Two modifications of a five-coordinate silicon complex

TBPY-5-34-(Butane-1,4-di­yl)(2-{[1-(2-oxidophen­yl)ethyl­idene-κO]amino-κN}ethano­lato-κO)silicon, C₁₄H₁₉NO₂Si, crystallizes in two modifications. The monoclinic form, (IIm), was obtained by crystallization over a period of 2 d at room temperature; the ortho­rhom­bic form, (IIo), crystallized overnight at 248 K. The main difference between the two mol­ecular structures involves the angles in the equatorial plane of the trigonal bipyramid around silicon. Form (IIm) has an O—Si—O angle of ca 121° and O—Si—C angles of ca 121 and 116°. In form (IIo), the corresponding angles are ∼123, 124 and 111°. There are also significant differences in the packing: (IIm) shows π stacking, whereas (IIo) does not.

S1. Comment

Silicon complexes with tridentate Schiff base ligands and O,N,O'-coordination mode are known, having been prepared by various groups (Prasad & Tandon, 1973; Abe et al., 1986; Singh & Singh, 1987; Koacher et al. 1980). A number of applications of these complexes have been proposed and described. Investigations have focused on photovoltaic applications (Nagao et al., 2004), colouring materials (Nagao et al., 2002; Misono et al., 1985, 1987), antimicrobial activity (Nath & Goyal, 2002), and use as electrophotographic toner (Yamanaka & Sugawara, 1991). The existence of polymorphs is of importance for many applications that depend on the solid-state properties of a given compound (Bernstein, 2003; Hilfiker, 2006). We communicate here the dimorphic solid-state structures of the title compound, (II).

The reaction of 2-aminoethanol with o-hydroxyacetophenone gives facile access to a Schiff base ligand (I) with O,N,O'-coordination ability. The reaction of this ligand with 1,1-dichlorosilacyclopentane in the presence of triethylamine yields the desired silicon complex (II), which was characterized by NMR spectroscopy. The ²⁹Si NMR chemical shift at −53.15 p.p.m. indicates the formation of a pentacoordinate silicon complex. A saturated solution of the reaction product was left standing for two days at room temperature. During this time, large clear colourless hexagonal prisms were formed from the pale-yellow solution. Investigation of several crystals from this crystallization batch showed the formation of monoclinic crystals, space group P2₁/c, which are denoted here as (IIm). Fig. 1 shows the molecular structure of (IIm) and the atomic labelling scheme. Selected bond lengths and angles are listed in Table 1.

The remaining solution was separated from this first batch and left overnight at 248 K in a freezer. Another crystalline fraction was formed, consisting of small colourless prisms with a rectangular shape. Investigation of the cell constants of several crystals from this crystallization batch showed – surprisingly – the exclusive formation of orthorhombic crystals, denoted (IIo). The orthorhombic dimorph crystallizes in the chiral space group P2₁2₁2₁. Fig. 2 shows the molecular structure of (IIo) and the atomic labelling scheme. Selected bond lengths and angles are listed in Table 3.

Because of the unusual crystallization behaviour, the crystallization experiments were repeated and were shown to be reproducible. Furthermore, mixtures of (IIm) and (IIo) are obtained by crystallization at 278 K. One dimorph can be transformed into the other by complete dissolution of the crystals in n-hexane and 1,2-dimethoxyethane, followed by choosing the crystallization conditions. Analysis of (IIo) with differential thermal analysis and thermogravimetry (DTA/TG) shows that there is a weakly endothermic effect at 349 K. Cooling of the sample to room temperature and repeated heating shows that this endothermic effect no longer occurs. This hints at a transformation point at 349 K from the orthorhombic to the monoclinic form. The DTA sample melts after repeated heating at 387 K. Investigation of a sample of (IIo) with powder diffraction shows the presence of orthorhombic and monoclinic phases in the finely ground substance. Therefore, we assume that the sample of (IIo) is contaminated by small amounts of (IIm). Heating of this sample to 363 K shows that a complete transformation into the monoclinic phase takes place. It therefore seems that (IIm) is the thermodynamically stable modification and (IIo) is a kinetically formed modification. Usually the thermodynamically more stable product has the greater density (Bernstein, 2003). Exceptions to this rule have been discussed in the literature (Burger & Ramberger, 1979). In the present case, the less stable orthorhombic form has the greater density.

The two molecular structures have common features. The Si atom is bound to the cyclopentane ring and to atoms O1, N1 and O2 of the chelate ligand. The coordination geometry is trigonal–bipyramidal, as seen from the bond angles. Atoms N1 and C11 occupy the apical positions, with a C11—Si1—N1 bond angle of 177.51 (5)° for (IIm) and 178.35 (6)° for (IIo); atoms O1, O2 and C14 are situated in the equatorial plane. The chelate ligand coordinates in a capping fashion, with the two terminal O atoms in equatorial positions and the central N atom in an apical position. The Si—O bonds are rather short, at 1.676 (1) to 1.712 (1) Å. The coordinative bond Si1—N1 is substantially longer; 2.067 (1) and 2.055 (1) Å. The Si—O bond to the phenolate atom O2 is somewhat longer than that to the aliphatic atom O1. This can be explained by postulating a stronger C—O bond from the phenoxy group and was also observed in related silicon and titanium complexes (Böhme & Günther, 2006, 2007). The Si1—C11 bond is longer than Si1—C14, consistent with the different positions of these two C atoms in the coordination polyhedron. The main differences between the molecular structures are found in the bond angles in the equatorial plane. Form (IIm) has O1—Si1—O2 and O1—Si1—C14 bond angles of ca 121°, and a O2—Si1—C14 bond angle of 115.72 (5)°. In (IIo), the first two angles are expanded to ca 123°, and the latter is compressed to only 111.44 (6)°. These differences are illustrated by a least-squares fit of the two molecules (Fig. 3). The fit of atoms Si1, O1, O2, N1 and C1–C11 has an r.m.s deviation of 0.0921 Å. The plot clearly shows the differing orientations of the five-membered ring.

Furthermore, the two structures are different with respect to the conformation of the silacyclopentane ring. The plane of the envelope is formed by atoms C11, Si1, C14 and C13 [the r.m.s. deviation of fitted atoms is 0.026 Å for (IIo) and 0.053 Å for (IIm)]. Atom C12 lies out of this plane by 0.669 (2) Å in (IIo) and 0.609 (2) Å in (IIm). This means that the envelope of the silacyclopentane ring is more folded in (IIo).

The polymorphs necessarily show major differences in molecular packing; whereas form (IIm) is a racemate, only one enantiomer is present in the packing structure of (IIo). The main characteristic of the (IIm) packing is the stacking of the substituted phenyl rings (Fig. 4). These rings form pairs with a distance of 3.430 Å (normal between the least-squares planes; symmetry code: −x + 1, −y + 1, −z + 1). Between successive pairs is a distance of 4.076 Å (normal between least-squares planes; symmetry operator 2 − x,1 − y,1 − z). Besides these contacts there are also two weak hydrogen bonds (see Table 2). The packing of form (IIo) (Fig. 5) shows two weak intermolecular hydrogen bonds, one of which, C7—H7···O1(-x + 3/2, −y + 1, z − 1/2), is essentially linear (Table 4).

Related literature

For related literature, see: Abe et al. (1986); Böhme & Günther (2006, 2007); Bernstein (2003); Burger & Ramberger (1979); Hilfiker (2006); Koacher et al. (1980); Misono et al. (1985, 1987); Nagao et al. (2002, 2004); Nath & Goyal (2002); Prasad & Tandon (1973); Singh & Singh (1987); Yamanaka & Sugawara (1991).

S2. Experimental

o-Hydroxyacetophenone-N-(2-hydroxyethyl)imine, (I), was prepared by reaction of o-hydroxyacetophenone (10.89 g, 0.08 mol) with 2-aminoethanol (4.76 g, 0.078 mol) in absolute ethanol (150 ml). The mixture was refluxed for 2 h and cooled to room temperature, and the volume of the solvent was reduced with a rotary evaporator to about 50 ml. The remaining solid was filtered off, washed twice with small portions of diethyl ether and dried in air overnight [yellow crystals, yield 14.44 g (100%), m.p. 366 K].

The preparation of (II) was performed in Schlenk tubes under Argon with dry and air-free solvents. Compound (II) was prepared by reaction of triethylamine (5.1 ml, 3.72 g, 36.8 mmol) and 1,1-dichlorosilacyclopentane (2.59 g, 16.7 mmol) with (I) (3.0 g, 16.7 mmol) in dry tetrahydrofuran at 273 K. A white precipitate of triethylamine hydrochloride formed immediately upon addition of (I). The reaction mixture was warmed to room temperature and stirred for one week. The triethylamine hydrochloride was filtered off and washed with tetrahydrofuran. The solvent was removed in vacuo from the resulting clear yellow solution. The remaining solid was extracted with n-hexane and a small amount of 1,2-dimethoxyethane. Filtration of this solution gave the solid product for NMR investigations and a suitable solution for growing single crystals. Analysis calcualted for C₁₄H₁₉NO₂Si: C 64.33, H 7.33, N 5.36%; found: C 64.57, H 7.26, N 5.54%. ¹H NMR (CDCl₃): δ 0.26–0.33 (m, 4H, CH₂—Si), 1.32–1.42 (m, 4H, CH₂), 2.41 (s, 3H, CH₃), 3.79–3.89 (m, 4H, CH₂—N, CH₂—O), 6.97–7.03 (m, 2H, ar), 7.37–7.55 (m, 2H, ar). ¹³C NMR (CDCl₃): δ 14.02 (CH₂—Si), 17.11 (CH₃), 25.28 (CH₂), 48.28 (CH₂—N), 59.20 (CH₂—O), 119.97, 121.91, 122.46, 127.98, 133.72 (ar), 158.57 (C═N), 165.76 (ar, C—O). ²⁹Si NMR (CDCl₃): δ −52.99.

S3. Refinement

Please check H-atom treatment; data in CIF appear to conflict with original claim that H-atom positional parameters were refined.]

Computing details

For both compounds, data collection: SMART (Bruker, 2004); cell refinement: SAINT (Bruker, 2004); data reduction: SAINT (Bruker, 2004); program(s) used to solve structure: SHELXS97 (Sheldrick, 1997); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: ORTEP-3 (Farrugia, 1997); software used to prepare material for publication: SHELXL97 (Sheldrick, 1997).

Figures

	Fig. 1. The molecular structure of (IIm), drawn with 50% probability displacement ellipsoids. (Atom coordinates were inverted to facilitate comparison of the two forms.)
	Fig. 2. The molecular structure of (IIo), drawn with 50% probability displacement ellipsoids.
	Fig. 3. A least-squares fit of the two structures. The solid line is for (IIo), the broken line for (IIm). Fitted atoms are labelled.
	Fig. 4. The packing of (IIm), showing the stacking of the molecules parallel to the a axis and hydrogen bonds as dashed lines. Displacement ellipsoids are drawn with 50% probability. H atoms that do not participate in the hydrogen bonds have been omitted for clarity.
	Fig. 5. The packing of (IIo), viewed parallel to the b axis, showing hydrogen bonds as dashed lines. Displacement ellipsoids are drawn with 50% probability. H atoms that do not participate in the hydrogen bonds have been omitted for clarity.

(IIm) (Ethane-1,2-diyl)(2-{[1-(2-oxidophenyl)ethylidene-κO]amino-κN}ethanolato-κO)silicon

Crystal data

C14H19NO2Si	F(000) = 560
Mr = 261.39	Dx = 1.314 Mg m^−3
Monoclinic, P21/c	Melting point: 383 K
Hall symbol: -P 2ybc	Mo Kα radiation, λ = 0.71073 Å
a = 8.2780 (17) Å	Cell parameters from 5780 reflections
b = 10.694 (2) Å	θ = 2.4–35.8°
c = 15.155 (3) Å	µ = 0.17 mm^−1
β = 99.86 (3)°	T = 93 K
V = 1321.8 (5) Å^3	Piece, colourless-yellow
Z = 4	0.60 × 0.40 × 0.33 mm

Data collection

Bruker SMART CCD area-detector diffractometer	3522 independent reflections
Radiation source: sealed tube	3115 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.029
phi and ω scans	θmax = 29.0°, θmin = 2.3°
Absorption correction: multi-scan (SADABS; Sheldrick, 1996)	h = −11→11
Tmin = 0.90, Tmax = 0.95	k = −14→14
25940 measured reflections	l = −20→20

Refinement

Refinement on F^2	Primary atom site location: structure-invariant direct methods
Least-squares matrix: full	Secondary atom site location: difference Fourier map
R[F^2 > 2σ(F^2)] = 0.035	Hydrogen site location: inferred from neighbouring sites
wR(F^2) = 0.102	H-atom parameters constrained
S = 1.07	w = 1/[σ^2(Fo^2) + (0.0556P)^2 + 0.6087P] where P = (Fo^2 + 2Fc^2)/3
3522 reflections	(Δ/σ)max < 0.001
164 parameters	Δρmax = 0.83 e Å^−3
0 restraints	Δρmin = −0.32 e Å^−3

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 F² against ALL reflections. The weighted R-factor wR and goodness of fit S are based on F², conventional R-factors R are based on F, with F set to zero for negative F². The threshold expression of F² > σ(F²) is used only for calculating R-factors(gt) etc. and is not relevant to the choice of reflections for refinement. R-factors based on F² 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 (Ų)

	x	y	z	Uiso*/Ueq
Si1	0.75250 (4)	0.43595 (3)	0.23148 (2)	0.01263 (10)
O1	0.90593 (10)	0.39365 (8)	0.17737 (6)	0.01722 (18)
O2	0.78673 (11)	0.53198 (8)	0.32267 (6)	0.01695 (18)
N1	0.85151 (12)	0.29696 (9)	0.31911 (6)	0.01353 (19)
C1	1.01892 (15)	0.29615 (12)	0.20998 (8)	0.0194 (2)
H1A	1.1198	0.3324	0.2453	0.023*
H1B	1.0496	0.2490	0.1591	0.023*
C2	0.93687 (15)	0.20921 (11)	0.26863 (8)	0.0172 (2)
H2A	0.8587	0.1519	0.2319	0.021*
H2B	1.0190	0.1593	0.3091	0.021*
C3	0.84985 (13)	0.28496 (10)	0.40388 (8)	0.0135 (2)
C4	0.92288 (15)	0.17211 (11)	0.45659 (8)	0.0163 (2)
H4A	0.9061	0.0976	0.4185	0.024*
H4B	0.8692	0.1603	0.5088	0.024*
H4C	1.0406	0.1854	0.4766	0.024*
C5	0.78314 (14)	0.38999 (11)	0.44950 (7)	0.0147 (2)
C6	0.76272 (14)	0.50900 (11)	0.40757 (8)	0.0151 (2)
C7	0.71663 (15)	0.61214 (12)	0.45484 (8)	0.0193 (2)
H7	0.7077	0.6924	0.4275	0.023*
C8	0.68393 (16)	0.59814 (13)	0.54111 (9)	0.0224 (3)
H8	0.6522	0.6686	0.5723	0.027*
C9	0.69745 (17)	0.48076 (13)	0.58227 (9)	0.0229 (3)
H9	0.6725	0.4708	0.6408	0.027*
C10	0.74773 (15)	0.37844 (12)	0.53696 (8)	0.0189 (2)
H10	0.7584	0.2991	0.5656	0.023*
C11	0.66947 (14)	0.56697 (11)	0.14849 (8)	0.0169 (2)
H11A	0.7075	0.6499	0.1727	0.020*
H11B	0.7064	0.5546	0.0903	0.020*
C12	0.48125 (16)	0.55706 (12)	0.13737 (10)	0.0224 (3)
H12A	0.4421	0.5966	0.1889	0.027*
H12B	0.4292	0.6001	0.0819	0.027*
C13	0.43727 (16)	0.41763 (12)	0.13254 (9)	0.0230 (3)
H13A	0.4565	0.3820	0.0749	0.028*
H13B	0.3201	0.4062	0.1367	0.028*
C14	0.54725 (14)	0.35048 (11)	0.21199 (8)	0.0172 (2)
H14A	0.5628	0.2616	0.1971	0.021*
H14B	0.4961	0.3542	0.2664	0.021*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
Si1	0.01272 (16)	0.01230 (16)	0.01279 (16)	−0.00026 (10)	0.00193 (11)	0.00120 (11)
O1	0.0171 (4)	0.0200 (4)	0.0153 (4)	0.0041 (3)	0.0050 (3)	0.0039 (3)
O2	0.0228 (4)	0.0135 (4)	0.0144 (4)	−0.0015 (3)	0.0029 (3)	0.0008 (3)
N1	0.0136 (4)	0.0135 (4)	0.0135 (4)	0.0009 (3)	0.0023 (3)	−0.0002 (3)
C1	0.0175 (5)	0.0239 (6)	0.0176 (6)	0.0067 (4)	0.0052 (4)	0.0034 (4)
C2	0.0200 (5)	0.0174 (5)	0.0144 (5)	0.0056 (4)	0.0040 (4)	0.0001 (4)
C3	0.0122 (5)	0.0133 (5)	0.0145 (5)	−0.0010 (4)	0.0012 (4)	0.0006 (4)
C4	0.0190 (5)	0.0148 (5)	0.0148 (5)	0.0021 (4)	0.0022 (4)	0.0018 (4)
C5	0.0151 (5)	0.0150 (5)	0.0137 (5)	0.0004 (4)	0.0019 (4)	−0.0006 (4)
C6	0.0150 (5)	0.0157 (5)	0.0140 (5)	−0.0006 (4)	0.0007 (4)	−0.0015 (4)
C7	0.0207 (6)	0.0153 (5)	0.0209 (6)	0.0013 (4)	0.0009 (4)	−0.0028 (4)
C8	0.0243 (6)	0.0222 (6)	0.0204 (6)	0.0048 (5)	0.0027 (5)	−0.0071 (5)
C9	0.0267 (6)	0.0271 (7)	0.0154 (5)	0.0059 (5)	0.0050 (5)	−0.0027 (5)
C10	0.0218 (6)	0.0199 (6)	0.0152 (5)	0.0033 (4)	0.0037 (4)	0.0009 (4)
C11	0.0157 (5)	0.0160 (5)	0.0182 (5)	−0.0011 (4)	0.0009 (4)	0.0045 (4)
C12	0.0194 (6)	0.0192 (6)	0.0273 (7)	0.0014 (4)	0.0004 (5)	0.0045 (5)
C13	0.0178 (6)	0.0216 (6)	0.0275 (7)	−0.0023 (5)	−0.0018 (5)	0.0036 (5)
C14	0.0158 (5)	0.0145 (5)	0.0206 (6)	−0.0016 (4)	0.0009 (4)	0.0031 (4)

Geometric parameters (Å, º)

Si1—O1	1.687 (1)	C5—C6	1.4196 (16)
Si1—O2	1.706 (1)	C6—C7	1.4032 (16)
Si1—C14	1.907 (1)	C7—C8	1.3879 (18)
Si1—C11	1.929 (1)	C7—H7	0.9500
Si1—N1	2.067 (1)	C8—C9	1.3977 (19)
O1—C1	1.4310 (15)	C8—H8	0.9500
O2—C6	1.3577 (14)	C9—C10	1.3928 (17)
N1—C3	1.2934 (15)	C9—H9	0.9500
N1—C2	1.4663 (15)	C10—H10	0.9500
C1—C2	1.5241 (17)	C11—C12	1.5418 (18)
C1—H1A	0.9900	C11—H11A	0.9900
C1—H1B	0.9900	C11—H11B	0.9900
C2—H2A	0.9900	C12—C13	1.5337 (19)
C2—H2B	0.9900	C12—H12A	0.9900
C3—C5	1.4749 (16)	C12—H12B	0.9900
C3—C4	1.5148 (16)	C13—C14	1.5553 (18)
C4—H4A	0.9800	C13—H13A	0.9900
C4—H4B	0.9800	C13—H13B	0.9900
C4—H4C	0.9800	C14—H14A	0.9900
C5—C10	1.4110 (16)	C14—H14B	0.9900
O1—Si1—O2	121.37 (5)	O2—C6—C7	115.99 (11)
O1—Si1—C14	121.40 (5)	O2—C6—C5	124.12 (10)
O2—Si1—C14	115.72 (5)	C7—C6—C5	119.88 (11)
O1—Si1—C11	95.26 (5)	C8—C7—C6	120.67 (12)
O2—Si1—C11	94.71 (5)	C8—C7—H7	119.7
C14—Si1—C11	92.21 (6)	C6—C7—H7	119.7
O1—Si1—N1	82.58 (4)	C7—C8—C9	120.24 (12)
O2—Si1—N1	85.40 (5)	C7—C8—H8	119.9
C14—Si1—N1	89.98 (5)	C9—C8—H8	119.9
C11—Si1—N1	177.51 (5)	C10—C9—C8	119.56 (12)
C1—O1—Si1	121.96 (7)	C10—C9—H9	120.2
C6—O2—Si1	128.89 (8)	C8—C9—H9	120.2
C3—N1—C2	122.87 (10)	C9—C10—C5	121.47 (12)
C3—N1—Si1	129.72 (8)	C9—C10—H10	119.3
C2—N1—Si1	107.37 (7)	C5—C10—H10	119.3
O1—C1—C2	108.40 (9)	C12—C11—Si1	105.18 (8)
O1—C1—H1A	110.0	C12—C11—H11A	110.7
C2—C1—H1A	110.0	Si1—C11—H11A	110.7
O1—C1—H1B	110.0	C12—C11—H11B	110.7
C2—C1—H1B	110.0	Si1—C11—H11B	110.7
H1A—C1—H1B	108.4	H11A—C11—H11B	108.8
N1—C2—C1	102.51 (10)	C13—C12—C11	107.41 (10)
N1—C2—H2A	111.3	C13—C12—H12A	110.2
C1—C2—H2A	111.3	C11—C12—H12A	110.2
N1—C2—H2B	111.3	C13—C12—H12B	110.2
C1—C2—H2B	111.3	C11—C12—H12B	110.2
H2A—C2—H2B	109.2	H12A—C12—H12B	108.5
N1—C3—C5	117.30 (10)	C12—C13—C14	108.01 (11)
N1—C3—C4	122.12 (10)	C12—C13—H13A	110.1
C5—C3—C4	120.47 (10)	C14—C13—H13A	110.1
C3—C4—H4A	109.5	C12—C13—H13B	110.1
C3—C4—H4B	109.5	C14—C13—H13B	110.1
H4A—C4—H4B	109.5	H13A—C13—H13B	108.4
C3—C4—H4C	109.5	C13—C14—Si1	106.64 (8)
H4A—C4—H4C	109.5	C13—C14—H14A	110.4
H4B—C4—H4C	109.5	Si1—C14—H14A	110.4
C10—C5—C6	118.09 (11)	C13—C14—H14B	110.4
C10—C5—C3	121.90 (11)	Si1—C14—H14B	110.4
C6—C5—C3	119.89 (10)	H14A—C14—H14B	108.6
O2—Si1—O1—C1	80.08 (10)	C4—C3—C5—C6	160.36 (10)
C14—Si1—O1—C1	−85.31 (11)	Si1—O2—C6—C7	−147.42 (9)
C11—Si1—O1—C1	178.86 (9)	Si1—O2—C6—C5	33.28 (16)
N1—Si1—O1—C1	0.10 (9)	C10—C5—C6—O2	−177.54 (11)
O1—Si1—O2—C6	−119.76 (10)	C3—C5—C6—O2	6.32 (17)
C14—Si1—O2—C6	46.41 (11)	C10—C5—C6—C7	3.19 (17)
C11—Si1—O2—C6	141.15 (10)	C3—C5—C6—C7	−172.95 (11)
N1—Si1—O2—C6	−41.35 (10)	O2—C6—C7—C8	177.94 (11)
O1—Si1—N1—C3	152.34 (11)	C5—C6—C7—C8	−2.74 (18)
O2—Si1—N1—C3	29.85 (10)	C6—C7—C8—C9	0.3 (2)
C14—Si1—N1—C3	−85.96 (11)	C7—C8—C9—C10	1.5 (2)
O1—Si1—N1—C2	−25.16 (8)	C8—C9—C10—C5	−1.0 (2)
O2—Si1—N1—C2	−147.65 (8)	C6—C5—C10—C9	−1.35 (18)
C14—Si1—N1—C2	96.54 (8)	C3—C5—C10—C9	174.70 (12)
Si1—O1—C1—C2	24.11 (13)	O1—Si1—C11—C12	139.90 (9)
C3—N1—C2—C1	−137.43 (11)	O2—Si1—C11—C12	−97.94 (9)
Si1—N1—C2—C1	40.28 (10)	C14—Si1—C11—C12	18.09 (9)
O1—C1—C2—N1	−40.98 (12)	Si1—C11—C12—C13	−40.70 (12)
C2—N1—C3—C5	170.24 (10)	C11—C12—C13—C14	49.28 (14)
Si1—N1—C3—C5	−6.93 (15)	C12—C13—C14—Si1	−33.49 (12)
C2—N1—C3—C4	−5.86 (17)	O1—Si1—C14—C13	−89.15 (9)
Si1—N1—C3—C4	176.98 (8)	O2—Si1—C14—C13	104.69 (9)
N1—C3—C5—C10	168.22 (11)	C11—Si1—C14—C13	8.38 (9)
C4—C3—C5—C10	−15.62 (17)	N1—Si1—C14—C13	−170.43 (9)
N1—C3—C5—C6	−15.80 (16)

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
C4—H4B···O1^i	0.98	2.59	3.445 (2)	147
C1—H1B···O2^ii	0.99	2.68	3.330 (2)	124

Symmetry codes: (i) x, −y+1/2, z+1/2; (ii) −x+2, y−1/2, −z+1/2.

(IIo) (Ethane-1,2-diyl)(2-{[1-(2-oxidophenyl)ethylidene-κO]amino-κN}ethanolato-κO)silicon

Crystal data

C14H19NO2Si	F(000) = 560
Mr = 261.39	Dx = 1.325 Mg m^−3
Orthorhombic, P212121	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: P 2ac 2ab	Cell parameters from 6464 reflections
a = 9.5798 (4) Å	θ = 2.5–32.1°
b = 9.9284 (5) Å	µ = 0.17 mm^−1
c = 13.7788 (6) Å	T = 93 K
V = 1310.53 (10) Å^3	Prism, colourless
Z = 4	0.56 × 0.50 × 0.35 mm

Data collection

Bruker SMART CCD area-detector diffractometer	3813 independent reflections
Radiation source: sealed tube	3525 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.034
phi and ω scans	θmax = 30.0°, θmin = 2.5°
Absorption correction: multi-scan (SADABS; Sheldrick, 1996)	h = −13→11
Tmin = 0.90, Tmax = 0.95	k = −13→13
15312 measured reflections	l = −17→19

Refinement

Refinement on F^2	Secondary atom site location: difference Fourier map
Least-squares matrix: full	Hydrogen site location: inferred from neighbouring sites
R[F^2 > 2σ(F^2)] = 0.034	H-atom parameters constrained
wR(F^2) = 0.087	w = 1/[σ^2(Fo^2) + (0.0513P)^2 + 0.2422P] where P = (Fo^2 + 2Fc^2)/3
S = 1.04	(Δ/σ)max < 0.001
3813 reflections	Δρmax = 0.49 e Å^−3
164 parameters	Δρmin = −0.23 e Å^−3
0 restraints	Absolute structure: Flack (1983), 1638 Friedel pairs
Primary atom site location: structure-invariant direct methods	Absolute structure parameter: −0.10 (9)

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. The silicon atom in this molecule is pentacoordinated.

Refinement. Refinement of F² against ALL reflections. The weighted R-factor wR and goodness of fit S are based on F², conventional R-factors R are based on F, with F set to zero for negative F². The threshold expression of F² > σ(F²) is used only for calculating R-factors(gt) etc. and is not relevant to the choice of reflections for refinement. R-factors based on F² 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 (Ų)

	x	y	z	Uiso*/Ueq
Si1	0.63018 (4)	0.43223 (4)	0.07930 (3)	0.01239 (9)
O1	0.70500 (11)	0.43835 (10)	0.18919 (7)	0.0165 (2)
O2	0.71257 (11)	0.37059 (9)	−0.02158 (7)	0.0147 (2)
N1	0.60081 (12)	0.23369 (12)	0.11610 (9)	0.0143 (2)
C1	0.72175 (16)	0.32158 (14)	0.24785 (10)	0.0176 (3)
H1A	0.7157	0.3460	0.3174	0.021*
H1B	0.8142	0.2803	0.2358	0.021*
C2	0.60632 (16)	0.22264 (14)	0.22187 (10)	0.0173 (3)
H2A	0.6304	0.1300	0.2425	0.021*
H2B	0.5164	0.2490	0.2518	0.021*
C3	0.57243 (14)	0.13512 (13)	0.05852 (9)	0.0132 (3)
C4	0.52470 (16)	−0.00058 (14)	0.09407 (10)	0.0174 (3)
H4A	0.5107	0.0028	0.1645	0.026*
H4B	0.5957	−0.0684	0.0786	0.026*
H4C	0.4366	−0.0245	0.0623	0.026*
C5	0.59053 (14)	0.15759 (13)	−0.04634 (10)	0.0128 (2)
C6	0.66265 (13)	0.27264 (13)	−0.08047 (10)	0.0127 (2)
C7	0.68894 (16)	0.28678 (14)	−0.18005 (10)	0.0159 (3)
H7	0.7371	0.3640	−0.2032	0.019*
C8	0.64512 (16)	0.18897 (14)	−0.24482 (10)	0.0182 (3)
H8	0.6636	0.1997	−0.3121	0.022*
C9	0.57405 (16)	0.07461 (16)	−0.21233 (10)	0.0187 (3)
H9	0.5445	0.0076	−0.2570	0.022*
C10	0.54730 (15)	0.06039 (15)	−0.11421 (10)	0.0159 (3)
H10	0.4985	−0.0170	−0.0921	0.019*
C11	0.66296 (15)	0.61671 (13)	0.04632 (11)	0.0159 (3)
H11A	0.6566	0.6755	0.1042	0.019*
H11B	0.7557	0.6286	0.0157	0.019*
C12	0.54477 (16)	0.64652 (13)	−0.02585 (10)	0.0171 (3)
H12A	0.5626	0.6006	−0.0884	0.021*
H12B	0.5378	0.7446	−0.0379	0.021*
C13	0.40912 (15)	0.59374 (14)	0.02016 (11)	0.0178 (3)
H13A	0.3335	0.5924	−0.0288	0.021*
H13B	0.3802	0.6535	0.0741	0.021*
C14	0.43547 (15)	0.44991 (13)	0.05872 (10)	0.0153 (3)
H14A	0.4030	0.3824	0.0109	0.018*
H14B	0.3843	0.4357	0.1203	0.018*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
Si1	0.01210 (16)	0.01147 (15)	0.01361 (16)	−0.00082 (13)	−0.00008 (14)	−0.00074 (13)
O1	0.0189 (5)	0.0142 (4)	0.0164 (4)	−0.0016 (4)	−0.0035 (4)	0.0001 (4)
O2	0.0151 (5)	0.0130 (4)	0.0160 (5)	−0.0027 (4)	0.0026 (4)	−0.0024 (4)
N1	0.0147 (6)	0.0141 (5)	0.0141 (5)	−0.0005 (4)	−0.0004 (4)	0.0002 (4)
C1	0.0194 (7)	0.0172 (6)	0.0163 (7)	0.0011 (5)	−0.0036 (6)	0.0006 (5)
C2	0.0227 (8)	0.0172 (6)	0.0121 (6)	−0.0015 (5)	−0.0006 (5)	0.0013 (5)
C3	0.0113 (6)	0.0124 (6)	0.0160 (6)	0.0003 (5)	0.0004 (5)	0.0011 (5)
C4	0.0199 (7)	0.0150 (6)	0.0174 (7)	−0.0035 (5)	0.0008 (5)	0.0016 (5)
C5	0.0120 (6)	0.0126 (6)	0.0137 (6)	0.0010 (4)	−0.0006 (5)	0.0001 (4)
C6	0.0098 (6)	0.0129 (5)	0.0154 (6)	0.0007 (4)	0.0001 (5)	−0.0012 (5)
C7	0.0152 (7)	0.0155 (6)	0.0171 (7)	0.0006 (5)	0.0009 (5)	0.0025 (5)
C8	0.0177 (7)	0.0220 (7)	0.0148 (6)	−0.0005 (6)	0.0008 (6)	−0.0001 (5)
C9	0.0206 (7)	0.0185 (6)	0.0169 (6)	−0.0015 (6)	−0.0028 (5)	−0.0036 (5)
C10	0.0147 (6)	0.0140 (6)	0.0191 (6)	−0.0022 (5)	−0.0010 (5)	−0.0002 (5)
C11	0.0166 (7)	0.0133 (6)	0.0179 (6)	−0.0028 (5)	−0.0001 (5)	−0.0014 (5)
C12	0.0220 (7)	0.0137 (6)	0.0157 (6)	0.0005 (5)	−0.0002 (5)	0.0014 (5)
C13	0.0168 (7)	0.0183 (6)	0.0184 (6)	0.0042 (5)	−0.0004 (5)	0.0019 (5)
C14	0.0144 (6)	0.0154 (6)	0.0161 (6)	−0.0004 (5)	0.0001 (5)	0.0004 (5)

Geometric parameters (Å, º)

Si1—O1	1.676 (1)	C5—C6	1.4154 (18)
Si1—O2	1.712 (1)	C6—C7	1.4020 (19)
Si1—C14	1.895 (2)	C7—C8	1.384 (2)
Si1—C11	1.913 (1)	C7—H7	0.9500
Si1—N1	2.055 (1)	C8—C9	1.398 (2)
O1—C1	1.4225 (17)	C8—H8	0.9500
O2—C6	1.3539 (16)	C9—C10	1.3832 (19)
N1—C3	1.2889 (18)	C9—H9	0.9500
N1—C2	1.4625 (17)	C10—H10	0.9500
C1—C2	1.522 (2)	C11—C12	1.536 (2)
C1—H1A	0.9900	C11—H11A	0.9900
C1—H1B	0.9900	C11—H11B	0.9900
C2—H2A	0.9900	C12—C13	1.538 (2)
C2—H2B	0.9900	C12—H12A	0.9900
C3—C5	1.4723 (18)	C12—H12B	0.9900
C3—C4	1.5046 (19)	C13—C14	1.5444 (19)
C4—H4A	0.9800	C13—H13A	0.9900
C4—H4B	0.9800	C13—H13B	0.9900
C4—H4C	0.9800	C14—H14A	0.9900
C5—C10	1.4062 (19)	C14—H14B	0.9900
O1—Si1—O2	123.32 (6)	O2—C6—C7	116.82 (11)
O1—Si1—C14	123.55 (6)	O2—C6—C5	123.57 (12)
O2—Si1—C14	111.44 (6)	C7—C6—C5	119.58 (12)
O1—Si1—C11	96.29 (6)	C8—C7—C6	120.42 (13)
O2—Si1—C11	94.23 (6)	C8—C7—H7	119.8
C14—Si1—C11	92.14 (6)	C6—C7—H7	119.8
O1—Si1—N1	82.55 (5)	C7—C8—C9	120.75 (13)
O2—Si1—N1	85.44 (5)	C7—C8—H8	119.6
C14—Si1—N1	89.49 (5)	C9—C8—H8	119.6
C11—Si1—N1	178.35 (6)	C10—C9—C8	119.09 (13)
C1—O1—Si1	122.14 (9)	C10—C9—H9	120.5
C6—O2—Si1	125.50 (9)	C8—C9—H9	120.5
C3—N1—C2	124.33 (12)	C9—C10—C5	121.69 (13)
C3—N1—Si1	127.26 (10)	C9—C10—H10	119.2
C2—N1—Si1	108.24 (9)	C5—C10—H10	119.2
O1—C1—C2	108.09 (11)	C12—C11—Si1	102.55 (9)
O1—C1—H1A	110.1	C12—C11—H11A	111.3
C2—C1—H1A	110.1	Si1—C11—H11A	111.3
O1—C1—H1B	110.1	C12—C11—H11B	111.3
C2—C1—H1B	110.1	Si1—C11—H11B	111.3
H1A—C1—H1B	108.4	H11A—C11—H11B	109.2
N1—C2—C1	102.25 (11)	C11—C12—C13	106.88 (11)
N1—C2—H2A	111.3	C11—C12—H12A	110.3
C1—C2—H2A	111.3	C13—C12—H12A	110.3
N1—C2—H2B	111.3	C11—C12—H12B	110.3
C1—C2—H2B	111.3	C13—C12—H12B	110.3
H2A—C2—H2B	109.2	H12A—C12—H12B	108.6
N1—C3—C5	117.66 (12)	C12—C13—C14	108.59 (11)
N1—C3—C4	122.94 (12)	C12—C13—H13A	110.0
C5—C3—C4	119.40 (11)	C14—C13—H13A	110.0
C3—C4—H4A	109.5	C12—C13—H13B	110.0
C3—C4—H4B	109.5	C14—C13—H13B	110.0
H4A—C4—H4B	109.5	H13A—C13—H13B	108.4
C3—C4—H4C	109.5	C13—C14—Si1	107.34 (9)
H4A—C4—H4C	109.5	C13—C14—H14A	110.2
H4B—C4—H4C	109.5	Si1—C14—H14A	110.2
C10—C5—C6	118.47 (12)	C13—C14—H14B	110.2
C10—C5—C3	120.93 (12)	Si1—C14—H14B	110.2
C6—C5—C3	120.39 (12)	H14A—C14—H14B	108.5
O2—Si1—O1—C1	−75.75 (12)	C4—C3—C5—C6	−166.51 (12)
C14—Si1—O1—C1	88.18 (12)	Si1—O2—C6—C7	142.94 (10)
C11—Si1—O1—C1	−175.03 (11)	Si1—O2—C6—C5	−38.96 (17)
N1—Si1—O1—C1	3.77 (10)	C10—C5—C6—O2	−178.04 (12)
O1—Si1—O2—C6	125.96 (11)	C3—C5—C6—O2	−3.3 (2)
C14—Si1—O2—C6	−39.69 (12)	C10—C5—C6—C7	0.01 (19)
C11—Si1—O2—C6	−133.66 (11)	C3—C5—C6—C7	174.76 (12)
N1—Si1—O2—C6	47.96 (11)	O2—C6—C7—C8	178.04 (13)
O1—Si1—N1—C3	−162.39 (13)	C5—C6—C7—C8	−0.1 (2)
O2—Si1—N1—C3	−37.91 (12)	C6—C7—C8—C9	0.0 (2)
C14—Si1—N1—C3	73.65 (12)	C7—C8—C9—C10	0.3 (2)
O1—Si1—N1—C2	22.15 (9)	C8—C9—C10—C5	−0.4 (2)
O2—Si1—N1—C2	146.63 (10)	C6—C5—C10—C9	0.3 (2)
C14—Si1—N1—C2	−101.81 (10)	C3—C5—C10—C9	−174.46 (14)
Si1—O1—C1—C2	−27.84 (15)	O1—Si1—C11—C12	−153.64 (9)
C3—N1—C2—C1	145.95 (13)	O2—Si1—C11—C12	82.15 (10)
Si1—N1—C2—C1	−38.43 (12)	C14—Si1—C11—C12	−29.54 (10)
O1—C1—C2—N1	41.34 (15)	Si1—C11—C12—C13	47.92 (12)
C2—N1—C3—C5	−171.47 (13)	C11—C12—C13—C14	−47.39 (14)
Si1—N1—C3—C5	13.75 (18)	C12—C13—C14—Si1	22.89 (13)
C2—N1—C3—C4	7.4 (2)	O1—Si1—C14—C13	103.25 (9)
Si1—N1—C3—C4	−167.34 (10)	O2—Si1—C14—C13	−91.13 (9)
N1—C3—C5—C10	−172.95 (13)	C11—Si1—C14—C13	4.25 (9)
C4—C3—C5—C10	8.1 (2)	N1—Si1—C14—C13	−176.04 (9)
N1—C3—C5—C6	12.43 (19)

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
C7—H7···O1^i	0.95	2.52	3.424 (2)	159
C4—H4C···O2^ii	0.98	2.69	3.406 (2)	130

Symmetry codes: (i) −x+3/2, −y+1, z−1/2; (ii) x−1/2, −y+1/2, −z.