Publications by authors named "K Holldack"
Article Synopsis
- Recent studies on stable monocoordinated organobismuthinidenes have revealed unique chemical and electronic structures.
- Quantum chemical calculations indicated that Bu-MFluind-Bi(I) has a triplet ground state with a significant zero-field splitting (ZFS) greater than 4500 cm, which had not been verified experimentally before.
- This research successfully measured a ZFS of 5422 cm using magneto-optical infrared spectroscopy, marking the highest ZFS recorded to date.
Article Synopsis
- - The study focuses on high-valent iron species, particularly the characterization of iron complexes with the tris-skatylmethylphosphonium (TSMP) scorpionate ligand, which have potential significance in catalytic oxidation reactions.
- - Researchers explore the redox chemistry of the bis-ligated iron complex [(TSMP)Fe], demonstrating its transformation to the octahedral form and a thermally induced spin-cross-over, using advanced techniques like SQUID and nuclear magnetic resonance spectroscopy.
- - Findings indicate that the iron complex can be reversibly oxidized to a stable high-valent form, providing insights into its electronic properties and contributing to the broader understanding of octahedral Fe(IV) complexes in chemistry.
Record-breaking magnetic exchange interactions have previously been reported for 3d-metal dimers of the form [M(Pt(SAc))(pyNO)] (M = Ni or Co) that are linked in the solid state metallophilic Pt⋯Pt bridges. This contrasts the terminally capped monomers [M(Pt(SAc))(py)], for which neither metallophilic bridges nor magnetic exchange interactions are found. Computational modeling has shown that the magnetic exchange interaction is facilitated by the pseudo-closed shell d⋯d metallophilic interaction between the filled Pt 5d orbitals.
View Article and Find Full Text PDFWe report on a novel multi-color method of X-ray spectroscopy at a Synchrotron radiation source that uses two simultaneously filled electron orbits in an electron storage ring to generate multiple soft or tender X-ray beams of different wavelength. To establish the second orbit, we use nonlinear beam dynamics in the so called TRIBs-transverse resonance island buckets-mode of the BESSY II storage ring, where a second electron orbit winds around the regular one leading to transversely separated source points. X-ray beams of multiple colors are generated by imaging the individual source points via different pathways through a monochromator.
View Article and Find Full Text PDFSynthesis and characterization of structure and magnetic properties of the quasi-octahedral complex (pipH)[Co(TDA)] 2HO (I), (pipH = piperazine dication, TDA = thiodiacetic anion) are described. X-ray diffraction studies reveal the first coordination sphere of the Co(II) ion, consisting of two chelating tridentate TDA ligands with a mixed sulfur-oxygen strongly elongated octahedral coordination environment. SQUID magnetometry, frequency-domain Fourier-transform (FD-FT) THz-EPR spectroscopy, and high-level SA-CASSCF/NEVPT2 quantum chemical calculations reveal a strong "easy-plane" type magnetic anisotropy ( ≈ +54 cm) of complex I.
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