Simple, common but functional: biocompatible and luminescent rare-earth doped magnesium and calcium hydroxides from miniemulsion.

Nanostructured (d∼ 20-35 nm) and highly luminescent Ca(OH)2:Ln and Mg(OH)2:Ln (Ln = EuIII, SmIII, TbIII, Mg(Ca)/Ln = 20 : 1 atomic) nanostructures were obtained in inverse (water in oil - w/o) miniemulsion (ME), by exploiting the nanosized compartments of the droplets to spatially confine the hydroxide precipitation in basic environment (NaOH). The functional nanostructures were prepared using different surfactants (Span80 (span) and a mixture of Igepal co-630 and Brij 52 (mix)) to optimise ME stability and hydroxide biocompatibility as well as tune the droplet sizes. X-Ray diffraction (XRD) analyses testify the achievement of a pure brucite-Mg(OH)2-phase and pure portlandite-Ca(OH)2-phase with a high degree of crystallinity. Besides structural characterisations, the products were thoroughly characterised by means of several and complementary techniques (dynamic light scattering (DLS), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC), micro-Raman spectroscopy, inductively coupled plasma mass spectrometry (ICP-MS) and Fourier transform infrared spectroscopy (FT-IR)) to assess their chemico-physical properties as well as their morphological and microstructural features. The stoichiometry of the doped systems was confirmed using ICP-MS measurements. Finally, the cytotoxicity of the nanoparticles was assessed by in vitro tests using ES2 cells in order to provide preliminary data on the biocompatibility of this kind of nanoparticles. The luminescence of the Eu-doped and Tb-doped materials is clearly visible to the naked eye in the red and green regions, respectively, corroborating their employment as materials for imaging in the optical window of interest.

[Management strategies and choice of antithrombotic treatment in patients admitted with acute coronary syndrome--executive summary for clinical practice. Consensus Document of the Regional Chapters of the Italian National Association of Hospital Cardiologists (ANMCO) and of the Italian Society of Emergency Medicine (SIMEU)]. / Strategie Assistenziali e Scelta della Terapia Antitrombotica nei Pazienti Ricoverati con Diagnosi di Sindrome Coronarica Acuta--Sintesi Operativa per la Pratica Clinica. Documento congiunto delle Sezioni Regionali del Lazio dell'Associazione Nazionale Medici Cardiologi Ospedalieri (ANMCO) e della Società Italiana di Medicina di Emergenza-Urgenza (SIMEU).

This document has been developed by the Lazio regional chapters of two scientific associations, the Italian National Association of Hospital Cardiologists (ANMCO) and the Italian Society of Emergency Medicine (SIMEU), whose members are actively involved in the everyday management of Acute Coronary Syndromes (ACS). The document is aimed at providing a specific, practical, evidence-based guideline for the effective management of antithrombotic treatment (antiplatelet and anticoagulant) in the complex and ever changing scenario of ACS. The document employs a synthetic approach which considers two main issues: the actual operative context of treatment delivery and the general management strategy.

From thioxo cluster to dithio cluster: exploring the chemistry of polynuclear zirconium complexes with S,O and S,S ligands.

Three different zirconium thio and oxothio clusters, characterized by different coordination modes of dithioacetate and/or monothioacetate ligands, were obtained by the reaction of monothioacetic acid with zirconium n-butoxide, Zr(O(n)Bu)4, in different experimental conditions. In particular, we isolated the three polynuclear Zr3(µ3-SSSCCH3)2(SSCCH3)6·2(n)BuOH (Zr3), Zr4(µ3-O)2(µ-η(1)-SOCCH3)2(SOCCH3)8(O(n)Bu)2 (Zr4), and Zr6(µ3-O)5(µ-SOCCH3)2(µ-OOCCH3)(SOCCH3)11((n)BuOH) (Zr6) derivatives, presenting some peculiar characteristics. Zr6 has an unusual star-shaped structure. Only sulfur-based ligands, viz., chelating dithioacetate monoanions and an unusual ethane-1,1,1-trithiolate group µ3 coordinating the Zr ions, were observed in the case of Zr3. 1D and 2D NMR analyses confirmed the presence of differently coordinated ligands. Raman spectroscopy was further used to characterize the new polynuclear complexes. Time-resolved extended X-ray absorption fine structure measurements, devoted to unraveling the cluster formation mechanisms, evidenced a fast coordination of sulfur ligands and subsequent relatively rapid rearrangements.

Tuning the functional properties of metal complexes containing polytopic heteroaromatic nitrogen ligands.

The preparation, characterization, and optimization of the functional properties of mono- and polynuclear coordination complexes containing heteroaromatic nitrogen ligands are discussed here, taking the advantage of numerous studies performed in our laboratories on exploring a variety of different metal ions and polytopic ligands. We highlight how very minor changes in connectivity, composition, and polarity of the molecular entities employed in the self-assembly steps may significantly affect the structural, thermal, sorptive, magnetic, and mesomorphic behavior of the resulting materials. Examples from three different classes are included: 1) pyrazolate-based polynuclear coordination compounds, 2) homoleptic and heteroleptic coordination polymers, and 3) 2,2'-bipyridine metal-based liquid crystals.

New coordination polymers based on the triangular [Cu3(mu3-OH)(mu-pz)3]2+ unit and unsaturated carboxylates.

By reacting copper(II) acrylate with pyrazole (Hpz), two trinuclear copper derivatives [Cu3(mu3-OH)(mu-pz)3(CH2CHCOO)2(H2O)2(Hpz)], 1, and [Cu3(mu3-OH)(mu-pz)3(CH2CHCOO)2(CH3OH)], 2, are obtained, in water and methanol respectively, while copper(II) methacrylate affords [Cu3(mu3-OH)(mu-pz)3(CH2C(CH3)COO)2], 3, independently from the solvent used. In 1 and 2 two triangular trinuclear units are connected through acrylate bridges forming hexanuclear clusters that, in the case of 2 are further connected through double syn-syn carboxylate bridges, generating a 1-D coordination polymer. In the case of 3 a different 1-D coordination polymer is obtained by alternating syn-syn and syn-anti double carboxylate bridges connecting the trinuclear clusters. In all cases H-bonds contribute both to the stabilization of these arrangements and to the formation of more extended supramolecular networks. Compounds 1-3 are valuable catalysts in the peroxidative oxidation with aqueous H2O2, in MeCN at 25 degrees C, of cycloalkanes (i.e. cyclohexane and cyclopentane) to the corresponding ketones and alcohols (overall yield up to 36%, TON = 36), following a radical mechanism as shown by radical trap experiments, and the effects of various factors are studied. Electrochemical experiments show that the copper(II) centres are reduced to copper(I) and copper(0).

Magnetic properties and vapochromic reversible guest-induced transformation in a bispyrazolato copper(II) polymer: an experimental and dispersion-corrected density functional theory study.

Dispersion-corrected density functional theory (DFT-D) calculations, Electron Spin Resonance spectroscopy (EPR), and variable temperature magnetic moment measurements were used to investigate the structure and the electronic/magnetic properties of bispyrazolato-copper(II) coordination polymer and of its hydration product. The Cu(II) ions are antiferromagnetically coupled through the sigma system of the pyrazolate rings in both compounds. Theoretical electron density maps reveal that water molecules interact simultaneously and to a comparable extent with two Cu(II) centers (through the electronegative O end) and two pyrazolate rings (through the partly positively charged H atoms), which is compatible with the observed internuclear distances. DFT-D calculations indicate that low kinetic barriers are involved in the rearrangement of the host structure.

Carbonyl copper(I) complexes with hydrotris(1,2,4-triazolyl)borate, hydrotris(pyrazolyl)borate, and tris(pyrazolyl)methane ligands: a DFT study.

Theoretical evidence supporting the use of hydrotris(1,2,4-triazolyl)borate (ttz) ligands as a proper alternative to the hydrotris(pyrazolyl)borate (tp) ones is provided by density functional calculations.

Density functional theory study of the binding capability of tris(pyrazol-1-yl)methane toward Cu(I) and Ag(I) cations.

Density functional theory (DFT) has been used to look into the electronic structure of [M(tpm)]+ molecular ion conformers (M = Cu, Ag; tpm = tris(pyrazol-1-yl)methane) and to study the energetics of their interconversion. Theoretical data pertaining to the free tpm state the intrinsic instability of its kappa3-like conformation, thus indicating that, even though frequently observed, the kappa3-tripodal coordinative mode is unlikely to be directly achieved through the interaction of M(I) with the kappa3-like tpm conformer. It is also found that the energy barrier for the kappa2-[M(tpm)]+ --> kappa3-[M(tpm)]+ conversion is negligible. As far as the bonding scheme is concerned, the tpm --> M(I) donation, both sigma and pi in character, is the main source of the M(I)-tpm bonding, whereas back-donation from completely occupied M(I) d orbitals into tpm-based pi* levels plays a negligible role.

Supramolecular assemblies of trinuclear triangular copper(II) secondary building units through hydrogen bonds. Generation of different metal-organic frameworks, valuable catalysts for peroxidative oxidation of alkanes.

Formation of the trinuclear triangular copper derivative [Cu3(mu3-OH)(mu-pz)3(EtCOO)2(H2O)] x H2O, 1b (Hpz = pyrazole), has been simply achieved by addition of Hpz to a water solution of Cu(EtCOO)2 x H2O and leaving the resulting solution to crystallize at ca. 12 degrees C. When the reaction and crystallization were carried out at a slightly higher temperature (18-22 degrees C), the compound [Cu3(mu3-OH)(mu-pz)3(EtCOO)2(H2O)], 1c, formed. Single-crystal X-ray molecular structure determinations show that both compounds have analogous trinuclear triangular structures, but very different supramolecular assemblies, due mainly, but not only, to the crystallization molecule of H2O in 1b. In particular, contrarily to the previously reported, strictly related, [Cu3(mu3-OH)(mu-pz)3(EtCOO)2(EtOH)], 1a, the propionate ions in 1b and 1c do not bridge different triangular units, whereas they are involved in intra- and intermolecular H-bonds, generating complex supramolecular 2-D MOFs. Compounds 1a and 1c act as remarkably active and selective catalysts or catalyst precursors for liquid biphasic (MeCN/H2O) peroxidative oxidation of cyclohexane and cyclopentane to the corresponding alcohols and ketones.

Synthesis, solid-state NMR, and X-ray powder diffraction characterization of group 12 coordination polymers, including the first example of a C-mercuriated pyrazole.

Cadmium and mercury acetates have been reacted with pyrazole (Hpz) and 3,5-dimethylpyrazole (Hdmpz), affording distinct mixed-ligand species, selectively prepared upon slightly modifying the reaction conditions. Two polymorphs of [{Cd(mu-ac)2(Hpz)2}n], as well as the [{Cd(mu-ac)2(Hdmpz)2}n] species (Hac = acetic acid), were obtained by solution chemistry, while the two-dimensional [{Cd3(mu3-ac)4(mu-pz)2(Hpz)2}n] and [{Cd(mu-ac)(mu-pz)}n] polymers were prepared upon controlled thermal treatment of one of the [{Cd(mu-ac)2(Hpz)2}n] forms. Two mercury derivatives, [{Hg3(mu-ac)3(mu-pz)3}n] and [{Hg(ac)(mu-dmpz)}n], were also prepared, the latter containing one-dimensional chains of Hg(II) ions bridged by C-mercuriated Hdmpz ligands. All their crystal structures (but one) were determined by powder diffraction methods using conventional X-ray laboratory equipment, supported by 13C CPMAS NMR measurements. The latter method helped in assigning a C-metalated nature to an amorphous material of [Hg(ac)(pz)] formula, obtained by employing EtOH as a solvent. A few other Hdmpz-containing cadmium acetates were also prepared, but their polyphasic nature, evidenced by diffraction methods, hampered their complete structural characterization.

The competition between acetate and pyrazolate in the formation of polynuclear Zn(II) coordination complexes.

Hydrated zinc(II) acetate reacts with pyrazole (Hpz) and, depending on the reaction conditions, forms different pyrazole-containing species, i.e. [[Zn(CH3COO)(mu-pz)(Hpz)]2] (1), [[Zn(CH3COO)2(Hpz)2.CH3COOH]] (2), [[Zn(mu-pz)2]n] (3), and [[Zn(mu-CH3COO)(mu-pz)]n] (4). Their structural models have been derived from single-crystal X-ray diffractometry as well as from less conventional ab-initio X-ray powder methods. All species contain tetrahedrally coordinated Zn(II) ions, with Zn-N and Zn-O bond distances close to 2.0 angstroms. The existence of the [Zn(mu-pz)]2 core in the species 1, 3 and 4 indicates the propensity for the formation, in the presence of pyrazolate ligands, of well-defined dinuclear entities (with Zn...Zn contacts in the range 3.6-3.8 angstroms). The latter can mutually interact, in the crystals, through either hydrogen-bonding of ancillary ligands (as in 1) or coordinative bonds (via acetates, as in 4, or by self-complementarity, as in 3). The interconversion paths among these species have been studied, employing chemical and thermal methods. In particular, the topotactic and quantitative transformation of 1 into 3 by moderate heating is likely based on a solid-state cooperative condensation mechanism of the dangling pyrazolates toward neighbouring zinc(II) ions, with concomitant acetic acid extrusion.

One-dimensional and two-dimensional coordination polymers from self-assembling of trinuclear triangular Cu(II) secondary building units.

The reactions of pyrazole (Hpz) with some copper(II) carboxylates in the presence of water yield trinuclear copper derivatives characterized by the triangular core [Cu3mu3-OH)(mu-pz)3(RCOO)2] (R = H, C2H5, C3H7). Copper(II) formate gives [Cu3(mu3-OH)(mu-pz)3(HCOO)2(Hpz)2] (1), whereas copper propionate and butyrate afford [Cu3(mu3-OH)(mu-pz)3(C2H5COO)2(EtOH)] (2) and [Cu3(mu3-OH)(mu-pz)3(C3H7COO)2(MeOH)(H2O)] (3), respectively, both containing solvent molecules coordinated to copper atoms. Magnetic susceptibilities are consistent with a single unpaired electron for each trinuclear unit of 1-3, and EPR measurements indicate that higher spin states, generated by exchange coupling between copper atoms, may be populated at room temperature. Density-functional calculations provide the description of the electronic structures of 1-3, allowing, at the same time, the assignment of their UV-vis absorption spectra. X-ray molecular structure determinations show that triangular trinuclear units of 1 are connected to each other through single formate bridges, forming one-dimensional (1D) zigzag coordination polymers, whereas in 2 and 3, two oxygen atoms of two carboxylate ions doubly bridge two copper atoms of different triangles, thus generating hexanuclear units. Moreover, in 2, two other propionate ions link together two hexanuclear units yielding a 12-membered cycle and giving rise to 1D coordination polymers. The supramolecular assemblies of 1-3 are compared to that of the previously reported trinuclear triangular copper(II) derivative [Cu3(mu3-OH)(mu-pz)3(CH3COO)2(Hpz)] (A), where a two-dimensional (2D) coordination polymer is present. The reactions of 3,5-dimethylpyrazole (Hpz) with copper(II) carboxylates in the same conditions yield 1:2 Cu(RCOO)2/Hpz adducts.

Sorption-desorption behavior of bispyrazolato-copper(II) 1D coordination polymers.

A new polycrystalline vapochromic polymorph of the one-dimensional copper bispyrazolate polymer reversibly and selectively absorbs a number of small molecules; the crystal structures of the anhydrous and fully hydrated species, determined by powder diffraction methods, are markedly different despite their simple, fast, and reversible interconversion.

Spontaneous self-assembly of an unsymmetric trinuclear triangular copper(II) pyrazolate complex, [Cu3(micro3-OH)(micro-pz)3(MeCOO)2(Hpz)] (Hpz = pyrazole). synthesis, experimental and theoretical characterization, reactivity, and catalytic activity.

The almost quantitative formation of the triangular trinuclear copper derivative [Cu3(3-OH)(-pz)3(MeCOO)2(Hpz)] (1) (Hpz = pyrazole), has been simply achieved by adding Hpz to an ethanol solution of Cu(MeCOO)2 x H2O. An X-ray molecular structure determination shows that 1 is completely unsymmetric and that trinuclear units result assembled in an extended bidimensional network formed through acetate bridges and hydrogen bonds. EPR and magnetic measurements are consistent with the presence of a single unpaired electron. Theoretical density functional calculations carried out for S = 1/2 provide a thorough description of the electronic structure of 1, allowing a detailed assignment of its UV-vis absorption spectrum. Compound 1 reacts with MeONa, yielding [Cu3(micro3-OH)(micro-pz)3(MeCOO)(MeO)(Hpz)] (2) and [Cu3(micro3-OH)(micro-pz)3(MeO)2(Hpz)] (3) through the substitution of one and two acetate ions, respectively, with MeO- ion(s). The spontaneous self-assembly of the triangular trinuclear Cu3 moiety seems to occur only with pyrazole as can be inferred by the results obtained in the reactions of copper(II) acetate with some substituted pyrazoles leading to the formation of mononuclear [Cu(MeCOO)2(L)2] (4-8) and dinuclear [Cu(MeCOO)2(L)]2 (9-11) (L = substituted pyrazole) compounds. Also the presence of acetate ions seems to play a leading role in determining the formation of the trinuclear triangular arrangement, as indicated by the formation of a mononuclear derivative, [Cu(CF3COO)2(Hpz)]2 (compound 12), in the reaction of copper(II) trifluoroacetate with pyrazole. Compounds 1-3, as well as some other mono- and dinuclear copper(II)-substituted pyrazole complexes, have been tested as catalyst precursors in cyclopropanation reaction, observing the formation of products in a syn:anti ratio opposite that normally reported.

[Electrical cardioversion for atrial fibrillation: advantages of the transthoracic biphasic method]. / Cardioversione elettrica della fibrillazione atriale: vantaggio della cardioversione transtoracica ad onda bifasica.

BACKGROUND: The purpose of this study was to evaluate efficacy and safety of biphasic shock for atrial fibrillation cardioversion to sinus rhythm. A second endpoint was to evaluate myocardial damage by means of cardiac troponin I dosage. METHODS: We studied 164 patients, with drug-resistant atrial fibrillation (208 episodes). Group A patients underwent biphasic shock normalized with respect to weight: 50 J (weight < 60 kg), 70 J (weight 61-84 kg) and 100 J (weight > 84 kg; the second and third shocks were 2 and 3 times higher than the first. Group B underwent sequential monophasic shock of 200, 300 and 360 J. Troponin I was evaluated at baseline, and 6, 12 and 24 hours after cardioversion. RESULTS: Total efficacy was 92% for biphasic shock and 89% for monophasic shock. First-shock efficacy with biphasic waveform (57.3%) was significantly greater than with first monophasic waveform (21.5%) (p = 0.000). Cardiac troponin I increased from 0.4 +/- 1.1 to 0.8 +/- 2.2 compared to a normal value of 2 ng/ml. CONCLUSIONS: For transthoracic cardioversion of atrial fibrillation, biphasic shock has a greater efficacy requiring less energy compared to monophasic shock. Normal mean values of cardiac troponin I proved the absence of myocardial damage.

Experimental and Theoretical Investigation of the Molecular and Electronic Structure of [Zn(4)(&mgr;(4)-S){&mgr;-S(2)As(CH(3))(2)}(6)] and [Cd(4)(&mgr;(4)-S){&mgr;-S(2)As(CH(3))(2)}(6)]: Two Possible Molecular Models of Extended Metal Chalcogenide Semiconductors.

The molecular and electronic structure of hexakis[&mgr;-(dimethylarsinodithioate-S:S')]-&mgr;(4)-thioxotetrazinc has been investigated by combining X-ray diffraction measurements, electrospray mass spectrometry (ESI), UV absorption spectroscopy, and density functional calculations. The polynuclear zinc complex consists of discrete "tetrazinc sulfide" moieties held together by van der Waals interactions. The unit cell contains four independent molecules and four solvent molecules. Each independent unit is characterized by a central &mgr;(4)-S coordinated to four Zn ions, each of them at the center of an irregular tetrahedron of S atoms. ESI measurements point out that the synthesis of the analogous Cd derivative was successful. Crystal data are as follows: chemical formula, C(12)H(36)As(6)Cl(1.5)S(13)Zn(4); monoclinic space group P2(1)/n (no. 14); a = 30.4228(7) Å, b = 18.3720(5) Å, c = 32.3758(8) Å, beta = 95.857(1) degrees; Z = 16. Theoretical calculations indicate that, despite their structural arrangement, neither the Zn nor the Cd complex can be considered molecular models of the extended ZnS and CdS. Nevertheless, the electronic transitions localized in the Zn(4)(&mgr;(4)-S) and Cd(4)(&mgr;(4)-S) inner cores of the title compounds have the same nature as those giving rise to the maxima in the excitation spectra of the extended Zn(4)S(BO(2))(6) and Cd(4)S(AlO(2))(6) [Blasse, G.; Dirksen, G. J.; Brenchley, M. E.; Weller, M. T. Chem. Phys. Lett. 1995, 234, 177].

An Experimental and Theoretical Study of the Electronic Structure of Zinc Thiophenolate-Capped Clusters.

The electronic structure of a series of thiophenolate-capped ionic/neutral clusters ([Zn(SPh)(4)](2)(-) (1); [Zn(4)(&mgr;(2)-SPh)(6)(SPh)(4)](2)(-) (2); Zn(10)(&mgr;(3)-S)(4)(&mgr;(2)-SPh)(12) (3); and [Zn(10)(&mgr;(3)-S)(4)(&mgr;(2)-SPh)(12)(SPh)(4)](4)(-) (4), Ph = phenyl), indicated as supertetrahedral fragments and possible molecular models of cubic ZnS, has been investigated by coupling density functional calculations to UV electronic and X-ray photoelectron (XP) spectroscopy. Theoretical outcomes indicate that, on passing from the tetrametallic to the decametallic clusters, there is a modification in the nature of the outermost occupied and lowermost unoccupied molecular orbitals. Actually, both in 1 and in 2 the frontier orbitals are delocalized and mainly composed of the S 3p pairs strongly mixed with the Ph pi levels (the HOMOs) and of the linear combinations of Ph pi orbitals, the LUMOs. At variance to that, in 3 and 4 both the HOMO and LUMO are highly localized, the former on &mgr;(3)-S atoms occupying C(3)(v)() coordinatively unsaturated tetrahedral positions and the latter on peripheral Zn atoms. The nature of the electronic levels involved in the UV absorption bands is discussed, and the agreement between theory and experiment is satisfactory. Neither experimental nor theoretical electronic excitation energies are influenced by the cluster size. Moreover, XPS data match quite well variations of the Zn and S gross atomic charges along the series. The different Zn-S bonding scheme characterizing terminal, &mgr;(2)-bridging, and &mgr;(3)-pyramidal S atoms allows a rationalization of the cluster behavior in solution. Along the investigated series, the only species reasonably mimicking both the structural arrangement and the electronic structure of the solid ZnS is Zn(10)(&mgr;(3)-S)(4)(&mgr;(2)-SPh)(12), which can be considered a molecular model of ZnS nonpolar surfaces.