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Bulky 2,6-disubstituted aryl siloxanes and a disilanamine

aDepartamento de Química, Universidade Estadual de Ponta Grossa, 84030-900, Ponta Grossa, Paraná, Brazil, and bChemistry and Biochemistry, University of Lethbridge, 4401 University Drive West, Lethbridge, Alberta, T1K 3M4, Canada
*Correspondence e-mail: boere@uleth.ca

Edited by W. T. A. Harrison, University of Aberdeen, Scotland (Received 8 January 2020; accepted 31 January 2020; online 6 February 2020)

The crystal structures of 5-bromo-1,3-di-tert-butyl-2-[(tri­methyl­sil­yl)­oxy]benzene, C17H29BrOSi, (I), 1,3-di-tert-butyl-2-[(tri­methyl­sil­yl)­oxy]benzene, C17H30OSi, (II), and N-(2,6-diiso­propyl­phen­yl)-1,1,1-trimethyl-N-(tri­methyl­sil­yl)silanamine, C18H35NSi2, (III), are reported. Compound (I) crystallizes in space group P21/c with Z′ = 1, (II) in Pnma with Z′ = 0.5 and (III) in Cmcm with Z′ = 0.25. Consequently, the mol­ecules of (II) are constrained by m and those of (III) by m2m site symmetries. Despite this, both (I) and (II) are distorted towards mild boat conformations, as is typical of 2,6-di-tert-butyl-substituted phenyl compounds, reflecting the high local steric pressure of the flanking alkyl groups. Compound (III) by contrast is planar and symmetric, and this lack of distortion is compatible with the lower steric pressure of the flanking 2,6-diisopropyl substituents.

1. Chemical context

Aryl siloxanes and silanamines are important reaction inter­mediates, especially as protecting groups for phenols and anilines (Lucente-Schultz et al., 2009[Lucente-Schultz, R. M., Moore, V. C., Leonard, A. D., Price, B. K., Kosynkin, D. V., Lu, M., Partha, R., Conyers, J. L. & Tour, J. M. (2009). J. Am. Chem. Soc. 131, 3934-3941.]). Thus, 5-bromo-1,3-di-tert-butyl-2-[(tri­methyl­sil­yl)­oxy]benzene, (I)[link], is used as a synthetic inter­mediate to form inter alia p-conjugated aryl­boron radicals (Chung et al., 2018[Chung, M.-H., Yu, I. F., Liu, Y.-H., Lin, T.-S., Peng, S.-M. & Chiu, C. W. (2018). Inorg. Chem. 57, 11732-11737.]), p-quinone methides (Wang et al., 2018[Wang, J., Pan, X., Liu, J., Zhao, L., Zhi, Y., Zhao, K. & Hu, L. (2018). Org. Lett. 20, 5995-5998.]) and spin-labelled polymers (Otaki & Goto, 2019[Otaki, M. & Goto, H. (2019). Macromolecules, 52, 3199-3209.]). Recently a new cross-coupling reaction using the parent phenol was shown to be more effective than using protected 1,3-di-tert-butyl-2-[(tri­methyl­sil­yl)­oxy]benzene, (II)[link] (Nieves-Quinones et al., 2019[Nieves-Quinones, Y., Paniak, T. J., Lee, Y. E., Kim, S. M., Tcyrulnikov, S. & Kozlowski, M. C. (2019). J. Am. Chem. Soc. 141, 10016-10032.]). Silanamines such as N-(2,6-diiso­propyl­phen­yl)-1,1,1-trimethyl-N-(tri­methyl­sil­yl)silanamine, (III)[link], can support chemistry at the 4-position of the ring, including robust heteroelement derivatives (Maaninen et al., 1999[Maaninen, A., Boeré, R. T., Chivers, T. & Parvez, M. (1999). Z. Naturforsch. B, 54, 1170-1174.]), and are also good sources for the controlled synthesis of early transition-metal amides (Siemeling et al., 1999[Siemeling, U., Neumann, B., Stammler, H.-G. & Kuhnert, O. (1999). Polyhedron, 18, 1815-1819.]; Pennington et al., 2005[Pennington, D. A., Horton, P. N., Hursthouse, M. B., Bochmann, M. & Lancaster, S. J. (2005). Polyhedron, 24, 151-156.]). Similarly, substitution of (II)[link] at the 4-position of the ring leads to numerous intrinsic heteroatom derivatives in addition to follow-up reactivity at oxygen (Kindra et al., 2013[Kindra, D. R., Casely, I. J., Fieser, M. E., Ziller, J. W., Furche, F. & Evans, W. J. (2013). J. Am. Chem. Soc. 135, 7777-7787.]; Poverenov et al., 2007[Poverenov, E., Shimon, L. J. W. & Milstein, D. (2007). Organometallics, 26, 2178-2182.]; Satoh & Shi, 1994[Satoh, Y. & Shi, C. (1994). Synthesis, pp. 1146-1148.]; Healy & Barron, 1990[Healy, M. D. & Barron, A. R. (1990). J. Organomet. Chem. 381, 165-172.]). Herein we report the single-crystal X-ray diffraction structures of (I)[link], (II)[link] and (III)[link].

2. Structural commentary

Compound (I)[link] crystallizes on a general position in P21/c and adopts a distortion towards boat-shaped (Fig. 1[link]a) in which all of the atoms along the central ridge of the substituted benzene ring tilt above a best plane defined by the central C2/C3/C5/C6 ring carbon atoms, whilst the tBu groups tilt below. Inter­estingly, (II)[link] crystallizes with a similar degree of distortion towards a boat conformation (Fig. 1[link]b): deviations from the central planes in (I)[link] and (II)[link] are 1.401 (6) and 1.446 (5) Å for Si1, 0.226 (4) and 0.227 (3) Å for O1, 0.111 (3) and 0.107 (2) Å for C1, 0.039 (3) and 0.040 (3) Å for C4 and an average of −0.117 (4) and −0.112 (2) Å for the two tBu central carbon atoms; note, however, that (II)[link] has bilateral symmetry from the occupation of Wyckoff site 4c in Pnma with Si1, O1, C1, C4 and C15 on the mirror. The Si1—O1 bond lengths in (I)[link] and (II)[link] are closely comparable at 1.6617 (15) and 1.6655 (12) Å, respectively, as are the C1—O1 lengths at 1.379 (2) and 1.3821 (19) Å. Noticeably, all these dimensions are long, corresponding to the upper quartiles of the compiled values (1.652 and 1.373 Å, respectively; Lide, 2004[Lide, D. R. (2004). Editor. CRC Handbook of Chemistry and Physics, 85th ed, sect. 9.1. Boca Raton: CRC Press.]) for all organic Si—O bond lengths. In both mol­ecules, the Me3SiO groups are strongly tilted out of the mol­ecular planes and the C1—O1—Si1 angles are similar but not identical at 139.75 (13) and 137.9 (1)°. Consideration of space-filling representations strongly suggest that these angles allow the best fitting of the bulky Me3Si groups between flanking tBu groups, with very specific orientations of the H atoms on all the components.

[Figure 1]
Figure 1
Displacement ellipsoids plot of the mol­ecular structures of (a) (I)[link] at the 50% probability level; (b) (II)[link], also at the 50% probability level, and (c) (III)[link] at the 40% probability level. H atoms have been omitted and the atom numbering schemes are shown. [Symmetry codes: (i): x, [{1\over 2}] − y, z; (ii) 1 − x, y, [{3\over 2}] − z; (iii) x, y, [{3\over 2}] − z; (iv) 1 − x, y, z.]

In contrast to the two siloxanes, the silanamine (III)[link] is rigorously planar with the N(SiMe3)2 moiety strictly orthogonal to the aryl ring (Fig. 1[link]c) as required by m2m symmetry at Wyckoff site 4c in space group Cmcm. Consideration of a space-filling model also confirms the tight fit of the two Me3Si groups between the flanking isopropyl moieties, and the constraints on orientations of the Me groups of all the substituents are also considerable, inducing a constrained inter­nal orientation in (III)[link]. The N1—Si1 bond lengths are 1.7529 (13) Å, approaching the upper quartile of the compiled standard values of 1.755 Å for all aromatic N—Si bond lengths (Lide, 2004[Lide, D. R. (2004). Editor. CRC Handbook of Chemistry and Physics, 85th ed, sect. 9.1. Boca Raton: CRC Press.]). The C1—N1—Si1 angles are 116.92 (7)°, considerably smaller than the C—O—Si angles in (I)[link] and (II)[link], consistent with trigonal substitution at N1.

[Scheme 1]

The close inter­locking of the methyl group atoms belonging to the tBu/iPr and Me3Si substituents in all three mol­ecules is very evident in Fig. 1[link].

3. Supra­molecular features

Compound (I)[link] is gently packed (Fig. 2[link]) in its extended structure with few contacts shorter than ΣrvdW. By contrast, (II)[link] forms stacks along the a-axis direction (Fig. 3[link]) with some contacts from SiMe3 H atoms to aromatic rings at 2.80 Å, within (ΣrvdW – 0.1 Å), indicative of weak dispersion inter­actions; this is consistent with the high crystallinity encountered when (II)[link] is a synthetic by-product. The structure of (III)[link] has very high symmetry as a consequence of space group Cmcm and Z′ = 0.25 but there are no contacts shorter than ΣrvdW. The resultant weak packing (Fig. 4[link]) may be a contrib­uting factor to the rather large displacement ellipsoids occurring in the anisotropic refinement of (III)[link].

[Figure 2]
Figure 2
Unit-cell packing diagram for (I)[link] viewed bisecting γ with H atoms shown with arbitrary radii and intermolecular contacts less than ΣrvdW as dashed blue lines.
[Figure 3]
Figure 3
Unit-cell packing diagram for (II)[link] viewed perpendicular to c with H atoms shown with arbitrary radii and intermolecular contacts less than ΣrvdW as dashed blue lines.
[Figure 4]
Figure 4
Unit-cell packing diagram for (III)[link] viewed perpendicular to c with H atoms shown with arbitrary radii. Small, non solvent-accessible, voids of 22 Å3 are shaded ochre.

4. Database survey

The geometry of (I)[link] may be compared to that of 4-bromo-2,6-di-tertbutyl­phenol, for which a modern low-temperature area-detector structure has been reported in the Cambridge Structure Database (CSD, Version 5.40, with updates to February 2019; Groom et al., 2016[Groom, C. R., Bruno, I. J., Lightfoot, M. P. & Ward, S. C. (2016). Acta Cryst. B72, 171-179.]) with refcode BBPHOL02 (Marszaukowski & Boeré, 2019[Marszaukowski, F. & Boeré, R. T. (2019). CSD Communication (refcode CCDC 1907965). CCDC, Cambridge, England. https://doi.org/10.5517/ccdc.csd.cc221d8t]). The C—Br distance of 1.904 (2) Å in (I)[link] is indistinguishable from 1.905 (3) Å in the latter at the 99% confidence level. Both (I)[link] and (II)[link] can be compared with five other reported structures in the CSD that share the same combination of 2,6-di-tert-butyl­phenyl rings and 1-tri­methyl­siloxane substituents, with CSD refcodes: GIFCEE (Poverenov et al., 2007[Poverenov, E., Shimon, L. J. W. & Milstein, D. (2007). Organometallics, 26, 2178-2182.]), JEHDOP (Healy & Barron, 1990[Healy, M. D. & Barron, A. R. (1990). J. Organomet. Chem. 381, 165-172.]), LIKYEJ, which has three independent such moieties attached to a B3O3 ring (Satoh & Shi, 1994[Satoh, Y. & Shi, C. (1994). Synthesis, pp. 1146-1148.]), TIXZUK, in which two such groups are attached to bis­muth atoms that are dimerized through a short MM contact (Kindra et al., 2013[Kindra, D. R., Casely, I. J., Fieser, M. E., Ziller, J. W., Furche, F. & Evans, W. J. (2013). J. Am. Chem. Soc. 135, 7777-7787.]) and TIYBEK (Kindra et al., 2013[Kindra, D. R., Casely, I. J., Fieser, M. E., Ziller, J. W., Furche, F. & Evans, W. J. (2013). J. Am. Chem. Soc. 135, 7777-7787.]). All the inter­atomic distances and angles in (I)[link] and in (II)[link] are indistinguishable from the mean values for the eight independent comparators at the 99% confidence level (nine when BBPHOL02 is included for the non-tri­methyl­silyl dimensions). This allows for the computation of global mean values (Table 1[link]). Thus, the Si—O distances of 1.6617 (15) and 1.6655 (12) Å in (I)[link] and (II)[link] fit within an average of 1.657 (10) Å for this set of di-tBu-flanked tri­methyl­siloxanes, and close to the upper quartile value of 1.652 Å for all organic Si—O bond lengths (Lide, 2004[Lide, D. R. (2004). Editor. CRC Handbook of Chemistry and Physics, 85th ed, sect. 9.1. Boca Raton: CRC Press.]). A comparison of symmetry-averaged inter­atomic distances (Å) and angles (°) for (I)[link], (II)[link] and (III)[link] with the discussed comparator sets is presented in Table 1[link].

Table 1
Average inter­atomic distances and angles (Å, °) in (I)[link], (II)[link] and (III)[link] with comparators

Atom numbers taken from (I)[link].

Parameter (I) (II) Mean siloxanea (III) Mean silanamineb  
Si1—O1,N1 1.6617 (15)   1.657 (10) 1.7529 (13) 1.762 (18)  
Ave Si—C 1.865 (2) 1.8666 (15) 1.861 (8) 1.861 (2) 1.859 (6)  
C1—O1,N1 1.379 (2) 1.3823 (19) 1.385 (7) 1.448 (4) 1.453 (8)  
Av C1—C2,6 1.419 (3) 1.4183 (14) 1.415 (5) 1.405 (3) 1.403 (4)  
Av C2,5—C3,6 1.395 (3) 1.3977 (17) 1.395 (7) 1.398 (3) 1.389 (3)  
Av C2,6—C7,11 1.542 (3) 1.5459 (16) 1.546 (4) 1.513 (3) 1.519 (7)  
Av C3,5—C4 1.379 (3) 1.3798 (15) 1.385 (6) 1.373 (3) 1.378 (11)  
Av C7,11-meth­yl 1.540 (3) 1.5386 (17) 1.537 (7) 1.530 (2) 1.523 (6)  
             
Av C—Si—C 109.88 (9) 109.21 (6) 110.0 (8) 110.76 (11) 110.7 (5)  
Av O,N—Si—C 109.01 (11) 109.68 (7) 108.9 (18) 107.79 (13) 107.84 (9)  
C1—O1,N1—Si1 139.75 (13) 137.90 (10) 140 (5) 116.92 (7) 117.0 (10)  
Av C2,6—C1—O,N 119.42 (17) 119.31 (7) 119.2 (10) 119.81 (13) 119.8 (2)  
C2—C1—C6 120.97 (18) 121.23 (15) 121.4 (5) 120.4 (3) 120.5 (4)  
Av C1—C2,6—C3,5 117.75 (18) 117.12 (11) 117.9 (6) 118.5 (2) 118.7 (4)  
Av C1—C2,6—C7,11 123.92 (17) 124.64 (11) 124.3 (10) 123.05 (19) 123.2 (4)  
Av C3,5—C2,6—C7,C11 118.34 (17) 118.24 (10) 112.5 (13) 118.5 (2) 118.6 (11)  
Av C2,6—C3,5—C4 120.59 (18) 122.25 (12) 122.5 (11) 121.6 (2) 121.1 (10)  
C3—C4—C5 121.40 (18) 119.17 (16) 118.5 (16) 119.5 (3) 119.9 (16)  
Av C2,6—C7,11—Me 110.79 (16) 110.86 (10) 110.7 (11) 111.78 (14) 111.83 (15)  
Av Me—C7,11—Me 108.12 (16) 108.04 (10) 108.2 (14) 109.5 (2) 109.55 (7)  
Notes: (a) Mean values taken over (I)[link], (II)[link], BBPHOL02, GIFCEE, JEHDOP, LIKYEJ, TIXZUK and TIYBEK, treating crystallographically independent entities separately. (b) Mean values taken over (III)[link], CAQWUW, CORKAV and QOCSEI.

One exception to taking meaningful averages concerns the C1—O1—Si1 angles, which though similar in (I)[link] and (II)[link] at 139.75 (13) and 137.91 (10)°, are both inter­mediate with respect to an overall range from a low of 126.8 (1) in GIFCEE to a high of 150.3 (2)° in one of the TIKZUK components. Evidently, this angle has a wide variability and a low specificity, so it was of inter­est to investigate if the values are independent of other structural parameters. For example, attempted correlation of these angles with the C1—O1 bond length shows an almost random scatter. However, all members of this series show mild distortions of the substituted benzene rings towards a boat conformation in which S11, O1, C1 and C4 deviate in the same direction from planar and the tBu group C7 and C11 atoms deviate in the opposite direction. A strong correlation is found between the deviation of Si1 from the mean planes defined by C2, C3, C5 and C6 (and hence with the C1—O1—Si1 angle) and similar deviations of smaller magnitude for O1, C1 and C4 (correlation coefficients of 0.98, 0.93 and 0.83, respectively). Thus, bends at the siloxane oxygen atoms smoothly pucker the whole rings toward boat conformations. A consideration of the fits between the tBu and Me3Si groups also indicates that the former undergo rotation so as to accommodate the various tilt angles of the latter from the mean mol­ecular planes – a double turnstile motion that accommodates variations in their relative positions despite the inter­locking inter­actions within these structures.

A close structural analogue to (III)[link] has been reported for an amino­silanetri­thiol analogue (IV[link]), which has one of the SiMe3 groups replaced by Si(SH)3) (CSD refcode QOCSEI; Li et al., 2014[Li, Y., Zhu, H., Andrada, D. M., Frenking, G. & Roesky, H. W. (2014). Chem. Commun. 50, 4628-4630.]). This is almost isostructural and crystallizes in space group Cmc21 with a unit cell that is imperceptibly different at the 99% confidence level (0.6% shorter in a but 0.6% longer in c, leading to a volume just 0.1% lower). It has a mirror disorder of the SiMe3 and Si(SH)3 groups as a consequence of being positioned with the aryl ring on a lattice mirror plane. Mol­ecules of (IV) share the same relative lattice positions as those of (III)[link] in Cmcm.

[Scheme 2]

The reduced site symmetry [compared to m2m in (III)] results in considerable asymmetry in the benzene ring in QOCSEI and a small deviation from full orthogonality of the N-SiR3 units w.r.t. the benzene ring (dihedral angle of 88.1°). By contrast, orthogonal arrangements of the aryl and CNSi2 planes are found in the (ordered) structures of two ring-substituted derivatives of (III)[link] with refcodes CORKAV (4-SeCl3) and QOCSEI (4-ferro­cen­yl­ethyn­yl), neither of which have site-symmetry restraints (Maaninen et al. 1999[Maaninen, A., Boeré, R. T., Chivers, T. & Parvez, M. (1999). Z. Naturforsch. B, 54, 1170-1174.]; Siemeling et al., 1999[Siemeling, U., Neumann, B., Stammler, H.-G. & Kuhnert, O. (1999). Polyhedron, 18, 1815-1819.]). This suggests that it is the inter­locking steric constraints of the 2,6-diisopropyl and N(SiMe3)2 groups that induces these highly regular structures, and greater planarity of the aromatic rings and substituents compared to the typical distortions observed for 2,6-di-tert-butyl phenol derivatives such as (I)[link] and (II)[link]. Notably, there is only one reported crystal structure of a 2,6-di-tert-butyl­aniline with two silyl substituents, in the form of a four-membered N2(SiiPr2)2 ring (refcode: FOTWEQ; Stalke et al., 1987[Stalke, D., Keweloh, N., Klingebiel, U., Noltemeyer, M. & Sheldrick, G. M. (1987). Z. Naturforsch. B, 42, 1237-1244.]) and this is severely distorted from planarity towards a boat conformation with the N atoms 0.60 and 0.69 Å out of the planes of the four central ring carbon atoms.

Within the comparison set of these three previously reported structures, the Si1—N1 distance of 1.7529 (13) Å in (III)[link] compares well with the mean value of 1.750 (2) Å for CAQWUW and CORKAV, whereas the value in QOCSEI of 1.788 (8) Å is different at the 99% confidence level and may have been elongated by the disorder refinement, in agreement with the author's report that the DFT-computed value for this bond is noticeably shorter at 1.744 Å (Li et al., 2014[Li, Y., Zhu, H., Andrada, D. M., Frenking, G. & Roesky, H. W. (2014). Chem. Commun. 50, 4628-4630.]). There is also considerable variation amongst the four structures for the individual Si—C lengths in different positions (e.g. Si1—C7 versus Si1—C8) but the average of Si—C distances of 1.861 (2) Å, and N—Si—C and C—Si—C angles of 110.76 (11) and 107.79 (13)°, respectively in (III)[link] are not significantly different at the 99% confidence level from the corresponding mean values for the comparison set of 1.859 (6) Å, 110.7 (5) and 107.84 (9)°, respectively. All other inter­atomic distances and angles found for (III)[link] are similarly indistinguishable from the comparison set at the 99% confidence level.

5. Synthesis and crystallization

2,6-Di-tert-butyl-phenol (Acros), 2,6-di-tert-butyl-4-bromo­phenol and 2,6-diiso­propyl­anilene (Aldrich) were commercial products and used as received except where noted. The technical grade anilene was purified by vacuum distillation. Solvents (BDH) were chromatographic grade and dried before use by standard methods. NMR spectra were recorded on a 300 MHz Bruker Avance II spectrometer and are referenced to tetra­methyl­silane at 0 (1H) and CDCl3 at 77.23 (13C) ppm.

5.1. Preparation of (I)

Compound (I)[link] was prepared by modification of a literature method (Lucente-Schultz et al., 2009[Lucente-Schultz, R. M., Moore, V. C., Leonard, A. D., Price, B. K., Kosynkin, D. V., Lu, M., Partha, R., Conyers, J. L. & Tour, J. M. (2009). J. Am. Chem. Soc. 131, 3934-3941.]). A 250 ml side-arm RBF was charged with 2.85 g (10 mmol) of 2,6-di-tert-butyl-4-bromo­phenol in 50 ml of dry THF. The solution was cooled to 195 K for 10 min with stirring. Then 6.0 ml (15 mmol) nBuLi (2.5 M in hexa­nes) was slowly added and the resulting mixture was stirred for 1 h. Next, chloro­trimethilsylane (2.17 g, 20 mmol) was added to the mixture and the reaction was stirred for 1 h while warming to RT. The product was poured into water (50 ml) and extracted with hexa­nes twice (2 × 20 ml). The organic layer was washed with water (30 ml), dried with anhydrous MgSO4 and filtered. The product was isolated as a colorless crystalline solid on evaporation and found to be synthetically pure. Yield 3.21 g (90%). 1H NMR (300.13 MHz, CDCl3): δ 0.41 (SiCH3, s, 9H); 1.38 [C(CH3)3, s, 18H]; 7.32 (CH, s, 2H). 13C NMR (75.48 MHz, CDCl3): δ 3.90 (SiCH3); 31.04 [C(CH3)3]; 35.31 [–C(CH3)3]; 113.82 (C4); 128.69 (C3,5); 143.12 (C2,6); 152.44 (C1). Crystals were grown from hexa­nes.

5.2. Preparation of (II)

Compound (II)[link] was prepared in an analogous manner to (I)[link] from 2.06 g (10 mmol) of 2,6-di-tert-butyl­phenol. Other reagent qu­anti­ties match those used for (I)[link]. The colorless crystalline product solidified on evaporation and was found to be synthetically pure (1.81 g, 65%). 1H NMR (300.13 MHz, CDCl3): δ 0.41 (SiCH3, s, 9H); 1.41 [C(CH3)3, s, 18H]; 6.86 (CH, t, 1H, JH–H = 7.9 Hz); 7.25 (CH, d, 2H, JH–H = 7.8 Hz). 13C NMR (75.48 MHz, CDCl3): δ 4.03 (SiCH3); 31.33 (C(CH3)3); 35.18 [–C(CH3)3]; 120.69 (C3); 125.80 (C4); 140.87 (C2); 153.20 (C1). NMR data was compared to the literature values (Goyal & Singh, 1996[Goyal, M. & Singh, A. (1996). Main Group Met. Chem. 19, 587-597.]). Crystals were grown from hexa­nes.

5.3. Preparation of (III)

Compound (III)[link] was prepared as reported in the literature (Maaninen et al., 1999[Maaninen, A., Boeré, R. T., Chivers, T. & Parvez, M. (1999). Z. Naturforsch. B, 54, 1170-1174.]). Crystals were grown by sublimation. 1H NMR agrees with the literature.

6. Refinement

Crystal data, data collection and structure refinement details are summarized in Table 2[link]. All H atoms in the three structures are attached to C atoms and are treated as riding, with C—H = 0.98 Å and Uiso = 1.5Ueq(C) for methyl, with C—H = 0.97 Å and Uiso = 1.3Ueq(C) for methine and with C—H = 0.95 Å and Uiso = 1.2Ueq(C) for aromatic. H atoms attached to methyl carbon atoms C15 in the structure of (II)[link] and C7 in the structure of (III)[link] are duplicated by the mirror symmetries and have been refined with half-occupancy.

Table 2
Experimental details

  (I) (II) (III)
Crystal data
Chemical formula C17H29BrOSi C17H30OSi C18H35NSi2
Mr 357.40 278.50 321.65
Crystal system, space group Monoclinic, P21/c Orthorhombic, Pnma Orthorhombic, Cmcm
Temperature (K) 100 100 173
a, b, c (Å) 13.0955 (1), 15.3457 (2), 9.0449 (1) 14.47237 (14), 17.4657 (2), 6.73933 (7) 12.199 (3), 12.091 (3), 14.177 (3)
α, β, γ (°) 90, 94.617 (1), 90 90, 90, 90 90, 90, 90
V3) 1811.76 (3) 1703.50 (3) 2091.1 (8)
Z 4 4 4
Radiation type Cu Kα Cu Kα Mo Kα
μ (mm−1) 3.67 1.13 0.17
Crystal size (mm) 0.42 × 0.21 × 0.13 0.31 × 0.11 × 0.07 0.19 × 0.16 × 0.10
 
Data collection
Diffractometer Rigaku Oxford Diffraction SuperNova, Dual, Cu at zero, Pilatus 200K Rigaku Oxford Diffraction SuperNova, Dual, Cu at zero, Pilatus 200K Bruker APEXII CCD
Absorption correction Multi-scan (CrysAlis PRO; Rigaku OD, 2018[Rigaku OD (2018). CrysAlis PRO. Rigaku Oxford Diffraction, Yarnton, England.]) Multi-scan (CrysAlis PRO; Rigaku OD, 2018[Rigaku OD (2018). CrysAlis PRO. Rigaku Oxford Diffraction, Yarnton, England.]) ψ scan (SADABS; Bruker, 2014[Bruker (2014). APEX2, SAINT and SADABS. Bruker AXS Inc. Madison, Wisconsin, USA.])
Tmin, Tmax 0.507, 1.000 0.773, 1.000 0.667, 0.746
No. of measured, independent and observed [I > 2σ(I)] reflections 20327, 3935, 3924 17855, 1793, 1663 8996, 1317, 1082
Rint 0.024 0.046 0.039
(sin θ/λ)max−1) 0.639 0.626 0.652
 
Refinement
R[F2 > 2σ(F2)], wR(F2), S 0.031, 0.073, 1.10 0.033, 0.093, 1.06 0.047, 0.126, 1.04
No. of reflections 3935 1793 1317
No. of parameters 191 99 64
No. of restraints 0 0 54
H-atom treatment H-atom parameters constrained H-atom parameters constrained H-atom parameters constrained
Δρmax, Δρmin (e Å−3) 0.66, −0.37 0.26, −0.28 0.36, −0.26
Computer programs: CrysAlis PRO (Rigaku OD, 2018[Rigaku OD (2018). CrysAlis PRO. Rigaku Oxford Diffraction, Yarnton, England.]), APEX2 and SAINT (Bruker, 2014[Bruker (2014). APEX2, SAINT and SADABS. Bruker AXS Inc. Madison, Wisconsin, USA.]), SHELXT (Sheldrick, 2015a[Sheldrick, G. M. (2015a). Acta Cryst. A71, 3-8.]), SHELXL (Sheldrick, 2015b[Sheldrick, G. M. (2015b). Acta Cryst. C71, 3-8.]), OLEX2 (Dolomanov et al., 2009[Dolomanov, O. V., Bourhis, L. J., Gildea, R. J., Howard, J. A. K. & Puschmann, H. (2009). J. Appl. Cryst. 42, 339-341.]) and publCIF (Westrip, 2010[Westrip, S. P. (2010). J. Appl. Cryst. 43, 920-925.]).

Supporting information


Computing details top

Data collection: CrysAlis PRO (Rigaku OD, 2018) for (I), (II); APEX2 (Bruker, 2014) for (III). Cell refinement: CrysAlis PRO (Rigaku OD, 2018) for (I), (II); SAINT (Bruker, 2014) for (III). Data reduction: CrysAlis PRO (Rigaku OD, 2018) for (I), (II); SAINT (Bruker, 2014) for (III). For all structures, program(s) used to solve structure: ShelXT (Sheldrick, 2015a); program(s) used to refine structure: SHELXL (Sheldrick, 2015b); molecular graphics: OLEX2 (Dolomanov et al., 2009); software used to prepare material for publication: publCIF (Westrip, 2010).

5-Bromo-1,3-di-tert-butyl-2-[(trimethylsilyl)oxy]benzene (I) top
Crystal data top
C17H29BrOSiF(000) = 752
Mr = 357.40Dx = 1.310 Mg m3
Monoclinic, P21/cCu Kα radiation, λ = 1.54184 Å
a = 13.0955 (1) ÅCell parameters from 18499 reflections
b = 15.3457 (2) Åθ = 4.4–79.8°
c = 9.0449 (1) ŵ = 3.67 mm1
β = 94.617 (1)°T = 100 K
V = 1811.76 (3) Å3Prism, clear colourless
Z = 40.42 × 0.21 × 0.13 mm
Data collection top
Rigaku Oxford Diffraction SuperNova, Dual, Cu at zero, Pilatus 200K
diffractometer
3935 independent reflections
Radiation source: micro-focus sealed X-ray tube, SuperNova (Cu) X-ray Source3924 reflections with I > 2σ(I)
Mirror monochromatorRint = 0.024
ω scansθmax = 80.1°, θmin = 3.4°
Absorption correction: multi-scan
(CrysAlisPro; Rigaku OD, 2018)
h = 1616
Tmin = 0.507, Tmax = 1.000k = 1918
20327 measured reflectionsl = 811
Refinement top
Refinement on F2Hydrogen site location: inferred from neighbouring sites
Least-squares matrix: fullH-atom parameters constrained
R[F2 > 2σ(F2)] = 0.031 w = 1/[σ2(Fo2) + (0.0196P)2 + 3.634P]
where P = (Fo2 + 2Fc2)/3
wR(F2) = 0.073(Δ/σ)max = 0.002
S = 1.10Δρmax = 0.66 e Å3
3935 reflectionsΔρmin = 0.36 e Å3
191 parametersExtinction correction: SHELXL-2018/3 (Sheldrick 2015b), Fc*=kFc[1+0.001xFc2λ3/sin(2θ)]-1/4
0 restraintsExtinction coefficient: 0.00139 (10)
Primary atom site location: dual
Special details top

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 (Å2) top
xyzUiso*/Ueq
Br10.51566 (2)0.21330 (2)0.45554 (3)0.01991 (9)
Si10.81135 (4)0.60159 (4)0.69256 (6)0.01462 (13)
O10.80844 (10)0.51233 (9)0.58830 (15)0.0137 (3)
C10.74581 (14)0.44182 (13)0.5533 (2)0.0122 (4)
C20.67726 (14)0.44492 (13)0.4237 (2)0.0124 (4)
C30.60978 (15)0.37556 (13)0.3970 (2)0.0139 (4)
H30.5628470.3765920.3141970.017*
C40.61193 (15)0.30530 (13)0.4923 (2)0.0143 (4)
C50.68503 (15)0.29845 (13)0.6102 (2)0.0136 (4)
H50.6868090.2490930.6700390.016*
C60.75644 (15)0.36495 (13)0.6406 (2)0.0128 (4)
C70.67316 (15)0.52100 (13)0.3119 (2)0.0141 (4)
C80.60959 (17)0.49792 (14)0.1665 (2)0.0183 (4)
H8A0.6366340.4460320.1250380.027*
H8B0.6128940.5450900.0973530.027*
H8C0.5396010.4882460.1865430.027*
C90.61968 (17)0.59939 (14)0.3782 (2)0.0196 (4)
H9A0.5485980.5860740.3851490.029*
H9B0.6256050.6493470.3155990.029*
H9C0.6514590.6116860.4753450.029*
C100.78100 (17)0.54395 (15)0.2675 (2)0.0200 (4)
H10A0.8233270.5614820.3539770.030*
H10B0.7762900.5908270.1969910.030*
H10C0.8106200.4938660.2238750.030*
C110.84163 (15)0.35033 (13)0.7659 (2)0.0140 (4)
C120.85418 (16)0.25267 (14)0.8049 (2)0.0184 (4)
H12A0.7932620.2318980.8456880.028*
H12B0.9117670.2451760.8763940.028*
H12C0.8653180.2202700.7168340.028*
C130.94702 (15)0.37909 (14)0.7187 (2)0.0183 (4)
H13A0.9636970.3456610.6342500.027*
H13B0.9982220.3696670.7992050.027*
H13C0.9447850.4398420.6933880.027*
C140.81303 (17)0.39676 (14)0.9074 (2)0.0181 (4)
H14A0.8000680.4572430.8861970.027*
H14B0.8685050.3915920.9829390.027*
H14C0.7526350.3704550.9412730.027*
C150.69125 (17)0.61128 (15)0.7890 (2)0.0223 (5)
H15A0.6450760.6506920.7350700.033*
H15B0.7072320.6330970.8875830.033*
H15C0.6596110.5550320.7938560.033*
C160.83126 (18)0.69902 (14)0.5749 (3)0.0238 (5)
H16A0.8889920.6892850.5180190.036*
H16B0.8438860.7491670.6371850.036*
H16C0.7711380.7087480.5090580.036*
C170.92756 (18)0.59976 (15)0.8263 (3)0.0247 (5)
H17A0.9211550.5539170.8971760.037*
H17B0.9341200.6546700.8770090.037*
H17C0.9871890.5897370.7734740.037*
Atomic displacement parameters (Å2) top
U11U22U33U12U13U23
Br10.01809 (13)0.01465 (12)0.02615 (14)0.00553 (8)0.00349 (8)0.00120 (8)
Si10.0148 (3)0.0125 (3)0.0165 (3)0.00183 (19)0.0007 (2)0.0017 (2)
O10.0135 (6)0.0125 (6)0.0153 (6)0.0022 (5)0.0009 (5)0.0006 (5)
C10.0107 (8)0.0117 (9)0.0145 (9)0.0004 (7)0.0029 (7)0.0023 (7)
C20.0120 (9)0.0134 (9)0.0121 (9)0.0027 (7)0.0024 (7)0.0002 (7)
C30.0128 (9)0.0154 (9)0.0132 (9)0.0006 (7)0.0002 (7)0.0003 (7)
C40.0118 (9)0.0130 (9)0.0183 (10)0.0021 (7)0.0021 (7)0.0029 (7)
C50.0140 (9)0.0127 (9)0.0142 (9)0.0002 (7)0.0018 (7)0.0017 (7)
C60.0124 (9)0.0146 (9)0.0119 (9)0.0015 (7)0.0037 (7)0.0013 (7)
C70.0158 (9)0.0129 (9)0.0136 (9)0.0005 (7)0.0012 (7)0.0015 (7)
C80.0228 (10)0.0177 (10)0.0142 (9)0.0003 (8)0.0000 (8)0.0022 (8)
C90.0240 (11)0.0149 (10)0.0198 (10)0.0054 (8)0.0002 (8)0.0007 (8)
C100.0210 (10)0.0230 (11)0.0166 (10)0.0039 (8)0.0045 (8)0.0029 (8)
C110.0139 (9)0.0147 (9)0.0131 (9)0.0006 (7)0.0004 (7)0.0006 (7)
C120.0175 (10)0.0176 (10)0.0197 (10)0.0027 (8)0.0015 (8)0.0037 (8)
C130.0132 (9)0.0198 (10)0.0215 (10)0.0009 (8)0.0005 (8)0.0020 (8)
C140.0204 (10)0.0194 (10)0.0142 (9)0.0001 (8)0.0006 (8)0.0004 (8)
C150.0215 (11)0.0246 (11)0.0214 (11)0.0014 (9)0.0049 (8)0.0021 (9)
C160.0261 (11)0.0157 (10)0.0294 (12)0.0049 (9)0.0021 (9)0.0007 (9)
C170.0230 (11)0.0209 (11)0.0291 (12)0.0048 (9)0.0042 (9)0.0035 (9)
Geometric parameters (Å, º) top
Br1—C41.904 (2)C10—H10A0.9600
Si1—O11.6617 (15)C10—H10B0.9600
Si1—C151.865 (2)C10—H10C0.9600
Si1—C161.865 (2)C11—C121.545 (3)
Si1—C171.866 (2)C11—C131.542 (3)
O1—C11.379 (2)C11—C141.537 (3)
C1—C21.419 (3)C12—H12A0.9600
C1—C61.420 (3)C12—H12B0.9600
C2—C31.392 (3)C12—H12C0.9600
C2—C71.543 (3)C13—H13A0.9600
C3—H30.9300C13—H13B0.9600
C3—C41.379 (3)C13—H13C0.9600
C4—C51.378 (3)C14—H14A0.9600
C5—H50.9300C14—H14B0.9600
C5—C61.397 (3)C14—H14C0.9600
C6—C111.541 (3)C15—H15A0.9600
C7—C81.540 (3)C15—H15B0.9600
C7—C91.538 (3)C15—H15C0.9600
C7—C101.540 (3)C16—H16A0.9600
C8—H8A0.9600C16—H16B0.9600
C8—H8B0.9600C16—H16C0.9600
C8—H8C0.9600C17—H17A0.9600
C9—H9A0.9600C17—H17B0.9600
C9—H9B0.9600C17—H17C0.9600
C9—H9C0.9600
O1—Si1—C15110.45 (9)H10A—C10—H10B109.5
O1—Si1—C16109.57 (9)H10A—C10—H10C109.5
O1—Si1—C17109.61 (9)H10B—C10—H10C109.5
C15—Si1—C16111.39 (11)C6—C11—C12111.50 (16)
C15—Si1—C17111.88 (11)C6—C11—C13111.48 (16)
C16—Si1—C17103.75 (11)C13—C11—C12105.05 (16)
C1—O1—Si1139.75 (13)C14—C11—C6109.51 (16)
O1—C1—C2119.25 (17)C14—C11—C12106.75 (16)
O1—C1—C6119.59 (17)C14—C11—C13112.41 (17)
C2—C1—C6120.97 (18)C11—C12—H12A109.5
C1—C2—C7123.59 (17)C11—C12—H12B109.5
C3—C2—C1117.91 (18)C11—C12—H12C109.5
C3—C2—C7118.50 (17)H12A—C12—H12B109.5
C2—C3—H3119.7H12A—C12—H12C109.5
C4—C3—C2120.58 (18)H12B—C12—H12C109.5
C4—C3—H3119.7C11—C13—H13A109.5
C3—C4—Br1119.37 (15)C11—C13—H13B109.5
C5—C4—Br1119.17 (15)C11—C13—H13C109.5
C5—C4—C3121.40 (18)H13A—C13—H13B109.5
C4—C5—H5119.7H13A—C13—H13C109.5
C4—C5—C6120.60 (18)H13B—C13—H13C109.5
C6—C5—H5119.7C11—C14—H14A109.5
C1—C6—C11124.24 (17)C11—C14—H14B109.5
C5—C6—C1117.59 (18)C11—C14—H14C109.5
C5—C6—C11118.17 (17)H14A—C14—H14B109.5
C8—C7—C2111.93 (16)H14A—C14—H14C109.5
C8—C7—C10105.93 (16)H14B—C14—H14C109.5
C9—C7—C2109.21 (16)Si1—C15—H15A109.5
C9—C7—C8106.33 (16)Si1—C15—H15B109.5
C9—C7—C10112.26 (17)Si1—C15—H15C109.5
C10—C7—C2111.09 (16)H15A—C15—H15B109.5
C7—C8—H8A109.5H15A—C15—H15C109.5
C7—C8—H8B109.5H15B—C15—H15C109.5
C7—C8—H8C109.5Si1—C16—H16A109.5
H8A—C8—H8B109.5Si1—C16—H16B109.5
H8A—C8—H8C109.5Si1—C16—H16C109.5
H8B—C8—H8C109.5H16A—C16—H16B109.5
C7—C9—H9A109.5H16A—C16—H16C109.5
C7—C9—H9B109.5H16B—C16—H16C109.5
C7—C9—H9C109.5Si1—C17—H17A109.5
H9A—C9—H9B109.5Si1—C17—H17B109.5
H9A—C9—H9C109.5Si1—C17—H17C109.5
H9B—C9—H9C109.5H17A—C17—H17B109.5
C7—C10—H10A109.5H17A—C17—H17C109.5
C7—C10—H10B109.5H17B—C17—H17C109.5
C7—C10—H10C109.5
Br1—C4—C5—C6179.69 (15)C2—C3—C4—C54.7 (3)
Si1—O1—C1—C295.3 (2)C3—C2—C7—C813.1 (2)
Si1—O1—C1—C689.5 (2)C3—C2—C7—C9104.4 (2)
O1—C1—C2—C3175.38 (17)C3—C2—C7—C10131.27 (19)
O1—C1—C2—C74.2 (3)C3—C4—C5—C63.1 (3)
O1—C1—C6—C5173.89 (17)C4—C5—C6—C14.7 (3)
O1—C1—C6—C116.3 (3)C4—C5—C6—C11175.10 (17)
C1—C2—C3—C41.6 (3)C5—C6—C11—C1218.1 (2)
C1—C2—C7—C8167.30 (18)C5—C6—C11—C13135.20 (19)
C1—C2—C7—C975.2 (2)C5—C6—C11—C1499.8 (2)
C1—C2—C7—C1049.1 (2)C6—C1—C2—C39.5 (3)
C1—C6—C11—C12161.65 (18)C6—C1—C2—C7170.85 (17)
C1—C6—C11—C1344.6 (3)C7—C2—C3—C4178.75 (18)
C1—C6—C11—C1480.4 (2)C15—Si1—O1—C12.0 (2)
C2—C1—C6—C511.0 (3)C16—Si1—O1—C1125.1 (2)
C2—C1—C6—C11168.74 (17)C17—Si1—O1—C1121.7 (2)
C2—C3—C4—Br1178.09 (15)
1,3-Di-tert-butyl-2-[(trimethylsilyl)oxy]benzene (II) top
Crystal data top
C17H30OSiDx = 1.086 Mg m3
Mr = 278.50Cu Kα radiation, λ = 1.54184 Å
Orthorhombic, PnmaCell parameters from 12570 reflections
a = 14.47237 (14) Åθ = 5.1–74.4°
b = 17.4657 (2) ŵ = 1.13 mm1
c = 6.73933 (7) ÅT = 100 K
V = 1703.50 (3) Å3Needle, clear colourless
Z = 40.31 × 0.11 × 0.07 mm
F(000) = 616
Data collection top
Rigaku Oxford Diffraction SuperNova, Dual, Cu at zero, Pilatus 200K
diffractometer
1793 independent reflections
Radiation source: micro-focus sealed X-ray tube, SuperNova (Cu) X-ray Source1663 reflections with I > 2σ(I)
Mirror monochromatorRint = 0.046
ω scansθmax = 74.7°, θmin = 5.1°
Absorption correction: multi-scan
(CrysAlisPro; Rigaku OD, 2018)
h = 1817
Tmin = 0.773, Tmax = 1.000k = 2120
17855 measured reflectionsl = 88
Refinement top
Refinement on F2Primary atom site location: dual
Least-squares matrix: fullHydrogen site location: inferred from neighbouring sites
R[F2 > 2σ(F2)] = 0.033H-atom parameters constrained
wR(F2) = 0.093 w = 1/[σ2(Fo2) + (0.0463P)2 + 0.6892P]
where P = (Fo2 + 2Fc2)/3
S = 1.06(Δ/σ)max < 0.001
1793 reflectionsΔρmax = 0.26 e Å3
99 parametersΔρmin = 0.28 e Å3
0 restraints
Special details top

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 (Å2) top
xyzUiso*/UeqOcc. (<1)
Si10.44620 (3)0.2500000.02273 (7)0.01982 (15)
O10.55464 (8)0.2500000.10549 (17)0.0194 (3)
C10.59998 (11)0.2500000.2860 (2)0.0181 (3)
C20.62564 (8)0.32076 (6)0.37337 (17)0.0195 (3)
C30.66393 (8)0.31815 (7)0.56362 (18)0.0228 (3)
H30.6790790.3648590.6280930.027*
C40.68049 (12)0.2500000.6610 (3)0.0244 (4)
H40.7029930.2500010.7934540.029*
C70.61394 (8)0.39980 (7)0.27322 (18)0.0219 (3)
C80.67393 (10)0.46122 (7)0.3744 (2)0.0309 (3)
H8A0.6528330.4686500.5112290.046*
H8B0.6685680.5095540.3014450.046*
H8C0.7385940.4445590.3749470.046*
C90.64519 (9)0.39815 (7)0.05482 (18)0.0249 (3)
H9A0.7105770.3838080.0479810.037*
H9B0.6367150.4489720.0040680.037*
H9C0.6081630.3606250.0184200.037*
C100.51286 (9)0.42590 (7)0.29218 (19)0.0268 (3)
H10A0.4723540.3880990.2290550.040*
H10B0.5051560.4755970.2267340.040*
H10C0.4966310.4306300.4328220.040*
C150.36580 (12)0.2500000.2393 (3)0.0259 (4)
H15A0.3069650.2265950.2005280.039*0.5
H15B0.3549890.3027880.2827530.039*0.5
H15C0.3932420.2206170.3482490.039*0.5
C160.42870 (9)0.16623 (8)0.1452 (2)0.0282 (3)
H16A0.4759830.1666580.2493300.042*
H16B0.3673040.1693300.2060600.042*
H16C0.4336240.1187480.0685070.042*
Atomic displacement parameters (Å2) top
U11U22U33U12U13U23
Si10.0205 (2)0.0176 (3)0.0213 (3)0.0000.00179 (16)0.000
O10.0212 (6)0.0171 (6)0.0198 (6)0.0000.0020 (4)0.000
C10.0178 (7)0.0194 (8)0.0170 (8)0.0000.0020 (6)0.000
C20.0194 (5)0.0178 (6)0.0214 (6)0.0005 (4)0.0031 (4)0.0006 (5)
C30.0258 (6)0.0213 (6)0.0213 (6)0.0011 (5)0.0027 (5)0.0037 (5)
C40.0277 (9)0.0274 (9)0.0182 (8)0.0000.0006 (7)0.000
C70.0266 (6)0.0154 (6)0.0237 (6)0.0013 (5)0.0008 (5)0.0012 (5)
C80.0402 (8)0.0188 (6)0.0338 (7)0.0063 (5)0.0060 (6)0.0002 (5)
C90.0303 (6)0.0189 (6)0.0256 (6)0.0033 (5)0.0024 (5)0.0028 (5)
C100.0315 (7)0.0197 (6)0.0291 (7)0.0050 (5)0.0000 (5)0.0031 (5)
C150.0230 (8)0.0266 (9)0.0280 (9)0.0000.0007 (7)0.000
C160.0297 (6)0.0263 (7)0.0286 (7)0.0000 (5)0.0057 (5)0.0048 (5)
Geometric parameters (Å, º) top
Si1—O11.6655 (12)C8—H8A0.9800
Si1—C151.8664 (19)C8—H8B0.9800
Si1—C161.8671 (13)C8—H8C0.9800
Si1—C16i1.8671 (13)C9—H9A0.9800
O1—C11.3821 (19)C9—H9B0.9800
C1—C21.4185 (14)C9—H9C0.9800
C1—C2i1.4185 (14)C10—H10A0.9800
C2—C31.3976 (17)C10—H10B0.9800
C2—C71.5461 (16)C10—H10C0.9800
C3—H30.9500C15—H15A0.9800
C3—C41.3802 (15)C15—H15B0.9800
C4—H40.9500C15—H15C0.9800
C7—C81.5393 (17)C16—H16A0.9800
C7—C91.5400 (16)C16—H16B0.9800
C7—C101.5376 (17)C16—H16C0.9800
O1—Si1—C15109.00 (7)H8A—C8—H8B109.5
O1—Si1—C16i109.32 (5)H8A—C8—H8C109.5
O1—Si1—C16109.32 (5)H8B—C8—H8C109.5
C15—Si1—C16i112.92 (5)C7—C9—H9A109.5
C15—Si1—C16112.92 (5)C7—C9—H9B109.5
C16—Si1—C16i103.18 (9)C7—C9—H9C109.5
C1—O1—Si1137.91 (10)H9A—C9—H9B109.5
O1—C1—C2119.32 (7)H9A—C9—H9C109.5
O1—C1—C2i119.32 (7)H9B—C9—H9C109.5
C2—C1—C2i121.21 (15)C7—C10—H10A109.5
C1—C2—C7124.62 (10)C7—C10—H10B109.5
C3—C2—C1117.15 (11)C7—C10—H10C109.5
C3—C2—C7118.24 (10)H10A—C10—H10B109.5
C2—C3—H3118.9H10A—C10—H10C109.5
C4—C3—C2122.23 (12)H10B—C10—H10C109.5
C4—C3—H3118.9Si1—C15—H15A109.5
C3—C4—C3i119.16 (16)Si1—C15—H15B109.5
C3—C4—H4120.4Si1—C15—H15C109.5
C3i—C4—H4120.4H15A—C15—H15B109.5
C8—C7—C2111.54 (10)H15A—C15—H15C109.5
C8—C7—C9105.71 (10)H15B—C15—H15C109.5
C9—C7—C2111.61 (9)Si1—C16—H16A109.5
C10—C7—C2109.43 (10)Si1—C16—H16B109.5
C10—C7—C8107.06 (10)Si1—C16—H16C109.5
C10—C7—C9111.37 (10)H16A—C16—H16B109.5
C7—C8—H8A109.5H16A—C16—H16C109.5
C7—C8—H8B109.5H16B—C16—H16C109.5
C7—C8—H8C109.5
Si1—O1—C1—C292.19 (12)C2i—C1—C2—C7170.19 (9)
Si1—O1—C1—C2i92.19 (12)C2—C3—C4—C3i3.9 (2)
O1—C1—C2—C3174.50 (12)C3—C2—C7—C817.63 (15)
O1—C1—C2—C75.3 (2)C3—C2—C7—C9135.63 (11)
C1—C2—C3—C42.89 (19)C3—C2—C7—C10100.63 (12)
C1—C2—C7—C8162.53 (12)C7—C2—C3—C4177.26 (12)
C1—C2—C7—C944.53 (16)C15—Si1—O1—C10.000 (1)
C1—C2—C7—C1079.20 (15)C16i—Si1—O1—C1123.87 (5)
C2i—C1—C2—C310.0 (2)C16—Si1—O1—C1123.87 (5)
Symmetry code: (i) x, y+1/2, z.
N-(2,6-Diisopropylphenyl)-1,1,1-trimethyl-N-(trimethylsilyl)silanamine (III) top
Crystal data top
C18H35NSi2Dx = 1.022 Mg m3
Mr = 321.65Mo Kα radiation, λ = 0.71073 Å
Orthorhombic, CmcmCell parameters from 4098 reflections
a = 12.199 (3) Åθ = 2.4–27.5°
b = 12.091 (3) ŵ = 0.17 mm1
c = 14.177 (3) ÅT = 173 K
V = 2091.1 (8) Å3Block, clear colourless
Z = 40.19 × 0.16 × 0.10 mm
F(000) = 712
Data collection top
Bruker APEXII CCD
diffractometer
1082 reflections with I > 2σ(I)
Graphite monochromatorRint = 0.039
φ and ω scansθmax = 27.6°, θmin = 2.4°
Absorption correction: ψ scan
(SADABS; Bruker, 2014)
h = 1515
Tmin = 0.667, Tmax = 0.746k = 1515
8996 measured reflectionsl = 1817
1317 independent reflections
Refinement top
Refinement on F2Primary atom site location: dual
Least-squares matrix: fullHydrogen site location: inferred from neighbouring sites
R[F2 > 2σ(F2)] = 0.047H-atom parameters constrained
wR(F2) = 0.126 w = 1/[σ2(Fo2) + (0.0516P)2 + 2.3874P]
where P = (Fo2 + 2Fc2)/3
S = 1.04(Δ/σ)max < 0.001
1317 reflectionsΔρmax = 0.36 e Å3
64 parametersΔρmin = 0.26 e Å3
54 restraints
Special details top

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 (Å2) top
xyzUiso*/UeqOcc. (<1)
Si10.62813 (7)0.91524 (6)0.7500000.0459 (3)
N10.5000000.8496 (2)0.7500000.0315 (6)
C10.5000000.7298 (2)0.7500000.0262 (6)
C20.5000000.67207 (17)0.66401 (16)0.0308 (5)
C30.5000000.55648 (18)0.6663 (2)0.0402 (6)
H30.5000000.5165290.6086500.048*
C40.5000000.4993 (3)0.7500000.0446 (9)
H40.5000000.4207460.7500000.053*
C50.5000000.7292 (2)0.56902 (17)0.0396 (6)
H50.5000000.8107960.5803800.047*
C60.39760 (16)0.70083 (19)0.51164 (15)0.0572 (5)
H6A0.3959260.6211200.4991700.086*
H6B0.3992110.7411610.4517000.086*
H6C0.3320660.7220350.5472910.086*
C70.7385 (2)0.8087 (3)0.7500000.0656 (9)
H7A0.8069540.8417860.7272700.098*0.5
H7B0.7175500.7474650.7084700.098*0.5
H7C0.7491740.7808280.8142600.098*0.5
C80.6484 (3)1.0030 (3)0.8562 (2)0.1024 (11)
H8A0.5956391.0640920.8553110.154*
H8B0.7230891.0327430.8561530.154*
H8C0.6370790.9583080.9130290.154*
Atomic displacement parameters (Å2) top
U11U22U33U12U13U23
Si10.0650 (5)0.0344 (4)0.0382 (4)0.0227 (3)0.0000.000
N10.0452 (14)0.0211 (11)0.0281 (13)0.0000.0000.000
C10.0233 (13)0.0231 (13)0.0323 (15)0.0000.0000.000
C20.0253 (9)0.0293 (10)0.0377 (12)0.0000.0000.0060 (9)
C30.0345 (11)0.0283 (11)0.0578 (16)0.0000.0000.0132 (10)
C40.0329 (16)0.0222 (14)0.079 (3)0.0000.0000.000
C50.0492 (13)0.0382 (12)0.0313 (12)0.0000.0000.0087 (10)
C60.0526 (11)0.0753 (14)0.0437 (11)0.0083 (10)0.0095 (9)0.0060 (10)
C70.0414 (15)0.076 (2)0.080 (2)0.0221 (15)0.0000.000
C80.117 (2)0.0922 (19)0.098 (2)0.0496 (19)0.0103 (19)0.0548 (17)
Geometric parameters (Å, º) top
Si1—N11.7529 (13)C1—C2i1.405 (3)
Si1—C71.864 (4)C2—C31.398 (3)
Si1—C81.858 (2)C2—C51.513 (3)
Si1—C8i1.858 (2)C3—C41.373 (3)
N1—C11.448 (4)C5—C61.530 (2)
C1—C21.405 (3)C5—C6ii1.530 (2)
N1—Si1—C7109.36 (12)C2—C1—N1119.81 (13)
N1—Si1—C8112.15 (10)C2i—C1—C2120.4 (3)
N1—Si1—C8i112.15 (10)C1—C2—C5123.05 (19)
C8—Si1—C7107.37 (13)C3—C2—C1118.5 (2)
C8i—Si1—C7107.37 (13)C3—C2—C5118.5 (2)
C8—Si1—C8i108.2 (2)C4—C3—C2121.6 (2)
Si1iii—N1—Si1126.17 (15)C3i—C4—C3119.5 (3)
C1—N1—Si1iii116.92 (7)C2—C5—C6ii111.78 (14)
C1—N1—Si1116.92 (7)C2—C5—C6111.78 (14)
C2i—C1—N1119.81 (13)C6—C5—C6ii109.5 (2)
Symmetry codes: (i) x, y, z+3/2; (ii) x+1, y, z; (iii) x+1, y, z+3/2.
Average interatomic distances and angles (Å, °) in (I), (II) and (III) with comparators top
Atom numbers taken from (I).
Parameter(I)(II)Mean siloxanea(III)Mean silanamineb
Si1—O1,N11.6617 (15)1.657 (10)1.7529 (13)1.762 (18)
Ave Si—C1.865 (2)1.8666 (15)1.861 (8)1.861 (2)1.859 (6)
C1—O1,N11.379 (2)1.3823 (19)1.385 (7)1.448 (4)1.453 (8)
Av C1—C2,61.419 (3)1.4183 (14)1.415 (5)1.405 (3)1.403 (4)
Av C2,5—C3,61.395 (3)1.3977 (17)1.395 (7)1.398 (3)1.389 (3)
Av C2,6—C7,111.542 (3)1.5459 (16)1.546 (4)1.513 (3)1.519 (7)
Av C3,5—C41.379 (3)1.3798 (15)1.385 (6)1.373 (3)1.378 (11)
Av C7,11-methyl1.540 (3)1.5386 (17)1.537 (7)1.530 (2)1.523 (6)
Av C—Si—C109.88 (9)109.21 (6)110.0 (8)110.76 (11)110.7 (5)
Av O,N—Si—C109.01 (11)109.68 (7)108.9 (18)107.79 (13)107.84 (9)
C1—O1,N1—Si1139.75 (13)137.90 (10)140 (5)116.92 (7)117.0 (10)
Av C2,6—C1—O,N119.42 (17)119.31 (7)119.2 (10)119.81 (13)119.8 (2)
C2—C1—C6120.97 (18)121.23 (15)121.4 (5)120.4 (3)120.5 (4)
Av C1—C2,6—C3,5117.75 (18)117.12 (11)117.9 (6)118.5 (2)118.7 (4)
Av C1—C2,6—C7,11123.92 (17)124.64 (11)124.3 (10)123.05 (19)123.2 (4)
Av C3,5—C2,6—C7,C11118.34 (17)118.24 (10)112.5 (13)118.5 (2)118.6 (11)
Av C2,6—C3,5—C4120.59 (18)122.25 (12)122.5 (11)121.6 (2)121.1 (10)
C3—C4—C5121.40 (18)119.17 (16)118.5 (16)119.5 (3)119.9 (16)
Av C2,6—C7,11—Me110.79 (16)110.86 (10)110.7 (11)111.78 (14)111.83 (15)
Av Me—C7,11—Me108.12 (16)108.04 (10)108.2 (14)109.5 (2)109.55 (7)
Notes: (a) Mean values taken over (I), (II), BBPHOL02, GIFCEE, JEHDOP, LIKYEJ, TIXZUK and TIYBEK, treating crystallographically independent entities separately. (b) Mean values taken over (III), CAQWUW, CORKAV and QOCSEI.
 

Acknowledgements

We thank the University of Lethbridge and the Faculty of Arts&Science as well as the NSERC-Canada (RTI program) for the purchase of the diffractometers.

Funding information

Funding for this research was provided by: Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (Brazil); Natural Sciences and Engineering Research Council of Canada.

References

First citationBruker (2014). APEX2, SAINT and SADABS. Bruker AXS Inc. Madison, Wisconsin, USA.  Google Scholar
First citationChung, M.-H., Yu, I. F., Liu, Y.-H., Lin, T.-S., Peng, S.-M. & Chiu, C. W. (2018). Inorg. Chem. 57, 11732–11737.  Web of Science CSD CrossRef CAS PubMed Google Scholar
First citationDolomanov, O. V., Bourhis, L. J., Gildea, R. J., Howard, J. A. K. & Puschmann, H. (2009). J. Appl. Cryst. 42, 339–341.  Web of Science CrossRef CAS IUCr Journals Google Scholar
First citationGoyal, M. & Singh, A. (1996). Main Group Met. Chem. 19, 587–597.  CrossRef CAS Google Scholar
First citationGroom, C. R., Bruno, I. J., Lightfoot, M. P. & Ward, S. C. (2016). Acta Cryst. B72, 171–179.  Web of Science CrossRef IUCr Journals Google Scholar
First citationHealy, M. D. & Barron, A. R. (1990). J. Organomet. Chem. 381, 165–172.  CSD CrossRef CAS Web of Science Google Scholar
First citationKindra, D. R., Casely, I. J., Fieser, M. E., Ziller, J. W., Furche, F. & Evans, W. J. (2013). J. Am. Chem. Soc. 135, 7777–7787.  Web of Science CSD CrossRef CAS PubMed Google Scholar
First citationLi, Y., Zhu, H., Andrada, D. M., Frenking, G. & Roesky, H. W. (2014). Chem. Commun. 50, 4628–4630.  Web of Science CSD CrossRef CAS Google Scholar
First citationLide, D. R. (2004). Editor. CRC Handbook of Chemistry and Physics, 85th ed, sect. 9.1. Boca Raton: CRC Press.  Google Scholar
First citationLucente-Schultz, R. M., Moore, V. C., Leonard, A. D., Price, B. K., Kosynkin, D. V., Lu, M., Partha, R., Conyers, J. L. & Tour, J. M. (2009). J. Am. Chem. Soc. 131, 3934–3941.  Web of Science PubMed CAS Google Scholar
First citationMaaninen, A., Boeré, R. T., Chivers, T. & Parvez, M. (1999). Z. Naturforsch. B, 54, 1170–1174.  Web of Science CrossRef CAS Google Scholar
First citationMarszaukowski, F. & Boeré, R. T. (2019). CSD Communication (refcode CCDC 1907965). CCDC, Cambridge, England. https://doi.org/10.5517/ccdc.csd.cc221d8t  Google Scholar
First citationNieves-Quinones, Y., Paniak, T. J., Lee, Y. E., Kim, S. M., Tcyrulnikov, S. & Kozlowski, M. C. (2019). J. Am. Chem. Soc. 141, 10016–10032.  Web of Science CAS PubMed Google Scholar
First citationOtaki, M. & Goto, H. (2019). Macromolecules, 52, 3199–3209.  Web of Science CrossRef CAS Google Scholar
First citationPennington, D. A., Horton, P. N., Hursthouse, M. B., Bochmann, M. & Lancaster, S. J. (2005). Polyhedron, 24, 151–156.  Web of Science CSD CrossRef CAS Google Scholar
First citationPoverenov, E., Shimon, L. J. W. & Milstein, D. (2007). Organometallics, 26, 2178–2182.  Web of Science CSD CrossRef CAS Google Scholar
First citationRigaku OD (2018). CrysAlis PRO. Rigaku Oxford Diffraction, Yarnton, England.  Google Scholar
First citationSatoh, Y. & Shi, C. (1994). Synthesis, pp. 1146–1148.  CSD CrossRef Google Scholar
First citationSheldrick, G. M. (2015a). Acta Cryst. A71, 3–8.  Web of Science CrossRef IUCr Journals Google Scholar
First citationSheldrick, G. M. (2015b). Acta Cryst. C71, 3–8.  Web of Science CrossRef IUCr Journals Google Scholar
First citationSiemeling, U., Neumann, B., Stammler, H.-G. & Kuhnert, O. (1999). Polyhedron, 18, 1815–1819.  Web of Science CSD CrossRef CAS Google Scholar
First citationStalke, D., Keweloh, N., Klingebiel, U., Noltemeyer, M. & Sheldrick, G. M. (1987). Z. Naturforsch. B, 42, 1237–1244.  CrossRef CAS Google Scholar
First citationWang, J., Pan, X., Liu, J., Zhao, L., Zhi, Y., Zhao, K. & Hu, L. (2018). Org. Lett. 20, 5995–5998.  Web of Science CSD CrossRef CAS PubMed Google Scholar
First citationWestrip, S. P. (2010). J. Appl. Cryst. 43, 920–925.  Web of Science CrossRef CAS IUCr Journals Google Scholar

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