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An integrated study of microclimate monitoring, IR thermography (IRT), gravimetric tests and portable unilateral nuclear magnetic resonance (NMR) was applied in the framework of planning emergency intervention on a very deteriorated wall painting in San Rocco church, Cornaredo (Milan, Italy). The IRT investigation supported by gravimetric tests showed that the worst damage, due to water infiltration, was localized on the wall painting of the northern wall. Unilateral NMR, a new non-destructive technique which measures the hydrogen signal of the moisture and that was applied directly to the wall, allowed a detailed map of the distribution of the moisture in the plaster underlying the wall panting to be obtained. With a proper calibration of the integral of the recorded signal with suitable specimens, each area of the map corresponded to an accurate amount of moisture. IRT, gravimetric tests and unilateral NMR applied to investigate the northern wall painting showed the presence of two wet areas separated by a dry area. The moisture found in the lower area was ascribed to the occurrence of rising damp at the bottom of the wall due to the slope of the garden soil towards the northern exterior. The moisture found in the upper area was ascribed to condensation phenomena associated with the presence of a considerable amount of soluble, hygroscopic salts. In the framework of this integrated study, IRT investigation and gravimetric methods validated portable unilateral NMR as a new analytical tool for measuring in situ and without any sampling of the distribution and amount of moisture in wall paintings. [ABSTRACT FROM AUTHOR]

Charge storage in 40/60 TiFe alloy has been investigated using electrode fabrication powder material, either of true alloy or of alloy precursor grades. The true alloy activated very reluctantly in that its maximum charge (i.e., hydrogen) capacity remained below 100 mA h g– 1. In contrast, the alloy precursor could be activated to an intrinsic capacity of ~300 mA h g–1. Charge storage of the 40/60 TiFe alloy precursor was certainly affected by the redox reactions of surface Fe, but a large amount was stored as hydrogen absorbed by the material, as indicated by a dialometric test and the poison effect. X-ray and EDAX analyses of the two materials can account for their differing abilities to store charge. [ABSTRACT FROM AUTHOR]

The crystal structure of the dinuclear complex [Cu(CH-NO)(HO)](BF) was determined by x-ray crystallography. The crystals are triclinic, P¯1, with a = 10.945(5), b = 8.703(5), c = 8.495(5) Å, α = 103.86(3)°, β = 105.73(3)°, γ = 85.77(3)°, V = 756 Å D = 1.65 g cm for Z = 1. The copper(II) atoms are 5-coordinate and square-pyramidal. Selected bond distances are: Cu-N, 1.91 Å (mean); Cu-O(base) = 1.90(1) and 1.91(1) Å; Cu-O(apical) = 2.47(1) Å; There are O(water)-H ... F interionic hydrogen bonds in the structure. The Cu .. Cu distance is 2.847 Å. [ABSTRACT FROM AUTHOR]

The compound [Re(CO)(PPh)Cl] reacts with the lithium salt of thiazole derivatives (LH = 2-amino-benzothiazole, LH = 2− N-methyl-aminothiazole, LH = 2− N-phenylaminothiazole, LH = 2− N-(4-methoxyphenyl)aminothiazole, LH = 2− N(4-nitrophenyl)aminothiazole) to give [Re(CO)-(PPh)(L)]. The compounds have been characterized by elemental analysis, i.r. andH n.m.r. spectra. At room temperature [Re(CO)(PPh)(L)] reacts with LH (LH = diphenylacetic acid), to give the carboxylato complex [Re(CO). The crystal structures of [Re(CO)(PPh)(L)] (2) and [Re(CO)(PPh)(L)] ( 6) were determined by x-ray crystallography. [Re(CO)(PPh)(L)] crystallizes in the monoclinic space group P2/m with a = 9.16(1), b= 24.82(2), c =9.12(1) Å, and β = 115.81(4)°; D = 1.56 g cmfor Z = 2. The structure was refined to a final R of 6.4%. The molecules have C symmetry. The rhenium atom is six-coordinate with approximately octahedral geometry. The anionic ligand is chelating through the nitrogen atoms and is strictly planar allowing delocalization of the π-electron density. [Re(CO)(PPh)(L)] (6) crystallizes in the monoclinic space group P2/n with a = 22.203(5), b = 18.651(5), c =10.653(3) Å, β = 91.08(3)°, Dc = 1.47 g cm for Z = 4. The structure was refined to a final R of 4.7%. The complex is monomeric and the rhenium atom is distorted octahedral with two mutually trans PPh ligands, two cis CO ligands and one chelating PhCHCO ion. [ABSTRACT FROM AUTHOR]

The complexes [Rh(TC)Cl] · MeCO and [Rh(TC)X] · 0.5 MeCO (TC=O-ethylthiocarbamate; X=Br or I) have been prepared and characterized by i.r. andH n.m.r. spectroscopy. The crystal structure of [Rh(TC)Cl] · MeCO has been determined by x-ray diffractometer data and refined to R=0.040. Crystals are monoclinic, space group P2, with a=9.101(5), b=15.785(8), c=8.776(5) Å, and β=103.00(3)°; Dx=1.57 gcn for Z=2. The complex is monomeric with octahedral Rh. Relevant distances are Rh-Cl ( trans to one another) 2.354(2) and 2.353(2) Å, Rh-Cl ( trans to S) 2.388(2) Å; Rh-S ( trans to one another) 2.376(3) and 2.369(3) Å, Rh-S ( trans to Cl) 2.332(3) Å. There is intramolecular, and possibly intermolecular, hydrogen bonding in the structure. [ABSTRACT FROM AUTHOR]

The reaction of [Re(NR)Cl(PPh)] (R = Me or p-MeCH) with salicylaldehyde (SalH) gives rise to new rhenium nitrene (imido) complexes [Re(NR)Cl(Sal)PPh]. The corresponding PMePh derivatives cis- and trans-[Re(NMe)Cl(PMePh)] and trans-[Re(NTo)Cl(PMePh)] (To = p-MeCH) do not react with SalH or SalLi under the same experimental conditions. By reaction of [Re(NTo)Cl (Sal)PPh] with PR (PR=PMePh, PEtPh, PEt, or PMePh) the complexes [Re(NTo)Cl(CHOSal)(PR)] are obtained, in which the ligand is monodentate. Reaction of [Re(NTo)Cl(CHOSal)(PMePh)] with p-toluidine, gives the Schiff base derivative [Re(NTo)Cl(S.B.)(PMePh)]. The crystal structure of the title compound was determined by x-ray crystallography. The compound is triclinic, space group PI, with a=11.698(5), b=11.445(5), c=11.725(5) Å, α= 74.12(3)°, β=102.65(3)°, γ=86.89(3)°; Dx=1.69 g cm for Z=2. The structure was refined to R=0.058 for 4400 observed reflections. The rhenium atom is in a distorted octahedral coordination with the chlorine atoms trans to each other. Relevant bond lengths are: Re-Cl, 2.381(3) and 2.424(3) Å; Re-P, 2.427(3) Å; Re-O, 2,01(1) and 2.08(1) Å; Re-N, 1.72(1) Å. [ABSTRACT FROM AUTHOR]

The electrochemical behaviour of mononuclear and dinuclear complexes of dioxouranium(VI) (or uranyl), nickel(II) and copper(II) ions with the ethylenediamine Schiff base derivate of o-acetoacetylphenol, Haapen, has been studied in dimethyl sulfoxide solvent both at platinum and mercury electrodes. In the mononuclear complexes the metal ion can occupy either the NO compartment or the OO compartment. In the dinuclear complexes, both homodinuclear and heterodinuclear species can be obtained. This paper deals with the following derivates; nickel and uranyl mononuclear complexes, with the nickel(II) ion coordinated in the inner NO compartment and with the uranyl ion coordinated in the outer OO compartment respectively; uranyl-nickel and uranyl-copper heterodinuclear complexes, with the uranyl ion in the OO site; copper and nickel homodinuclear complexes. The electrode mechanism has been investigated by cyclic voltammetry, chronoamperometry and controlled potential coulometry. For dinuclear complexes, formal potentials are also discussed in terms of the stabilisation of electrogenerated mixed-valence compounds. [ABSTRACT FROM AUTHOR]

Urea (ur), thiourea (tu) and diisopropylthiourea (diptu) form high-spin complexes with iron(II), for whichFe Mössbauer quadrupole splitting and spectroscopic data suggest an octahedral distorted geometry. The x-ray diffraction study on Fe(tu)Cl confirms this geometry. The crystals are tetragonal, space group P4/ n with a=13.71, c=8.94 Å and Z=4. The molecules are centrosymmetric with two axial chlorine atoms (Fe-Cl=2.46 Å) and four equatorial sulfur atoms (Fe-S=2.61 and 2.57 Å respectively). A similar trans-octahedral geometry is proposed for the new Fe(diptu)Cl complex and an octahedral metal coordination in the new [Fe(ur)]Br, Fe(tu)Br and Fe(ur)Br complexes. [ABSTRACT FROM AUTHOR]

The structure of the heterobinuclear complex of Cu and [UO] with the tetraanionic ligand derived from the condensation of 1,2-diaminoethane with o-acetoacetylphenol has been determined from diffractometer data and refined to R = 5.2%. The crystals are monoclinic, P2/ a, with a = 26.22(2), b = 14.79(2), c = 8.10(1) Å and β = 104.65(5)°; Z = 4. The ligand employed has two different coordination sets of atoms, NO and OO, two oxygen atoms being common to both donor sets. In the complex the copper atom, which is retained in the inner NO chamber, is five coordinate being axially bonded to a solvent molecule, whilst the uranyl ion is incorporated in the outer OO chamber. Another molecule of solvent is retained to preserve the preferred seven coordination of uranium. [ABSTRACT FROM AUTHOR]

The structure of the homobinuclear complex Cu(aapen)HO, where aapen is the tetraanionic ligand derived from the condensation of 1,2-diaminocthane with o-acetoacetylphenol, has been determined from diffractometer data and refined to R = 6.1%. The crystals are monoclinic, P2/c, with a = 12.991(5), b = 8.530(4), c = 18.546(6) Å, and β = 104.10(4)°; Z = 4. The ligand employed has two different coordination sets of atoms, NO and OO, two oxygen atoms being common to both donor sets. In the complex, one copper atom is retained in the plane of the inner NO chamber whilst the other, which is incorporated in the outer OO chamber, is five-coordinate, being axially bonded to a water molecule. [ABSTRACT FROM AUTHOR]

The title compound has been synthesized and characterized. The crystal structure has been determined by single-crystal x-ray analysis from diffractometer data, and refined to R= 0.063 for 1889 observed reflections. Crystals are monoclinic, space group P2/n, with a=21.97(2), b=8.21(1), c=10.44(1) A, and β=101.87(3), and Z=4. Both ligands are coordinated to nickel through sulphur and one oxygen atom to realize the cis form of the complex in the square planar coordination geometry. Bond distances are: Ni-S, 2.14(1), Ni-O, 1.87(1) and 1.90(1) Å. Each nickel atom also forms two close contacts with oxygen atoms from adjacent molecules. [ABSTRACT FROM AUTHOR]