A lens-shaped supramolecule based on the bulky pentaphosphaferrocene [CpBIGFe(η5-P5)] and CuBr2.

Besides inherent fullerene-like hollow spheres, the metallasupramolecular chemistry of pentaphosphaferrocenes and CuBr2 afforded a conceptually new product, a compact 3.2 nm sized supramolecule [{1d}6(CuBr)32(CH3CN)6] formed by six largest pentaphosphaferrocene units [CpBIGFe(η5-P5)] (1d: CpBIG = η5-C5(4-nBuC6H4)5) so far and a framework of 32 copper and 32 bromide ions.

Metal-Assisted Opening of Intact P4 Tetrahedra.

The reactivity of ruthenium and manganese complexes bearing intact white phosphorus in the coordination sphere was investigated towards the low-valent transition-metal species [Cp'''Co] (Cp'''=η5 -C5 H2 -1,2,4-tBu3 ) and [L0 M] (L0 =CH[CHN(2,6-Me2 C6 H3 )]2 ; M=Fe, Co). Remarkably, and irrespective of the metal species, the reaction proceeds by the selective cleavage of two P-P edges and the formation of a square-planar cyclo-P4 ligand. The reaction products [{CpRu(PPh3 )2 }{CoCp'''}(µ,η1:4 -P4 )][CF3 SO3 ] (5), [{CpBIG Mn(CO)2 }2 {CoCp'''}(µ,η1:1:4 -P4 )] (6) and [{CpBIG Mn(CO)2 }2 {ML0 }(µ,η1:1:4 -P4 )] (CpBIG =C5 (C6 H4 nBu)5 ; L0 =CH[CHN(2,6-Me2 C6 H3 )]2 ; M=Fe (7 a), Co (7 b)), respectively, were fully characterized by single-crystal X-ray diffraction and spectroscopic methods. The electronic structure of the cyclo-P4 ligand in the complexes 5-7 is best described as a π-delocalized P4 2- system, which is further stabilized by two and three metal moieties, respectively. DFT calculations envisaged a potential intermediate in the reaction to form 5, in which a quasi-butterfly-shaped P4 moiety bridges the two metals and behaves as an η3 -coordinated ligand towards the cobalt center.

Rearrangement of a P4 Butterfly Complex-The Formation of a Homoleptic Phosphorus-Iron Sandwich Complex.

The versatile coordination behavior of the P4 butterfly complex [{Cp'''Fe(CO)2 }2 (µ,η1:1 -P4 )] (1, Cp'''=η5 -C5 H2t Bu3 ) towards different iron(II) compounds is presented. The reaction of 1 with [FeBr2 ⋅dme] (dme=dimethoxyethane) leads to the chelate complex [{Cp'''Fe(CO)2 }2 (µ3 ,η1:1:2 -P4 ){FeBr2 }] (2), whereas, in the reaction with [Fe(CH3 CN)6 ][PF6 ]2 , an unprecedented rearrangement of the P4 butterfly structural motif leads to the cyclo-P4 moiety in {(Cp'''Fe(CO)2 )2 (µ3 ,η1:1:4 -P4 )}2 Fe][PF6 ]2 (3). Complex 3 represents the first fully characterized "carbon-free" sandwich complex containing cyclo-P4 R2 ligands in a homoleptic-like iron-phosphorus-containing molecule. Alternatively, 2 can be transformed into 3 by halogen abstraction and subsequent coordination of 1. The additional isolated side products, [{Cp'''Fe(CO)2 }2 (µ3 ,η1:1:2 -P4 ){Cp'''Fe(CO)}][PF6 ] (4) and [{Cp'''Fe(CO)2 }2 (µ3 ,η1:1:4 -P4 ){Cp'''Fe}][PF6 ] (5), give insight into the stepwise activation of the P4 butterfly moiety in 1.

CpPEt2 As4 -An Organic-Substituted As4 Butterfly Compound.

CpPEt2 As4 (CpPEt =C5 (4-EtC6 H4 )5 ) (1) is synthesized by the reaction of CpPEt. radicals with yellow arsenic (As4 ). In solution an equilibrium of the starting materials and the product is found. However, 1 can be isolated and stored in the solid state without decomposition. As4 can be easily released from 1 under thermal or photochemical conditions. From powder samples of CpPEt2 As4 , yellow arsenic can be sublimed under rather mild conditions (T=125 °C). A similar behavior for the P4 -releasing agent was determined for the related phosphorus compound CpBIG2 P4 (2; CpBIG =C5 (4-nBuC6 H4 )5 ). DFT calculations show the importance of dispersion forces for the stability of the products.

Synthesis and characterization of manganese triple-decker complexes.

The use of the highly sterically demanding Cp(BIG) ligand (Cp(BIG) = C5(4-nBuC6H4)5) and white phosphorus (P4) enables the synthesis of new P-rich derivatives of the rare Pn ligand complexes of manganese. The obtained complexes, [{Cp(BIG)Mn}2(µ,η(5:5)-P5)] (2) and [{Cp(BIG)Mn}2(µ,η(2:2)-P2)2] (3), exhibit the highest number of P atoms in this class of manganese compounds identified by X-ray structure analyses. The EPR spectrum of the 29 VE triple-decker complex 2 shows one unpaired electron coupling with two 5/2 spin Mn nuclei.

E4 Butterfly Complexes (E=P, As) as Chelating Ligands.

The coordination properties of new types of bidentate phosphane and arsane ligands with a narrow bite angle are reported. The reactions of [{Cp'''Fe(CO)2 }2 (µ,η(1:1) -P4 )] (1 a) with the copper salt [Cu(CH3 CN)4 ][BF4 ] leads, depending on the stoichiometry, to the formation of the spiro compound [{{Cp'''Fe(CO)2 }2 (µ3 ,η(1:1:1:1) -P4 )}2 Cu](+) [BF4 ](-) (2) or the monoadduct [{Cp'''Fe(CO)2 }2 (µ3 ,η(1:1:2) -P4 ){Cu(MeCN)}](+) [BF4 ](-) (3). Similarly, the arsane ligand [{Cp'''Fe(CO)2 }2 (µ,η(1:1) -As4 )] (1 b) reacts with [Cu(CH3 CN)4 ][BF4 ] to give [{{Cp'''Fe(CO)2 }2 (µ3 ,η(1:1:1:1) -As4 )}2 Cu](+) [BF4 ](-) (5). Protonation of 1 a occurs at the "wing tip" phosphorus atoms, which is in line with the results of DFT calculations. The compounds are characterized by spectroscopic methods (heteronuclear NMR spectroscopy and IR spectrometry) and by single-crystal X-ray diffraction studies.

Giant Spherical Cluster with I-C140 Fullerene Topology.

We report on an effective cluster expansion of CuBr-linked aggregates by the increase of the steric bulk of the Cp(R) ligand in the pentatopic molecules [Cp(R)Fe(η(5)-P5)]. Using [Cp(BIG)Fe(η(5)-P5)] (Cp(BIG)=C5(4-nBuC6H4)5), the novel multishell aggregate [{Cp(BIG)Fe(η(5:2:1:1:1:1:1)-P5)}12(CuBr)92] is obtained. It shows topological analogy to the theoretically predicted I-C140 fullerene molecule. The spherical cluster was comprehensively characterized by various methods in solution and in the solid state.

The synthesis of the heterocubane cluster [{CpMn}4(µ3-P)4] as a tetrahedral shaped starting material for the formation of polymeric coordination compounds.

Thermolysis of [CpMn(η(6)-cht)] with P4 in 1,3-diisopropylbenzene leads to the formation of the heterocubane [Cp4Mn4P4] () in high yields, as a rare example of 'naked' phosphorus containing complexes of manganese. Compound is characterized and studied by DFT calculations and reflection measurements. 1D coordination polymers [{(CpMn)4(µ3-P)4}(CuX)]n (2-Cl: X = Cl; 2-Br: X = Br) are obtained in the reaction with CuX. Furthermore, it is shown that all four P atoms in can be addressed for a coordination towards cymantrene resulting in [{(CpMn)4(µ3-P)4}{CpMn(CO)2}n] (: n = 1; : n = 2; : n = 3; : n = 4), and shows that is a tetra-topic building block in coordination chemistry.

Selective functionalization of P4 by metal-mediated C-P bond formation.

A new and selective one-step synthesis was developed for the first activation stage of white phosphorus by organic radicals. The reactions of NaCp(R) with P4 in the presence of CuX or FeBr3 leads to the clean formation of organic substituted P4 butterfly compounds Cp(R)2P4 (Cp(R): Cp(BIG)=C5(4-nBuC6H4)5 (1 a), Cp'''=C5H2tBu3 (1 b), Cp*=C5Me5 (1 c) und Cp(4iPr)=C5HiPr4 (1 d)). The reaction proceeds via the activation of P4 by Cp(R) radicals mediated by transition metals. The newly formed organic derivatives of P4 have been comprehensively characterized by NMR spectroscopy and X-ray crystallography.