Sandwich complexes are an indispensable part of organometallic chemistry, which is becoming increasingly important in the field of lanthanide-based single molecule magnets. Herein, a fundamental class of pure sandwich complexes, [(η 9 -C 9 H 9 )Ln(η 8 -C 8 H 8 )] (Ln=Nd, Sm, Dy, Er), is reported. These neutral and sandwiched lanthanide compounds exclusively contain fully π-coordinated coplanar eight and nine membered CH rings. The magnetic properties of these compounds are investigated, leading to the observation of slow relaxation of the magnetization, including open hysteresis loops up to 10 K for the Er(III) analogue. Fast relaxation of the magnetization is likewise observed near zero field, a highly important characteristic for quantum information processing schemes. Our synthetic strategy is straightforward and utilizes the reaction of [(η 8 -C 8 H 8 )LnI(thf) n ] complexes with [K(C 9 H 9 )]. Although all compounds are fully characterized, structural details of the title compounds can also be deduced by Raman spectroscopy only.

f-element sandwich complexes bearing a η5-plumbole ligand are reported. Quantum chemical calculations suggest that this ligand retains its aromaticity upon coordination. The Er complexes show SMM behavior including magnetic hysteresis.

Novel lanthanide multi-decker complexes were established utilizing dianionic group 14 metallole ligands. The dimensionality of the multidecker species increases from a dimeric structure to 2D depending on the lanthanide ion and the metallole ligand.

Reduction of [Sm III (COT 1,4-SiiPr3 )(BH 4 )(thf)] (COT 1,4-SiiPr3 = 1,4-( i Pr 3 Si) 3 C 8 H 6 ) with KC 8 resulted in [Sm III/II/III (COT 1,4-SiiPr3 ) 4 ], the first example of a homoleptic lanthanide quadruple-decker. As indicated by an analysis of the bond metrics in the solid-state, the inner Sm ion is present in the divalent oxidation state, while the outer ones are trivalent. This observation could be confirmed by quantum chemical calculations. Mechanistic studies revealed not only insight into possible formation pathways of [Sm III/II/III (COT 1,4-SiiPr3 ) 4 ] but also resulted in the transformation to other mixed metal sandwich complexes with unique structural properties. These are the 1D-polymeric chain structured [KSm III (COT 1,4-SiiPr3 )] n and the hexametallic species [(tol)K(COT 1,4-SiiPr3 )Sm II (COT 1,4- SiiPr3)K] 2 which were initially envisioned as possible building blocks as part of different retrosynthetically guided pathways that we developed.

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Solvation of [(CNT)Ln(η8‐COT)] (Ln=La, Ce, Nd, Tb, Er; CNT=cyclononatetraenyl, i.e., C9H9−; COT=cyclooctatetraendiid, i.e., C8H82−) complexes with tetrahydrofuran (THF) gives rise to neutral [(η4‐CNT)Ln(thf)2(η8‐COT)] (Ln=La, Ce) and ionic [Ln(thf)x(η8‐COT)][CNT] (x=4 (Ce, Nd, Tb), 3 (Er)) species in a solid‐to‐solid transformation. Due to the severe distortion of the ligand sphere upon solvation, these species act as switchable luminophores and single‐molecule magnets. The desolvation of the coordinated solvents can be triggered by applying a dynamic vacuum, as well as a temperature gradient stimulus. Raman spectroscopic investigations revealed fast and fully reversible solvation and desolvation processes. Moreover, we also show that a Nd:YAG laser can induce the necessary temperature gradient for a self‐sufficient switching process of the Ce(III) analogue in a spatially resolved manner.

Two similar amidinate samarium catalysts were synthesized in order to investigate the difference between a monometallic and a bimetallic system in the catalytic hydroamination cyclization reaction.

Sandwich complexes of lanthanides have recently attracted a considerable amount of interest due to their applications as Single Molecule Magnet (SMM). Herein, a comprehensive series of heteroleptic lanthanide sandwich complexes ligated by the cyclononatetraenyl (Cnt) and the cyclooctatetraenyl (Cot) ligand [Ln(Cot)(Cnt)] (Ln=Tb, Dy, Er, Ho, Yb, and Lu) is reported. The coordination behavior of the Cnt ligand has been investigated along the series and shows different coordination patterns in the solid‐state depending on the size of the corresponding lanthanide ion without altering its overall anisotropy. Besides the characterization in the solid state by single‐crystal X‐ray diffraction and in solution by 1H NMR, static magnetic studies and ab initio computational studies were performed.