A solution and solid state study of niobium complexes University of ...

Chapter 4
Figure 4.5: Packing of [NbCl(acac-κ 2 -O,O’)(OMe)3] along the a-axis.
Molecular packing within the unit cell (Figure 4.5) shows a “head-to-head”
arrangement of [NbCl(acac-κ 2 -O,O’)(OMe)3] complexes along the a-axis. No π-
stacking is observed.
The largest differential peak was 1.108 e.Å -3 , 0.72 Å from H4B and the deepest hole
-0.803 e.Å -3 , 0.89 Å from Nb1.
4.4 Crystal structure of [Nb(acac-κ 2 -O,O’)(OEt)2(µ 2 -O)]4.
4.4.1 Introduction
Colourless crystals of [Nb(acac-κ 2 -O,O’)(OEt)2(µ 2 -O)]4 were obtained as described in
Section 3.7.2.2. The complex crystallized in the monoclinic space group P21/c with
two independent molecules in the unit cell. The asymmetric unit of the title
tetranuclear niobium(V) complex contains two Nb(V) atoms, two bridging O atoms,
two acetylacetonate and four ethanolate ligands (Figure 4.6). The rest of the
tetranuclear unit is generated through an inversion centre. Each Nb(V) atom is six-
coordinated by the bridging O atoms, two ethanolate and one chelating
acetylacetonate ligands. 17
17 L. Herbst, H. G. Visser, A. Roodt, T. J. Muller, Acta Cryst., E67, m1669, 2011.
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