The synthesis, structure, and full characterization of a redox-switchable germylene based on a [3]ferrocenophane ligand arrangement, [Fc(NMes) Ge] (4), is presented. The mesityl (Mes)-substituted title compound is readily available from Fc(NHMes) (2) and Ge{N(SiMe ) } , or from the dilithiated, highly air- and moisture-sensitive compound Fc(NLiMes) ⋅3 Et O (3) and GeCl . Cyclic voltammetry studies are provided for 4, confirming the above-mentioned view of a redox-switchable germylene metalloligand. Although several 1:1 Rh and Ir complexes of 4 (5-7) are cleanly formed in solution, all attempts to isolate them in pure form failed due to stability problems. However, crystalline solids of [Mo(κ Ge-4) (CO) ] (8) and [W(κ Ge-4) (CO) ] (9) were isolated and fully characterized by common spectroscopic techniques (8 by X-ray diffraction). DFT calculations were performed on a series of model compounds to elucidate a conceivable interplay between the metal atoms in neutral and cationic bimetallic complexes of the type [Rh(κ E-qE)(CO) Cl] (qE=[Fc(NPh) E] with E=C, Si, Ge). The bonding characteristics of the coordinated Fc-based metalloligands (qE/qE ) are strongly affected upon in silico oxidation of the calculated complexes. The calculated Tolman electronic parameter (TEP) significantly increases by approximately 20 cm (E=C) to 25 cm (E=Si, Ge) upon oxidation. The change in the ligand-donating abilities upon oxidation can mainly be attributed to Coulombic effects, whereas an orbital-based interaction appears to have only a minor influence.

This paper presents a combined spectroscopic and theoretical analysis of a trinuclear [Pd3{Si(mt(Me))3}2] complex (mt(Me) = methimazole) which has been demonstrated to be a potential catalyst for coupling reactions. It is a highly symmetric model system (D3 in the electronic ground state) for the investigation of electronic states and the structure of polynuclear transition metal complexes. Different time-resolved IR spectroscopic methods covering the femtosecond up to the microsecond range as well as density functional computations are performed to unravel the structure and character of this complex in the electronically excited state. These are the first time-resolved IR studies on a trinuclear Pd complex. Based on the interplay between the computational results and those from the IR studies a (3)A state is identified as the lowest lying triplet state which has C2 symmetry.

A detailed theoretical and spectroscopic study on the electronically excited states of a trinuclear palladium complex is presented both in the gas phase and solution. The application of DFT and TDDFT methods as well as a variety of spectroscopic methods to the chosen complex [Pd3{Si(mt(Me))3}2] (1, mt(Me) = methimazole) leads to the first detailed analysis of the photophysics of a symmetric trinuclear complex. In combination with the calculations, energies, structures and lifetimes of the excited electronic states (with an (3)A1 state as the lowest one) are characterized by applying the resonant-2-photon-ionization method in a molecular beam experiment as well as luminescence, time-correlated single photon counting and excited state femtosecond absorption spectroscopy in solution. These investigations are of fundamental interest to analyze photophysical properties of metal containing complexes on a molecular level.

If modified for spikes and burst suppression, median frequency and spectral edge frequency as well as the unmodified approximate entropy were able to assess the anesthetic effect of desflurane, isoflurane, and sevoflurane in rats. For sevoflurane, the modified spectral edge frequency was best with regard to signal-to-noise ratio and prediction probability.