Bis(diethylamido-κN)(diethylamine-κN)bis(2,6-diisopropylphenylamido-κN)zirconium(IV)

In the title compound, [Zr(C12H18N)2(C4H10N)2(C4H11N)] or [Zr(HNC6H3 iPr2)2(NEt2)2(HNEt2)], which was obtained by the reaction of Zr(NEt)4 with iPr2C6H3NH2, the ZrIV atom is in a trigonal–bipiramidal geometry in which the N atoms from two iPr2C6H3NH and one NEt2 ligand occupy the equatorial positions, and the N atoms of an NEt2 and an Et2NH ligand occupy the apical positions. An intramolecular N—H⋯N contact occurs. There are two independent molecules in the asymmetric unit.

In the title compound, [Zr(C 12 H 18 N) 2 (C 4 H 10 N) 2 (C 4 H 11 N)] or [Zr(HNC 6 H 3 i Pr 2 ) 2 (NEt 2 ) 2 (HNEt 2 )], which was obtained by the reaction of Zr(NEt) 4 with i Pr 2 C 6 H 3 NH 2 , the Zr IV atom is in a trigonal-bipiramidal geometry in which the N atoms from two i Pr 2 C 6 H 3 NH and one NEt 2 ligand occupy the equatorial positions, and the N atoms of an NEt 2 and an Et 2 NH ligand occupy the apical positions. An intramolecular N-HÁ Á ÁN contact occurs. There are two independent molecules in the asymmetric unit.

Experimental
Crystal data [Zr(C 12  H atoms treated by a mixture of independent and constrained refinement Á max = 1.82 e Å À3 Á min = À2.13 e Å À3 Table 1 Hydrogen-bond geometry (Å , ). (5) 112 (4) actual angles are so close to said values that it is safe to say they resemble trigonal bipyramid.
The crystal packing diagram shows, that the compound crystallizes with two molecules in the unit cell in the triclinic space group. The crystal packing of the title compound is presented in Fig.2.

Experimental
To a 100 ml Schlenk flask, equipped with a magnetic stirrer, charged with a solution of 4,8 g (4,44 ml) Zr(NEt 2 ) 4 in 30 ml of pentane, 5 g (4,76 ml) of 2,6-diisopropylaniline in 10 ml of pentane was added dropwise. The reaction was carried on in a room temperature in an argon atmosphere. Solution was left on a magnetic stirrer. Over a week of stirring, the mixture changed colour from yellow to brown. The solvent was removed under vacuum. After evaporating most of the solvent, dark solid was obtained which after keeping it longer under vacuum got darker and became oil. Residue was dissolved in 8 ml of pentane, and recrystallized at 4°C to obtain about 2 g of colorless X-ray-quality crystals. highest residual electron density peaks are located within 1 Å from atom Zr1 and the deepest hole is located 0.78 Å from Zr1.

Figure 1
The molecular structure of the title molecule with the atom-numbering. Displacement ellipsoids are drawn at the 30% probability level H atoms connected to C have been omitted.  A view of the packing of the title compound alond the a axix.

Special details
Geometry. All e.s.d.'s (except the e.s.d. in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell e.s.d.'s are taken into account individually in the estimation of e.s.d.'s in distances, angles and torsion angles; correlations between e.s.d.'s in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell e.s.d.'s is used for estimating e.s.d.'s involving l.s. planes. Refinement. Refinement of F 2 against ALL reflections. The weighted R-factor wR and goodness of fit S are based on F 2 , conventional R-factors R are based on F, with F set to zero for negative F 2 . The threshold expression of F 2 > σ(F 2 ) is used only for calculating R-factors(gt) etc. and is not relevant to the choice of reflections for refinement. R-factors based on F 2 are statistically about twice as large as those based on F, and R-factors based on ALL data will be even larger.