C-H and C-F bond activation of fluorinated propenes at Rh: enabling cross-coupling reactions with outer-sphere C-C coupling.

The reaction of [Rh{()-CF[double bond, length as m-dash]CHCF}(PEt)] with Zn(CH) results in the methylation of the alkenyl ligand to give [Rh{(/)-C(CH)[double bond, length as m-dash]CHCF}(PEt)]. Variable temperature NMR studies allowed the identification of a heterobinuclear rhodium-zinc complex as an intermediate, for which the structure [Rh(CH)(ZnCH){()-C(CH)[double bond, length as m-dash]CHCF}(PEt)] is proposed. Based on these stoichiometric reactions, unique Negishi-type catalytic cross-coupling reactions of fluorinated propenes by consecutive C-H and C-F bond activation steps at room temperature were developed.

Evaluation of vital signs through a mobile application in patients with heart failure: a opportunity for remote titration?

Background: Virtual consultations have increased exponentially, but a limitation is the inability to assess vital signs (VS). This is particularly useful in patients with heart failure (HF) for titrating prognosis-modifying medication. This issue could potentially be addressed by a tool capable of measuring blood pressure (BP) and heart rate (HR) accurately, remotely, and conveniently.

Selective Schiff Base Formation of Group 9 Organometallic Complexes with Functionalized Spirobifluorene Ligands.

Organic amines are important compounds present in a wide variety of products, which makes the development of new systems for their detection an interesting field of study. New organometallic complexes of group 9 [MCp*X(2'-R-2-py-SBF)] (M = Ir, Rh; R = H, X = Cl (), R = H, X = OAc (), R = CHO, X = Cl ()), and [IrCp*Cl(2', 7-diCHO-2-py-SBF)] () (Cp* pentamethylcyclopentadienyl, SBF = 9,9'-spirobifluorene) bearing bidentate C-N ligands based on 9,9'-spirobifluorene were obtained and characterized by NMR spectroscopy, mass spectrometry, IR spectroscopy, and X-ray diffraction analysis when possible. The formation of a Schiff base to give complexes with the formula [MCp*Cl(2'-CH=NR-2-py-SBF)] (M = Ir, Rh; R = alkyl or aryl (-)), through condensation of an amine, and the aldehyde group present in these new complexes was studied leading to a selective reactivity depending on the nature of the amine and the metal center.

Development of robust chiroptical systems through spirobifluorenes.

Chiroptical responses are valuable for the structural determination of dissymmetric molecules. However, the development of everyday applications based on chiroptical systems is yet to come. We have been earlier using axially chiral allenes for the construction of linear, cyclic, and cage-shaped molecules that present remarkable chiroptical responses.

Multiple pre- and postzygotic components of reproductive isolation between two co-occurring Lysimachia species.

Genetic divergence between species depends on reproductive isolation (RI) due to traits that reduce interspecific mating (prezygotic isolation) or are due to reduced hybrid fitness (postzygotic isolation). Previous research found that prezygotic barriers tend to be stronger than postzygotic barriers, but most studies are based on the evaluation of F hybrid fitness in early life cycle stages. We combined field and experimental data to determine the strength of 17 prezygotic and postzygotic reproductive barriers between two Lysimachia species that often co-occur and share pollinators.

Optical and electrochemical properties of spirobifluorene iridanaphthalene complexes.

Three new spirobifluorene iridaaromatic compounds bearing electron-withdrawing or electron-donor substituents or another iridanaphthalene moiety have been synthesized and structurally characterized. Thorough experimental and theoretical evaluation revealed that these novel systems present a high thermal, air and electrochemical stability as well as low optical and electronic energy gap values with a significant redshift of the absorption maximum in the UV-Vis spectra and predicted remarkably higher first hyperpolarizabilities compared to their organic counterparts. Therefore, the combination of a metallaaromatic system with a spirobifluorene moiety leads to the design and development of new spirobifluorene derivatives.

ON/OFF Spiroconjugation through Peripheral Functionalization: Impact on the Reactivity and Chiroptical Properties of Spirobifluorenes.

Spirobifluorenes are an important class of spiro compounds frequently used in the field of organic electronics. However, harnessing spiroconjugation to obtain high-performance in such structural motifs remains unexplored. We herein propose that peripheral functionalization may serve as a useful tool to control spiroconjugation in an ON/OFF manner on both chemical reactivity and photophysical properties.

Competing C-H and C-F bond activation reactions of a fluorinated olefin at Rh: a fluorido vinylidene complex as an intermediate in an unprecedented dehydrofluorination step.

The hydrofluoroolefin -1,3,3,3-tetrafluoropropene has been activated an initial C-F bond activation and subsequent C-H bond activation using [Rh(H)(PEt)] (1) or C-H bond activation at [Rh(CH)(PEt)] (8). In both cases the formation of [Rh{()-CF[double bond, length as m-dash]CHCF}(PEt)] (3) was observed. Importantly, the C-F activation product [Rh{()-CH[double bond, length as m-dash]CHCF}(PEt)] (2) reacts in the presence of -1,3,3,3-tetrafluoropropene into 3.

Fluorination Reactions at a Platinum Carbene Complex: Reaction Routes to SF , S(=O)F and Fluorido Complexes.

The electron-rich Pt complex [Pt(IMes) ] (IMes: [1,3-bis(2,4,6-trimethylphenyl)-2-imidazolinylidine]) can be used as precursor for the syntheses of a variety of fluorido ligand containing compounds. The sulfur fluoride SF undergoes a rapid oxidative addition at Pt to yield trans-[Pt(F)(SF )(IMes) ]. A photolytic reaction of SF at [Pt(IMes) ] in the presence of IMes gave the fluorido complexes trans-[Pt(F) (IMes) ] and trans-[Pt(F)(SF )(IMes) ] along with trans-[Pt(F)(SOF)(IMes) ] and trans-[Pt(F)(IMes')(IMes)] (IMes': cyclometalated IMes ligand), the latter being products produced by reaction with adventitious water.

Iridaaromatics via Methoxy(alkenyl)carbeneiridium Complexes.

This review describes the development of a versatile methodology to synthesize polycyclic metallaaromatic hydrocarbons based on iridium, as well as the studies that helped us to determine and understand what is required in order to broaden the scope and the selectivity of the methodology and stabilize the complexes obtained. This methodology aims to open the door to new materials based on graphene fragments.

Key factors in the synthesis of polycyclic iridaaromatics via the methoxyalkenylcarbene pathway.

Polycyclic iridaaromatic compounds are of great interest not only because of the contributions made in "aromatic chemistry", but also because of the possibility of improving the results of the applications of the corresponding organic analogues in different fields. Therefore, understanding the requirements necessary to build on demand this type of compound with specific properties is of great importance. In this work, the keys to successfully synthesize iridaaromatic complexes via methoxyalkenylcarbenes are established.

Versatile Reaction Pathways of 1,1,3,3,3-Pentafluoropropene at Rh(I) Complexes [Rh(E)(PEt ) ] (E=H, GePh , Si(OEt) , F, Cl): C-F versus C-H Bond Activation Steps.

The reaction of the rhodium(I) complexes [Rh(E)(PEt ) ] (E=GePh (1), H (6), F (7)) with 1,1,3,3,3-pentafluoropropene afforded the defluorinative germylation products Z/E-2-(triphenylgermyl)-1,3,3,3-tetrafluoropropene and the fluorido complex [Rh(F)(CF CHCF )(PEt ) ] (2) together with the fluorophosphorane E-(CF )CH=CF(PFEt ). For [Rh(Si(OEt) )(PEt ) ] (4) the coordination of the fluoroolefin was found to give [Rh{Si(OEt) }(CF CHCF )(PEt ) ] (5). Two equivalents of complex 2 reacted further by C-F bond oxidative addition to yield [Rh(CF=CHCF )(PEt ) (μ-F) Rh(CF CHCF )(PEt )] (9).

Reproductive Assurance Maintains Red-Flowered Plants of in Mediterranean Populations Despite Inbreeding Depression.

Flower color polymorphism, an infrequent but phylogenetically widespread condition in plants, is captivating because it can only be maintained under a few selective regimes but also because it can drive intra-morph assortative mating and promote speciation. is a polymorphic species with red or blue flowered morphs. In polymorphic populations, which are mostly Mediterranean, pollinators prefer blue-flowered plants to the red ones, and abiotic factors also favors blue-flowered plants.

A SF Derivative of Triphenylphosphine as an Electron-Poor Ligand Precursor for Rh and Ir Complexes.

The synthesis of the triarylphosphine, P(-CHSF) containing a SF group, has been achieved. The experimental and theoretical studies showed that P(-CHSF) is a weaker σ-donor when compared with other substituted triarylphosphines, which is consistent with the electron-withdrawing effect of the SF moiety. The studies also revealed a moderate air stability of the phosphine.

Distinct Helical Molecular Orbitals through Conformational Lock*.

Several theoretical studies have proposed strategies to generate helical molecular orbitals (Hel-MOs) in [n]cumulenes and oligoynes. While chiral even-[n] cumulenes feature Hel-MOs, odd-[n] cumulenes may also present them if the terminal groups lie in different planes. However, the proposed systems have been either experimentally unfeasible or resulted in opposite pseudo-degenerated Hel-MOs.

C-F activation reactions at germylium ions: dehydrofluorination of fluoralkanes.

Reactions of the trityl cations with germanes afford the germylium ions [RGe][B(CF)] (1a: R = Et, 1b: R = Ph, 1c: R = nBu). These compounds react with germane or fluorogermane to give polynuclear species, which are sources of the mononuclear ions, The latter convert with phosphines to yield the [RGe-PR] (4a: R = Et, 4b: R = Ph) cations. Catalytic dehydrofluorination reactions were observed for the C-F bond activation of fluoroalkanes when using germanes as hydrogen source.

C-H and C-F bond activation reactions of pentafluorostyrene at rhodium complexes.

The rhodium(i) complexes [Rh(Bpin)(PEt)] (1), [Rh(H)(PEt)] (5) and [Rh(Me)(PEt)] (14) were employed in reactions with pentafluorostyrene affording coordination of the olefin and C-F or C-H bond activation. Control of the reaction conditions allowed for selective activation reactions at different positions at the fluorinated aromatic ring. The rhodacycle trans-[Rh(F)(CHCH(2-CF))(PEt)] (7) was identified as an intermediate for an activation at the 2-position.

Activation of tetrafluoropropenes by rhodium(i) germyl and silyl complexes.

The reaction of the rhodium(i) complexes [Rh(E)(PEt3)3] (E = GePh3 (1), Si(OEt)3 (5)) with HFO-1234yf (2,3,3,3-tetrafluoropropene) afforded [Rh(F)(PEt3)3] (2) and the functionalized olefins Z-CF3CH[double bond, length as m-dash]CH(E) (E = GePh3 (4a), Si(OEt)3 (7)). Conceivable reaction pathways were assessed using DFT calculations. Reactions of [Rh(E)(PEt3)3] with HFO-1234ze (E-1,3,3,3-tetrafluoropropene) yielded the rhodium fluorido complex 2 and [Rh{(E)-CH[double bond, length as m-dash]CH(CF3)}(PEt3)3] (9) via two different reaction pathways.

Detection of Cytomegalovirus in Intestinal Tissue of Infants with Necrotizing Enterocolitis or Spontaneous Intestinal Perforation.

Objective: To determine the frequency of detection of cytomegalovirus (CMV) in surgical or autopsy intestinal tissue from infants with necrotizing enterocolitis (NEC) or spontaneous intestinal perforation (SIP) of the small bowel.

Study Design: This was a retrospective cohort study of infants in the neonatal intensive care unit at Nationwide Children's Hospital, Columbus, Ohio, with NEC (Bell stage ≥2B) or SIP from 2000 to 2016. Paraffin-embedded surgical or autopsy intestinal tissues were examined for CMV by polymerase chain reaction (PCR) and immunohistochemistry (IHC), and clinical characteristics of CMV-positive vs CMV-negative cases were compared.

Spirobifluorene Metallaaromatics.

Spirobifluorene derivatives find use in many end-user applications. Therefore, further expansion of their scope is the focus of many research studies. However, although the optical properties of spirobifluorenes can be greatly tuned through incorporation of metal complexes, to date, spirobifluorene metallaaromatics remain unknown.

Dual-specificity phosphatase (DUSP) genetic variants predict pulmonary hypertension in patients with bronchopulmonary dysplasia.

Background: Pulmonary hypertension (PH) in patients with bronchopulmonary dysplasia (BPD) results from vasoconstriction and/or vascular remodeling, which can be regulated by mitogen-activated protein kinases (MAPKs). MAPKs are deactivated by dual-specificity phosphatases (DUSPs). We hypothesized that single-nucleotide polymorphisms (SNPs) in DUSP genes could be used to predict PH in BPD.

C-H and C-F Bond Activation Reactions of Fluorinated Propenes at Rhodium: Distinctive Reactivity of the Refrigerant HFO-1234yf.

The reaction of [Rh(H)(PEt ) ] (1) with the refrigerant HFO-1234yf (2,3,3,3-tetrafluoropropene) affords an efficient route to obtain [Rh(F)(PEt ) ] (3) by C-F bond activation. Catalytic hydrodefluorinations were achieved in the presence of the silane HSiPh . In the presence of a fluorosilane, 3 provides a C-H bond activation followed by a 1,2-fluorine shift to produce [Rh{(E)-C(CF )=CHF}(PEt ) ] (4).