Boron Difluoride Adducts of a Flexidentate Pyridine-Substituted Formazanate Ligand: Property Modulation via Protonation and Coordination Chemistry

The synthesis and characterization of a flexidentate pyridine-substituted formazanate ligand and its boron difluoride adducts, formed via two different coordination modes of the title ligand, are described. The first adduct adopted a structure that was typical of other boron difluoride adducts of triarylformazanate ligands and contained a free pyridine subsituent, while the second was formed via chelation of nitrogen atoms from the formazanate backbone and the pyridine substituent. Stepwise protonation of the pydridine-functionalized adduct, which is essentially non-emissive, resulted in a significant increase in the fluorescence quantum yield up to a maximum of 18%, prompting study of this adduct as a pH sensor. The coordination chemistry of each adduct was explored through reactions with nickel(II) bromide [NiBr2(CH3CN)2], triflate [Ni(OTf)2] and 1,1,1,4,4,4-hexafluoroacetylacetonate [Ni(hfac)2(H2O)2] salts. Coordination to nickel(II) ions altered the physical properties of the boron difluoride formazanate adducts, including red-shifted absorption maxima and less negative reduction potentials. Together, these studies have demonstrated that the physical and electronic properties of boron difluoride adducts of formazanate ligands can be readily modulated through protonation and coordination chemistry

Side-Chain Boron Difluoride Formazanate Polymers via Ring-Opening Metathesis Polymerization

The synthesis, characterization, and ring-opening methathesis polymerization (ROMP) of a novel norbornene-based boron difluoride (BF2) formazante monomer are described in detail. The polymerization studies confirmed ROMP to occur in the presence of BF2 formazanates, and also demonstrated the controlled nature of the polymerization. The polymers retained many of the unique characteristics of the monomers in dichloromethane, including absorption and emission at maximum wavelengths of 518 and 645 nm, large Stoke\u27s shifts (uST = 127 nm, 3,800 cm-1), and the ability to act as electron reservoirs to form borataverdazyl-based poly(radical anions) (E°red1 = -0.95 V). Furthermore, the results described in this paper demonstrate the potential of these and related polymers based on BF2 formazanates as redox-active, light-harvesting materials

Evaluation of Anisole-Substituted Boron Difluoride Formazanate Complexes for Fluorescence Cell Imaging

The evaluation of three subclasses of boron difluoride formazanate complexes bearing o-, m-, and p-anisole N-aryl substituents (Ar) as readily accessible alternatives to boron dipyrromethene (BODIPY) dyes for cell imaging applications is described. While the wavelengths of maximum absorption (lmax) and emission (lem) observed for each subclass of complexes, which differed by their carbon-bound substituents (R), were similar, the emission quantum yields for 7a-c (R = cyano) were enhanced relative to 8a-c (R = nitro) and 9a-c (R = phenyl). Complexes 7a-c and 8a-c were also significantly easier to reduce electrochemically to their radical anion and dianion forms compared to 9a-c. Within each subclass, the o-substituted derivatives were more difficult to reduce, had shorter lmax and lem, and lower emission quantum yields than the p-substituted analogs as a result of sterically-driven twisting of the N-aryl substituents and a decrease in the degree of p conjugation. The m-substituted complexes were the least difficult to reduce and possessed intermediate lmax,lem,and quantum yields. The complexes studied also exhibited large Stokes shifts (82-152 nm, 2143-5483 cm-1). Finally, the utility of complex 7c (Ar = p-anisole, R = cyano), which can be prepared for just a few dollars per gram, for fluorescence cell imaging was demonstrated. The use of 7c and 4\u27,6-diamino-2-phenylindole (DAPI) allowed for simultaneous imaging of the cytoplasm and nucleus of mouse fibroblast cells

A π-conjugated inorganic polymer constructed from boron difluoride formazanates and platinum(II) diynes

The first example of a π-conjugated polymer incorporating boron difluoride (BF2) formazanates is introduced. The film-forming properties, controllable reduction chemistry, and low optical band gap (ca. 1.4 eV) of the polymer make it an excellent candidate for use as a light-harvesting n-type semiconductor in organic electronics. Comparison of the polymer to model compounds confirmed that its unique optoelectronic properties can be directly attributed to the presence of the BF2 formazanate repeat unit and that the [Pt(PBu3)2]2+ unit must also be present to achieve the narrow band gaps observed

Lipids in meso- and bathypelagic fishes from the North Atlantic Ocean: dietary inputs suggested from fatty acid trophic markers

Trophic interactions of mesopelagic fishes are key pathways in the vertical transport of carbon through the biological carbon pump. However, diet and feeding behaviours of many members of the mesopelagic community, including lanternfish (Myctophidae) and bristlemouths (Gonostomatidae), remain poorly resolved. We obtained specimens from 1 species of lanternfish, Benthosema glaciale, and several bristlemouths of the genus Cyclothone, from 8 locations in the Northeast Atlantic Ocean, within 19-22° W and 20-55° N, at depths down to 1900 m, and used fatty acid trophic marker (FATM) analysis to assess the main dietary sources and potential feeding habits of those fish. We compared the FA profiles of the fish to those of their zooplankton prey sampled at the same time and locations. The fatty acid composition of the fish separated them into 3 distinct groups. The first group, which included only B. glaciale, was characterized by the phytoplankton trophic markers 16:4 and 18:4(n-3), indicating that the fish had fed on primary consumers, likely zooplankton. The second group included C. microdon and 2 unidentified Cyclothone sp. and was characterized by the monounsaturated FA markers 20:1(n-9) and 22:1(n-11), indicative of lipid-rich calanoid copepods. Finally, the third group, comprising C. pseudopallida and 22 unidentified Cyclothone sp., was characterized by bacterial FA markers (15:0 and 17:0) and saturated FAs (16:0 and 18:0) that, in the deep sea, are likely associated with marine snow. The results show that meso- and bathypelagic fishes sahttps://stirling-research.worktribe.com/record_edit.jx?recordid=1932531&goto=10&propertyrecordfieldsstring=|recordprogress|recordtext4|recordtext31|recordtext49|recordtext45|recordtext36|recordtext68|recordtext69|recordtext70|recordtext85|recordtext24|recordtext23|recordtext91|recordtext130|recordtext129|recordtext71|recordname|recordtext105|recordtext21|recordtext18|recorddate19|recorddate1|recorddate2|recorddate9|recorddate14|recorddate6|recordtext66|recordtext95|recordtext6|recordtext43|recordtext29|recordtext133|recordtext58|recordtext10|recordtext140|recordtext28|recordtext50|recordtext7|recordtext11|recordtext12|recordtext52|recordtext8|recordnumber6|recordtext44|recordtext112|recordtext106|recordtext17|recordtext65|recordtext128|recorddate4|recorddate5|recordtext113|recordtext114|recordtext74|recordtext48|recorddate13|recordtext76|recordtext77|recordtext72|recordtext61|recordtext80|recordtext81|recorddate11|recordtext59|recordtext46|recordtext63|recordtext62|recordnumber1|recordtext25|recordtext124|recordtext125|recordtext13|recordtext53|recordtext9|recordtext123|recordtext5|recordtext107|recordtext126|recordtext3|recordtext116|recordtext96|recordtext87|recordtext89|recordtext41|recordassignedto|#mpled at different locations will display differences in FA profiles, reflecting distinct dietary sources. In this way, FATMs may facilitate a better understanding of trophic interactions and energy transfer in deep ocean ecosystems

Ultrasound and Microbubbles Mediated Bleomycin Delivery in Feline Oral Squamous Cell Carcinoma-: An In Vivo Veterinary Study

To investigate the feasibility and tolerability of ultrasound and microbubbles (USMB)-enhanced chemotherapy delivery for head and neck cancer, we performed a veterinary trial in feline companion animals with oral squamous cell carcinomas. Six cats were treated with a combination of bleomycin and USMB therapy three times, using the Pulse Wave Doppler mode on a clinical ultrasound system and EMA/FDA approved microbubbles. They were evaluated for adverse events, quality of life, tumour response and survival. Furthermore, tumour perfusion was monitored before and after USMB therapy using contrast-enhanced ultrasound (CEUS). USMB treatments were feasible and well tolerated. Among 5 cats treated with optimized US settings, 3 had stable disease at first, but showed disease progression 5 or 11 weeks after first treatment. One cat had progressive disease one week after the first treatment session, maintaining a stable disease thereafter. Eventually, all cats except one showed progressive disease, but each survived longer than the median overall survival time of 44 days reported in literature. CEUS performed immediately before and after USMB therapy suggested an increase in tumour perfusion based on an increase in median area under the curve (AUC) in 6 out of 12 evaluated treatment sessions. In this small hypothesis-generating study, USMB plus chemotherapy was feasible and well-tolerated in a feline companion animal model and showed potential for enhancing tumour perfusion in order to increase drug delivery. This could be a forward step toward clinical translation of USMB therapy to human patients with a clinical need for locally enhanced treatment

DEVELOP EUROGOOS MARINE CLIMATE SERVICE WITH A SEAMLESS EARTH SYSTEM APPROACH

The ocean is an important pathway to a low-carbon and climate resilient society, e.g. in areas of blue carbon, green shipping, offshore renewable energy, aquaculture, fi shery and coastal adaptation. Currently, 26 EU member states have made their National Adaptation Strategy (NAS) and/or National Strategy Plan (NAP) which needs a strong climate information service. European Global Ocean Observing System (EuroGOOS) has a strategy to expand existing operational marine service to climate change in 2020-2030. As focal points of national marine, climate and/or weather services, ROOS (Regional Sea Operational Oceanographic System) members have extensive experiences in working with citizens, stakeholders and decision-makers at national, regional and municipality levels. This paper will review current marine climate service capacity in ROOS members, identify gaps in modelling, products and service, and propose a seamless earth system approach for developing EuroGOOS and ROOS marine climate service capacities.Versión del edito