Supporting information
Crystallographic Information File (CIF) https://doi.org/10.1107/S1600536807032102/mg2025sup1.cif | |
Structure factor file (CIF format) https://doi.org/10.1107/S1600536807032102/mg2025Isup2.hkl |
CCDC reference: 657690
All manipulations were carried out in the absence of atmospheric oxygen or moisture in either an Aldrich glove bag or using standard Schlenk line techniques and house nitrogen. Starting materials were obtained from Aldrich and Et3N was dried over 3 Å molecular sieves. 1.5996 g Si3N4, 1.27 ml Et3N.3HF and 7 ml Et3N (molar ratio 1 Si: 1 F: 12 Et3N) were combined and stirred to homogeneity. The mixture was placed inside a 25 ml teflon-lined autoclave and heated for 12 days at 240 °C. The autoclave was then cooled by removal from the oven and the mixture washed with dry Et3N and dried under vacuum. Products were stored in a Glovebox Technology argon-filled dry box. Powder X-ray diffraction showed Si3N4 and SiF4(NHEt2)2 to be the major phases, with SiF4(NH2Et)2 corresponding to approximately 15% of the product by reference to the observed intensities.
The NH hydrogen atoms were located in a difference Fourier map and their coordinates and isotropic displacement parameters subsequently refined. Other hydrogen atoms were positioned geometrically after each cycle of refinement. Examination of the packing of the structure shows that there are additional pseudosymmetry operators which would correspond to the (non-standard) space group A2/a, but in order to adopt this symmetry all atoms other than Si would be required to be disordered. Examination of the original intensity data clearly shows no absences indicative of the A-centring, confirming the original symmetry assignment.
The molecule is located on a centre of symmetry (Fig. 1). Intramolecular hydrogen bonds (N—H···F) link the molecules to form infinite sheets running parallel to the bc plane (Fig. 2). A third relatively short interaction (N1···F1 3.054 (2) Å) is apparently not a hydrogen bond and the largest N—H···F angle is ca 130°. The secondary C atom C1 has relatively large displacement parameters compared to its neighbours, suggesting that there may be some unresolved disorder of the ethyl group. Related adducts of silicon tetrafluoride are described in Ennan & Kats (1974).
For related literature, see: Ennan & Kats (1974).
Data collection: KappaCCD Server Software (Nonius, 1997); cell refinement: DENZO; data reduction: DENZO (Otwinowski & Minor, 1997); program(s) used to solve structure: SIR92 (Altomare et al., 1994); program(s) used to refine structure: CRYSTALS (Betteridge et al., 2003); molecular graphics: ATOMS (Dowty, 2005); software used to prepare material for publication: CRYSTALS.
C4H14F4N2Si | F(000) = 204 |
Mr = 194.25 | Dx = 1.536 Mg m−3 |
Monoclinic, P21/c | Mo Kα radiation, λ = 0.71073 Å |
Hall symbol: -P 2ybc | Cell parameters from 4140 reflections |
a = 8.4788 (4) Å | θ = 5–28° |
b = 6.9602 (3) Å | µ = 0.29 mm−1 |
c = 7.2206 (4) Å | T = 150 K |
β = 99.655 (2)° | Plate, colourless |
V = 420.08 (4) Å3 | 0.24 × 0.20 × 0.05 mm |
Z = 2 |
Nonius KappaCCD area-detector diffractometer | 670 reflections with I > 3σ(I) |
Graphite monochromator | Rint = 0.042 |
ω scans | θmax = 27.5°, θmin = 5.7° |
Absorption correction: multi-scan (DENZO/SCALEPACK; Otwinowski & Minor, 1997) | h = −10→10 |
Tmin = 0.93, Tmax = 0.99 | k = −8→8 |
4140 measured reflections | l = −9→9 |
946 independent reflections |
Refinement on F | Primary atom site location: structure-invariant direct methods |
Least-squares matrix: full | Hydrogen site location: inferred from neighbouring sites |
R[F2 > 2σ(F2)] = 0.034 | H atoms treated by a mixture of independent and constrained refinement |
wR(F2) = 0.042 | Method, part 1, Chebychev polynomial, (Watkin, 1994, Prince, 1982)
[weight] = 1.0/[A0*T0(x) + A1*T1(x) ··· + An-1]*Tn-1(x)]
where Ai are the Chebychev coefficients listed below and x = F /Fmax Method = Robust Weighting (Prince, 1982) W = [weight] * [1-(deltaF/6*sigmaF)2]2 Ai are: 1.21 0.411 0.931 |
S = 1.07 | (Δ/σ)max = 0.001 |
670 reflections | Δρmax = 0.24 e Å−3 |
60 parameters | Δρmin = −0.31 e Å−3 |
0 restraints |
C4H14F4N2Si | V = 420.08 (4) Å3 |
Mr = 194.25 | Z = 2 |
Monoclinic, P21/c | Mo Kα radiation |
a = 8.4788 (4) Å | µ = 0.29 mm−1 |
b = 6.9602 (3) Å | T = 150 K |
c = 7.2206 (4) Å | 0.24 × 0.20 × 0.05 mm |
β = 99.655 (2)° |
Nonius KappaCCD area-detector diffractometer | 946 independent reflections |
Absorption correction: multi-scan (DENZO/SCALEPACK; Otwinowski & Minor, 1997) | 670 reflections with I > 3σ(I) |
Tmin = 0.93, Tmax = 0.99 | Rint = 0.042 |
4140 measured reflections |
R[F2 > 2σ(F2)] = 0.034 | 0 restraints |
wR(F2) = 0.042 | H atoms treated by a mixture of independent and constrained refinement |
S = 1.07 | Δρmax = 0.24 e Å−3 |
670 reflections | Δρmin = −0.31 e Å−3 |
60 parameters |
x | y | z | Uiso*/Ueq | ||
Si1 | 0.5000 | 0.5000 | 0.5000 | 0.0222 | |
F1 | 0.54851 (14) | 0.26642 (17) | 0.51774 (15) | 0.0295 | |
F2 | 0.65474 (14) | 0.55391 (18) | 0.66675 (15) | 0.0293 | |
N1 | 0.6294 (2) | 0.5299 (3) | 0.3080 (2) | 0.0254 | |
C1 | 0.7992 (3) | 0.4765 (6) | 0.3436 (4) | 0.0634 | |
C2 | 0.8842 (3) | 0.5125 (4) | 0.1797 (4) | 0.0452 | |
H1 | 0.595 (4) | 0.463 (4) | 0.219 (5) | 0.042 (8)* | |
H2 | 0.622 (3) | 0.638 (5) | 0.266 (4) | 0.038 (7)* | |
H11 | 0.8538 | 0.5527 | 0.4533 | 0.0774* | |
H12 | 0.8073 | 0.3365 | 0.3748 | 0.0774* | |
H21 | 0.9988 | 0.4730 | 0.2139 | 0.0559* | |
H22 | 0.8783 | 0.6524 | 0.1475 | 0.0559* | |
H23 | 0.8319 | 0.4361 | 0.0690 | 0.0559* |
U11 | U22 | U33 | U12 | U13 | U23 | |
Si1 | 0.0300 (4) | 0.0208 (4) | 0.0167 (3) | 0.0004 (3) | 0.0061 (2) | −0.0001 (3) |
F1 | 0.0445 (7) | 0.0213 (6) | 0.0249 (5) | 0.0039 (5) | 0.0124 (4) | 0.0028 (4) |
F2 | 0.0316 (6) | 0.0361 (7) | 0.0200 (6) | −0.0021 (5) | 0.0035 (4) | −0.0027 (5) |
N1 | 0.0337 (9) | 0.0229 (10) | 0.0206 (8) | 0.0002 (7) | 0.0073 (6) | 0.0010 (7) |
C1 | 0.0404 (13) | 0.117 (3) | 0.0363 (13) | 0.0222 (16) | 0.0156 (10) | 0.0181 (16) |
C2 | 0.0438 (12) | 0.0520 (15) | 0.0439 (14) | −0.0004 (12) | 0.0199 (10) | −0.0006 (11) |
Si1—F1 | 1.6766 (12) | N1—H2 | 0.81 (3) |
Si1—F1i | 1.6766 (12) | C1—C2 | 1.506 (3) |
Si1—F2 | 1.6679 (11) | C1—H11 | 1.000 |
Si1—F2i | 1.6679 (11) | C1—H12 | 1.000 |
Si1—N1 | 1.9183 (17) | C2—H21 | 1.000 |
Si1—N1i | 1.9183 (17) | C2—H22 | 1.000 |
N1—C1 | 1.467 (3) | C2—H23 | 1.000 |
N1—H1 | 0.81 (3) | ||
F1—Si1—F1i | 180 | C1—N1—H1 | 102 (2) |
F1—Si1—F2 | 90.56 (6) | Si1—N1—H2 | 111 (2) |
F1i—Si1—F2 | 89.44 (6) | C1—N1—H2 | 108 (2) |
F1—Si1—F2i | 89.44 (6) | H1—N1—H2 | 104 (3) |
F1i—Si1—F2i | 90.56 (6) | N1—C1—C2 | 113.9 (2) |
F2—Si1—F2i | 180 | N1—C1—H11 | 108.357 |
F1—Si1—N1 | 89.86 (6) | C2—C1—H11 | 108.357 |
F1i—Si1—N1 | 90.14 (6) | N1—C1—H12 | 108.357 |
F2—Si1—N1 | 91.23 (6) | C2—C1—H12 | 108.357 |
F2i—Si1—N1 | 88.77 (6) | H11—C1—H12 | 109.467 |
F1—Si1—N1i | 90.14 (6) | C1—C2—H21 | 109.467 |
F1i—Si1—N1i | 89.86 (6) | C1—C2—H22 | 109.467 |
F2—Si1—N1i | 88.77 (6) | H21—C2—H22 | 109.476 |
F2i—Si1—N1i | 91.23 (6) | C1—C2—H23 | 109.467 |
N1—Si1—N1i | 180 | H21—C2—H23 | 109.476 |
Si1—N1—C1 | 120.61 (15) | H22—C2—H23 | 109.476 |
Si1—N1—H1 | 110 (2) |
Symmetry code: (i) −x+1, −y+1, −z+1. |
D—H···A | D—H | H···A | D···A | D—H···A |
N1—H1···F1ii | 0.81 (3) | 2.15 (3) | 2.938 (2) | 165 (3) |
N1—H2···F2iii | 0.81 (3) | 2.29 (3) | 3.091 (2) | 168 (3) |
Symmetry codes: (ii) x, −y+1/2, z−1/2; (iii) x, −y+3/2, z−1/2. |
Experimental details
Crystal data | |
Chemical formula | C4H14F4N2Si |
Mr | 194.25 |
Crystal system, space group | Monoclinic, P21/c |
Temperature (K) | 150 |
a, b, c (Å) | 8.4788 (4), 6.9602 (3), 7.2206 (4) |
β (°) | 99.655 (2) |
V (Å3) | 420.08 (4) |
Z | 2 |
Radiation type | Mo Kα |
µ (mm−1) | 0.29 |
Crystal size (mm) | 0.24 × 0.20 × 0.05 |
Data collection | |
Diffractometer | Nonius KappaCCD area-detector |
Absorption correction | Multi-scan (DENZO/SCALEPACK; Otwinowski & Minor, 1997) |
Tmin, Tmax | 0.93, 0.99 |
No. of measured, independent and observed [I > 3σ(I)] reflections | 4140, 946, 670 |
Rint | 0.042 |
(sin θ/λ)max (Å−1) | 0.649 |
Refinement | |
R[F2 > 2σ(F2)], wR(F2), S | 0.034, 0.042, 1.07 |
No. of reflections | 670 |
No. of parameters | 60 |
H-atom treatment | H atoms treated by a mixture of independent and constrained refinement |
Δρmax, Δρmin (e Å−3) | 0.24, −0.31 |
Computer programs: KappaCCD Server Software (Nonius, 1997), DENZO (Otwinowski & Minor, 1997), SIR92 (Altomare et al., 1994), CRYSTALS (Betteridge et al., 2003), ATOMS (Dowty, 2005), CRYSTALS.
Si1—F1 | 1.6766 (12) | N1—C1 | 1.467 (3) |
Si1—F2 | 1.6679 (11) | C1—C2 | 1.506 (3) |
Si1—N1 | 1.9183 (17) | ||
F1—Si1—F2 | 90.56 (6) | F2—Si1—N1 | 91.23 (6) |
F1i—Si1—F2 | 89.44 (6) | Si1—N1—C1 | 120.61 (15) |
F1—Si1—N1 | 89.86 (6) | N1—C1—C2 | 113.9 (2) |
Symmetry code: (i) −x+1, −y+1, −z+1. |
D—H···A | D—H | H···A | D···A | D—H···A |
N1—H1···F1ii | 0.81 (3) | 2.15 (3) | 2.938 (2) | 165 (3) |
N1—H2···F2iii | 0.81 (3) | 2.29 (3) | 3.091 (2) | 168 (3) |
Symmetry codes: (ii) x, −y+1/2, z−1/2; (iii) x, −y+3/2, z−1/2. |
The molecule is located on a centre of symmetry (Fig. 1). Intramolecular hydrogen bonds (N—H···F) link the molecules to form infinite sheets running parallel to the bc plane (Fig. 2). A third relatively short interaction (N1···F1 3.054 (2) Å) is apparently not a hydrogen bond and the largest N—H···F angle is ca 130°. The secondary C atom C1 has relatively large displacement parameters compared to its neighbours, suggesting that there may be some unresolved disorder of the ethyl group. Related adducts of silicon tetrafluoride are described in Ennan & Kats (1974).