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Aufsatz
Cross-π-conjugated enediyne with multioptic metal binding sites
(2020-10-20)
The synthesis of an enediyne molecule functionlized with different metal coordination sites in a cross-pconjugated fashion is reported. Using Pd-mediated cross-coupling reactions, 2,20-bipyridine units were attached at the periphery of diazafluorenemethylidene to obtain a multitopic ligand. UV-vis spectrosopic investigations along with electrochemical analyses reveal electronic communication along the conjugated path reflected in red-shifted absorption spectra and shifts of reduction potentials. The properties of the ...
Aufsatz
Preparation and Molecular Structure of a Cyclopentyl-Substituted Cage Hexasilsesquioxane T6 (T = cyclopentyl-SiO1.5) Starting from the Corresponding Silanetriol
(2017-10-04)
Cyclopentyl substituted silanetriol can be prepared and isolated. Its condensation yields the corresponding disiloxanetetrol as a primary condensation product. Further condensation leads to the hexameric polyhedral silsesquioxane cage T6. The latter has been mentioned in the literature before however, lacking structural data. All compounds have been characterized with multinuclear NMR spectroscopy and, in addition, the molecular structures have been determined in the case of the disiloxanetetrol and the hexasilsesquioxane ...
Aufsatz
Metallated [3]Ferrocenophanes Containing P3M Bridges (M = Li, Na, K)
(2018-07-11)
Alkali-metal phosphanides can be embedded into a [3]ferrocenophane scaffold giving rise to bicyclic ferrocenophanes [MFe(C5H4PtBu)2P] (M = Li, Na, K). Coordination of the alkali-metal ions takes place via the terminal phosphorus atoms adopting a puckered P3M four-membered ring. All compounds were characterized via single-crystal X-ray diffraction and multinuclear NMR spectroscopy (1H, 31P, 7Li), whereas 13C NMR data could only be recorded for the Li derivative, owing to the limited solubility of its heavier congeners ...
Aufsatz
Synthesis and crystal structure of μ-[1,1′-di(mesitylphosphanido)ferrocene]bis[η5-cyclopentadienylnickel(II)] tetrahydrofurane solvate, C42H48FeNi2OP2
(2018-03-08)
C42H48FeNi2OP2, orthorhombic, Pbca (no. 61), a = 9.4551(4) Å, b = 19.7133(9) Å, c = 39.693(2) Å, V = 7398.4(6) Å3, Z = 8, Rgt(F) = 0.0598, wRref(F2) = 0.1481, T = 100(2) K.
Aufsatz
Bis‐[3]Ferrocenophanes with Central >E−E’< Bonds (E, E’=P, SiH): Preparation, Properties, and Thermal Activation
(2019-06-26)
A series of bis‐[3]ferrocenophanes of the general type Fe(C5H4E’)2E−E(E'C5H4)2Fe (E=P, SiH and E’=PtBu, NneoPentyl, NSi(CH3)3) with an isolobal molecular framework have been prepared and characterized by heteronuclear NMR spectroscopy and X‐ray crystallography. The thermal dissociation behavior with respect to homolytic fission of the central bond generating phosphorus centered radicals was investigated using EPR spectroscopy and quantum chemical calculations.
Aufsatz
Vegetable Crop Biomass Estimation Using Hyperspectral and RGB 3D UAV Data
(2020-10-19)
Remote sensing (RS) has been an e ective tool to monitor agricultural production systems, but for vegetable crops, precision agriculture has received less interest to date. The objective of this study was to test the predictive performance of two types of RS data—crop height information derived from point clouds based on RGB UAV data, and reflectance information from terrestrial hyperspectral imagery—to predict fresh matter yield (FMY) for three vegetable crops (eggplant, tomato, and cabbage). The study was conducted ...
Aufsatz
A Study on the Influence of the Chemical Nature of Fillers on Rheological and Fatigue Behavior of Bitumen Emulsion Mastic
(2020-10-16)
Cold Bitumen Emulsion (CBE) mixture technologies have been recently developed to lower pavement construction temperatures to reduce environmental costs and control gas emissions. Due to its poor early mechanical strength, active fillers (i.e., cement) have been used to obtain high early sti ness in order to have the potential for timely construction of the next layer. There is, however, a lack of understanding about the impact of active fillers on the viscoelastic behavior and fatigue damage resistance of CBE mastics. ...
Aufsatz
Combined leaching and plant uptake simulations of PFOA and PFOS under field conditions
(2020-08-31)
Per- and polyfluoroalkyl substances (PFASs) are used in industrial production and manufacturing but were repeatedly detected in agricultural soils and therefore in cash crops in recent years. Dissipation of perfluoroalkyl acids (PFAAs), a sub-group of PFASs, in the environment was rather attributed to the formation of non-extractable residues (NER) than to degradation or transformation. Currently, there are no models describing the fate of PFAAs in the soil-plant continuum under field conditions, which hampers an ...
Aufsatz
Chalcogen‐Transfer Rearrangement: Exploring Inter‐ versus Intramolecular P−P Bond Activation
(2020-07-17)
tert‐Butyl‐substituted diphospha[2]ferrocenophane has been used as a stereochemically confined diphosphane to explore the addition of O, S, Se and Te. Although the diphosphanylchalcogane has been obtained for tellurium, all other chalcogens give diphosphane monochalcogenides. The latter transform via chalcogen‐transfer rearrangement to the corresponding diphosphanylchalcoganes upon heating. The kinetics of this rearrangement has been followed with NMR spectroscopy supported by DFT calculations. Intermediates during ...
Aufsatz
Influence of Accelerated Aging on the Fiber-Matrix Adhesion of Regenerated Cellulose Fiber-Reinforced Bio-Polyamide
(2023-03-23)
With regard to the sustainability and biological origin of plastic components, regenerated cellulose fiber (RCF)-reinforced polymers are expected to replace other composites in the future. For use under severe conditions, for example, as a housing in the engine compartment, the resistance of the composites and the impact on the fiber and fiber-matrix adhesion must be investigated. Composites of bio-polyamide with a reinforcement of 20 wt.% RCF were compounded using a twinscrew extruder. The test specimens were ...