Bis(N-triisopropylsilylquinolin-8-aminato)nickel(II)

The reddish-brown title complex, [Ni(C18H27N2Si)2], was prepared via the salt-metathesis reaction of N-triisopropylsilyl-8-amidoquinoline lithium with nickelocene (NiCp2). The asymmetric unit contains two symmetry-independent molecules with the Ni atoms in distorted tetrahedral environments.


Experimental
Crystal data [Ni(C 18

S2. Experimental
All manipulations were carried out by using modified Schlenk techniques under an atmosphere of argon. Prior to use, THF and diethyl ether were distilled over sodium/benzophenone. N-Triisopropylsilyl-8-aminochinolin (0.46 g, 1.54 mmol), dissolved at -78°C in 10 ml of THF, was lithiated with 1 mL of a 1,6 M solution of nBuLi in hexane. To this solution 0.15 g of [NiCp 2 ] (1.54 mmol) in 13 ml of THF was added dropwise while a temperature of -78°C was maintained in the reaction flask. The cooling bath was removed and the red-brown reaction mixture stirred for additional 12 h. Thereafter, all volatiles were removed in vacuum and the residue dissolved in 20 ml of diethyl ether. After filtration the volume of the mother liquor was reduced to half of the original volume. At -20°C reddish brown crystals precipitated. Yield: 0.10 g (0.15 mmol, 21%

S3. Refinement
All hydrogen atoms were set to idealized positions and refined with 1.2 times (1.5 for methyl groups) the isotropic displacement parameter of the corresponding carbon atom.

Figure 1
Molecular structure of I. Displacement ellipsoids are drawn at the 40% probability level. H atoms have been omitted for clarity.

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.

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å 2 )
x y z U iso */U eq