nitrite groups. The last two N atoms are located on a twofold axis (Wyckoff position 16f). The O atoms of the water molecules are situated on a twofold axis (Wyckoff position 16e). Short intermolecular contacts are observed in the crystal structure, viz. N-O***OW and N-O***H-OW contacts between nitrite and water, and weak C-H***OW hydrogen bonds between pyridine and water. Thus, the intercalated water molecules act as bridges connecting the trans-[Ru(NO(2))(2)(py)(4)] molecules into a three-dimensional network

Mechanism and oxidation state involved in the nitric oxide (NO) photorelease in a terpyridine-bipyridine-based ruthenium nitrosyl complex

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