Related literature {#sec1}
==================

For the hydrolysis of 1,3-bis-(hy­droxy­diphenyl­silan­yl)-2,2,4,4-tetra­phenyl­cyclo­disilazane, see: Voronkov *et al.* (1977[@bb3]).

Experimental {#sec2}
============

 {#sec2.1}

### Crystal data {#sec2.1.1}

C~48~H~42~N~2~O~2~Si~4~*M* *~r~* = 791.20Monoclinic,*a* = 12.1188 (18) Å*b* = 17.016 (3) Å*c* = 20.621 (3) Åβ = 93.216 (3)°*V* = 4245.8 (11) Å^3^*Z* = 4Mo *K*α radiationμ = 0.18 mm^−1^*T* = 173 K0.35 × 0.35 × 0.05 mm

### Data collection {#sec2.1.2}

Rigaku MM007-HF CCD (Saturn 724+) diffractometerAbsorption correction: multi-scan (*CrystalClear*; Rigaku, 2007[@bb1]) *T* ~min~ = 0.939, *T* ~max~ = 0.99114029 measured reflections4833 independent reflections4411 reflections with *I* \> 2σ(*I*)*R* ~int~ = 0.039

### Refinement {#sec2.1.3}

*R*\[*F* ^2^ \> 2σ(*F* ^2^)\] = 0.052*wR*(*F* ^2^) = 0.120*S* = 1.104833 reflections253 parametersH-atom parameters constrainedΔρ~max~ = 0.39 e Å^−3^Δρ~min~ = −0.30 e Å^−3^

 {#d5e345}

Data collection: *CrystalClear* (Rigaku, 2007[@bb1]); cell refinement: *CrystalClear*; data reduction: *CrystalClear*; program(s) used to solve structure: *SHELXS97* (Sheldrick, 2008[@bb2]); program(s) used to refine structure: *SHELXL97* (Sheldrick, 2008[@bb2]); molecular graphics: *SHELXTL* (Sheldrick, 2008[@bb2]); software used to prepare material for publication: *SHELXL97*.

Supplementary Material
======================

Crystal structure: contains datablocks I, global. DOI: [10.1107/S1600536811014851/lh5233sup1.cif](http://dx.doi.org/10.1107/S1600536811014851/lh5233sup1.cif)

Structure factors: contains datablocks I. DOI: [10.1107/S1600536811014851/lh5233Isup2.hkl](http://dx.doi.org/10.1107/S1600536811014851/lh5233Isup2.hkl)

Supplementary material file. DOI: [10.1107/S1600536811014851/lh5233Isup3.cml](http://dx.doi.org/10.1107/S1600536811014851/lh5233Isup3.cml)

Additional supplementary materials: [crystallographic information](http://scripts.iucr.org/cgi-bin/sendsupfiles?lh5233&file=lh5233sup0.html&mime=text/html); [3D view](http://scripts.iucr.org/cgi-bin/sendcif?lh5233sup1&Qmime=cif); [checkCIF report](http://scripts.iucr.org/cgi-bin/paper?lh5233&checkcif=yes)

Supplementary data and figures for this paper are available from the IUCr electronic archives (Reference: [LH5233](http://scripts.iucr.org/cgi-bin/sendsup?lh5233)).

The authors would like to thank the National Natural Science Foundation of China (grant No. 50803070) for financial support.

Comment
=======

The title compound is one of the hydrolysis products of 1,3-bis-(hydroxydiphenylsilanyl)-2,2,4,4-tetraphenylcyclodisilazane. Voronkov *et al.* (1977) reported that the hydrolysis of 1,3-bis-(hydroxydiphenylsilanyl)-2,2,4,4-tetraphenylcyclodisilazane in base medium could give 1,1,3,3,5,5,7,7-octaphenyl-2,4-dioxa-6,8,-diaza-1,3,5,7-tetrasilacyclo-octane and we have found that the title compound was also produced. Its crystal structure is presented herein. The molecular structure of the title compound is shown in Fig. 1. The eight-membered ring has a slightly disorted boat conformation.

Experimental {#experimental}
============

The reaction scheme is shown in Fig. 2. 1 ml aqueous solution of sodium hydroxide (0.1 mol/*L*) was added to a solution of 1,3-bis-(hydroxydiphenylsilanyl)-2,2,4,4-tetraphenylcyclodisilazane (1 g) in tetrahydrofuran (10 ml). After stirring for 30 min at room temprature, the solvents were removed under reduced pressure. The crude product was recrystallized from n-hexane to give colorless crystals.

Refinement {#refinement}
==========

All the H atoms were located in difference maps but were subsequently placed in calculated positions with C-H = 0.95Å and constrained in a riding-model approximation with *U*~iso~(H) = 1.2*U*~eq~(C).

Figures
=======

![The molecular structure of the title compound with 30% ellipsoids. H atoms are not shown (symmetry code (A): -x+1, y, -z+3/2).](e-67-o1233-fig1){#Fap1}

![The hydrolysis reaction of 1,3-bis-(hydroxydiphenylsilanyl)-2,2,4,4-tetraphenylcyclodisilazane](e-67-o1233-fig2){#Fap2}

Crystal data {#tablewrapcrystaldatalong}
============

  ------------------------- ---------------------------------------
  C~48~H~42~N~2~O~2~Si~4~   *F*(000) = 1664
  *M~r~* = 791.20           *D*~x~ = 1.238 Mg m^−3^
  Monoclinic, *C*2/*c*      Mo *K*α radiation, λ = 0.71073 Å
  Hall symbol: -C 2yc       Cell parameters from 7324 reflections
  *a* = 12.1188 (18) Å      θ = 2.1--27.5°
  *b* = 17.016 (3) Å        µ = 0.18 mm^−1^
  *c* = 20.621 (3) Å        *T* = 173 K
  β = 93.216 (3)°           Platelet, colorless
  *V* = 4245.8 (11) Å^3^    0.35 × 0.35 × 0.05 mm
  *Z* = 4                   
  ------------------------- ---------------------------------------

Data collection {#tablewrapdatacollectionlong}
===============

  ------------------------------------------------------------------ --------------------------------------
  Rigaku MM007-HF CCD (Saturn 724+) diffractometer                   4833 independent reflections
  Radiation source: rotating anode                                   4411 reflections with *I* \> 2σ(*I*)
  Confocal                                                           *R*~int~ = 0.039
  ω scans at fixed χ = 45°                                           θ~max~ = 27.5°, θ~min~ = 2.1°
  Absorption correction: multi-scan (*CrystalClear*; Rigaku, 2007)   *h* = −15→13
  *T*~min~ = 0.939, *T*~max~ = 0.991                                 *k* = −18→22
  14029 measured reflections                                         *l* = −26→24
  ------------------------------------------------------------------ --------------------------------------

Refinement {#tablewraprefinementdatalong}
==========

  ------------------------------------- ------------------------------------------------------------------------------------------------
  Refinement on *F*^2^                  Primary atom site location: structure-invariant direct methods
  Least-squares matrix: full            Secondary atom site location: difference Fourier map
  *R*\[*F*^2^ \> 2σ(*F*^2^)\] = 0.052   Hydrogen site location: inferred from neighbouring sites
  *wR*(*F*^2^) = 0.120                  H-atom parameters constrained
  *S* = 1.10                            *w* = 1/\[σ^2^(*F*~o~^2^) + (0.0442*P*)^2^ + 4.974*P*\] where *P* = (*F*~o~^2^ + 2*F*~c~^2^)/3
  4833 reflections                      (Δ/σ)~max~ = 0.001
  253 parameters                        Δρ~max~ = 0.39 e Å^−3^
  0 restraints                          Δρ~min~ = −0.30 e Å^−3^
  ------------------------------------- ------------------------------------------------------------------------------------------------

Special details {#specialdetails}
===============

  -----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
  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 *F*^2^ against ALL reflections. The weighted *R*-factor *wR* and goodness of fit *S* are based on *F*^2^, conventional *R*-factors *R* are based on *F*, with *F* set to zero for negative *F*^2^. The threshold expression of *F*^2^ \> σ(*F*^2^) is used only for calculating *R*-factors(gt) *etc*. and is not relevant to the choice of reflections for refinement. *R*-factors based on *F*^2^ 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 (Å^2^) {#tablewrapcoords}
==================================================================================================

  ------ -------------- --------------- -------------- -------------------- --
         *x*            *y*             *z*            *U*~iso~\*/*U*~eq~   
  Si1    0.34094 (4)    0.15720 (3)     0.71343 (2)    0.02431 (13)         
  Si2    0.55767 (4)    0.21644 (3)     0.65217 (2)    0.02461 (13)         
  O1     0.44552 (11)   0.16871 (8)     0.66768 (6)    0.0324 (3)           
  N1     0.35191 (13)   0.21530 (9)     0.78113 (7)    0.0282 (3)           
  H1A    0.3008         0.2520          0.7818         0.034\*              
  C1     0.21399 (15)   0.18949 (11)    0.66561 (8)    0.0269 (4)           
  C2     0.21930 (18)   0.23932 (15)    0.61226 (10)   0.0437 (5)           
  H2A    0.2895         0.2534          0.5975         0.052\*              
  C3     0.12476 (19)   0.26890 (15)    0.58017 (11)   0.0471 (6)           
  H3A    0.1310         0.3036          0.5445         0.057\*              
  C4     0.02258 (18)   0.24847 (14)    0.59954 (10)   0.0415 (5)           
  H4A    −0.0422        0.2684          0.5772         0.050\*              
  C5     0.01439 (18)   0.19908 (15)    0.65148 (12)   0.0478 (6)           
  H5A    −0.0564        0.1845          0.6651         0.057\*              
  C6     0.10912 (17)   0.17011 (13)    0.68447 (11)   0.0390 (5)           
  H6A    0.1019         0.1363          0.7207         0.047\*              
  C7     0.33633 (15)   0.05141 (11)    0.73523 (9)    0.0284 (4)           
  C8     0.29044 (18)   0.02462 (12)    0.79170 (11)   0.0405 (5)           
  H8A    0.2599         0.0613          0.8204         0.049\*              
  C9     0.2889 (2)     −0.05507 (14)   0.80646 (12)   0.0503 (6)           
  H9A    0.2573         −0.0725         0.8450         0.060\*              
  C10    0.3333 (2)     −0.10885 (13)   0.76511 (13)   0.0492 (6)           
  H10A   0.3335         −0.1632         0.7756         0.059\*              
  C11    0.3772 (2)     −0.08378 (13)   0.70882 (12)   0.0481 (6)           
  H11A   0.4062         −0.1209         0.6799         0.058\*              
  C12    0.37953 (19)   −0.00461 (12)   0.69411 (10)   0.0390 (5)           
  H12A   0.4111         0.0121          0.6553         0.047\*              
  C13    0.61490 (16)   0.16531 (11)    0.58150 (8)    0.0289 (4)           
  C14    0.5520 (2)     0.11582 (13)    0.54049 (10)   0.0416 (5)           
  H14A   0.4766         0.1068          0.5485         0.050\*              
  C15    0.5975 (2)     0.07921 (15)    0.48789 (12)   0.0550 (6)           
  H15A   0.5531         0.0461          0.4600         0.066\*              
  C16    0.7078 (2)     0.09105 (15)    0.47616 (12)   0.0545 (7)           
  H16A   0.7399         0.0647          0.4412         0.065\*              
  C17    0.7700 (2)     0.14071 (17)    0.51506 (12)   0.0543 (6)           
  H17A   0.8451         0.1501          0.5065         0.065\*              
  C18    0.72369 (18)   0.17780 (15)    0.56732 (11)   0.0434 (5)           
  H18A   0.7679         0.2125          0.5938         0.052\*              
  C19    0.52733 (15)   0.32134 (11)    0.63098 (9)    0.0306 (4)           
  C20    0.5545 (2)     0.38324 (14)    0.67257 (12)   0.0515 (6)           
  H20A   0.5909         0.3725          0.7136         0.062\*              
  C21    0.5299 (3)     0.46049 (16)    0.65572 (16)   0.0752 (9)           
  H21A   0.5515         0.5019          0.6846         0.090\*              
  C22    0.4745 (3)     0.47717 (17)    0.59751 (16)   0.0731 (9)           
  H22A   0.4558         0.5299          0.5866         0.088\*              
  C23    0.4461 (2)     0.41749 (17)    0.55499 (13)   0.0591 (7)           
  H23A   0.4083         0.4290          0.5145         0.071\*              
  C24    0.47270 (17)   0.34019 (14)    0.57119 (10)   0.0410 (5)           
  H24A   0.4535         0.2994          0.5412         0.049\*              
  ------ -------------- --------------- -------------- -------------------- --

Atomic displacement parameters (Å^2^) {#tablewrapadps}
=====================================

  ----- ------------- ------------- ------------- --------------- -------------- ---------------
        *U*^11^       *U*^22^       *U*^33^       *U*^12^         *U*^13^        *U*^23^
  Si1   0.0250 (2)    0.0252 (2)    0.0230 (2)    −0.00224 (18)   0.00372 (18)   −0.00254 (18)
  Si2   0.0258 (3)    0.0269 (2)    0.0213 (2)    −0.00168 (19)   0.00308 (18)   0.00178 (18)
  O1    0.0313 (7)    0.0380 (7)    0.0284 (6)    −0.0055 (6)     0.0064 (5)     −0.0020 (6)
  N1    0.0297 (8)    0.0287 (8)    0.0260 (7)    0.0041 (6)      0.0004 (6)     −0.0057 (6)
  C1    0.0293 (9)    0.0260 (8)    0.0254 (8)    −0.0021 (7)     0.0009 (7)     −0.0058 (7)
  C2    0.0334 (11)   0.0624 (14)   0.0353 (11)   −0.0068 (10)    0.0012 (9)     0.0122 (10)
  C3    0.0423 (12)   0.0627 (15)   0.0356 (11)   −0.0032 (11)    −0.0053 (9)    0.0159 (10)
  C4    0.0353 (11)   0.0478 (12)   0.0404 (11)   0.0012 (9)      −0.0074 (9)    −0.0009 (10)
  C5    0.0268 (10)   0.0570 (14)   0.0595 (14)   −0.0025 (10)    0.0014 (10)    0.0140 (12)
  C6    0.0333 (10)   0.0390 (11)   0.0449 (12)   −0.0033 (9)     0.0038 (9)     0.0096 (9)
  C7    0.0272 (9)    0.0271 (9)    0.0307 (9)    −0.0005 (7)     −0.0005 (7)    −0.0023 (7)
  C8    0.0443 (12)   0.0326 (10)   0.0455 (12)   −0.0048 (9)     0.0114 (9)     0.0010 (9)
  C9    0.0555 (15)   0.0413 (12)   0.0544 (14)   −0.0116 (11)    0.0062 (11)    0.0125 (11)
  C10   0.0524 (14)   0.0262 (10)   0.0674 (16)   −0.0051 (9)     −0.0129 (12)   0.0027 (10)
  C11   0.0611 (15)   0.0301 (11)   0.0521 (13)   0.0066 (10)     −0.0070 (11)   −0.0091 (10)
  C12   0.0493 (12)   0.0333 (10)   0.0340 (10)   0.0054 (9)      −0.0003 (9)    −0.0042 (8)
  C13   0.0335 (10)   0.0305 (9)    0.0232 (8)    0.0009 (7)      0.0058 (7)     0.0036 (7)
  C14   0.0483 (13)   0.0445 (12)   0.0328 (10)   −0.0049 (10)    0.0081 (9)     −0.0050 (9)
  C15   0.0738 (18)   0.0509 (14)   0.0413 (12)   −0.0061 (13)    0.0116 (12)    −0.0146 (11)
  C16   0.0748 (18)   0.0516 (14)   0.0393 (12)   0.0140 (13)     0.0235 (12)    −0.0043 (11)
  C17   0.0447 (13)   0.0709 (17)   0.0494 (14)   0.0074 (12)     0.0219 (11)    0.0007 (12)
  C18   0.0358 (11)   0.0563 (14)   0.0393 (11)   −0.0031 (10)    0.0110 (9)     −0.0057 (10)
  C19   0.0295 (9)    0.0315 (9)    0.0315 (9)    0.0007 (7)      0.0073 (7)     0.0071 (8)
  C20   0.0683 (17)   0.0350 (12)   0.0507 (13)   0.0018 (11)     −0.0019 (12)   −0.0010 (10)
  C21   0.113 (3)     0.0323 (13)   0.081 (2)     0.0055 (15)     0.0110 (19)    −0.0008 (13)
  C22   0.094 (2)     0.0425 (15)   0.086 (2)     0.0219 (15)     0.0350 (19)    0.0248 (15)
  C23   0.0513 (14)   0.0715 (18)   0.0562 (15)   0.0179 (13)     0.0186 (12)    0.0386 (14)
  C24   0.0368 (11)   0.0514 (13)   0.0355 (11)   0.0043 (9)      0.0075 (9)     0.0163 (9)
  ----- ------------- ------------- ------------- --------------- -------------- ---------------

Geometric parameters (Å, °) {#tablewrapgeomlong}
===========================

  ------------------------ -------------- ------------------------- --------------
  Si1---O1                 1.6338 (14)    C10---C11                 1.372 (4)
  Si1---N1                 1.7099 (15)    C10---H10A                0.9500
  Si1---C7                 1.8571 (19)    C11---C12                 1.381 (3)
  Si1---C1                 1.8630 (19)    C11---H11A                0.9500
  Si2---O1                 1.6302 (14)    C12---H12A                0.9500
  Si2---N1^i^              1.7098 (15)    C13---C18                 1.383 (3)
  Si2---C13                1.8643 (19)    C13---C14                 1.390 (3)
  Si2---C19                1.869 (2)      C14---C15                 1.392 (3)
  N1---Si2^i^              1.7098 (15)    C14---H14A                0.9500
  N1---H1A                 0.8800         C15---C16                 1.386 (4)
  C1---C6                  1.390 (3)      C15---H15A                0.9500
  C1---C2                  1.393 (3)      C16---C17                 1.363 (4)
  C2---C3                  1.385 (3)      C16---H16A                0.9500
  C2---H2A                 0.9500         C17---C18                 1.394 (3)
  C3---C4                  1.367 (3)      C17---H17A                0.9500
  C3---H3A                 0.9500         C18---H18A                0.9500
  C4---C5                  1.369 (3)      C19---C20                 1.386 (3)
  C4---H4A                 0.9500         C19---C24                 1.403 (3)
  C5---C6                  1.391 (3)      C20---C21                 1.388 (3)
  C5---H5A                 0.9500         C20---H20A                0.9500
  C6---H6A                 0.9500         C21---C22                 1.372 (4)
  C7---C8                  1.395 (3)      C21---H21A                0.9500
  C7---C12                 1.397 (3)      C22---C23                 1.373 (4)
  C8---C9                  1.390 (3)      C22---H22A                0.9500
  C8---H8A                 0.9500         C23---C24                 1.390 (3)
  C9---C10                 1.381 (4)      C23---H23A                0.9500
  C9---H9A                 0.9500         C24---H24A                0.9500
                                                                    
  O1---Si1---N1            112.01 (8)     C11---C10---H10A          120.0
  O1---Si1---C7            106.91 (8)     C9---C10---H10A           120.0
  N1---Si1---C7            111.40 (8)     C10---C11---C12           120.2 (2)
  O1---Si1---C1            107.65 (8)     C10---C11---H11A          119.9
  N1---Si1---C1            106.60 (8)     C12---C11---H11A          119.9
  C7---Si1---C1            112.27 (8)     C11---C12---C7            121.3 (2)
  O1---Si2---N1^i^         109.90 (7)     C11---C12---H12A          119.4
  O1---Si2---C13           105.76 (8)     C7---C12---H12A           119.4
  N1^i^---Si2---C13        111.95 (8)     C18---C13---C14           117.47 (18)
  O1---Si2---C19           111.49 (8)     C18---C13---Si2           119.63 (15)
  N1^i^---Si2---C19        107.92 (8)     C14---C13---Si2           122.87 (15)
  C13---Si2---C19          109.86 (8)     C13---C14---C15           121.1 (2)
  Si2---O1---Si1           148.79 (9)     C13---C14---H14A          119.4
  Si2^i^---N1---Si1        132.87 (10)    C15---C14---H14A          119.4
  Si2^i^---N1---H1A        113.6          C16---C15---C14           120.0 (2)
  Si1---N1---H1A           113.6          C16---C15---H15A          120.0
  C6---C1---C2             116.67 (18)    C14---C15---H15A          120.0
  C6---C1---Si1            121.53 (15)    C17---C16---C15           119.6 (2)
  C2---C1---Si1            121.61 (15)    C17---C16---H16A          120.2
  C3---C2---C1             121.7 (2)      C15---C16---H16A          120.2
  C3---C2---H2A            119.2          C16---C17---C18           120.2 (2)
  C1---C2---H2A            119.2          C16---C17---H17A          119.9
  C4---C3---C2             120.4 (2)      C18---C17---H17A          119.9
  C4---C3---H3A            119.8          C13---C18---C17           121.6 (2)
  C2---C3---H3A            119.8          C13---C18---H18A          119.2
  C3---C4---C5             119.4 (2)      C17---C18---H18A          119.2
  C3---C4---H4A            120.3          C20---C19---C24           117.0 (2)
  C5---C4---H4A            120.3          C20---C19---Si2           122.97 (16)
  C4---C5---C6             120.4 (2)      C24---C19---Si2           120.04 (16)
  C4---C5---H5A            119.8          C19---C20---C21           121.6 (2)
  C6---C5---H5A            119.8          C19---C20---H20A          119.2
  C1---C6---C5             121.4 (2)      C21---C20---H20A          119.2
  C1---C6---H6A            119.3          C22---C21---C20           120.2 (3)
  C5---C6---H6A            119.3          C22---C21---H21A          119.9
  C8---C7---C12            117.66 (18)    C20---C21---H21A          119.9
  C8---C7---Si1            122.53 (15)    C21---C22---C23           119.9 (2)
  C12---C7---Si1           119.81 (15)    C21---C22---H22A          120.0
  C9---C8---C7             120.8 (2)      C23---C22---H22A          120.0
  C9---C8---H8A            119.6          C22---C23---C24           120.0 (2)
  C7---C8---H8A            119.6          C22---C23---H23A          120.0
  C10---C9---C8            120.1 (2)      C24---C23---H23A          120.0
  C10---C9---H9A           120.0          C23---C24---C19           121.2 (2)
  C8---C9---H9A            120.0          C23---C24---H24A          119.4
  C11---C10---C9           120.0 (2)      C19---C24---H24A          119.4
                                                                    
  N1^i^---Si2---O1---Si1   55.8 (2)       C9---C10---C11---C12      1.5 (4)
  C13---Si2---O1---Si1     176.78 (17)    C10---C11---C12---C7      −0.9 (3)
  C19---Si2---O1---Si1     −63.8 (2)      C8---C7---C12---C11       −0.2 (3)
  N1---Si1---O1---Si2      −7.6 (2)       Si1---C7---C12---C11      −179.88 (17)
  C7---Si1---O1---Si2      −129.94 (18)   O1---Si2---C13---C18      −162.77 (16)
  C1---Si1---O1---Si2      109.24 (18)    N1^i^---Si2---C13---C18   −43.10 (19)
  O1---Si1---N1---Si2^i^   −66.15 (15)    C19---Si2---C13---C18     76.79 (18)
  C7---Si1---N1---Si2^i^   53.55 (15)     O1---Si2---C13---C14      18.92 (19)
  C1---Si1---N1---Si2^i^   176.34 (12)    N1^i^---Si2---C13---C14   138.60 (17)
  O1---Si1---C1---C6       164.56 (16)    C19---Si2---C13---C14     −101.52 (18)
  N1---Si1---C1---C6       −75.08 (18)    C18---C13---C14---C15     1.1 (3)
  C7---Si1---C1---C6       47.16 (18)     Si2---C13---C14---C15     179.47 (18)
  O1---Si1---C1---C2       −20.62 (19)    C13---C14---C15---C16     0.8 (4)
  N1---Si1---C1---C2       99.73 (18)     C14---C15---C16---C17     −2.2 (4)
  C7---Si1---C1---C2       −138.02 (17)   C15---C16---C17---C18     1.6 (4)
  C6---C1---C2---C3        0.8 (3)        C14---C13---C18---C17     −1.7 (3)
  Si1---C1---C2---C3       −174.23 (19)   Si2---C13---C18---C17     179.86 (19)
  C1---C2---C3---C4        −1.3 (4)       C16---C17---C18---C13     0.4 (4)
  C2---C3---C4---C5        0.7 (4)        O1---Si2---C19---C20      107.10 (19)
  C3---C4---C5---C6        0.2 (4)        N1^i^---Si2---C19---C20   −13.7 (2)
  C2---C1---C6---C5        0.1 (3)        C13---Si2---C19---C20     −135.99 (19)
  Si1---C1---C6---C5       175.18 (18)    O1---Si2---C19---C24      −71.58 (17)
  C4---C5---C6---C1        −0.6 (4)       N1^i^---Si2---C19---C24   167.65 (15)
  O1---Si1---C7---C8       153.74 (16)    C13---Si2---C19---C24     45.33 (18)
  N1---Si1---C7---C8       31.06 (19)     C24---C19---C20---C21     −0.6 (4)
  C1---Si1---C7---C8       −88.42 (18)    Si2---C19---C20---C21     −179.4 (2)
  O1---Si1---C7---C12      −26.55 (18)    C19---C20---C21---C22     2.0 (5)
  N1---Si1---C7---C12      −149.23 (15)   C20---C21---C22---C23     −1.9 (5)
  C1---Si1---C7---C12      91.29 (17)     C21---C22---C23---C24     0.6 (4)
  C12---C7---C8---C9       0.5 (3)        C22---C23---C24---C19     0.8 (4)
  Si1---C7---C8---C9       −179.76 (18)   C20---C19---C24---C23     −0.7 (3)
  C7---C8---C9---C10       0.1 (4)        Si2---C19---C24---C23     178.04 (17)
  C8---C9---C10---C11      −1.2 (4)                                 
  ------------------------ -------------- ------------------------- --------------

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