Search results for "Hydra"
showing 10 items of 4669 documents
CCDC 248544: Experimental Crystal Structure Determination
2004
Related Article: C.Boskovic, A.Sieber, G.Chaboussant, H.U.Gudel, J.Ensling, W.Wernsdorfer, A.Neels, G.Labat, H.Stoeckli-Evans, S.Janssen|2004|Inorg.Chem.|43|5053|doi:10.1021/ic049600f
CCDC 711358: Experimental Crystal Structure Determination
2010
Related Article: E.Pardo, D.Cangussu, R.Lescouezec, Y.Journaux, J.Pasan, F.S.Delgado, C.Ruiz-Perez, R.Ruiz-Garcia, J.Cano, M.Julve, F.Lloret|2009|Inorg.Chem.|48|4661|doi:10.1021/ic900055d
A new hydrogen bonding motif involved in self-recognition in the solid state by functionalised macrocycles
2011
Self-recognition within the crystal lattices of three functionalised macrocycles results in the formation of arrays of remarkably similar hermaphroditic pairs of macrocycles. In the case of two of the macrocycles containing acylhydrazine substituents, a hitherto unknown recognition pattern is found in the interaction of the hydrazine moiety with crown-ether oxygen atoms.
Energetic study of bifurcated hydrogen bonds in secondary structures of salts composed with dicarboxylic acids and ethylamine
2020
Abstract The nature of bifurcated hydrogen bonds prompted us to analyze the energy of supramolecular motifs on the example of new structures of carboxylic acids salts with amines, which guarantee a multitude of such interactions. Experimental and theoretical studies of four dicarboxylic salts with primary amine: ethylammonium succinate hydrate (1), tartrate hydrate (2) phthalate hydrate (3) and terephthalate (4) has been investigated along with study of the strength of interactions between the anions and cations. The complete topological analysis of the charge density for all new structures allowed designation of the estimated Cumulative Dissociation Energy (eCDE).
A robust viologen and Mn-based porous coordination polymer with two types of Lewis acid sites providing high affinity for H 2 O, CO 2 and NH 3
2017
A novel porous coordination polymer [Mn(pc3)(H2O)2]·xH2O (3 < x < 4) is synthesized in water at pH = 7 using the anionic viologen-carboxylate ligand 4,4′-bipyridinium,1,1′-bis-(2,4-dicarboxyphenyl) (pc32−). Dehydration of the material results in the formation of open pores containing two types of accessible Lewis acid sites: exposed Mn2+ cations and N+ atoms of viologen units. Due to this property the PCP shows high affinity and capacity in the adsorption of H2O, CO2 and NH3. Despite the presence of strong adsorption sites this material is stable in liquid water and in gaseous NH3.
Enantiomeric Resolution of Asymmetric-Carbon-Free Binuclear Double-Stranded Cobalt(III) Helicates and Their Application as Catalysts in Asymmetric Re…
2018
A series of double-stranded binuclear helicates [Co2(H1)2]4+, [Co2(H2)2]4+, and [Co2(H3)2]4+, derived from monodeprotonated bis-pyridyl hydrazine-based ligands of H21, H22, and H23 with one, two, and three -CH2 spacers, were obtained. These asymmetric-carbon-free racemic helicates were separated into their ΔΔ and ΛΛ enantiomers. The resolved helicates were examined for the first time as enantioselective catalysts in asymmetric benzoylation and nitroaldol reactions.
Estimating the macroscopic capillary length from Beerkan infiltration experiments and its impact on saturated soil hydraulic conductivity predictions
2020
International audience; The macroscopic capillary length, λc, is a fundamental soil parameter expressing the relative importance of the capillary over gravity forces during water movement in unsaturated soil. In this investigation, we propose a simple field method for estimating λc using only a single-ring infiltration experiment of the Beerkan type and measurements of initial and saturated soil water contents. We assumed that the intercept of the linear regression fitted to the steady-state portion of the experimental infiltration curve could be used as a reliable predictor of λc. This hypothesis was validated by assessing the proposed calculation approach using both analytical and field d…
Mapping Vegetation Density in a Heterogeneous River Floodplain Ecosystem Using Pointable CHRIS/PROBA Data
2012
River floodplains in the Netherlands serve as water storage areas, while they also have the function of nature rehabilitation areas. Floodplain vegetation is therefore subject to natural processes of vegetation succession. At the same time, vegetation encroachment obstructs the water flow into the floodplains and increases the flood risk for the hinterland. Spaceborne pointable imaging spectroscopy has the potential to quantify vegetation density on the basis of leaf area index (LAI) from a desired view zenith angle. In this respect, hyperspectral pointable CHRIS data were linked to the ray tracing canopy reflectance model FLIGHT to retrieve vegetation density estimates over a heterogeneous…
Comparing flow resistance law for fixed and mobile bed rills
2019
Rills caused by run-off concentration on erodible hillslopes have very irregular profiles and cross-section shapes. Rill erosion directly depends on the hydraulics of flow in the rills, which may differ greatly from hydraulics of flow in larger and regular channels. In this paper, a recently theoretically deduced rill flow resistance equation, based on a power–velocity profile, was tested experimentally on plots of varying slopes (ranging from 9% to 26%) in which mobile and fixed bed rills were incised. Initially, measurements of flow velocity, water depth, cross-section area, wetted perimeter, and bed slope, carried out in 320 reaches of mobile bed rills and in 165 reaches of fixed rills, …
Laboratory evaluation of falling-head infiltration for saturated soil hydraulic conductivity determination
2020
Falling-head one-dimensional infiltration procedures, such as the simplified falling-head (SFH) technique, yield estimates of saturated soil hydraulic conductivity, Ks, with parsimonious and rapid experiments. Factors that can influence determination of Ks by the SFH technique were tested in the laboratory on three repacked soils differing by particle diameter ranges (0-2000, 0- 105 and 105-2000 mm, respectively). Using the theoretically calculated depth of ponding on the infiltration surface, D, instead of the measured one had a small impact on the Ks calculations (means differing by a factor of 1.1-1.2, depending on the soil). For the finest soil, Ks decreased by 3.1 times as D increased …