The crystal structure of R,S-{N-[(2-oxidonaphthalen-1-yl)methylidene] phenylglycinato}divinylsilicon, C 23 H 19 NO 3 Si

C 23 H 19 NO 3 Si, monoclinic, P 2 1 / n (no. 14), a = 8.5543(3) Å, b = 24.0927(8) Å, c = 9.7971(4) Å, β = 113.265(3) ° , V = 1854.96(12) Å 3 , Z = 4, R gt ( F ) = 0.0355, wR ref ( F 2 ) = 0.0932, T = 153 K.

1 Source of materials All experiments were carried out under argon atmosphere using standard Schlenk technique [5].
In a representative experiment were placed 1.14 g [(2-hydroxynaphthalen-1-yl)methylidene]phenylglycine (3.73 mmol) in a Schlenk flask.Dry THF (30 mL) and 0.98 g triethylamine (30 % excess, 9.70 mmol) were added with a syringe.This mixture was stirred for 1 h with a magnetic stirring bar and cooled to 0 °C.Then 0.70 g dichlorodivinylsilane (23 % excess, 4.60 mmol) in 15 mL THF were added dropwise.The mixture was warmed to room temperature and stirred for three days.A white precipitate of triethylammonium chloride formed during this time.The precipitate was filtered off and washed three times with 10 mL THF each.The solvent was distilled off in a vacuum and the residue was solved in 3 mL CDCl 3 .This solution was utilized for recording of NMR spectra.Afterwards n-hexane was added to the solution, which leads to the formation of crystals after storage for 6 weeks.

Comment
Tridentate O,N,O′-chelate ligands based on Schiff bases allow easy access to pentacoordinated silicon complexes [6].Several closely related silicon complexes containing Schiff base ligands derived from naphthyl aldehyde have been published recently [7,8].
The asymmetric unit of the title compound contains one molecule R,S-{N-[(2-oxidonaphthalen-1-yl)methylidene]phe-nylglycinato}divinylsilicon.The molecular structure is shown in figure (50 % displacement ellipsoids).The central silicon atom is pentacoordinated with bonds to phenoxy-O1, carboxy-O2, imine-N1, and the two carbon atoms from the vinyl groups C20 and C22.The coordination geometry of pentacoordinated atoms can be analyzed with the parameter τ according to Addison et al. [9].The largest angle β and the second largest angle α at the central atom are used to calculate τ = (β − α)/60°.The value τ = 0 indicates a perfect square pyramid, while τ = 1 indicates a perfect trigonal bipyramid.The largest angle at the silicon atom is O1-Si1-O2 with 172.94(5)°and second largest N1-Si1-C22 with 124.25(5)°.This gives a parameter τ = 0.81 and indicates the presence of a distorted trigonal bipyramid.The apical positions in this coordination polyhedron are occupied by O1 and O2 of the tridentate ligand, while the atoms N1, C20, and C22 represent the atoms in the trigonal plane.This coordination geometry is very similar to the coordination

Experimental details
The carbon-bound H atoms of the phenyl and the vinyl groups were geometrically placed (C-H = 0.95 Å) and refined as riding atoms with U iso (H) = 1.2 U eq (C).The hydrogen atoms at C11 and C12 were located in a difference Fourier map and were freely refined.

Table  :
Data collection and handling.

Table  :
Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å  ).