{2,6-Bis[(di-tert-butylphosphino)methyl]phenyl}chloridonickel(II)

In the title compound, [Ni(C24H43P2)Cl], the Ni atom adopts a distorted square-planar geometry, with the P atoms of the 2,6-bis[(di-tert-butylphosphino)methyl]phenyl ligand trans to one another. The P—Ni—P plane is twisted out of the plane of the aromatic ring by 21.97 (6)°.


S1. Comment
The title compound, (I), was originally prepared by Moulton & Shaw (1976) but its crystal structure was not determined at that time. We have prepared (I) as part of our studies of PCP 'pincer′ complexes of divalent late transition metals, which show promise as catalysts for the epoxidation of olefins (Denney et al., 2006;Keith et al., 2006).

S2. Experimental
A solution of nickel chloride hexahydrate (0.6 g, 2.5 mmol) dissolved in 2 ml of degassed water was added to a solution of 2,6-bis-[(di-tert-butylphosphino)methyl]benzene (1.02 g, 2.6 mmol) in 10 ml ethanol. The solution was heated to reflux. A golden-yellow precipitate began to form only after 0.5 h. The solution was stirred under gentle reflux overnight.
After cooling, the product was collected by filtration and washed with cold ethanol. It was recrystallized from a concentrated solution of pentane at 238 K.

S3. Refinement
Hydrogen atoms were included at geometrically idealized positions with C-H distances 0.94, 0.97 and 0.98 Å, for aryl, methyl and methylene H-atoms in a riding mode on the respective heavy atoms. The isotropic displacement parameters for the hydrogen atoms were fixed at 1.5 and 1.2 times U eq of the parent methyl and non-methyl C-atoms. An absolute structure was determined (Flack, 1983) employing 4507 Friedel pairs of reflections which were not merged.

Figure 1
View of the title compound showing numbering scheme. Ellipsoids are shown at 50% probability and hydrogen atoms have been removed for clarity.

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