Neutral Eu Research Articles

Європейський Союз у постмодерній системі міжнародних відносин

In the history of international relations, discussions continue on the definition of criteria and chronological boundaries of different systems of international relations. The purpose of the article is to consider the theoretical and practical problems of positioning the European Union in the postmodern system of international relations. The Modern period was characterized by a block approach to security. The postmodern system of international security is based on a combination of hierarchical and network characteristics of the international system. The sovereign states of the European Union are often critical of each other, although this fact may for some time be masked by the need for solidarity in relations with the outside world and its risks. As soon as the factor of identity or proximity of interests is leveled off, the motives for concerted joint action disappear. Real politics is also influenced by the idea of European integration of many speeds. Following the enlargement of the EU to 28 member states (before the withdrawal of the United Kingdom), the core of European integration (the six founding members of the European Communities) and the concentric circles touching the core stood out. The accession of new EU member states to the highest achievements of European integration is possible at different speeds. Neutral EU countries such as Finland and Sweden have responded to Russia’s war against Ukraine by applying to join NATO. The United States still has a special consolidating role in the alliance. The postmodern multipolar system of international relations will consist of several hierarchical structures. First, it will be transformed military-political blocs, and secondly, networks of interaction between states that are regional leaders in their regions. Russia’s aggression against Ukraine has consolidated the European Union and the United States. The Euro-Atlantic space is in fact a consolidated pole of power in the postmodern system of international relations. The United Kingdom is ensuring the expansion of the Euro-Atlantic space through the AUCUS into the Pacific. The postmodern system of international relations is multipolar. It is not limited to bipolar US-China confrontation. In the postmodern system of international relations, the European Union is not only a pole of power, but also its typological symbol.

Consumers’ contribution to a climate neutral EU: What influences the adoption of food-related mitigation options?

The main aim of this contribution is to identify factors that influence consumers’ willingness to adopt food-related options to mitigate climate change and reveal how these factors are interlinked. In-depth interviews were carried out with 32 consumers in Germany, France and the UK; the results were analysed and described in the context of Alphabet Theory. The allocation of findings from the interviews to the theoretical framework helps to identify interrelations, to provide explanations and thereby achieve to take a holistic view on the topic, without neglecting contextual information. The findings of this study indicate that a higher level of knowledge will result in more personal responsibility assumed by the consumers and will increase their willingness to adopt mitigation options. Hence, public information campaigns and education programs initiated to enhance consumers’ knowledge on climate-friendly food choices. At the same time, climate-friendly food products need to be easily available and identifiable to help consumers to act according to their attitudes.

Sustainable renewable energy supply networks optimization – The gradual transition to a renewable energy system within the European Union by 2050

In order to achieve the goal of a carbon neutral EU by 2050 and meet the climate targets of the Paris Agreement, a sustainable, efficient, competitive and secure energy system needs to be developed. This paper presents the synthesis of sustainable renewable energy supply networks within the EU-27, proposing a stepwise energy transition in the transport and power sectors, achieving a carbon net neutral target by 2050. A multi-period mixed-integer programming model is developed, with the objective of maximizing sustainability net present value, considering different biomass and waste resources for the production of biofuels, renewable electricity, hydrogen, food and bioproducts, employing different types of technologies. The results show that, with further development of existing technologies, the goal of a carbon-neutral EU can be achieved without compromising food production. Wind farms have proven to be the most promising solution at present for the rapid expansion of electricity generation from renewable energy sources, while the importance of solar photovoltaics is increasing over the years, reaching the 43% share of electricity generation from RES in 2050. Moreover, the energy transition within the EU could have a significant positive impact on the economic, environmental and also social aspects of sustainability, with more than 1.5 million new job opportunities created across the EU over the next 30 years.

Energy Taxes and Emissions Trading on the Bumpy Road to a Climate Neutral EU

In her ‘Agenda for Europe’ (her electoral manifesto as candidate for the presidency of the European Commission) Ursula von der Leyen announced the proposal of an ambitious European Green Deal, including among others a review of the EU Energy Tax Directive and the introduction of a ‘Carbon Borden Tax’ (meanwhile re-titled into Carbon Border Adjustment Mechanism).1 In this editorial I will go into the development of these proposals in the Green Deal that was published on 11 December 2019, shortly after Von der Leyen took office. Before doing so, I will summarize the history of a long road that started around thirty years ago in the UN and eventually should lead to a climate-neutral EU in 2015.

Le prospettive della bioeconomia, tra strategie, Green Deal e Covid19

The importance of a sustainable and circular bioeconomy in achieving the Sustainable Development Goals (SDGs) has been recognized at various political levels. The EU Green Deal is one of the most transformative European political initiatives in recent decades. However, such a great vision and ambition can not be delivered without looking at the essence of the economic model we have created, without fundamentally rethinking the way we produce and consume. What is needed is a system change. We have to connect and implement transformative policies holistically to achieve the systemic change that is urgently needed. The bioeconomy, a circular economy based on renewable biological resources and sustainable biobased solutions, could certainly contribute. Three features could help to connect the dots in the Green Deal: bioeconomy is fundamental for inclusive prosperity and fair social transition; moving towards a carbon neutral EU requires moving towards fossil-free energy and fossil-free materials, to replace carbon intense products, such as nanocellulose, wood based textiles, wood engeenering; address the past failure of the economy to value nature and biodiversity. Biological diversity determines the capacity of biological resources to adapt and evolve in a changing environment and is a prerequisite for a long-term, sustainable and resilient bioeconomy. Therefore, bioeconomy is a great opportunity to modernize and make industries more circular: renewable biological resources, like forest resources, are, if managed sustainably at local and responsibly at global level, circular by nature and often easier to manufacture. The potential and crucial role of forests and forestry is not yet addressed enough at European level. Some good examples from member states and economic sectors should be adopted as the main way to promote sustainability at all levels, social, ecological, economic. The stewardship of forest ecosystem services such as biodiversity provision, hydrogeological protection and landscape conservation has increased. In addition to the main dramatic role for the conservation of biodiversity and the mitigation of climate crisis, forests could pave a strategic road to the creation of new green jobs, tackling the new direction that are requested after the current time of pandemic for rethinking our common future. Also in Italy, nowadays the conditions are ripe to plan for a responsible management of the natural capital in the country’s forests.

Tripyridinophane Platform Containing Three Acetate Pendant Arms: An Attractive Structural Entry for the Development of Neutral Eu(III) and Tb(III) Complexes in Aqueous Solution.

We report a detailed characterization of Eu3+ and Tb3+ complexes derived from a tripyridinophane macrocycle bearing three acetate side arms (H3tpptac). Tpptac3- displays an overall basicity (∑ log KiH) of 24.5, provides the formation of mononuclear ML species, and shows a good binding affinity for Ln3+ (log KLnL = 17.5-18.7). These complexes are also thermodynamically stable at physiological pH (pEu = 18.6, pTb = 18.0). It should be noted that the pGd value of Gd-tpptac (18.4) is only slightly lower than that of commercially available MRI contrast agents such as Gd-dota (pGd = 19.2). Moreover, a very good selectivity for these ions over the endogenous cations (log KCuL = 14.4, log KZnL = 12.9, and log KCaL = 9.3) is observed. The X-ray structure of the terbium complex shows the metal coordinated by the nine N6O3 donor set of the ligand and one inner-sphere water molecule. DFT calculations result in two Eu-tpptac structures with similar bond energies (ΔE = 0.145 eV): one structure in which the water is coordinated to the metal ion and one structure in which the water molecule is farther away from the ion, bound to the ligand with an OH-π bond. By detailed luminescence experiments, we demonstrate that the europium complex in aqueous solution presents a hydration equilibrium between nine-coordinate, dehydrated [Eu-tpptac]0 and ten-coordinate, monohydrated [Eu-tpptac(H2O)]0 species. A similar trend is observed for the terbium complex. Despite the presence of this hydration equilibrium, the H3tpptac ligand sensitizes Eu3+ and Tb3+ luminescence efficiently in buffered water at physiological pH. Particularly, the terbium complex displays a long excited-state lifetime of 2.24 ms and an overall quantum yield of 33% with a brightness of 3600 M-1 cm-1. Such features of Ln3+ complexes of H3tpptac indicate that this platform appears to be particularly appealing for the further development of luminescent lanthanide labels.

Synthesis and photophysical studies of new organic-soluble lanthanide complexes of 4-(4-alkoxyphenyl)-2,2′-bipyridine-6-carboxylic acids

A convenient synthetic approach has been developed for 4-aryl-2,2′-bipyridine-6-carboxylic acids bearing long chained para-alkoxy residues at the 4-aryl substituents. These ligands have been further used for the preparation of neutral Eu(III), Tb(III), Sm(III) and Dy(III) complexes, and their photophysical properties have been studied. The obtained photophysical data were compared with those previously reported for a number of similar neutral complexes.

Technology neutral EU law: digital goods within the traditional goods/services distinction

Technology neutral EU law: digital goods within the traditional goods/services distinction

In situ formation and characterisation of singly ionised atomic europium in rare gas matrices--luminescence spectroscopy and MP2 calculations.

Irradiation of atomic europium isolated in the solid rare gases, with low intensity laser excitation of the y(8)P←a(8)S resonance transition at ca. 465 nm, is found to produce singly charged europium cations (Eu(+)) in large amounts in xenon and in smaller amounts in argon. Confirmation of the formation of matrix-isolated Eu(+) is obtained from characteristic absorption bands in the UV and in the visible spectral regions. The luminescence produced with excitation of the cation bands is presented in greatest detail for Eu/Xe and assigned. Excitation of the 4f(7)((8)S7/2)6p3/2 absorption bands of Eu(+) between 390 and 410 nm produces emission which is quite distinct from that resulting from excitation of the 4f(7)((8)S7/2)6p1/2 absorption (430 to 450 nm) features. The latter consists of narrow, resolved emission bands with Stokes shifts ten times smaller than the former. The observed spectral differences are discussed in relation to the different spatial symmetries of the p3/2 and p1/2 orbitals in these j-j coupled (7/2, 3/2)J and the (7/2, 1/2)J levels. Møller-Plesset calculations are conducted to obtain the molecular parameters of the neutral Eu-RG and cationic Eu(+)-RG diatomics (RG = Ar, Kr, Xe). From the short bond lengths and the strong binding energies obtained for the Eu(+)-RG species, these values suggest the isolation of the ion in small, possibly interstitial sites especially in xenon. In contrast, but consistent with previous work [O. Byrne and J. G. McCaffrey, J. Chem. Phys. 134, 124501 (2011)], the interaction potentials calculated herein for the Eu-RG diatomics suggest that the neutral Eu atom occupies tetra-vacancy (tv) and hexa-vacancy (hv) sites in the solid rare gas hosts. Possible reasons for the facile production of Eu(+) in the solid rare gases are discussed. The mechanism proposed is that atomic europium is also acting as an electron acceptor, providing a temporary trap for the ionised electron in the matrices.

Experimental verification of isotope shift and hyperfine structure of some even parity levels of neutral Eu

The results of measurements of the hyperfine structure of 31 classified and four unclassified spectral lines in the europium atom, obtained by using the laser induced fluorescence method, are presented. On the basis of experimental results, the values of the hyperfine structure constants and the isotope shifts for seven hitherto unmeasured levels belonging to even configurations (among them for three entirely new levels with unknown energies) were determined and the respective values known from literature for another 19 levels were verified. Since the motivation for undertaking investigations within this work was an inconsistency in the semi-empirical description of the hyperfine structure and the isotope shifts for some even levels in the europium atom, a detailed discussion of this problem is presented.

Laser-induced fluorescence and infrared spectroscopic studies on the specific solvation of tris(1-(2-thienyl)-4,4,4-trifluoro-1,3-butanedionato)europium(III) in an ionic liquid

The extraction constant and the two-phase stability constant ( K D,M β 3) of tris(2-thenoyltrifluoroacetonato)europium(III) between 1-butyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide ([C 4mim][Tf 2N]) as an ionic liquid and an aqueous phase were determined by considering the extraction equilibria including anionic tetrakis(2-thenoyltrifluoroacetonato)europate(III). Specific solute–solvent interactions between the neutral Eu(III) chelate and [C 4mim][Tf 2N] molecules were revealed from the relationships between the distribution constant of the enol form of 2-thenoyltrifluoroacetone (Htta) as a proton chelate and the distribution constant ( K D,M) of the neutral Eu(III) chelate because the [C 4mim][Tf 2N] system gave the high K D,M β 3 value compared with those in conventional molecular solvents such as benzene and 1,2-dichloroethane. The coordination environment of Eu 3+ in the neutral Eu(III) chelate in [C 4mim][Tf 2N] was investigated by time-resolved laser-induced fluorescence spectroscopy and infrared absorption spectroscopy. Both methods consistently indicated that not only the Eu(III) chelate extracted but also Eu(tta) 3(H 2O) 3 synthesized as a solid crystal were almost completely dehydrated in [C 4mim][Tf 2N] saturated with water. Consequently, the higher K D,M or extractability of the neutral Eu(III) chelate in the [C 4mim][Tf 2N] system can be ascribed to the dehydration of the Eu(III) chelate, which is caused by the specific solvation with [C 4mim][Tf 2N] molecules.

Varieties of neutrality

With the end of the Cold War, the neutral countries of Austria, Finland, Ireland and Sweden have grappled with the question of what their neutrality means in relation to membership in the European Union’s (EU) Common Security and Defence Policy (CSDP) and the North Atlantic Treaty Organization’s (NATO) Partnership for Peace (PfP). The concept of neutrality has continued to inform the foreign and security policies of these four neutral EU members to varying degrees, but what explains these ‘varieties of neutrality’ and what does neutrality mean in relation to membership in the EU’s CSDP and NATO’s PfP? In this article, the primary focus is on neutrality as a norm. Understanding neutrality as a norm helps clarify how neutrality becomes embedded in national identity, what it shows about the interactions between domestic belief systems and international security conditions over time, and how the definition of a norm can be revised to allow for desired policy choices. To this end, the article asserts that there are four interrelated factors key to explaining how and why each state modified its interpretation of neutrality vis-à-vis international military institutions such as NATO, and the CSDP: the reason for and timing of institutionalizing neutrality (coerced or voluntary), the form of institutionalization ( de jure or de facto), political elite opinion and public opinion/belief.

Eu(III) and Tb(III) luminescent lanthanide systems derived from DTPA-bisamide and DTTA-based ligands incorporating bipyridine antenna

Four new polycarboxylate ligands H 3 L n have been synthesized by the attachment of two or one 2,2′-bipyridine subunits onto a diethylenetriamine pentacarboxylic acid (DTPA-bisamide derivatives: H 3 L 1 , H 3 L 2 ) or a diethylenetriamine tricarboxylic acid (DTTA derivatives: H 3 L 3 , H 3 L 4 ) core. The neutral Eu III and Tb III complexes of these chelates have been prepared and studied from their UV–vis and luminescence data. The main photophysical characteristics of these complexes, i.e. the absorption and luminescence spectra, the metal-centred lifetimes and the overall luminescence yields ( Φ) were measured in buffered aqueous solutions. In addition the role played by non-radiative paths (vibrational energy transfer involving coordinated water molecules, involvement of ligand-to-metal charge-transfer excited states, or metal→ligand back-transfer) was investigated. In all complexes, we found that the bidentate bipyridine chromophore is not coordinated to the lanthanide ion, allowing one (Ln L 1 , Ln L 2 ) or two (Ln L 3 , Ln L 4 ) water molecules to penetrate the first coordination sphere of the metal. Although the bipyridine chromophore behaves as remote (from the binding site) light-harvesting unit for the lanthanide ion in these systems, a sizeable sensitization of the Eu- and Tb-centred luminescence can be effective (Ln L 2 , Ln L 3 , Φ=16–19% in aerated D 2O solutions). Our photophysical investigations show that overall non-radiative deactivation is not dependant of thermally activated non-radiative channels but the efficiency of the ligand→Ln intramolecular energy transfer has to be taken into account to explain the obtained results.

Highly Efficient Blue Photoexcitation of Europium in a Bimetallic Pt–Eu Complex

We report the preparation and characterization of dinuclear Pt-Ln complexes constructed from a square-planar Pt(II) core bearing an ethynyl-terpyridine residue connected to platinum by the ethynyl bond. Complexation of the neutral Eu(hfac)3 (hfac = hexafluoroacetylacetonate) fragment to free terpyridine (terpy) gives a stable bimetallic complex (log beta = 6.7). In the crystal structure, the flat Pt[triple bond]terpy core coordinates to Eu(III), which is nonacoordinated with the three nitrogen atoms of the terpy subunit and six oxygen atoms of the three hfac ligands. These atoms form a distorted monocapped square antiprism with a pseudo-C2 symmetry axis passing through the nitrogen atom of the central pyridine ring and the Eu atom. Spectroscopic measurements showed that irradiation with visible light of wavelength up to 460 nm in the 1MLCT state of the Pt subunit resulted in a quantitative energy transfer to the Eu center, which strongly luminesces in the red with an overall luminescence quantum yield of 38%. The energy-transfer process is quantitative and not sensitive to oxygen, and the complexation of Eu to the Pt metallosynthon allows the recovery of the energy lost due to triplet-oxygen quenching of the 3MLCT state observed in the uncomplexed Pt precursor.

Wavelength and Metal Dependence in the Photofragmentation of a Gas-Phase Lanthanide β-Diketonate Complex

The time-of-flight mass spectra of tris(2,2,6,6-tetramethyl-3,5-heptanedionato) lanthanide(III) [or Ln(thd)3 with Ln = Eu, Tb, Gd] produced by laser-induced multiphoton ionization in a supersonic expansion were studied as a function of laser excitation wavelength. Resonance-enhanced multiphoton ionization (REMPI), monitoring the Eu(I) ion signal from gas-phase Eu(thd)3, was observed in three distinct visible-excitation regions, corresponding to electronic absorption transitions on neutral Eu(0) atoms. The confirmation of the presence of Eu(0) atoms in the beam supports the proposed mechanism for the production of Ln atoms through sequential dissociation of neutral thd ligands from the metal following photoexcitation into ligand-to-metal charge-transfer (LMCT) states. Evidence is also presented that the LnO+ and LnOH+ fragments observed in the mass spectrum are produced via a separate, competing fragmentation pathway. The branching ratios between the two fragmentation pathways are compared for Ln(thd)3 (Ln = Eu, Tb, Gd). The ligand-dissociation pathway that produces Ln atoms appears to be more favorable in Ln(thd)3 complexes with low-lying LMCT states. Finally, the observation of the Tb2(thd)6+ dimer and its associated fragmentation pattern, as well as the presence of metal carbides, which are relevant to carbon contamination in chemical vapor deposition, is discussed.

Synthesis, Characterization, and Luminescence Properties of a New Series of Eu3+-Containing Macrocycles

The synthesis and structural characterization of a series of neutral Eu(3+)-containing macrocyclic complexes, Eu(4)-Eu(7), are reported. The synthetic pathway herein allows for the size and functionality of the macrocycle to be tailored in one step from a common precursor (N,N' '-bis(p-isothiocyanatobenzylcarbamoylmethyl)diethylenetriamine-N,N'N' '-triacetic acid, (3) in high yield. The macrocyclic ligands 4-7 have within their structure a bis-amide derivative of diethylenetriaminepentaacetic acid (DTPA) functioning as the europium chelate that is bridged through thiourea groups by either a butyl (4), hexyl (5), octyl (6), or m-benzyl (7) linker. The two thiourea groups were designed into the host macrocycle to serve as hydrogen-bond donors to potential guest molecules that may alter the luminescence properties of the parent macrocycle. Characterization of the luminescence of Eu(4)-Eu(7) reveals an antenna effect from the ligand, and the luminescence lifetime data reveals the presence of one coordinated water molecule in aqueous solution.

Lanthanide cationextraction by malonamideligands: from liquid–liquid interfaces to microemulsions. A molecular dynamics study

According to molecular dynamics simulations, uncomplexed malonamide ligands L and their neutral Eu(NO3)3L2 or charged EuL4(3+) complexes are surface active and adsorb at a water-"oil" interface, where "oil" is modeled by chloroform. Aqueous solvation at the interface is found to induce a trans to gauche rearrangement of the carbonyl groups, i.e., to preorganize the chelating L ligands for complexation. The interface also induces a larger proportion of extended amphiphilic forms, of EE-gauche type. The effect of increased oil/water ratio is also investigated. It shown that the system evolves from a well-defined interface between immiscible phases to water-in-oil cylindrical micelles and micro-droplets, onto which L ligands and the lanthanide complexes adsorb, while other ligands are extracted in organic phase. Two electrostatic models of the complexes are compared and, in no case is the neutral or charged complex fully extracted to the organic phase. These features allow us to better understand synergistic and solvation effects in the assisted liquid-liquid extraction of lanthanide or actinide cations.

Sharp and window resonances in the4dphotoabsorption spectrum ofEu+ions

We have studied the $4d$ photoabsorption process of ${\mathrm{Eu}}^{+}$ ions by the linear-density-response theory with the density-functional theory and an optimized effective potential and self-interaction correction. Different from the recent experimental observation, which found that the $4d$ photoabsorption spectrum of ${\mathrm{Eu}}^{+}$ ions is almost the same as that of neutral Eu atoms, our calculated $4d$ photoabsorption spectrum of ${\mathrm{Eu}}^{+}$ ions shows many sharp and window resonances, which do not appear in case of neutral Eu atoms. The discrepancies between the experimental observation and our calculation are due to the experimental energy resolution. The convoluted spectrum with the experimental energy resolution is in good agreement with the experimental observation. Moreover, we predict the $4d$ photoabsorption spectra with several given energy resolutions, which call for a further higher-resolution experiment.

Photoion yield spectroscopy in the 4d photoionization of

Using an ion-photon merged-beam apparatus, photoion yield spectra of and from the 4d photoionization of were measured as a function of photon energy in the range 110-160 eV. The measured spectra look very similar to those from a neutral Eu target. Both and yield spectra, a broad `giant resonance' appears at 140 eV with some preceding small peaks at 131.5, 132.8 and 134.7 eV. The summit of the `giant resonance' in the spectrum is split into two peaks. This is not observed in neutral Eu photoionization.