Securitization of pandemic risk by using coronabond.

This article investigates the pandemic risk coverage within the European Union member states through insurance securitization. This strategy allows the transfer of health risks from the insurance market to the financial markets. We focus on the financial market crisis caused by the COVID-19 pandemic to securitize the losses caused by the latter. Over the period from 24/01/2020 (the first proven case of contamination in Europe) to 31/03/2020 (end of the dramatic decrease in financial markets), we apply the extreme value theory allowing the selection of the trigger threshold. We identify an immediate reaction of the financial markets following a pandemic shock, the effect of which fades after a few days. The response of stock market indices, measured by the fluctuation of return rates, is not very high. Nevertheless, the reaction of the financial markets is sufficient for the corona bond triggering, provided that the threshold for triggering the incidence rate is optimal. In addition, the securitization of insurance risk could be an alternative process to the classic risk transfer techniques such as co-insurance and reinsurance. Finally, a reinsurance pool dedicated to the insurance scheme's management against the effects of a pandemic is crucial for insurance securitization. These results could have implications for various actors such as insurers, financial investors, and States.

The Influence of Economic Policy Uncertainty and Business Cycles on Fine Wine Prices.

This study investigates the impact of both economic policy uncertainty (EPU) and business cycles on the fine wine market. We use a nonlinear autoregressive distributed lag model to measure the influence of these two variables on three major Liv-ex indices over the period 2005M01-2020M12. Our results are multiple. First, fine wine prices are relatively unaffected asymmetrically by EPU, while the economic cycle has a more pronounced asymmetric effect, especially in the short run. Second, uncertainty in Europe and the USA affect fine wine prices more than in China. Third, in the short term, fine wine prices react more strongly to changes in business cycles than to uncertainty. Finally, prices of the five first growths of Bordeaux are asymmetrically influenced by EPU, unlike of the rest of the most prestigious Bordeaux wines. The study also has implications for investment. We argue that a strong and professional strategic intelligence watch would help stakeholders in the secondary wine market to improve their returns, especially when European and US wines are involved. While short-runners should focus on information relative to changes in the business cycle, long-term investors would find it more interesting to closely monitor policy decisions liable to have long-term effects on wine prices (such as taxation, monetary measures…).

Rationalization of solid-state NMR multi-pulse decoupling strategies: Coupling of spin I = ½ and half-integer quadrupolar nuclei.

In this paper we undertake a study of the decoupling efficiency of the Multiple-Pulse (MP) scheme, and a rationalization of its parameterization and of the choice of instrumental set up. This decoupling scheme is known to remove the broadening of spin-1/2 spectra I, produced by the heteronuclear scalar interaction with a half-integer quadrupolar nucleus S, without reintroducing heteronuclear dipolar interaction. The resulting resolution enhancement depends on the set-up of the length of the series of pulses and delays of the MP, and some intrinsic material and instrumental parameters. Firstly through a numerical approach, this study investigates the influence of the main intrinsic material parameters (heteronuclear dipolar and J coupling, quadrupolar interaction, spin nature) and instrumental parameters (spinning rate, pulse field strength) on efficiency and resolution enhancement of the scalar decoupling scheme. A guideline is then proposed to obtain quickly and easily the best resolution enhancement via the rationalization of the instrumental and parameter set up. It is then illustrated and tested through experimental data, probing the efficiency of MP-decoupling set up using this guideline. Various spin systems were tested (31P-51V in VOPO4, 31P-93Nb in NbOPO4, 119Sn-17O in Y2Sn2O7), combined with simulations results.

First copper(ii) phase M'0.2Mn0.8PS3·0.25H2O and analogous M' = Co(II), Ni(II) and Zn(II) materials obtained by microwave assisted synthesis.

M'0.2Mn0.8PS3·0.25H2O materials are obtained by a mild microwave assisted reaction (M' = Co(II), Ni(II), Cu(II), Zn(II)), which permitted us to obtain the first copper(ii) bimetallic phase. All these materials have a lower energy gap and antiferromagnetic interactions with lower values of the Weiss constant, than that of the pristine phase MnPS3.

Crystal lattice effect on the quenching of the intracluster magnetic interaction in [V12B18O60H6](10-) polyoxometalate.

In the present work, the synthesis and structural characterization of four new polyoxovanadoborate (BVO) frameworks based on the [V12B18O60H6](10-) polyanion are reported: (NH4)8(1,3-diapH2)[V12B18O60H6]·5H2O (1), K8(NH4)2[V12B18O60H6]·18H2O (2), K10[V12B18O60H6]·10H2O (3) and K8Cs2[V12B18O60H6]·10H2O (4). A global antiferromagnetic behaviour is observed for these 10V(IV)/2V(V) mixed valence clusters. The magnetic data of 1, 2 and 3, which present different countercation environments, show that 1 is more coupled than 2 and 3. DFT calculations show that the positive charges strongly influence the polarization mechanism of the spin density of the vanadyl groups and the extent of the magnetic orbitals, therefore corroborating the experimental observation of the quenching effect of the magnetic coupling between vanadium centres of 2 and 3.

K6[Fe8.27(HPO3)12]: a new mixed-valence iron phosphite.

The title compound, hexapotassium octairon(II,III) dodecaphosphonate, exhibiting a two-dimensional structure, is a new mixed alkali/3d metal phosphite. It crystallizes in the space group R3m, with two crystallographically independent Fe atoms occupying sites of 3m (Fe1) and 3m (Fe2) symmetry. The Fe2 site is fully occupied, whereas the Fe1 site presents an occupancy factor of 0.757 (3). The three independent O atoms, one of which is disordered, are situated on a mirror and all other atoms are located on special positions with 3m symmetry. Layers of formula [Fe3(HPO3)4](2-) are observed in the structure, formed by linear Fe3O12 trimer units, which contain face-sharing FeO6 octahedra interconnected by (HPO3)(2-) phosphite oxoanions. The partial occupancy of the Fe1 site might be described by the formation of two [Fe(HPO3)2](-) layers derived from the [Fe3(HPO3)4](2-) layer when the Fe1 atom is absent. Fe(2+) is localized at the Fe1 and Fe2 sites of the [Fe3(HPO3)4](2-) sheets, whereas Fe(3+) is found at the Fe2 sites of the [Fe(HPO3)2](-) sheets, according to bond-valence calculations. The K(+) cations are located in the interlayer spaces, between the [Fe3(HPO3)4](2-) layers, and between the [Fe3(HPO3)4](2-) and [Fe(HPO3)2](-) layers.

Ammonium diphosphitoindate(III).

The crystal structure of the title compound, NH4[In(HPO3)2], is built up from In(III) cations (site symmetry 3m.) adopting an octa-hedral environment and two different phosphite anions (each with site symmetry 3m.) exhibiting a triangular-pyramidal geometry. Each InO6 octa-hedron shares its six apices with hydrogen phosphite groups. Reciprocally, each HPO3 group shares all its O atoms with three different metal cations, leading to [In(HPO3)2](-) layers which propagate in the ab plane. The ammonium cation likewise has site symmetry 3m.. In the structure, the cations are located between the [In(HPO3)2](-) layers of the host framework. The sheets are held together by hydrogen bonds formed between the NH4 (+) cations and the O atoms of the framework.

DFT-assisted structure determination of α1- and α2-VOPO4: new insights into the understanding of the catalytic performances of vanadium phosphates.

Structural investigations on vanadium phosphates, which are extensively used as catalysts in industry, often resulted in important advances in the understanding of the mechanisms driving the catalytic oxidation of light hydrocarbons. Layer translations in the two lamellar vanadium phosphates α1- and α2-VOPO4 phases identified during the catalysis were investigated by the combination of first-principles calculations, synchrotron X-ray powder diffraction, single-crystal X-ray diffraction and solid-state NMR. This analysis reveals an important feature: the α1-form is the only polymorph of VOPO4 to exhibit layer translations that prevent the formation of infinite VO6 chains. A detailed investigation of this structural characteristic in vanadium phosphates reveals the correlation between the presence of infinite VO6 chains and the catalytic performances of related phases.

77Se solid-state NMR of As2Se3, As4Se4 and As4Se3 crystals: a combined experimental and computational study.

(77)Se NMR parameters for three prototypical crystalline compounds (As2Se3, As4Se4 and As4Se3) have been determined from solid-state NMR spectra in the framework of an investigation concerning AsxSe(1-x) glass structure understanding. Density functional NMR calculations using the gauge including projector augmented wave methodology have been performed on X-ray and optimized crystal structures for a set of selenium-based crystals. These theoretical results have been combined with the experimental data in order to achieve a precise assignment of the spectral lines. This work and the high sensitivity of solid-state NMR to local order show that the structure of As4Se3 should be reinvestigated using state-of-the-art diffraction techniques. Calculations performed on several molecules derived from the crystal structures have demonstrated the limited effect of interlayer or intermolecular interactions on the isotropic chemical shifts. These interactions are therefore not responsible for the unexpected large chemical shift difference observed between these three systems that could mostly be attributed to the presence of short rings.

A new hybrid organic-inorganic chain: [(phen)Cu-µ-(κ2O:O'-VP2O10H3)2-Cu(phen)]n.

The structure of the title compound, poly[(dihydrogenphosphato-κO)(µ(3)-hydrogenphosphato)di-µ-oxido-(1,10-phenanthroline)copper(II)vanadium(V)], [CuV(HPO(4))(H(2)PO(4))O(2)(C(12)H(8)N(2))](n), is defined by [(phen)Cu-µ-(κ(2)O:O'-VP(2)O(10)H(3))(2)-Cu(phen)] units (phen is 1,10-phenanthroline), which are connected to neighbouring units through vanadyl bridges. Neighbouring chains have no covalent bonds between them, although they interdigitate through the phen groups via π-π interactions.

VOPO4·H2O: a stacking faults structure studied by X-ray powder diffraction and DFT-D calculations.

The dehydration process of VOPO(4)·2H(2)O occurs in two steps corresponding to successive elimination of the two crystallographically distinct water molecules. The intermediate phase VOPO(4)·H(2)O has been stabilized for X-ray powder diffraction studies. The resulting data suggest a tetragonal cell (a = 6.2203(2) Å and c = 6.18867(7) Å), but an important anisotropy in the line broadening points out the necessity of considering a not perfectly organized structure. Because of the layered structure of this compound, density functional theory calculations including dispersion corrections have been carried out to evaluate the possible presence of stacking faults. The results of these calculations give information about the nature of the translations and their probabilities using a Boltzmann distribution. DIFFaX+ simulations of the X-ray powder diffraction pattern have been carried out using the results of the theoretical calculations and confirm the presence and nature of stacking faults.

Two caesium vanadium hydrogenphosphates with tunnelled structures: Cs(2)V(2)O(3)(PO(4))(HPO(4)) and Cs(2)[(VO)(3)(HPO(4))(4)(H(2)O)].H(2)O.

Dicaesium divanadium trioxide phosphate hydrogenphosphate, Cs(2)V(2)O(3)(PO(4))(HPO(4)), (I), and dicaesium tris[oxidovanadate(IV)] hydrogenphosphate dihydrate, Cs(2)[(VO)(3)(HPO(4))(4)(H(2)O)].H(2)O, (II), crystallize in the monoclinic system with all atoms in general positions. The structures of the two compounds are built up from VO(6) octahedra and PO(4) tetrahedra. In (I), infinite chains of corner-sharing VO(6) octahedra are connected to V(2)O(10) dimers by phosphate and hydrogenphosphate groups, while in (II) three vanadium octahedra share vertices leading to V(3)O(15)(H(2)O) trimers separated by hydrogenphosphate groups. Both structures show three-dimensional frameworks with tunnels in which Cs(+) cations are located.

Dipotassium trimanganese(II) tetrakis(hydrogenphosphite), K2[Mn3(HPO3)4].

The title compound is a new mixed alkali/3d metal phosphite. It exhibits a layered structure formed by linear Mn(3)O(12) trimer units which contain face-sharing MnO(6) octahedra interconnected by (HPO(3))(2-) phosphite oxoanions. The K(+) cations located between the anionic [Mn(3)(HPO(3))(4)](2-) sheets are ninefold coordinated. The presence of the alkaline ion leads to the highest symmetry and shortest interlayer distance compared with two previous compounds showing the same anionic framework and having ammonium salts as cations. The compound crystallizes in the space group R3m, with two crystallographically independent Mn atoms occupying sites of 3m and 3m symmetry. All the other atoms, except for the phosphite O atoms, are located on special positions with 3m symmetry.

The first three-dimensional vanadium hypophosphite.

The title synthesized hypophosphite has the formula V(H(2)PO(2))(3). Its structure is based on VO(6) octahedra and (H(2)PO(2))(-) pseudo-tetrahedra. The asymmetric unit contains two crystallographically distinct V atoms and six independent (H(2)PO(2))(-) groups. The connection of the polyhedra generates [VPO(6)H(2)](6-) chains extended along a, b and c, leading to the first three-dimensional network of an anhydrous transition metal hypophosphite.

DFT calculations of quadrupolar solid-state NMR properties: Some examples in solid-state inorganic chemistry.

This article presents results of first-principles calculations of quadrupolar parameters measured by solid-state nuclear magnetic measurement (NMR) spectroscopy. Different computational methods based on density functional theory were used to calculate the quadrupolar parameters. Through a series of illustrations from different areas of solid state inorganic chemistry, it is shown how quadrupolar solid-state NMR properties can be tackled by a theoretical approach and can yield structural information.

Structure and stability of VO2+ in aqueous solution: a Car-Parrinello and static ab initio study.

Quantum chemical calculations have been carried out to get some insight concerning the effects of temperature and solvent acidity on the structure and stability of solvated VO2+ as the elementary chemical unit involved in the nucleation of vanadophosphates. First, because some recent theoretical studies have suggested a tendency of density functional theory (DFT) to favor lower coordination numbers for such systems, static calculations have been performed on [VO2(H2O)(4-n)]+.nH2O (n=0-2) conformers at the MP2 and DFT level of theory, using two different combinations of basis sets. The results of two pure-GGA (BP86 and PBEPBE), two hybrid-GGA (PBE1PBE and mPWPW91), and two hybrid-meta-GGA (mPW1B95 and B1B95) functionals were analyzed on these systems. The comparison of the results indicates that the stability differences between the two methodologies are resolved when hydration energy is taken into account, provided that some amount of HF exchange is introduced in the DFT calculations. In a second step, Car-Parrinello simulations have been carried out starting from VO2(H2O)4+ surrounded by water molecules. The calculations at 300 K show the natural tendency of VO2(H2O)4+ to decompose to VO2(OH)2- and the requirements to work with an already acidified medium to be able to investigate the coordination sphere of VO2+ for an extended period of time. Under such conditions, we have obtained a clear preference for a five-coordinated vanadium. The molecular dynamics simulations performed at 500 K starting from hydrated VO2+ in a protonated medium found VO(OH)3 to be the most stable structure, whereas this ideal candidate for oxolation reactions is expected to be a very minor species at room temperature.

Two new hybrid organic/inorganic copper(II)-oxovanadate(V) diphosphonates: [Cu2(phen)2(O3PCH2PO3)(V2O5)(H2O)] x H2O and [Cu2(phen)2(O3P(CH2)3PO3)(V2O5)] x C3H8. Synthesis, structure, and magnetic properties.

Two new hybrid organic/inorganic copper oxovanadium diphosphonates [Cu2(phen)2(O3PCH2PO3)(V2O5)(H2O)] x H2O (1) and [(Cu2(phen)2(O3P(CH2)3PO3)(V2O5)] x C3H8 (2) have been obtained by hydrothermal synthesis. The compounds are monoclinic, and they crystallize in the space group P2(1)/n with cell parameters of a = 11.788(2) A, b = 17.887(3) A, c = 14.158(2) A, and beta = 93.99(0) degrees and in the space group C2/c with cell parameters of a = 11.025(1) A, b = 18.664(2) A, c = 15.054(2) A, and beta = 90.06(0) degrees, respectively. Both compounds present two-dimensional frameworks built up from infinite chains of corner-sharing vanadium tetrahedra and diphosphonate groups connected by copper tetramers for (1) and copper dimers for (2). The remarkable feature of (2) is the encapsulation of propane molecules, stabilized by strong hydrogen bonding between the layers. The magnetic properties of the compounds have been investigated showing antiferromagnetic coupling with Tmax = 64 K for (1) and Curie-like paramagnetic behavior for (2).