Coordination Behavior of [Cp''2 Zr(η1:1 -P4 )] towards Different Lewis Acids.

A detailed method for the preparation of [Cp''2 Zr(η1:1 -P4 )] (1) is presented. The coordination behavior of 1 towards Lewis acidic transition metal complexes of tungsten, manganese, and iron, respectively, and main group compounds (AlMe3 , AlEt3 ) 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[1.1.0]butane framework were synthesized. All products, as well as the starting materials, were comprehensively characterized by NMR spectroscopy, mass spectrometry, elemental analysis, and single crystal X-ray structural analysis.

Selective dimerization of Lewis-acid/base-stabilized phosphanylalanes.

The reaction of [{(CO)(5)W}PRH(2)] (R = H, Ph) with H(3)Al⋅NR(3) (R = Et, Me) leads to the formation of four-membered heterocyclic compounds [({(CO)(5)W}P(H)AlH⋅NEt(3))(2)] and [({(CO)(5)W}PhPAlH⋅NMe(3))(2)]. Upon dissolving the solid compounds, fast equilibria between the isomers are observed on the NMR timescale. Further insight into the stability and reactivity of the isomers was gained by applying theoretical methods. DFT calculations predict that hydrogen elimination in the case of [({(CO)(5)W}PhPAlH⋅NMe(3))(2)] may be reversible.

Controlled oligomerization of Lewis acid/base-stabilized phosphanylalanes.

PAls should stick together: The cyclo-trimer 2 is obtained by H(2) elimination of Lewis acid/base-stabilized parent compound of the phosphanylalanes 1. The elimination is controlled by fine tuning the temperature and solvent conditions. A subsequent H(2) elimination produces the ladder compound 3. Compounds 2 and 3 are the first of a new class of Group 13/15 compounds which show no additionally donor-acceptor bonds within the framework.

Copper(I) mediated oligomerisation of a phosphaalkyne.

The oligomerisation of tert-butylphosphaalkyne, tBuC[triple bond, length as m-dash]P, mediated by Cu(I) complexes yields an unprecedented C4P5 cage compound, which is stabilised in a matrix of copper(I) iodide.

The surprising and stereoselective formation of P2C10 cages by the reduction of Cp*PCl2.

Reactions of Cp*PCl2 with Group 13 reducing agents result in a cascade of P-C, P-P and C-C bond forming reactions and the stereoselective formation of P2C10 cages.

The stabilization of monomeric parent compounds of phosphanyl- and arsanylboranes.

The structures of the parent compounds of phosphanyl- and arsanylboranes, H(2)BPH(2) and H(2)BAsH(2), were calculated by DFT-B3LYP methods. Such compounds have not previously been obtained preparatively. By applying the concept of Lewis acid/base stabilisation, [(CO)(5)W(H(2)EBH(2).NMe(3))] (E=P (3), As (4)) derivatives have been synthesised by the metathesis reactions between Li[(CO)(5)WEH(2)] and ClH(2)BNMe(3) (E=P, As). Comprehensive thermodynamic studies on these systems verify the high stability of the Lewis acid/base stabilised complexes. Unexpected based on the thermodynamic calculations, UV radiation of the phosphanylborane 3 leads to the dinuclear phosphanido-bridged complex [(CO)(8)W(2)(mu-PHBH(2).NMe(3))(2)] (5) by H(2) and CO elimination.

Complex Chemical Stabilization of Dichlorodiphosphene.

In contrast to the cis configuration of N2 F2 , the analogous phosphorus subhalogenides, P2 X2 (X=F, Cl) adopt a trans configuration according to density functional theory calculations. Now for the first time dichlorodiphosphene has been stabilized in the coordination sphere of transition metals in the form of complex 1.