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Aufsatz
Ferrocene-Based N-Heterocyclic Plumbylenes [Fe{(η⁵- C₅H₄)NSiMe₂R}₂Pb:]: Influence of the Steric Demand of the NSubstituents on Their Dimerization via C-H Activation with Pbᴵᴵ
(2023-05-12)
Ferrocene-based N-heterocyclic plumbylenes fc[(NSiMe₂R)₂Pb:] (1; fc=1,1’-ferrocenylene) are easily accessible by transamination from [(Me₃Si)₂N]₂Pb and the corresponding 1,1’-diaminoferrocene derivatives fc(NHSiMe₂R)₂. They may form unconventional dimers 2 by a process, which causes the cleavage of a cyclopentadienyl C−H bond and the formation of a Pb−C and an N−H bond. The monomer-dimer equilibrium (2 1⇆2) has been addressed experimentally and computationally. It critically depends on the steric demand of the ...
Aufsatz
Observation of a Long-lived Electronic Coherence Modulated by Vibrational Dynamics in Molecular Nd³+- Complexes at Room Temperature
(2023-03-23)
Temporally delayed, phase-locked coherent pairs of near IR femtosecond laser pulses were employed to study electronic coherences in molecular Nd³+-complexes at room temperature. Dissolved and solid complexes were studied under a confocal microscope set-up with fluorescence detection. The observed electronic coherence on a few hundred femtoseconds time scale is modulated by additional coherent wave packet dynamics, which we attribute mainly to be vibrational in nature. In future, the complexes may serve as prototypes ...
Aufsatz
Reduction Behavior of Anisyl-substituted P-Ferrocenyl Phospholes
(2023-05-26)
P-Ferrocenylphospholes with differing substituents in α-position have been synthesized and their identity and purity was confirmed using multinuclear NMR spectroscopy, MS, elemental analysis and single crystal X-ray diffraction. Furthermore, the redox properties have been explored with electrochemical measurements. Transferring the reduction to a preparative scale using lithium leads to reductive P−C bond cleavage furnishing the corresponding phospholide which has been transformed to P-tert-butyl substituted phosphole. ...
Aufsatz
Lanthanide Complexes (Ln=La, Nd, Dy) of Octaethyl propane-1,1,3,3-tetrayltetrakis(phosphonate): Multidentate Binding Competing with Monodentate DMSO Complexes
(2022-12-09)
The preparation of lanthanide nitrate complexes [Ln(NO₃)₃{L}]ₙ (Ln³+=La, Nd, Dy) supported by the octaethyl propane-1,1,3,3-tetrayltetrakis(phosphonate) (L) chelate ligand platform is presented. Re-crystallization of these compounds from DMSO/THF led to a complete replacement of the multidentate phosphonate ester ligand and the formation of exclusively DMSO-supported lanthanide nitrate species [Ln(NO₃)₃(DMSO)₄]. The relative basicity of a model phosphonate ester vs. DMSO is explored with theoretical means, pointing ...
Aufsatz
Emission and Mechanical Properties of Glass and Cellulose Fiber Reinforced Bio-Polyamide Composites
(2023-06-07)
Climate change, access, and monopolies to raw material sources as well as politically motivated trade barriers are among the factors responsible for a shortage of raw materials. In the plastics industry, resource conservation can be achieved by substituting commercially available petrochemical-based plastics with components made from renewable raw materials. Innovation potentials are often not used due to a lack of information on the use of bio-based materials, efficient processing methods, and product technologies ...
Aufsatz
The Influence of Thermal and Mechanical Stress on the Electrical Conductivity of ITO-Coated Polycarbonate Films
(2023-05-31)
The influence of thermomechanical stress on the conductivity of indium tin oxide (ITO)-coated polycarbonate (PC) films was investigated. PC is the industry’s standard material for window panes. ITO coatings on polyethylene terephthalate (PET) films are the main commercially available option; as such, most investigations refer to this combination. The investigations in this study aim to investigate the critical crack initiation strain at different temperatures and crack initiation temperatures for two different coating ...
Aufsatz
Small villages and their sanitary infrastructure—an unnoticed influence on water quantity and a threat to water quality in headwater catchments
(2023-11-16)
In rural catchments, villages often feature their own, separate urban water infrastructure, including combined sewer overflows (CSOs) or wastewater treatment plants (WWTPs). These point sources affect the water quantity and quality of the receiving low order streams. However, the extent of this impact is rarely monitored. We installed discharge and water quality measurements at the outlet of two small, neighbouring headwater catchments, one that includes a village, a WWTP, and two CSOs, while the other is predominantly ...
Aufsatz
Yeast gene KTI13 (alias DPH8) operates in the initiation step of diphthamide synthesis on elongation factor 2
(2023-08-08)
In yeast, Elongator-dependent tRNA modifications are regulated by the Kti11•Kti13 dimer and hijacked for cell killing by zymocin, a tRNase ribotoxin. Kti11 (alias Dph3) also controls modification of elongation factor 2 (EF2) with diphthamide, the target for lethal ADP-ribosylation by diphtheria toxin (DT). Diphthamide formation on EF2 involves four biosynthetic steps encoded by the DPH1-DPH7 network and an ill-defined KTI13 function. On further examining the latter gene in yeast, we found that kti13Δ null-mutants ...
Aufsatz
Gradual Coordination and Reversible P–P Bond Activation of a P3-Unit with Transition Metal Carbony
(2024-03-20)
Coordination of a stereochemically defined P3-chain to a series of transition metal carbonyls [M(CO)x]z− (M = Mn (x = 5, z = 1), Fe (x = 4, z = 2) or Co (x = 4, z = 1)) is explored using a 3]ferrocenophane scaffold. A gradual transition from 𝜼1-, 𝜼2- to 𝜼3-coordination is observed where in the 𝜼2-mode the terminal positions of the phosphorus chain are bridged. With an excess of cobalt carbonyl successive P–P bond activation and gradual separation of the central phosphorus atoms from the phosphorus chain has been ...
Aufsatz
On the Influence of Microstructure on the Corrosion Behavior of Fe–Mn–Al–Ni Shape Memory Alloy in 5.0 wt% NaCl Solution
(2020-10-03)
Herein the corrosion behavior of Fe–Mn–Al–Ni shape memory alloys characterized by different microstructures in a 5.0 wt% NaCl solution is investigated. Open circuit potential and potentiodynamic polarisation tests are conducted. Generally, Fe–Mn–Al–Ni shows corrosion properties being similar to pure iron. However, the polarization curves of single crystals indicate the presence of an unstable passive system. The corrosion damage is analyzed by means of optical microscopy and electron microscopy. It is revealed that ...