Trimethyl­ammonium tetra­fluoro­borate at 100 K

The crystal structure of the title compound, C₃H₁₀N⁺·BF₄⁻, has been redetermined at 100 K and shows the BF₄⁻ anion to be ordered at this temperature. Both the anion and the cation lie on a mirror plane and they are connected by N—H...F and C—H...F hydrogen bonds.

Key indicators

• Single-crystal X-ray study
• T = 100 K
• Mean [sigma](F-B)= 0.002 Å
• R factor = 0.045
• wR factor = 0.140
• Data-to-parameter ratio = 14.6

checkCIF/PLATON results

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Computing details

Data collection: RAPID-AUTO (Rigaku/MSC and Rigaku Corporation, 2004); cell refinement: RAPID-AUTO; data reduction: CrystalStructure (Rigaku/MSC and Rigaku Corporation, 2005); program(s) used to solve structure: SIR92 (Altomare et al., 1994); program(s) used to refine structure: CRYSTALS (Watkin et al., 1996); molecular graphics: ORTEP-3 (Farrugia, 1997); software used to prepare material for publication: CrystalStructure and PLATON (Spek, 2003).

Trimethylammonium tetrafluoroborate

Crystal data

C3H10N^+·BF4^−	F(000) = 152
Mr = 146.92	Dx = 1.457 Mg m^−3
Monoclinic, P21/m	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2yb	Cell parameters from 3348 reflections
a = 5.460 (6) Å	θ = 3.7–30.0°
b = 8.496 (7) Å	µ = 0.16 mm^−1
c = 7.433 (6) Å	T = 100 K
β = 103.80 (4)°	Prism, colorless
V = 334.9 (5) Å^3	0.30 × 0.20 × 0.12 mm
Z = 2

Data collection

Rigaku R-AXIS RAPID diffractometer	Rint = 0.045
Detector resolution: 10.00 pixels mm^-1	θmax = 30.0°
ω scans	h = −7→7
4017 measured reflections	k = −11→10
1038 independent reflections	l = −10→10
760 reflections with F^2 > 2σ(F^2)

Refinement

Refinement on F^2	All H-atom parameters refined
R[F^2 > 2σ(F^2)] = 0.045	w = 1/[0.002Fo^2 + σ(Fo^2)]/(4Fo^2)
wR(F^2) = 0.140	(Δ/σ)max < 0.001
S = 1.01	Δρmax = 0.36 e Å^−3
1038 reflections	Δρmin = −0.43 e Å^−3
71 parameters

Special details

Refinement. Refinement using all reflections. The weighted R-factor (wR) and goodness of fit (S) are based on F². R-factor (gt) are based on F. The threshold expression of F² > 2.0 σ(F²) is used only for calculating R-factor (gt).

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Ų)

	x	y	z	Uiso*/Ueq
F1	0.7779 (2)	0.25	0.33095 (14)	0.0250 (2)
F2	0.4462 (2)	0.25	0.46247 (16)	0.0369 (3)
F3	0.42138 (19)	0.11702 (11)	0.19219 (13)	0.0370 (2)
N1	0.9189 (2)	0.25	0.7426 (2)	0.0171 (3)
C1	1.0710 (2)	0.10505 (14)	0.7379 (2)	0.0236 (3)
C2	0.8065 (3)	0.25	0.9071 (2)	0.0226 (4)
B1	0.5155 (3)	0.25	0.2926 (2)	0.0188 (4)
H1	0.791 (4)	0.25	0.643 (3)	0.013 (4)*
H2	1.197 (4)	0.101 (2)	0.846 (2)	0.034 (4)*
H3	1.144 (4)	0.112 (2)	0.630 (2)	0.034 (4)*
H4	0.962 (4)	0.016 (2)	0.735 (2)	0.035 (4)*
H5	0.711 (3)	0.346 (2)	0.904 (2)	0.024 (4)*
H6	0.941 (5)	0.2500	1.017 (3)	0.019 (5)*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
F1	0.0176 (5)	0.0338 (5)	0.0232 (5)	0	0.0040 (4)	0
F2	0.0241 (6)	0.0670 (9)	0.0210 (5)	0	0.0080 (4)	0
F3	0.0345 (5)	0.0302 (5)	0.0420 (5)	−0.0077 (3)	0.0009 (4)	−0.0120 (3)
N1	0.0168 (6)	0.0176 (6)	0.0164 (6)	0	0.0027 (5)	0
C1	0.0277 (6)	0.0187 (5)	0.0266 (6)	0.0036 (4)	0.0107 (5)	−0.0002 (5)
C2	0.0242 (9)	0.0228 (8)	0.0238 (8)	0	0.0118 (7)	0
B1	0.0187 (8)	0.0205 (8)	0.0162 (7)	0	0.0019 (6)	0

Geometric parameters (Å, º)

F1—B1	1.392 (2)	C1—H2	0.93 (2)
F2—B1	1.402 (2)	C1—H3	0.98 (2)
F3—B1	1.3836 (13)	C1—H4	0.96 (2)
N1—C1	1.4904 (16)	C2—H5	0.967 (18)
N1—C1^i	1.4904 (16)	C2—H5^i	0.967 (18)
N1—C2	1.493 (2)	C2—H6	0.96 (2)
N1—H1	0.89 (2)
F1···N1	2.972 (4)	F1···H6^v	2.69 (2)
F1···C1	3.304 (4)	F2···N1	2.904 (4)
F1···C1^ii	3.201 (4)	F2···H1	2.04 (2)
F1···C1^iii	3.201 (4)	F2···H3^vi	2.58 (2)
F1···C1^i	3.304 (4)	F2···H3^vii	2.58 (2)
F1···C2^iv	3.191 (4)	F3···H2^viii	2.576 (15)
F1···H1	2.30 (2)	F3···H2^iii	2.85 (2)
F1···H3	2.862 (18)	F3···H4^ix	2.55 (2)
F1···H3^i	2.862 (18)	F3···H5^x	2.468 (17)
F1···H4^ii	2.774 (19)	F3···H5^v	2.97 (2)
F1···H4^iii	2.774 (19)	F3···H6^viii	2.87 (2)
F1···H6^iv	2.69 (2)	B1···H1	2.68 (2)
C1—N1—C1^i	111.43 (12)	N1—C1—H2	108.0 (13)
C1—N1—C2	111.04 (9)	N1—C1—H3	107.8 (11)
C1^i—N1—C2	111.04 (9)	N1—C1—H4	107.8 (13)
F1—B1—F2	107.52 (13)	H2—C1—H3	110.5 (19)
F1—B1—F3	110.01 (11)	H2—C1—H4	108.7 (18)
F1—B1—F3^i	110.01 (11)	H3—C1—H4	113.7 (17)
F2—B1—F3	109.90 (11)	N1—C2—H5	107.6 (11)
F2—B1—F3^i	109.90 (11)	N1—C2—H5^i	107.6 (11)
F3—B1—F3^i	109.48 (12)	N1—C2—H6	108.5 (17)
C1—N1—H1	108.1 (9)	H5—C2—H5^i	115.8 (16)
C1^i—N1—H1	108.1 (9)	H5—C2—H6	108.6 (12)
C2—N1—H1	106.9 (18)	H5^i—C2—H6	108.6 (12)

Symmetry codes: (i) x, −y+1/2, z; (ii) −x+2, y+1/2, −z+1; (iii) −x+2, −y, −z+1; (iv) x, y, z−1; (v) x, −y+1/2, z−1; (vi) x−1, y, z; (vii) x−1, −y+1/2, z; (viii) x−1, y, z−1; (ix) −x+1, −y, −z+1; (x) −x+1, y−1/2, −z+1.

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
N1—H1···F1	0.89 (2)	2.30 (2)	2.972 (4)	132 (2)
N1—H1···F2	0.89 (2)	2.04 (2)	2.904 (4)	166 (2)
C1—H4···F3^ix	0.960 (19)	2.55 (2)	3.424 (4)	151.8 (15)
C2—H5···F3^xi	0.965 (17)	2.468 (17)	3.373 (4)	156.1 (13)

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