171,002 research outputs found
Bifunctional Cp boolean AND N complexes - Unusual structural features and electronic coupling in highly preorganized bimetallic systems
No full textScaffolds: Effects of Bulky Substituents and Coligands on Structures and M···H−C Interactions
No full textA series of nickel(II) and palladium(II) complexes [L2M2](2+) have been prepared and structurally characterized, where L is a pyrazolate ligand with bulky 2,6-dimethyl- or 2,6-di(isopropyl)anilinomethyl side arms. Coordinating counter anions such as chloride can bind to axial sites of the dinickel species in a solvent-dependent process, giving rise to five-coordinate high-spin metal ions. In the case of weakly coordinating anions, the metal ions are found in roughly square-planar environments, and the structures are governed by the tendency of the bulky aryl groups to avoid each other, which forces the methyl or isopropyl substituents in the aryl 2- and 6-positions to approach the metal ions from the axial directions. This leads to drastic low-field shifts of the respective H-1 NMR signals, e.g. delta = 7.86 ppm for the isopropyl -CH which comes in close proximity to the low-spin nickel(II) center. The relevance of such low-field NMR resonances of protons close to the axial sites of d(8) metal ions for possible three-center four-electron (MH)-H-...-C hydrogen bonds involving the filled d(z)(2) orbital of the metal ion is discussed. In the present case, attractive (MH)-H-... interactions are assumed to be of no major significance. This was corroborated by the structure of a further [L2Ni2](2+) type complex where the anilinomethyl side arms bear only a single 2-isopropyl group, which was found rotated away from the metal. Additional spectroscopic and electrochemical properties of the various complexes are reported. ((C) Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004)
A homoleptic zirconium complex with four bulky eta(2)-pyrazolato ligands
No full textTwo new tetrakis(eta(2)-pyrazolato) zirconium complexes are prepared from the reaction of Zr(CH2Ph)(4) with bulky pyrazolate ligands bearing indenylmethyl (HL1) or fluorenylmethyl (HL2) substituents, respectively. Zr(L-2)(4) has been analyzed by X-ray crystallography, which represents the first structural characterisation of a homoleptic eta(2)-pyrazolato zirconium compound
A homoleptic zirconium complex with four bulky eta(2)-pyrazolato ligands
No full textTwo new tetrakis(eta(2)-pyrazolato) zirconium complexes are prepared from the reaction of Zr(CH2Ph)(4) with bulky pyrazolate ligands bearing indenylmethyl (HL1) or fluorenylmethyl (HL2) substituents, respectively. Zr(L-2)(4) has been analyzed by X-ray crystallography, which represents the first structural characterisation of a homoleptic eta(2)-pyrazolato zirconium compound
Factores bióticos relacionados con el decaimiento de Pinus pinaster en Castilla y León
No full textDoes exclusion of cancers registered only from death-certificate information diminish socio-demographic disparities in recorded survival?
No full textAbstract not availableHanna E. Tervonen, David Roder, Stephen Morrell, Hui You, David C. Curro
Comparing soil organic carbon stocks in contrasting Mediterranean pedosystems: How physical-chemical properties and land uses influence its behavior
No full textSoils play a pivotal role in the global carbon cycle processes and behavior, with soil organic carbon stocks (SOCs) representing the largest terrestrial carbon (C) pool. Soil C sequestration enhanced soil quality and the overall ecosystem goods and services, together with socio-economic benefits. The Mediterranean areas are one of the world’s biodiversity hotspots for conservation priorities. The Sardinia Island (south Italy) hosts peculiar eco- and pedosystems thanks to its peculiar climatic, geological, geomorphological, and ancient land use history featured for one of the oldest civilizations (Nuragic, 6,000 BC). All factors are brought together in extremely peculiar soil conditions. This study aimed to investigate SOCs and related behavior in two contrasting Mediterranean pedosystems in Sardinia (Cambisols developed on granite vs Luvisols on limestone), featuring different land covers, by comparing: i) surface vs deep soil horizons (A vs B); ii) different land covers inside and between the two investigated pedosystems. Several properties were assessed, including vegetation (vascular plants), litter (C, N, C/N, litter carbon stocks, P, Ca, Mg, Na, K, Cu, Fe, Mn, and Zn), and soil physical- (sand, silt, and clay contents, bulk density) chemical features (pH, electrical conductivity, soil organic matter, total N, total P, available P, C/N, exchangeable H+Al, exchangeable cations, cation-exchange capacity, base saturation, Cu, Fe, Mn, and Zn), wherever feasible. Statistical analyses were performed to determine: i) significant differences (p < 0.05) between and among investigated horizons and land uses; ii) bivariate correlation between investigated parameters (Pearson’s Correlation Matrix (CM)); variability and complex multiple relationships among investigated parameters through factor analysis (FA), while a principal component analysis (PCA) was conducted to identify the soil physical-chemical parameters having greater importance in terms of observed variability within (a) the investigated pedosystem, as well as (b) among the different land covers. Results revealed that areas with natural or close-to-natural features exhibited significantly higher SOCs amounts compared to more intense and human-influenced land covers. Furthermore, the differences in substrate and following soil formation processes between the two investigated pedosystems led to different SOCs behaviors, demonstrating a strong relation between SOCs and intrinsic soil features. This emphasizes the greater importance of soil nature in influencing SOCs, greater compared to that shown by land cover variations. Consequently, this study blatantly demonstrates that SOCs investigations, if not carried out through an in-depth soil investigation, may lead to inaccurate, or even wrong, outcomes and following considerations.Soils play a pivotal role in the global carbon cycle processes and behavior, with soil organic carbon stocks (SOCs) representing the largest terrestrial carbon (C) pool. Soil C sequestration enhanced soil quality and the overall ecosystem goods and services, together with socio-economic benefits. The Mediterranean areas are one of the world’s biodiversity hotspots for conservation priorities. The Sardinia Island (south Italy) hosts peculiar eco- and pedosystems thanks to its peculiar climatic, geological, geomorphological, and ancient land use history featured for one of the oldest civilizations (Nuragic, 6,000 BC). All factors are brought together in extremely peculiar soil conditions. This study aimed to investigate SOCs and related behavior in two contrasting Mediterranean pedosystems in Sardinia (Cambisols developed on granite vs Luvisols on limestone), featuring different land covers, by comparing: i) surface vs deep soil horizons (A vs B); ii) different land covers inside and between the two investigated pedosystems. Several properties were assessed, including vegetation (vascular plants), litter (C, N, C/N, litter carbon stocks, P, Ca, Mg, Na, K, Cu, Fe, Mn, and Zn), and soil physical- (sand, silt, and clay contents, bulk density) chemical features (pH, electrical conductivity, soil organic matter, total N, total P, available P, C/N, exchangeable H+Al, exchangeable cations, cation-exchange capacity, base saturation, Cu, Fe, Mn, and Zn), wherever feasible. Statistical analyses were performed to determine: i) significant differences (p < 0.05) between and among investigated horizons and land uses; ii) bivariate correlation between investigated parameters (Pearson’s Correlation Matrix (CM)); variability and complex multiple relationships among investigated parameters through factor analysis (FA), while a principal component analysis (PCA) was conducted to identify the soil physical-chemical parameters having greater importance in terms of observed variability within (a) the investigated pedosystem, as well as (b) among the different land covers. Results revealed that areas with natural or close-to-natural features exhibited significantly higher SOCs amounts compared to more intense and human-influenced land covers. Furthermore, the differences in substrate and following soil formation processes between the two investigated pedosystems led to different SOCs behaviors, demonstrating a strong relation between SOCs and intrinsic soil features. This emphasizes the greater importance of soil nature in influencing SOCs, greater compared to that shown by land cover variations. Consequently, this study blatantly demonstrates that SOCs investigations, if not carried out through an in-depth soil investigation, may lead to inaccurate, or even wrong, outcomes and following considerations
8. Brochetta C., Perrotta M.G., Jeromin A., Romano M., Soranzo MR., Borelli V., Roder J. And Zabucchi G. Identification and Subcellular Localization of Neurtonal Calcium Sensor-1 (NCS-1) in Human Neutrophils and HL-60 cells.
No full textUno studio applicativo della Collaborative Interactions Scale alla Dialectical Behavior Therapy
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