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Aufsatz
Reactions of Mesityl Azide with Ferrocene-Based N-Heterocyclic Germylenes, Stannylenes and Plumbylenes, Including PPh₂-Functionalised Congeners
(2022-05-05)
The active PbII/P Lewis pair nature of a PPh₂-functionalised ferrocene-based N-heterocyclic plumbylene is demonstrated by its reaction with mesityl azide to afford a phosphazide, which is in contrast to the inertness of the unfunctionalised congener. The lighter analogues most likely react with MesN₃ at their respective tetrel atom Eᴵᴵ, leading to the formation of N₂ and an Eᶦᵛ=NMes unit, followed by NMes transfer from the Eᶦᵛ to the Pᴵᴵᴵ atom.
The reactivity of ferrocene-based N-heterocyclic tetrylenes ...
Aufsatz
Asymmetrically Substituted Phospholes as Ligands for Coinage Metal Complexes
(2022-05-24)
A series of coinage metal complexes asymmetrically substituted 2,5-diaryl phosphole ligands is reported. Structure, identity, and purity of all obtained complexes were corroborated with state-of-the-art techniques (multinuclear NMR, mass spectrometry, elemental analysis, X-ray diffraction) in solution and solid state. All complexes obtained feature luminescence in solution as well as in the solid state. Additionally, DOSY-MW NMR estimation experiments were performed to achieve information about the aggregation behavior ...
Aufsatz
Synthesis of Geminal Bis- and Tetrakisphosphonate Ester Derivatives and Their Coordination Behavior Towards Ca(II) Ions
(2022-04-05)
Geminal Bisphosphonate (BP) Esters in Ca(II) Ion Coordination. A series of geminal BPs was prepared starting from their corresponding ethyl- or isopropyl (arylmethylene)phosphonate ester precursors. Complexation with CaCl₂ yields the derived coordination compounds [Ca(H₂O)₂(L1–L3)₂]Cl₂ or [Ca(L8)Cl₂]ₙ. Their structures in the solid- (SCXRD) as well as solution-state (¹H DOSY NMR) are evaluated and comprehensively compared to literature data.
The preparation and thorough characterization of a variety of (arylmethy ...
Aufsatz
Application of mixed-effects modelling and rule-based models to explain copper variation in soil profiles of southern Germany
(2022-05-25)
Copper (Cu) is an essential element for plants and microorganisms and at larger concentrations a toxic pollutant. A number of factors controlling Cu dynamics have been reported, but information on quantitative relationships is scarce. We aimed to (i) quantitatively describe and predict soil Cu concentrations (CuAR) in aqua regia considering site-specific effects and effects of pH, soil organic carbon (SOC) and cation exchange capacity (CEC), and (ii) study the suitability of mixed-effects modelling and rule-based ...
Aufsatz
Molecular Basis for Ser/Thr Specificity in PKA Signaling
(2020-06-25)
cAMP-dependent protein kinase (PKA) is the major receptor of the second messenger cAMP and a prototype for Ser/Thr-specific protein kinases. Although PKA strongly prefers serine over threonine substrates, little is known about the molecular basis of this substrate specificity. We employ classical enzyme kinetics and a surface plasmon resonance (SPR)-based method to analyze each step of the kinase reaction. In the absence of divalent metal ions and nucleotides, PKA binds serine (PKS) and threonine (PKT) substrates, ...
Aufsatz
A simulation-based approach to evaluate objective material parameters from concrete rheometer measurements
(2019-12-31)
Modern concretes such as ultra-high performance concrete (UHPC) show excellent strength properties combined with favorable flow properties. However, the flow properties depend strongly on process parameters during production (temperature, humidity etc.), but also change sensitively even with slight variations in the mixture. In order to ensure desired processing of the fluidlike material and consistent process quality, the flow properties of the concrete must be evaluated quantitatively and objectively. The usual ...
Aufsatz
Recent Progress in Synthesis and Application of Nanosized and Hierarchical Mordenite—A Short Review
(2021-02-26)
Zeolites with their unique properties find applications in various fields, including medicine, agronomy, ecology, production of detergents and drying agents, and in a number of industrial processes. Among zeolites, mordenite is particularly widespread because of its high silica/alumina ratio, which allows it to resist exposure to high temperatures and to acidic gases and liquids. Mordenite is commercially available as a natural mineral and as a synthesized material. This zeolite is mostly used in its synthetic form ...
Aufsatz
Binding of the Human 14-3-3 Isoforms to Distinct Sites in the Leucine-Rich Repeat Kinase 2
(2020-04-07)
Proteins of the 14-3-3 family are well known modulators of the leucine-rich repeat kinase 2 (LRRK2) regulating kinase activity, cellular localization, and ubiquitylation. Although binding between those proteins has been investigated, a comparative study of all human 14-3-3 isoforms interacting with LRRK2 is lacking so far. In a comprehensive approach, we quantitatively analyzed the interaction between the seven human 14-3-3 isoforms and LRRK2-derived peptides covering both, reported and putative 14-3-3 binding sites. ...
Aufsatz
3D Micro/Nanopatterning of a Vinylferrocene Copolymer
(2020-05-23)
In nanoimprint lithography (NIL), a pattern is created by mechanical deformation of an imprint resist via embossing with a stamp, where the adhesion behavior during the filling of the imprint stamp and its subsequent detachment may impose some practical challenges. Here we explored thermal and reverse NIL patterning of polyvinylferrocene and vinylferrocene-methyl methacrylate copolymers to prepare complex non-spherical objects and patterns. While neat polyvinylferrocene was found to be unsuitable for NIL, freshly-prepared ...
Aufsatz
Homodinuclear Rhˡ and Irˡ Complexes Derived from Imidazolium-Benzimidazolates
(2020-11-19)
The reactions of [M(μ-Cl)(COD)]2 (M=Rh, Ir) with the conjugated mesomeric betaines 2-(3-methyl-1-imidazolium)-benzimidazolate (1aH), 2-(3-isopropyl-1-imidazolium)-benzimidazolate (1bH) and 2-(3-tert-butyl-1-imidazolium)-benzimidazolate (1cH) in equilibrium with their carbenic tautomers 1’aH, 1’bH and 1’cH were investigated. In the case of 1aH and 1bH, the homodinuclear complexes [MCl(COD){M(μ-1’a)(COD)}] and [MCl(COD){M(μ-1’b)(COD)}] were obtained, whose anionic NHC ligand 1’a− or 1’b− bridges the metal centres in a ...