N2 Activation in NiI–NN–NiI Units: The Influence of Alkali Metal Cations and CO Reactivity


  • Dedicated to Professor Wolfgang Kaim on the Occasion of His 60th Birthday

  • Supporting information for this article is available on the WWW under http://dx.doi.org/10.1002/zaac.201100140 or from the author.


After single electron reduction of the dinitrogen complex [LtBuNi(μ-η11-N2)NiLtBu] (I) with KC8, reaction of the resulting compound K[LtBuNi(μ-η11-N2)NiLtBu] (II) with sodium sand yields KNa[LtBuNi(μ-η11-N2)NiLtBu] (1), which contains two different alkali metal ions. Treatment of I with two equivalents of sodium sand leads to the symmetric complex Na2[LtBuNi(μ-η11-N2)NiLtBu] (2). Complexes 1 and 2 were investigated by single crystal X-ray diffraction analysis as well as by Raman spectroscopy, and the results were compared with the data of K2[LtBuNi(μ-η11-N2)NiLtBu] (III), which contains two K+ ions. Thus, it became obvious that the nature of the alkali metal ion M in compounds M2[LtBuNi(μ-η11-N2)NiLtBu] has hardly any influence on the degree of NN bond activation. Furthermore, it was shown that treatment of the dinickel(I) complex III with CO leads to the dinickel(0) compound K2[LtBuNi(CO)]2 (4) and N2. Reaction of the unreduced dinickel(I) complex I with CO leads to a more simple replacement of the N2 ligand and formation of [LtBuNi(CO)] (3).