Crystal structure of the η4-ketimine titanium complex (diphenylamido-κN){3-methyl-6-[(4-methylphenyl)(phenylazanidyl)methylidene]cyclohexa-2,4-dien-1-yl-κ2 N,C 1}(η5-pentamethylcyclopentadienyl)titanium(IV)

The molecular structure of the titanium(IV) half-sandwich title complex comprises one pentamethylcyclopentadienyl ligand, one diphenylamido ligand and one η4-bound ketimine ligand, leading to a three-legged piano-stool geometry.


Supramolecular features
There are no significant supramolecular features in the crystal structure of 1. The crystal packing, shown in Fig. 2, appears to be dominated by van der Waals interactions only.

Synthesis and crystallization
All operations were carried out under a dry nitrogen atmosphere using Schlenk techniques or in a glove box. The 4ketimine complex [( 5 -Cp*)Ti( 4 -C 21 H 19 N)(Cl)] and lithium diphenyl amide were prepared according to published procedures (Fischer et al., 2017;Hatakeyama et al., 2012). Solvents were dried according to standard procedures over Na/K alloy with benzophenone as indicator and distilled under a nitrogen atmosphere.
[( 5 -Cp*)Ti( 4 -C 21 H 19 N)(Cl)] (0.500 g, 0.992 mmol) and lithium diphenyl amide (0.174 g, 0.992 mmol) were dissolved in 12 ml of tetrahydrofuran. After stirring the reaction mixture for 16 h at room temperature, the solvent was evaporated in a vacuum. The residue was dissolved in 12 ml of toluene, filtered, and the precipitate of LiCl was washed with toluene (2 Â10 ml). The combined filtrates were evaporated in a vacuum and the residue was recrystallized from n-hexane to yield complex 1 as dark-red prisms in 15% crystalline yield.

Refinement
Crystal data, data collection and structure refinement details are summarized in Table 1. Hydrogen atoms bonded to carbon atoms, with the exception of H30 bonded to the ortho-carbon atom that is bonded to titanium, were located from difference-Fourier maps but were subsequently fixed in idealized positions using appropriate riding models. Atom H30 was refined freely. The absolute structure was determined (   Data collection: APEX2 (Bruker, 2015); cell refinement: SAINT (Bruker, 2015); data reduction: SAINT (Bruker, 2015); program(s) used to solve structure: SHELXT (Sheldrick, 2015a); program(s) used to refine structure: SHELXL2014 (Sheldrick, 2015b); molecular graphics: DIAMOND (Brandenburg & Putz, 2006); software used to prepare material for publication: publCIF (Westrip, 2010).

Special details
Geometry. All esds (except the esd in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell esds are taken into account individually in the estimation of esds in distances, angles and torsion angles; correlations between esds in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell esds is used for estimating esds involving l.s. planes.

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