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

Journeys from quantum optics to quantum technology

Sir Peter Knight is a pioneer in quantum optics which has now grown to an important branch of modern physics to study the foundations and applications of quantum physics. He is leading an effort to develop new technologies from quantum mechanics. In this collection of essays, we recall the time we were working with him as a postdoc or a PhD student and look at how the time with him has influenced our research

Elective cancer surgery in COVID-19-free surgical pathways during the SARS-CoV-2 pandemic: An international, multicenter, comparative cohort study

PURPOSE As cancer surgery restarts after the first COVID-19 wave, health care providers urgently require data to determine where elective surgery is best performed. This study aimed to determine whether COVID-19–free surgical pathways were associated with lower postoperative pulmonary complication rates compared with hospitals with no defined pathway. PATIENTS AND METHODS This international, multicenter cohort study included patients who underwent elective surgery for 10 solid cancer types without preoperative suspicion of SARS-CoV-2. Participating hospitals included patients from local emergence of SARS-CoV-2 until April 19, 2020. At the time of surgery, hospitals were defined as having a COVID-19–free surgical pathway (complete segregation of the operating theater, critical care, and inpatient ward areas) or no defined pathway (incomplete or no segregation, areas shared with patients with COVID-19). The primary outcome was 30-day postoperative pulmonary complications (pneumonia, acute respiratory distress syndrome, unexpected ventilation). RESULTS Of 9,171 patients from 447 hospitals in 55 countries, 2,481 were operated on in COVID-19–free surgical pathways. Patients who underwent surgery within COVID-19–free surgical pathways were younger with fewer comorbidities than those in hospitals with no defined pathway but with similar proportions of major surgery. After adjustment, pulmonary complication rates were lower with COVID-19–free surgical pathways (2.2% v 4.9%; adjusted odds ratio [aOR], 0.62; 95% CI, 0.44 to 0.86). This was consistent in sensitivity analyses for low-risk patients (American Society of Anesthesiologists grade 1/2), propensity score–matched models, and patients with negative SARS-CoV-2 preoperative tests. The postoperative SARS-CoV-2 infection rate was also lower in COVID-19–free surgical pathways (2.1% v 3.6%; aOR, 0.53; 95% CI, 0.36 to 0.76). CONCLUSION Within available resources, dedicated COVID-19–free surgical pathways should be established to provide safe elective cancer surgery during current and before future SARS-CoV-2 outbreaks

Elective Cancer Surgery in COVID-19-Free Surgical Pathways During the SARS-CoV-2 Pandemic: An International, Multicenter, Comparative Cohort Study.

PURPOSE: As cancer surgery restarts after the first COVID-19 wave, health care providers urgently require data to determine where elective surgery is best performed. This study aimed to determine whether COVID-19-free surgical pathways were associated with lower postoperative pulmonary complication rates compared with hospitals with no defined pathway. PATIENTS AND METHODS: This international, multicenter cohort study included patients who underwent elective surgery for 10 solid cancer types without preoperative suspicion of SARS-CoV-2. Participating hospitals included patients from local emergence of SARS-CoV-2 until April 19, 2020. At the time of surgery, hospitals were defined as having a COVID-19-free surgical pathway (complete segregation of the operating theater, critical care, and inpatient ward areas) or no defined pathway (incomplete or no segregation, areas shared with patients with COVID-19). The primary outcome was 30-day postoperative pulmonary complications (pneumonia, acute respiratory distress syndrome, unexpected ventilation). RESULTS: Of 9,171 patients from 447 hospitals in 55 countries, 2,481 were operated on in COVID-19-free surgical pathways. Patients who underwent surgery within COVID-19-free surgical pathways were younger with fewer comorbidities than those in hospitals with no defined pathway but with similar proportions of major surgery. After adjustment, pulmonary complication rates were lower with COVID-19-free surgical pathways (2.2% v 4.9%; adjusted odds ratio [aOR], 0.62; 95% CI, 0.44 to 0.86). This was consistent in sensitivity analyses for low-risk patients (American Society of Anesthesiologists grade 1/2), propensity score-matched models, and patients with negative SARS-CoV-2 preoperative tests. The postoperative SARS-CoV-2 infection rate was also lower in COVID-19-free surgical pathways (2.1% v 3.6%; aOR, 0.53; 95% CI, 0.36 to 0.76). CONCLUSION: Within available resources, dedicated COVID-19-free surgical pathways should be established to provide safe elective cancer surgery during current and before future SARS-CoV-2 outbreaks

Nouveaux complexes de ruthénium riches en carbone pour l'élaboration de fils et interrupteurs moléculaires originaux

rLa première partie de ce travail est consacrée à l étude de nouveaux interrupteurs moléculaires redox magnétiques, basés sur l association d unités paramagnétiques de cuivre, de manganèse, ou de radicaux nitronyle nitroxydes, avec des complexes de ruthénium de type acétylure. L objectif est d observer une modulation redox des propriétés magnétiques de ces composés. La seconde partie traite de l association de divers ions trivalents lanthanides à un complexe de ruthénium acétylure pour réaliser la première modulation redox de la luminescence des lanthanides. La troisième partie présente la synthèse et l étude de nouveaux fils moléculaires bimétalliques asymétriques dans le but d obtenir l un des premiers exemples de système asymétrique permettant une excellente délocalisation électronique dans l état oxydé. Enfin, la dernière partie aborde la synthèse et l étude de précurseurs pour le greffage sur surfaces des interrupteurs obtenus dans les parties précédentes, via la formation de SAMs.The first part of this work deals with the synthesis and characterization of new magnetic redox switches based on the association of paramagnetic units such as nitronyl nitroxide, or copper and manganese compounds with ruthenium carbon-rich acetylides. The aim was to modulate the magnetic properties by changing the oxidation state of the ruthenium center. The second part treats of the association of different trivalent lanthanide ions with acetylide carbon-rich ruthenium complexes in order to achieve the first redox modulation of lanthanide luminescence. The third part deals with the synthesis and the study of new asymmetric bimetallic molecular wires to get an efficient electronic delocalization all over the asymmetric compounds. The last part reports the synthesis and the study of new model compounds in order to further realize the grafting on gold surface of the molecular switches obtained in the first two parts. The aim was to retain the switching properties observed in solution within the SAMs.RENNES1-BU Sciences Philo (352382102) / SudocSudocFranceF

Dithiafulvenylphosphine as P- and P,S-ligand towards metal carbonyl fragments

International audienceThe ability of the dithiafulvenylphosphine (P-DTF) to react as a monodentate (P) or a bidentate (P,S) ligand with metal carbonyl complexes such as Mo(CO)6 and MnBr(CO)5 is presented. A series of metal carbonyl complexes are synthesised and characterised by IR, 1H NMR and 31P NMR spectroscopy. X-ray crystallographic analyses on the Mo(CO)5(P-DTF) and Mo(CO)4(P,S-DTF) complexes are reported together with the structural investigations on the dithiafulvenes precursors. The electrochemical properties of the various complexes investigated by cyclic voltammetry are discussed

d-f heterobimetallic association between ytterbium and ruthenium carbon-rich complexes: redox commutation of near-IR luminescence.

International audienceWe describe how the association between an ytterbium ion and a ruthenium carbon-rich complex enables the first switching of the near-IR Yb(III) luminescence by taking advantage of the redox commutation of the carbon-rich antenna

Ruthenium Carbon-Rich Complexes as Redox Switchable Metal Coupling Units

International audienceWith the help of EPR spectroscopy, we show that the diamagnetic [Ru(dppe)2(-C≡C-R)2] system sets up a magnetic coupling between two organic radicals R, i.e., two nitronyl nitroxide or two verdazyl units, which is stronger than that of related platinum organometallic systems. Surprisingly, further oxidation of the ruthenium redox-active metal coupling unit (MCU), which introduces an additional spin unit on the carbon-rich part, leads to the switching off of this interaction. On the contrary, in simpler complexes bearing only one of the organic radical ligands [C6H5-C≡C-Ru(dppe)2-C≡C-R], one-electron oxidation of the transition metal unit generates an interaction between the two spin carriers of comparable magnitude to that observed in the above corresponding neutral systems

Fully delocalized (ethynyl)(vinyl)phenylene-bridged diruthenium radical complexes.

International audienceDiruthenium complexes [(X)(dppe)2Ru-C≡C-1,4-C6H4-CH:CH-RuCl(CO)(PiPr3)2] (1a,b, X = = Cl, C≡CPh) contg. an unsym. (ethynyl)(vinyl)phenylene bridging ligand were prepd. by alkyne insertion into Ru-H-bond and compared to their sym. 1,4-bis(ethynyl)phenylene- and 1,4-divinylphenylene-bridged congeners and their mononuclear alkynyl precursors. Electrochem. and UV/vis/NIR, IR, and EPR spectroscopic studies on the neutral complexes and their various oxidized forms indicate bridging ligand-centered oxidn. processes and uniform charge and spin delocalization over both dislike organoruthenium moieties despite differences in their intrinsic redox potentials. Comparison between the chloro and the phenylacetylide-terminated derivs. 1a,b suggests further that the conjugated organometallic π-system extends over the entire unsatd. backbone including the terminal ligand at the alkynyl ruthenium site. This paves the way to even more extended π-conjugated organoruthenium arrays for long-range electronic interactions. [on SciFinder(R)

Redox -active ruthenium(II) σ-arylacetylide wires for molecular electronics incorporating insulating chains

International audienceThe preparation and properties of novel carbon-rich mono-, bi-, and tri-metallic ruthenium complexes terminated with protected thiol functions for further surface binding are reported. These new structurally rigid complexes include a short chain (SC) or a long (LC ) saturated chain between the terminal linking functions and the conjugated carbon-rich pathway in order to increase contact resistance. They display low oxidation potential, and IR studies of the neutral complexes and of their various oxidized forms indicate the high bridging ligand implication in the oxidation processes and charge delocalization. These molecules are expected to facilitate coulomb blockade behaviour in molecular junctions, and are thus excellent candidates to contribute to the establishment of the structure-property relationships of metal containing molecular wires