Cycloheptatrienyl-Bridged Triple-Decker Complexes.

The first structurally characterized organometallic multidecker sandwich complexes featuring a cycloheptatrienyl ring (Cht, CH) in the coordination sphere are presented. The synthesis of inverse sandwich complexes of the rare earth elements Y and Er with a bridging cycloheptatrienyl ligand of the type [(thf)(BH)Ln(μ-η:η-Cht)Ln(BH)(thf)] is described first. The subsequent introduction of the Cot ligand (Cot = 1,4-(PrSi)CH) into the coordination sphere of the rare earth cations resulted in the isolation of unprecedented triple-decker compounds with the formula [(thf)K{(η-Cot)Ln}(μ-η:η-Cht)], bearing a seven-membered aromatic carbon ring as a middle deck.

Unique Double and Triple Decker Arrangements of Rare-Earth 9,10-Diborataanthracene Complexes Featuring Single-Molecule Magnet Characteristics.

Herein, we present the first report on the synthesis of rare-earth complexes featuring a 9,10-diborataanthracene ligand. This 14-π-electron ligand is highly reductive and was previously used in small-molecule activation. Salt elimination reactions between dipotassium 9,10-diethyl-9,10-diborataanthracene [K(DEDBA)] and [Ln(η-Cot)(BH)(thf)] (Cot=1,4-(PrSi)CH) in a 1 : 1 ratio yielded heteroleptic sandwich complexes [K(η-Cot)Ln(η-DEDBA)] (Ln=Y, Dy, Er).

It's not just the size that matters: crystal engineering of lanthanide-based coordination polymers.

Synthesis and characterization of Lewis base free coordination polymers of selected lanthanides are presented. For this purpose, the substituted Cot ligand (Cot = 1,4-bis-triisopropylsilyl-cyclo-octatetraendiide) was used to synthesize homoleptic, anionic multidecker compounds of the type [K{Ln(ɳ-Cot)}]. Depending on the solvent used for crystallization and the ionic radii of the lanthanide cations, three different categories of one-dimensional heterobimetallic coordination polymers were obtained in the solid state.

Bi- and tridentate coordination behaviour of a novel bis(phosphinimino)methanide ligand.

Herein, we report the synthesis of a novel ferrocenyl-functionalized bis(phosphinimino)methane ligand (CH (PPh NFc) ). Deprotonation of CH (PPh NFc) with KN(SiMe ) gave the dimeric species [K{CH(PPh NFc) }] , which was further reacted with ECl (E=Ge, Sn) to yield the tetrylene compounds [{CH(PPh NFc) }ECl]. The ligand and the resulting tetrylenes were examined for their electrochemical properties with the aid of cyclic voltammetry.

Synthesis and properties of cyclic sandwich compounds.

Cyclic nanometre-scale sandwich complexes assembled from individual building blocks were synthesized. Sandwich complexes, in which a metal ion is π-coordinated by two planar aromatic organic rings belong to the foundations of organometallic chemistry. They have been successfully used in a wide variety of applications ranging from catalysis, synthesis and electrochemistry to nanotechnology, materials science and medicine.

Mono-cyclononatetraenyl lanthanide complexes.

The synthesis of the first half-sandwich complexes based on the cyclononatetraenyl (Cnt = CH) ligand ([Ln(-Cnt)(-BH)(thf)] (Ln = La, Ce)) is reported. The title compounds were obtained from the reaction of [Ln(BH)(thf)] and [K(Cnt)]. Further solvation of [Ln(-Cnt)(-BH)(thf)] with tetrahydrofuran (THF) resulted in a reversible decoordination of the Cnt ring and the formation of the ionic species [Ln(-BH)(thf)][Cnt].

Molecular -P complexes of the rare-earth elements a one-pot reaction and selective reduction.

Synthesis of new organo-lanthanide polyphosphides with an aromatic -[P] moiety and a -[P] moiety is presented. For this purpose, the divalent Ln-complexes [(NON)Ln(thf)] (Ln = Sm, Yb) ((NON) = 4,5-bis(2,6-diisopropylphenyl-amino)-2,7-di--butyl-9,9-dimethylxanthene) and trivalent Ln-complexes [(NON)LnBH(thf)] (Ln = Y, Sm, Dy) were used as precursors in the reduction process of white phosphorus. While using [(NON)Ln(thf)] as a one-electron reducing agent the formation of organo-lanthanide polyphosphides with a -[P] Zintl anion was observed.

Silole and germole complexes of lanthanum and cerium.

Using dianionic metallole ligands (silole or germole) and the cyclooctatetraendiide dianion, heteroleptic lanthanide multi-decker complexes have been prepared. Due to the heteroatom of the metallole ligands intermolecular bridging between the sandwich complexes takes place. Our work highlights that different combinations of the lanthanide and heterocycle lead to different intermolecular interactions including a dimeric La-silole sandwich complex, a La-germole ladder-type polymeric species and a Ce-germole coordination polymer.

From a nanoparticular solid-state material to molecular organo-f-element-polyarsenides.

A convenient pathway to new molecular organo-lanthanide-polyarsenides in general and to a f-element complex with the largest polyarsenide ligand in detail is reported. For this purpose, the activation of the solid state material As (nanoscale gray arsenic) by the multi electron reducing agents [K(18-crown-6)][(Ln)(μ-η:η-CH)] (Ln = La, Ce, Cp'' = 1,3-bis(trimethylsilyl)cyclopentadienyl anion) and [K(18-crown-6)][(Ln)(μ-η:η-CH)] (Ln = Ce, Nd) is shown. These non-classical divalent lanthanide compounds were used as three and four electron reducing agents where the product formation can be directed by variation of the applied reactant.

Introduction of plumbole to f-element chemistry.

Herein, we present the synthesis and characterization of heteroleptic lanthanide complexes bearing a dianionic η-plumbole ligand in their coordination sphere. The reaction proceeds a salt elimination reaction between the dilithioplumbole ([Li(thf)][1,4-bis--butyl-dimethylsilyl-2,3-bis-phenyl-plumbolyl] = [Li(thf)(η-L)]) and specifically designed [Ln(η-COT)BH] precursors (Ln = lanthanide, La, Ce, Sm, Er; COT = 1,4-bis-triisopropylsilyl-cyclooctatetraenyl), that are capable of stabilizing a planar plumbole moiety in the coordination sphere of different trivalent lanthanide ions. In-depth calculations show that the aromaticity of the dianionic plumbole is retained upon coordination.

The Archetypal Homoleptic Lanthanide Quadruple-Decker-Synthesis, Mechanistic Studies, and Quantum Chemical Investigations.

Reduction of [Sm (COT )(BH )(thf)] (COT =1,4-( Pr Si) C H ) with KC resulted in [Sm (COT ) ], 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.

Reactivity of mono- and divalent aluminium compounds towards group 15 nanoparticles.

Herein, we present a novel approach towards organometallic group 13/15-compounds, i.e. the reaction of nanoparticular arsenic and antimony with low-valent aluminium species.

Efficient Extraction from Mice Feces for NMR Metabolomics Measurements with Special Emphasis on SCFAs.

Nuclear magnetic resonance (NMR) spectroscopy is one of the most promising methods for use in metabolomics studies as it is able to perform non targeted measurement of metabolites in a quantitative and non-destructive way. Sample preparation of liquid samples like urine or blood serum is comparatively easy in NMR metabolomics, because mainly buffer and chemical shift reference substance are added. For solid samples like feces suitable extraction protocols need to be defined as initial step, where the exact protocol depends on sample type and features.