Unusual cleavage of phosphaalkynes triple bond in the coordination sphere of transition metals.

The reaction of RCP (R = Me, Bu, iPr) with Co(CO) and Fe(CO) under mild conditions led to unpredictable fragmentations of the CP triple bond and subsequent formation of clusters with a dimeric CoE (E = P and RC) and an FeP(CR) core, respectively.

Coordination Behavior of [Cp″Zr(µ-As)] towards Lewis Acids.

The functionalization of the arsenic transfer reagent [Cp″Zr(η-As)] () focuses on modifying its properties and enabling a broader scope of reactivity. The coordination behavior of towards different Lewis-acidic transition metal complexes and main group compounds is investigated by experimental and computational studies. Depending on the steric requirements of the Lewis acids and the reaction temperature, a variety of new complexes with different coordination modes and coordination numbers could be synthesized.

E Transfer (E=P, As) to Ni Complexes.

The use of [Cp'' Zr(η -E )] (E=P (1 a), As (1 b), Cp''=1,3-di-tert-butyl-cyclopentadienyl) as phosphorus or arsenic source, respectively, gives access to novel stable polypnictogen transition metal complexes at ambient temperatures. The reaction of 1 a/1 b with [Cp NiBr] (Cp =Cp (1,2,3,4,5-pentabenzyl-cyclopentadienyl), Cp''' (1,2,4-tri-tert-butyl-cyclopentadienyl)) was studied, to yield novel complexes depending on steric effects and stoichiometric ratios. Besides the transfer of the complete E unit, a degradation as well as aggregation can be observed.

Transfer Reagent for Bonding Isomers of Iron Complexes.

The cothermolysis of As and [Cp″Zr(CO)] (Cp″ = η-CHtBu) results in the formation of [Cp″Zr(η-As)] (1) in high yields and the arsenic-rich complex [(Cp″Zr)(Cp″Zr)(μ,η-As)] (2) as a minor product. In contrast to yellow arsenic, 1 is a light-stable, weighable and storable arsenic source for subsequent reactions. The transfer reaction of 1 with [Cp‴Fe(μ-Br)] (Cp‴ = η-CHtBu) yields the unprecedented bond isomeric complexes [(Cp‴Fe)(μ,η-As)] (3a) and [(Cp‴Fe)(μ,η-cyclo-As)] (3b).

Coordination Behavior of [Cp'' Zr(η -P )] towards Different Lewis Acids.

A detailed method for the preparation of [Cp'' Zr(η -P )] (1) is presented. The coordination behavior of 1 towards Lewis acidic transition metal complexes of tungsten, manganese, and iron, respectively, and main group compounds (AlMe , AlEt ) was investigated in detail by computational and experimental studies. In doing so, a series of unprecedented complexes with different coordination modes and multiple coordination numbers of the tetraphosphabicyclo[1.

Different Reactivity of As towards Disilenes and Silylenes.

The activation of yellow arsenic is possible with the silylene [PhC(NtBu) SiN(SiMe ) ] (1) and the disilene [(Me Si) N(η -Me C )Si=Si(η -Me C )N(SiMe ) ] (3). The reaction of As with 1 leads to the unprecedented As cage compound [(LSiN(SiMe ) ) As ] (2; L=PhC(NtBu) ) with an As nortricyclane core stabilized by arsasilene moieties containing silicon(II)bis(trimethylsilyl)amide substituents. In contrast, the compound [Cp*{(SiMe ) N}SiAs] (4) containing a butterfly-like diarsadisilabicyclo[1.

Pnictogen-Silicon Analogues of Benzene.

Since the discovery of the first "inorganic benzene" (borazine, B3N3H6), the synthesis of other noncarbon derivatives is an ongoing challenge in Inorganic Chemistry. Here we report on the synthesis of the first pnictogen-silicon congeners of benzene, the triarsa- and the triphospha-trisilabenzene [(PhC(NtBu)2)3Si3E3] (E = P (1a), As (1b)) by a simple metathesis reaction. These compounds are formed by the reaction of [Cp″2Zr(η(1:1)-E4)] (E = P, As; Cp″ = C5H3tBu2) with [PhC(NtBu)2SiCl] in toluene at room temperature along with the silicon pnictogen congeners of the cyclobutadiene, [(PhC(NtBu)2)2Si2E2] (E = P (2a), As (2b)), which is unprecedented for the arsenic system 2b.

A stable cation of a CSi3P five-membered ring with a weakly coordinating chloride anion.

Don't count on counterions: The cyclic five-membered CSi(3)P cation 1 is synthesized in the reaction of benzamidinato-stabilized chlorosilylene and methyl phosphaalkyne. The presence of four π electrons in 1 means it can be considered as a formal, heavier analogue of the cyclopentadienyl cation. Surprisingly the small counteranion (Cl(-)) does not contribute to the ring stability.