Dimethyl­ammonium 3,5-bis­(trifluoro­meth­yl)pyrazolide

The title compound, C₂H₈N⁺·C₅HF₆N₂⁻, crystallizes with discrete anions and cations, which are linked by N—H...N hydrogen bonds to form centrosymmetric dimers. Geometric parameters are in the usual ranges.

Key indicators

• Single-crystal X-ray study
• T = 173 K
• Mean [sigma](C-C) = 0.005 Å
• R factor = 0.067
• wR factor = 0.191
• Data-to-parameter ratio = 12.5

checkCIF/PLATON results

No syntax errors found



Alert level C
PLAT042_ALERT_1_C Calc. and Rep. MoietyFormula Strings Differ ....          ?
PLAT242_ALERT_2_C Check Low       Ueq as Compared to Neighbors for         C4
PLAT242_ALERT_2_C Check Low       Ueq as Compared to Neighbors for         C5
PLAT340_ALERT_3_C Low Bond Precision on C-C Bonds (x 1000) Ang ...          5
PLAT353_ALERT_3_C Long    N-H Bond (0.87A)   N3     -   H3B    ...       1.02 Ang.

   0 ALERT level A = In general: serious problem
   0 ALERT level B = Potentially serious problem
   5 ALERT level C = Check and explain
   0 ALERT level G = General alerts; check

   1 ALERT type 1 CIF construction/syntax error, inconsistent or missing data
   2 ALERT type 2 Indicator that the structure model may be wrong or deficient
   2 ALERT type 3 Indicator that the structure quality may be low
   0 ALERT type 4 Improvement, methodology, query or suggestion
   0 ALERT type 5 Informative message, check

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S1. Comment

Tris(1-pyrazolyl)borates ("scorpionates") were invented by Trofimenko more than 30 years ago and are today well established as ligands in coordination chemistry (Trofimenko, 1993). The degree of steric crowding around the boron center appears to be an important factor influencing the stability of scorpionates. The results of earlier studies and investigations in our group have shown that the scorpinates R'B(3-Rpz)₃^- (II) and R'B(3,5-R2pz)₃^- (III) decompose much more easily when R and R' are bulky (Bieller et al. 2006, Graziani et al. 2002). We have now discovered that (I) was obtained as a side product of the reaction between K[3,5-(CF₃)₂Pz] and 3,5-(CF₃)₂PzH on the one side and C₆F₅B(NMe₂)₂ on the other side. Geometric parameters of the title compound (I) (Fig. 1) are in the usual ranges. In the crystal, anions and cations form centrosymmetric dimers linked by N—H···N hydrogen bonds (Fig. 2).

Related literature

For related literature, see: Bieller et al. (2006); Graziani et al. (2002); Trofimenko (1993).

S2. Experimental

All experiments were carried out under dry argon or nitrogen using standard Schlenk techniques. 0.385 g (1.45 mmol) (C₆F₅)B(NMe₂)₂, 0.350 g (1.45 mmol) 3,5-(CF₃)₂PzH and 0.585 g (2.9 mmol) K[3,5-(CF₃)₂Pz] were solved in 9 ml THF. After stirring for 4 days at room temperature. The solvent was removed in vacuo. Thereby we obtained colourless crystals of the title compound (I) from the residual oil as a side product of the reaction of K[3,5-(CF₃)₂Pz] and 3,5-(CF₃)₂PzH with C₆F₅B(NMe₂)₂.

S3. Refinement

H atoms bonded to C were refined using a riding model with fixed individual displacement parameters [U(H) = 1.2 U_eq(C) or U(H) = 1.5 U_eq(C_methyl)] with C—H ranging from 0.95Å to 0.98 Å. The H atoms bonded to N were located in a difference map and refined freely.

Computing details

Data collection: X-AREA (Stoe & Cie, 2001); cell refinement: X-AREA; data reduction: X-AREA; program(s) used to solve structure: SHELXS97 (Sheldrick, 1997); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: XP in SHELXTL-Plus (Sheldrick, 1991); software used to prepare material for publication: SHELXL97 and PLATON (Spek, 2003).

Figures

	Fig. 1. Perspective view of the title compound (I) with the atom numbering scheme. Displacement ellipsoids are at the 50% probability level. H atoms are drawn as small spheres of arbitrary radii. Hydrogen bonds are shown as dashed lines.
	Fig. 2. Partial packing diagram of the title compound (I); hydrogen bonds are shown as dashed lines.
	Fig. 3. Compounds (II) and (III).

Dimethylammonium 3,5-bis(trifluoromethyl)pyrazolide

Crystal data

C2H8N^+·C5HF6N2^−	F(000) = 504
Mr = 249.17	Dx = 1.517 Mg m^−3
Monoclinic, P21/c	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2ybc	Cell parameters from 5427 reflections
a = 5.9507 (11) Å	θ = 3.5–25.1°
b = 15.4492 (19) Å	µ = 0.17 mm^−1
c = 11.8647 (18) Å	T = 173 K
β = 90.362 (13)°	Needle, colourless
V = 1090.7 (3) Å^3	0.25 × 0.12 × 0.12 mm
Z = 4

Data collection

Stoe IPDSII two-circle diffractometer	1287 reflections with I > 2σ(I)
Radiation source: fine-focus sealed tube	Rint = 0.062
Graphite monochromator	θmax = 25.0°, θmin = 3.4°
ω scans	h = −7→7
8093 measured reflections	k = −18→17
1911 independent reflections	l = −13→14

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)] = 0.067	Hydrogen site location: inferred from neighbouring sites
wR(F^2) = 0.191	H atoms treated by a mixture of independent and constrained refinement
S = 1.02	w = 1/[σ^2(Fo^2) + (0.1128P)^2] where P = (Fo^2 + 2Fc^2)/3
1911 reflections	(Δ/σ)max < 0.001
153 parameters	Δρmax = 0.30 e Å^−3
0 restraints	Δρmin = −0.36 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
N1	0.2583 (4)	0.55360 (16)	0.3472 (2)	0.0434 (7)
N2	0.3744 (4)	0.48549 (17)	0.3036 (2)	0.0423 (6)
N3	0.3413 (4)	0.62168 (17)	0.5653 (3)	0.0411 (6)
H3A	0.322 (6)	0.598 (3)	0.497 (4)	0.060 (11)*
H3B	0.451 (7)	0.586 (3)	0.612 (3)	0.060 (10)*
C1	0.1235 (5)	0.5846 (2)	0.2647 (3)	0.0436 (8)
C2	0.1473 (6)	0.5373 (2)	0.1658 (3)	0.0473 (8)
H2	0.0727	0.5450	0.0954	0.057*
C3	0.3069 (5)	0.4762 (2)	0.1955 (3)	0.0434 (7)
C4	−0.0324 (6)	0.6564 (2)	0.2881 (3)	0.0549 (9)
C5	0.4053 (6)	0.4066 (2)	0.1254 (3)	0.0543 (9)
C31	0.1198 (6)	0.6163 (3)	0.6213 (4)	0.0584 (10)
H31A	0.0687	0.5560	0.6218	0.088*
H31B	0.0107	0.6519	0.5800	0.088*
H31C	0.1334	0.6374	0.6989	0.088*
C32	0.4315 (6)	0.7110 (2)	0.5599 (3)	0.0538 (9)
H32A	0.5774	0.7104	0.5221	0.081*
H32B	0.4500	0.7338	0.6365	0.081*
H32C	0.3267	0.7478	0.5176	0.081*
F41	−0.1977 (5)	0.63381 (18)	0.3586 (3)	0.0956 (10)
F42	−0.1288 (5)	0.68795 (18)	0.1954 (2)	0.0934 (10)
F43	0.0655 (5)	0.72381 (15)	0.3391 (2)	0.0815 (8)
F51	0.2993 (6)	0.3963 (2)	0.0282 (2)	0.1060 (12)
F52	0.6212 (5)	0.4206 (2)	0.0986 (3)	0.0970 (10)
F53	0.4094 (5)	0.32993 (14)	0.1768 (2)	0.0803 (8)

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
N1	0.0449 (14)	0.0413 (14)	0.0442 (16)	0.0022 (11)	0.0044 (12)	−0.0043 (11)
N2	0.0438 (13)	0.0425 (14)	0.0409 (15)	0.0030 (11)	0.0046 (11)	−0.0013 (11)
N3	0.0421 (14)	0.0421 (14)	0.0391 (16)	0.0015 (11)	0.0029 (12)	−0.0019 (12)
C1	0.0451 (17)	0.0436 (17)	0.0422 (19)	0.0023 (13)	−0.0005 (14)	0.0047 (13)
C2	0.0528 (19)	0.0509 (18)	0.0380 (18)	0.0020 (15)	−0.0044 (14)	0.0033 (14)
C3	0.0498 (17)	0.0429 (17)	0.0375 (18)	0.0003 (13)	0.0026 (13)	0.0017 (13)
C4	0.056 (2)	0.052 (2)	0.057 (2)	0.0114 (16)	−0.0082 (17)	−0.0055 (17)
C5	0.068 (2)	0.055 (2)	0.040 (2)	0.0085 (17)	0.0063 (16)	−0.0007 (15)
C31	0.0456 (18)	0.066 (2)	0.064 (2)	−0.0067 (16)	0.0150 (16)	0.0052 (18)
C32	0.053 (2)	0.0518 (19)	0.057 (2)	−0.0080 (16)	0.0023 (17)	0.0020 (16)
F41	0.0723 (16)	0.0850 (18)	0.130 (3)	0.0210 (13)	0.0406 (17)	0.0022 (16)
F42	0.113 (2)	0.0882 (18)	0.0785 (19)	0.0518 (16)	−0.0357 (16)	−0.0122 (14)
F43	0.0949 (18)	0.0526 (13)	0.0967 (19)	0.0166 (12)	−0.0201 (14)	−0.0215 (12)
F51	0.145 (3)	0.114 (2)	0.0582 (17)	0.060 (2)	−0.0348 (16)	−0.0388 (15)
F52	0.0852 (18)	0.099 (2)	0.108 (2)	0.0051 (15)	0.0506 (16)	−0.0257 (16)
F53	0.127 (2)	0.0465 (12)	0.0674 (16)	0.0130 (13)	0.0239 (15)	−0.0008 (10)

Geometric parameters (Å, º)

N1—C1	1.350 (4)	C4—F42	1.330 (4)
N1—N2	1.363 (4)	C4—F43	1.336 (4)
N2—C3	1.349 (4)	C4—F41	1.342 (5)
N3—C31	1.482 (4)	C5—F51	1.321 (4)
N3—C32	1.482 (4)	C5—F53	1.332 (4)
N3—H3A	0.90 (4)	C5—F52	1.343 (4)
N3—H3B	1.02 (4)	C31—H31A	0.9800
C1—C2	1.391 (5)	C31—H31B	0.9800
C1—C4	1.474 (5)	C31—H31C	0.9800
C2—C3	1.383 (5)	C32—H32A	0.9800
C2—H2	0.9500	C32—H32B	0.9800
C3—C5	1.481 (5)	C32—H32C	0.9800
C1—N1—N2	107.4 (2)	F43—C4—C1	113.5 (3)
C3—N2—N1	107.2 (2)	F41—C4—C1	112.7 (3)
C31—N3—C32	113.3 (3)	F51—C5—F53	107.4 (3)
C31—N3—H3A	106 (2)	F51—C5—F52	105.4 (3)
C32—N3—H3A	112 (3)	F53—C5—F52	103.7 (3)
C31—N3—H3B	107 (2)	F51—C5—C3	112.9 (3)
C32—N3—H3B	107 (2)	F53—C5—C3	113.3 (3)
H3A—N3—H3B	110 (3)	F52—C5—C3	113.5 (3)
N1—C1—C2	111.3 (3)	N3—C31—H31A	109.5
N1—C1—C4	120.2 (3)	N3—C31—H31B	109.5
C2—C1—C4	128.5 (3)	H31A—C31—H31B	109.5
C3—C2—C1	102.5 (3)	N3—C31—H31C	109.5
C3—C2—H2	128.7	H31A—C31—H31C	109.5
C1—C2—H2	128.7	H31B—C31—H31C	109.5
N2—C3—C2	111.7 (3)	N3—C32—H32A	109.5
N2—C3—C5	119.6 (3)	N3—C32—H32B	109.5
C2—C3—C5	128.7 (3)	H32A—C32—H32B	109.5
F42—C4—F43	105.9 (3)	N3—C32—H32C	109.5
F42—C4—F41	107.3 (3)	H32A—C32—H32C	109.5
F43—C4—F41	103.9 (3)	H32B—C32—H32C	109.5
F42—C4—C1	112.9 (3)
C1—N1—N2—C3	−0.3 (3)	N1—C1—C4—F43	50.2 (5)
N2—N1—C1—C2	0.4 (4)	C2—C1—C4—F43	−133.8 (4)
N2—N1—C1—C4	177.0 (3)	N1—C1—C4—F41	−67.5 (4)
N1—C1—C2—C3	−0.3 (4)	C2—C1—C4—F41	108.4 (4)
C4—C1—C2—C3	−176.5 (3)	N2—C3—C5—F51	169.9 (3)
N1—N2—C3—C2	0.1 (3)	C2—C3—C5—F51	−10.5 (5)
N1—N2—C3—C5	179.9 (3)	N2—C3—C5—F53	47.5 (5)
C1—C2—C3—N2	0.1 (4)	C2—C3—C5—F53	−132.8 (4)
C1—C2—C3—C5	−179.6 (3)	N2—C3—C5—F52	−70.3 (4)
N1—C1—C4—F42	170.7 (3)	C2—C3—C5—F52	109.3 (4)
C2—C1—C4—F42	−13.4 (6)

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
N3—H3A···N1	0.90 (4)	1.94 (5)	2.834 (4)	175 (4)
N3—H3B···N2^i	1.02 (4)	1.81 (4)	2.826 (4)	175 (3)

Symmetry code: (i) −x+1, −y+1, −z+1.