Homo- and heterobimetallic transition metal cluster derived from [Cp*Fe(η5-E5)] (E = P, As) - unprecedented structural motifs of the resulting polypnictogen ligands.

A general synthetic procedure to neutral homo- and heterobimetallic cage compounds exhibiting various structural motifs of the polypnictogen ligands starting from [Cp*Fe(η5-E5)] (E = P (1), As (2); Cp* = C5Me5) is reported. The impact of the implemented transition metal precursors {Cp'''M} (M = Cr, Mn, Fe, Ni; Cp''' = 1,2,4-tBu3C5H2) emphasises the variability of the isolated complexes exhibiting a broad variety of structural motifs of the pnictogen ligands. Spectroscopic, crystallographic, and theoretical investigations provide insight into the structure of the partially unprecedented polypnictogen ligands.

Transformation of the cyclo-P5 Middle Deck in [(Cp*Fe)(Cp'''Co)(µ,η5 :η4 -P5 )] upon Functionalization - A Comprehensive Study of Reactivity.

The heterobimetallic triple-decker complex [(Cp*Fe)(Cp'''Co)(µ,η5 : η4 -P5 )] (1) was functionalized by main group nucleophiles and subsequently electrophilically quenched or oxidized. Reacting 1 with group 14 nucleophiles revealed different organo-substituted P5 R middle-decks depending on the steric and electronic effects of the used alkali metal organyls (2: R=tBu; 3: R=Me). Further, with group 15 nucleophiles, the first structural characterized monosubstituted complexes with phosphanides could be obtained as P5 ligands containing exocyclic {PR2 } units (4: R=Cy, H; 5: R=Ph). These monoanionic complexes 2-5 were isolated and subsequent electrophilic quenching revealed novel types of neutral functionalized polyphosphorus complexes. These complexes bear formal chains of P5 R'R'' (6: R'=tBu, R'=Me) in a 1,3-disubstitution pattern or P6 R'R''R''' units (7: R'=Cy, R''=H, R'''=Me; 8: R'=Me, R''=Ph, R'''=Me) in a 1,1,3-substitution as middle-decks stabilized by one {Cp'''Co} and one {Cp*Fe} fragment. One-electron oxidation of 2, 3 or 5 by AgBF4 gave access to paramagnetic triple-decker complexes bearing P5 R middle-decks in various coordination fashions (R=tBu (10), R=PPh2 (12)). Interestingly, for R=Me (11), a dimerization is observed revealing a diamagnetic tetranuclear cluster containing a unique dihydrofulvalene-type P10 R2 ligand. All complexes were characterized by crystallographic and spectroscopic methods (EPR, multinuclear NMR and mass spectrometry) and their electronic structures were elucidated by DFT calculations.

Across the Dimensions: A Three-Component Self-Assembly of Pentaphosphaferrocene-based Coordination Polymers.

Pentaphosphaferrocenes [CpR Fe(η5 -P5 )] (Cp*=η5 -C5 Me5 ) (A), Cp''=η5 -C5 H3 tBu2 -1,3 (B)) are excellent building blocks for polymeric assemblies in supramolecular chemistry in combination with coinage metal salts of weakly coordinating anions such as AgSbF6 . Adding rigid aromatic dinitriles ortho/meta/para-(NC)2 C6 H4 in a one-pot reaction between [CpR Fe(η5 -P5 )] and AgSbF6 leads to various coordination polymers (CPs) by a three-component self-assembly. The sterical demand of the differently substituted cyclopentadiene ligands as well as the rigid constitution of the isomeric dinitriles (NC)2 C6 H4 play a key role in the formation of the isolated CPs. All CPs were characterized by NMR spectroscopy, mass spectrometry, elemental analysis, and single-crystal X-ray diffraction.