Inorganica Chimica Acta 

About: Inorganica Chimica Acta is an academic journal. The journal publishes majorly in the area(s): Ligand & Crystal structure. It has an ISSN identifier of 0020-1693. Over the lifetime, 28355 publication(s) have been published receiving 429784 citation(s).

Conversion constants for redox potentials measured versus different reference electrodes in acetonitrile solutions at 25°C

Abstract: Caution should be exercised when one is comparing the redox potentials of complexes measured in CH 3 CN solutions versus different reference electrodes. A critical review of conversion constants amongst various reference electrodes reported in the literature reveals that in most cases the comparisons of redox potential values are far from accurate. From measurements of relationships amongst various common reference electrodes in CH 3 CN solutions, conversion constants for redox potentials measured versus different reference electrodes in acetonitrile solutions at 25°C are proposed, along with a convention for reporting redox potential values.

Counter electrodes for DSC: Application of functional materials as catalysts

Abstract: Counter electrodes (CEs) of dye-sensitized solar cells (DSCs) can be prepared with different materials and methods. This review covers recent research on CEs using platinum, graphite, activated carbon, carbon black, single-wall carbon nanotubes, poly( 3,4-ethylenedioxythiophene) (PEDOT), polypyrrole, and polyaniline as catalysts for reduction of triiodide. Moreover, for the ultimate in low-cost counter electrodes, we have prepared a carbon-black-loaded stainless steel electrode for use as a novel CE. This counter electrode exhibits good photovoltaic performance; the efficiency reaches 9.15% (16.3 mA cm(-2) J(sc), 785 mV V-oc, and 71.4% fill factor) with SUS-316 stainless steel, equivalent to the performance with an FTO-glass substrate. (c) 2007 Published by Elsevier B.V.

On the determination of the number of water molecules, q, coordinated to europium(III) ions in solution from luminescence decay lifetimes

Abstract: A refined equation (in its simplest form: q=1.11[τ−1H2O−τ−1D2O−0.31]) which allows the prediction of the number of water molecules in the first coordination sphere of a europium(III) (Eu3+) complex, q, in aqueous solution is presented. It is recognized that in the long history of the determination of the q-values of Eu3+ complexes from luminescent data of the excited metal ions in H2O and D2O solutions, certain inconsistencies are present. In some cases the q-values determined have either been non-integral when they should be integral, or have been in conflict with q-values predicted by other means. The original q-value equation put forth by this laboratory correlated the luminescence lifetime data of crystalline Eu3+ complexes to the known q-values based on XRD data from single crystals. In the current report, the difference in the decay rate of the Eu3+ luminescence of metal complexes in H2O and D2O solution is linearly correlated to q-values predicted using the original equation as a guide. Our current interpretation of the luminescence data of 25 Eu3+ complexes taken from the literature, along with the extensive research of many labs involving the effect of oscillators other than water molecules in the first coordination sphere of the Eu3+ ion, has yielded the following equation: q=1.11[τ−1H2O−τ−1D2O−0.31+0.45nOH+0.99nNH+0.075nOCNH] where nOH is the number of alcoholic OH oscillators in the first coordination sphere of Eu3+, nNH is the number of amine NH oscillators in the first coordination sphere of Eu3+, and nOCNH is the number of amide NH oscillators in which the amide carboxylic oxygen is in the first coordination sphere of Eu3+. The coefficient of determination parameter of the linear least-squares fit to the data is 0.998 and the standard error of the fit is ±0.1 in q. The equation is used to account for the effect of water molecules in the second coordination sphere of the Eu3+ ion as well as to cast light on aqueous Eu3+ complexes that have known labile coordination spheres.

Inorganic and organic UV filters: Their role and efficacy in sunscreens and suncare products

Abstract: Minerals such as titanium dioxide, TiO2, and zinc oxide, ZnO, are well known active semiconductor photocatalysts used extensively in heterogeneous photocatalysis to destroy environmental pollutants that are organic in nature. They are also extensively used in sunscreen lotions as active broadband sunscreens that screen both UVB (290–320 nm) and UVA (320–400 nm) sunlight radiation and as high SPF makers. When so photoactivated by UV light, however, these two particular metal oxides are known to generate highly oxidizing radicals ( OH and O 2 - ) and other reactive oxygen species (ROS) such as H2O2 and singlet oxygen, 1O2, which are known to be cytotoxic and/or genotoxic. Hydroxyl ( OH) radicals photogenerated from photoactive TiO2 specimens extracted from commercial sunscreen lotions [R. Dunford, A. Salinaro, L. Cai, N. Serpone, S. Horikoshi, H. Hidaka, J. Knowland, FEBS Lett. 418 (1997) 87] induce damage to DNA plasmids in vitro and to whole human skin cells in cultures. Accordingly, the titanium dioxide particle surface was modified to produce TiO2 specimens of considerably reduced photoactivity. Deactivation of TiO2 diminishes considerably, in some cases completely suppresses damage caused to DNA plasmids, to human cells, and to yeast cells compared to non-modified specimens exposed to UVB/UVA simulated solar radiation. The photostabilities of sunscreen organic active agents in neat polar and apolar solvents and in actual commercial formulations have been examined [N. Serpone, A. Salinaro, A.V. Emeline, S. Horikoshi, H. Hidaka, J. Zhao, Photochem. Photobiol. Sci. 1 (2002) 970]. With rare exceptions, the active ingredients undergo photochemical changes (in some cases form free radicals) and the sunscreen lotions lose considerable Sun protection efficacy only after a relatively short time when exposed to simulated sunlight UVB/UVA radiation, confirming the recent findings by Sayre et al. [R.M. Sayre, J.C. Dowdy, A.J. Gerwig, W.J. Shields, R.V. Lloyd, Photochem. Photobiol. 81 (2005) 452].

Prediction and interpretation of the 57Fe isomer shift in Mössbauer spectra by density functional theory

Abstract: The calibration of two popular density functionals (B3LYP and BP86) for the prediction of isomer shifts (IS) in 57Fe Mossbauer (MB) spectra is reported. A linear correlation between non-relativistically calculated theoretical electron densities and experimentally measured ISs is established. Both functionals lead to accurate predictions of MB ISs with standard deviations on the order of approximately 0.1 mm s−1 over a range of approximately 2 mm s−1. The correlation holds for complexes of different total charge, total spin, valence state at the iron, coordination number and coordination geometry. A detailed analysis of the contributions to the IS is presented. It is shown that the important contributions are: (a) the variation of the 3s-contribution which is mainly caused by differing shielding according to the d-population of the metal; and (b) variations in the valence shell contribution. The latter contribution accounts for approximately 70% of the totally observed variation. The interpretation of the valence contribution is complex and involves contributions from changes in covalencies, orbital distortions due to bonding and shielding effects. The changes in metalligand distances are also an important factor, which influences the shape of the 4s-orbital and therefore modulates ISs.