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The electronic structure of [OsF6]2− and PtF6 complexes was studied by means of CASSCF/NEVPT2 multiconfigurational calculations, including spin–orbital coupling, which is very relevant in the case of these metals. From these calculations, it is possible to establish that in the octahedral symmetry (Oh), the ground state is non-magnetic (Jeff = 0) because of the strong ligand field, and the interaction with paramagnetic excited states is almost negligible, resulting in a non-magnetic behavior, which is in agreement with the experimental evidence. [ABSTRACT FROM AUTHOR]

This work present a detailed theoretical determination of the spin-Hamiltonian parameters for Ce 2 (COT) 3 molecule. A qualitative model to explain the origin of the small value of the Zero Field Splitting (ZFS) is developed concluding that, because of the symmetry reasons the spin orbit coupling (SOC) contribution to ZFS value is minimal and the value is the result only of dipole-dipole interaction. Magnetic susceptibility and g-factors are determined from the analysis of the magnetization matrices using different active spaces and the properties could be rationalized throughout the relationship between the monomer [Ce(COT) 2 ] − and bimetallic molecule. Finally a possible mechanism to explain the antiferromagnetic coupling of the magnetic moments of both centers is proposed using the states generated when 4 f z 3 and 5 d z 2 metal orbitals are included in the calculations. The active space employed in this point produce the best results at all levels of theory used in this work (CASSCF, MRCI + CIS and DDCIn n = 2, 3). [ABSTRACT FROM AUTHOR]

The electronic structure and magnetic properties of a series of Kramers ions with f1 configuration in axial symmetry have been analyzed with a combination of theoretical methods: ab initio relativistic wavefunction methods as well as a crystal-field (CF) model with parameters extracted from the ab initio calculations. The molecules were treated in an idealized D8h and D7h symmetry and different combinations of active electrons and orbitals were used to describe correctly the nature of the ground and excited states. The spin Hamiltonian parameters for the Kramers doublet derived from the ground multiplet were determined and discussed on the basis of the crystal-field (CF) and spin–orbit interaction. The prime interests were the electron paramagnetic resonance g-factors and their relation to the complex geometry, crystal-field (CF) and spin–orbit coupling. The developed models agree well with the ab initio calculations and experimental reports. [ABSTRACT FROM AUTHOR]

The electronic structure of [OsF 6 ] 2- and PtF 6 complexes was studied by means of CASSCF/NEVPT2 multiconfigurational calculations, including spin-orbital coupling, which is very relevant in the case of these metals. From these calculations, it is possible to establish that in the octahedral symmetry ( O h ), the ground state is non-magnetic ( J eff = 0) because of the strong ligand field, and the interaction with paramagnetic excited states is almost negligible, resulting in a non-magnetic behavior, which is in agreement with the experimental evidence.

Sodium-dodecyl-sulfate polyacrylamide gel electrophoresis (SDS-PAGE) can be used to separate proteins based mainly on their size such as in denaturing gels. Different staining methods have been reported to observe proteins in the gel matrix, where the most used dyes are generally anionic. Anionic dyes allow for interactions with protonated amino acids, retaining the dye in the proteins. Fluorescent staining is an alternative technique considered to be sensitive, safe, and versatile. Some anionic complexes based on d 6 transition metals have been used for this purpose, where cationic dyes have been less explored in this context. In this work, we synthesized and characterized a new monocationic rhenium complex fac -[Re(CO) 3 ( deeb ) B2 ] + (where deeb is 4,4'-bis(ethoxycarbonyl)-2,2'-bpy and B2 is 2,4-di- tert - butyl -6-(3H-imidazo[4,5-c]pyridine-2-yl)phenol). We carried out a structural characterization of this complex by MS + , FTIR, 1 H NMR, D 2 O exchange, and HHCOSY. Moreover, we carried out UV-Vis, luminescence, and cyclic voltammetry experiments to understand the effect of ligands on the complex's electronic structure. We also performed relativistic theoretical calculations using the B3LYP/TZ2P level of theory and R-TDDFT within a dielectric continuum model (COSMO) to better understand electronic transitions and optical properties. We finally assessed the potential of fac -[Re(CO) 3 ( deeb ) B2 ] + (as well as the precursor fac -Re(CO) 3 ( deeb )Br and the free ligand B2 ) to stain proteins separated by SDS-PAGE. We found that only fac -[Re(CO) 3 ( deeb ) B2 ] + proved viable to be directly used as a luminescent dye for proteins, presumably due to its interaction with negatively charged residues in proteins and by weak interactions provided by B2 . In addition, fac -[Re(CO) 3 ( deeb ) B2 ] + seems to interact preferentially with proteins and not with the gel matrix despite the presence of sodium dodecyl sulfate (SDS). In future applications, these alternative cationic complexes might be used alone or in combination with more traditional anionic compounds to generate counterion dye stains to improve the process., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2021 Carreño, Gacitúa, Solis-Céspedes, Páez-Hernández, Swords, Meyer, Preite, Chávez, Vega and Fuentes.)

The electronic structure and magnetic properties of a series of Kramers ions with f 1 configuration in axial symmetry have been analyzed with a combination of theoretical methods: ab initio relativistic wavefunction methods as well as a crystal-field (CF) model with parameters extracted from the ab initio calculations. The molecules were treated in an idealized D 8h and D 7h symmetry and different combinations of active electrons and orbitals were used to describe correctly the nature of the ground and excited states. The spin Hamiltonian parameters for the Kramers doublet derived from the ground multiplet were determined and discussed on the basis of the crystal-field (CF) and spin-orbit interaction. The prime interests were the electron paramagnetic resonance g-factors and their relation to the complex geometry, crystal-field (CF) and spin-orbit coupling. The developed models agree well with the ab initio calculations and experimental reports.