High-temperature phase of 5-tert-butyl­pyrazole

The title compound, C₇H₁₂N₂, has two independent mol­ecules in the asymmetric unit. The structure contains N—H...N hydrogen-bonded tetramers. The tert-butyl groups show large amplitudes of internal rotational motion.

Key indicators

• Single-crystal X-ray study
• T = 195 K
• Mean [sigma](C-C) = 0.003 Å
• R factor = 0.060
• wR factor = 0.151
• Data-to-parameter ratio = 22.7

checkCIF/PLATON results

No syntax errors found



Alert level B
PLAT242_ALERT_2_B Check Low    U(eq) as Compared to Neighbors  for         C4

Alert level C
PLAT026_ALERT_3_C Ratio Observed / Unique Reflections too Low ....         44 Perc.
PLAT220_ALERT_2_C Large Non-Solvent    C     Ueq(max)/Ueq(min) ...       3.19 Ratio
PLAT222_ALERT_3_C Large Non-Solvent    H     Ueq(max)/Ueq(min) ...       3.96 Ratio
PLAT230_ALERT_2_C Hirshfeld Test Diff for    C11    -   C12     ..       5.11 su
PLAT242_ALERT_2_C Check Low    U(eq) as Compared to Neighbors  for        C11
PLAT480_ALERT_4_C Long H...A H-Bond Reported H7B    ..  CG2     ..       3.01 Ang.
PLAT480_ALERT_4_C Long H...A H-Bond Reported H12B   ..  CG1     ..       3.03 Ang.
PLAT480_ALERT_4_C Long H...A H-Bond Reported H14B   ..  CG2     ..       3.07 Ang.
PLAT481_ALERT_4_C Long D...A H-Bond Reported C7     ..  CG2     ..       3.93 Ang.
PLAT481_ALERT_4_C Long D...A H-Bond Reported C12    ..  CG1     ..       3.97 Ang.
PLAT790_ALERT_4_C Centre of Gravity not Within Unit Cell: Resd.  #          2
              C7 H12 N2

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

   0 ALERT type 1 CIF construction/syntax error, inconsistent or missing data
   4 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
   6 ALERT type 4 Improvement, methodology, query or suggestion

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Computing details

Data collection: SMART (Siemens, 1995); cell refinement: SMART; data reduction: SAINT (Siemens, 1995); program(s) used to solve structure: SHELXS97 (Sheldrick, 1997); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: SHELXTL (Sheldrick, 1996); software used to prepare material for publication: SHELXL97.

5-tert-butylpyrazole

Crystal data

C7H12N2	F(000) = 1088
Mr = 124.19	Dx = 1.030 Mg m^−3
Monoclinic, C2/c	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -C 2yc	Cell parameters from 185 reflections
a = 22.105 (3) Å	θ = 3–26°
b = 10.7547 (13) Å	µ = 0.06 mm^−1
c = 17.074 (2) Å	T = 195 K
β = 127.879 (4)°	Rod, colorless
V = 3203.8 (7) Å^3	0.44 × 0.12 × 0.12 mm
Z = 16

Data collection

Siemens SMART 1K CCD diffractometer	1858 reflections with I > 2σ(I)
Radiation source: normal-focus sealed tube	Rint = 0.088
Graphite monochromator	θmax = 29.5°, θmin = 2.2°
ω scans	h = −30→30
24776 measured reflections	k = −14→14
4268 independent reflections	l = −23→22

Refinement

Refinement on F^2	Secondary atom site location: difference Fourier map
Least-squares matrix: full	Hydrogen site location: inferred from neighbouring sites
R[F^2 > 2σ(F^2)] = 0.060	H atoms treated by a mixture of independent and constrained refinement
wR(F^2) = 0.151	w = 1/[σ^2(Fo^2) + (0.06P)^2] where P = (Fo^2 + 2Fc^2)/3
S = 1.06	(Δ/σ)max = 0.001
4268 reflections	Δρmax = 0.18 e Å^−3
188 parameters	Δρmin = −0.16 e Å^−3
0 restraints	Extinction correction: SHELXL97, Fc^*=kFc[1+0.001xFc^2λ^3/sin(2θ)]^-1/4
Primary atom site location: structure-invariant direct methods	Extinction coefficient: 0.0035 (6)

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	0.05960 (9)	0.24862 (15)	0.20117 (12)	0.0424 (4)
N2	−0.01390 (9)	0.21910 (14)	0.12527 (12)	0.0487 (4)
C1	−0.04066 (13)	0.3213 (2)	0.07014 (17)	0.0559 (6)
C2	0.01433 (12)	0.4140 (2)	0.10983 (16)	0.0523 (6)
C3	0.07882 (10)	0.36475 (16)	0.19459 (14)	0.0405 (5)
C4	0.15732 (11)	0.41775 (18)	0.27179 (15)	0.0538 (6)
C5	0.16555 (15)	0.5397 (2)	0.2328 (2)	0.1079 (11)
H5A	0.1270	0.5992	0.2204	0.162*
H5B	0.1581	0.5238	0.1709	0.162*
H5C	0.2169	0.5741	0.2822	0.162*
C6	0.21901 (12)	0.3282 (2)	0.29238 (19)	0.0769 (7)
H6A	0.2697	0.3643	0.3424	0.115*
H6B	0.2126	0.3135	0.2310	0.115*
H6C	0.2144	0.2492	0.3170	0.115*
C7	0.16805 (17)	0.4383 (3)	0.3679 (2)	0.1290 (13)
H7A	0.1298	0.4981	0.3563	0.194*
H7B	0.2196	0.4709	0.4187	0.194*
H7C	0.1616	0.3592	0.3904	0.194*
H1N	0.0913 (11)	0.1893 (17)	0.2493 (15)	0.058 (6)*
H1	−0.0940 (12)	0.3245 (18)	0.0103 (16)	0.066 (6)*
H2	0.0107 (10)	0.4909 (17)	0.0865 (13)	0.049 (6)*
N3	0.10234 (8)	0.01749 (15)	0.37919 (12)	0.0456 (4)
N4	0.13963 (9)	0.05227 (15)	0.34252 (12)	0.0506 (5)
C8	0.17931 (11)	−0.0490 (2)	0.35414 (15)	0.0510 (6)
C9	0.16786 (10)	−0.14592 (19)	0.39749 (13)	0.0441 (5)
C10	0.11789 (9)	−0.10055 (16)	0.41294 (13)	0.0386 (5)
C11	0.08145 (10)	−0.15873 (17)	0.45524 (13)	0.0434 (5)
C12	0.09548 (12)	−0.07806 (19)	0.53887 (16)	0.0632 (6)
H12A	0.1507	−0.0705	0.5919	0.095*
H12B	0.0712	−0.1168	0.5653	0.095*
H12C	0.0735	0.0047	0.5129	0.095*
C13	0.11638 (15)	−0.28663 (19)	0.49742 (19)	0.0757 (7)
H13A	0.1071	−0.3399	0.4445	0.113*
H13B	0.0928	−0.3241	0.5251	0.113*
H13C	0.1717	−0.2781	0.5498	0.113*
C14	−0.00491 (12)	−0.1698 (2)	0.37399 (16)	0.0811 (8)
H14A	−0.0149	−0.2227	0.3204	0.122*
H14B	−0.0266	−0.0870	0.3477	0.122*
H14C	−0.0286	−0.2068	0.4017	0.122*
H3N	0.0713 (11)	0.0800 (17)	0.3788 (14)	0.065 (6)*
H8	0.2138 (11)	−0.0465 (16)	0.3356 (14)	0.067 (6)*
H9	0.1894 (9)	−0.2294 (16)	0.4123 (13)	0.045 (5)*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
N1	0.0438 (10)	0.0421 (10)	0.0415 (10)	−0.0021 (8)	0.0264 (9)	0.0025 (8)
N2	0.0448 (10)	0.0520 (11)	0.0502 (10)	−0.0055 (8)	0.0295 (9)	−0.0014 (9)
C1	0.0476 (13)	0.0694 (15)	0.0490 (13)	0.0068 (12)	0.0288 (12)	0.0070 (12)
C2	0.0591 (14)	0.0440 (13)	0.0603 (14)	0.0061 (11)	0.0400 (12)	0.0132 (12)
C3	0.0494 (11)	0.0351 (11)	0.0489 (12)	−0.0005 (9)	0.0362 (10)	0.0003 (9)
C4	0.0545 (13)	0.0468 (12)	0.0607 (14)	−0.0102 (10)	0.0356 (12)	−0.0074 (10)
C5	0.0721 (17)	0.0572 (16)	0.153 (3)	−0.0156 (13)	0.0481 (19)	0.0190 (17)
C6	0.0499 (13)	0.0739 (16)	0.0866 (18)	−0.0041 (11)	0.0316 (13)	−0.0027 (14)
C7	0.107 (2)	0.199 (3)	0.092 (2)	−0.074 (2)	0.066 (2)	−0.092 (2)
N3	0.0448 (9)	0.0481 (11)	0.0517 (10)	0.0089 (8)	0.0336 (9)	0.0093 (8)
N4	0.0497 (10)	0.0570 (11)	0.0543 (11)	0.0054 (8)	0.0366 (9)	0.0134 (8)
C8	0.0451 (11)	0.0653 (15)	0.0520 (13)	0.0102 (10)	0.0345 (11)	0.0114 (11)
C9	0.0422 (11)	0.0467 (13)	0.0442 (12)	0.0120 (9)	0.0269 (10)	0.0108 (10)
C10	0.0352 (10)	0.0401 (11)	0.0351 (10)	0.0033 (8)	0.0189 (9)	0.0036 (8)
C11	0.0404 (10)	0.0497 (12)	0.0415 (11)	−0.0024 (9)	0.0258 (9)	0.0024 (9)
C12	0.0702 (14)	0.0756 (15)	0.0608 (14)	−0.0057 (12)	0.0488 (13)	−0.0024 (12)
C13	0.1025 (19)	0.0591 (15)	0.1005 (19)	0.0094 (13)	0.0801 (17)	0.0205 (13)
C14	0.0536 (14)	0.125 (2)	0.0578 (15)	−0.0281 (14)	0.0307 (13)	0.0023 (14)

Geometric parameters (Å, º)

N1—C3	1.346 (2)	N3—C10	1.349 (2)
N1—N2	1.354 (2)	N3—N4	1.358 (2)
N1—H1N	0.931 (19)	N3—H3N	0.957 (19)
N2—C1	1.327 (2)	N4—C8	1.335 (2)
C1—C2	1.385 (3)	C8—C9	1.389 (3)
C1—H1	0.98 (2)	C8—H8	0.988 (19)
C2—C3	1.369 (3)	C9—C10	1.373 (2)
C2—H2	0.900 (18)	C9—H9	0.975 (16)
C3—C4	1.505 (2)	C10—C11	1.509 (2)
C4—C7	1.522 (3)	C11—C13	1.525 (3)
C4—C6	1.524 (3)	C11—C14	1.527 (3)
C4—C5	1.531 (3)	C11—C12	1.531 (3)
C5—H5A	0.9800	C12—H12A	0.9800
C5—H5B	0.9800	C12—H12B	0.9800
C5—H5C	0.9800	C12—H12C	0.9800
C6—H6A	0.9800	C13—H13A	0.9800
C6—H6B	0.9800	C13—H13B	0.9800
C6—H6C	0.9800	C13—H13C	0.9800
C7—H7A	0.9800	C14—H14A	0.9800
C7—H7B	0.9800	C14—H14B	0.9800
C7—H7C	0.9800	C14—H14C	0.9800
C3—N1—N2	113.10 (16)	C10—N3—N4	112.87 (15)
C3—N1—H1N	127.2 (12)	C10—N3—H3N	131.1 (11)
N2—N1—H1N	119.6 (12)	N4—N3—H3N	116.0 (11)
C1—N2—N1	103.59 (16)	C8—N4—N3	103.65 (15)
N2—C1—C2	112.0 (2)	N4—C8—C9	111.94 (17)
N2—C1—H1	119.8 (12)	N4—C8—H8	119.7 (11)
C2—C1—H1	128.3 (12)	C9—C8—H8	128.3 (11)
C3—C2—C1	105.70 (19)	C10—C9—C8	105.49 (17)
C3—C2—H2	125.1 (12)	C10—C9—H9	127.0 (10)
C1—C2—H2	129.1 (12)	C8—C9—H9	127.5 (10)
N1—C3—C2	105.66 (17)	N3—C10—C9	106.05 (16)
N1—C3—C4	122.11 (17)	N3—C10—C11	121.60 (15)
C2—C3—C4	132.22 (18)	C9—C10—C11	132.33 (17)
C3—C4—C7	109.37 (17)	C10—C11—C13	109.63 (15)
C3—C4—C6	110.49 (16)	C10—C11—C14	109.54 (15)
C7—C4—C6	108.5 (2)	C13—C11—C14	110.31 (18)
C3—C4—C5	108.93 (17)	C10—C11—C12	110.46 (15)
C7—C4—C5	111.3 (2)	C13—C11—C12	108.48 (17)
C6—C4—C5	108.25 (18)	C14—C11—C12	108.41 (16)
C4—C5—H5A	109.5	C11—C12—H12A	109.5
C4—C5—H5B	109.5	C11—C12—H12B	109.5
H5A—C5—H5B	109.5	H12A—C12—H12B	109.5
C4—C5—H5C	109.5	C11—C12—H12C	109.5
H5A—C5—H5C	109.5	H12A—C12—H12C	109.5
H5B—C5—H5C	109.5	H12B—C12—H12C	109.5
C4—C6—H6A	109.5	C11—C13—H13A	109.5
C4—C6—H6B	109.5	C11—C13—H13B	109.5
H6A—C6—H6B	109.5	H13A—C13—H13B	109.5
C4—C6—H6C	109.5	C11—C13—H13C	109.5
H6A—C6—H6C	109.5	H13A—C13—H13C	109.5
H6B—C6—H6C	109.5	H13B—C13—H13C	109.5
C4—C7—H7A	109.5	C11—C14—H14A	109.5
C4—C7—H7B	109.5	C11—C14—H14B	109.5
H7A—C7—H7B	109.5	H14A—C14—H14B	109.5
C4—C7—H7C	109.5	C11—C14—H14C	109.5
H7A—C7—H7C	109.5	H14A—C14—H14C	109.5
H7B—C7—H7C	109.5	H14B—C14—H14C	109.5
C3—N1—N2—C1	−0.03 (19)	C10—N3—N4—C8	0.2 (2)
N1—N2—C1—C2	0.0 (2)	N3—N4—C8—C9	−0.2 (2)
N2—C1—C2—C3	0.1 (2)	N4—C8—C9—C10	0.1 (2)
N2—N1—C3—C2	0.1 (2)	N4—N3—C10—C9	−0.1 (2)
N2—N1—C3—C4	179.07 (15)	N4—N3—C10—C11	−178.96 (15)
C1—C2—C3—N1	−0.1 (2)	C8—C9—C10—N3	0.0 (2)
C1—C2—C3—C4	−178.94 (18)	C8—C9—C10—C11	178.64 (18)
N1—C3—C4—C7	−69.2 (3)	N3—C10—C11—C13	−173.79 (17)
C2—C3—C4—C7	109.4 (3)	C9—C10—C11—C13	7.7 (3)
N1—C3—C4—C6	50.2 (2)	N3—C10—C11—C14	65.0 (2)
C2—C3—C4—C6	−131.2 (2)	C9—C10—C11—C14	−113.4 (2)
N1—C3—C4—C5	168.96 (19)	N3—C10—C11—C12	−54.3 (2)
C2—C3—C4—C5	−12.4 (3)	C9—C10—C11—C12	127.2 (2)

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
N1—H1N···N4	0.93 (2)	1.94 (2)	2.858 (2)	169 (2)
N3—H3N···N2^i	0.96 (2)	1.94 (2)	2.889 (3)	174 (2)
C7—H7B···Cg2^ii	0.98	3.01	3.935	158
C12—H12B···Cg1^iii	0.98	3.03	3.972	161
C14—H14B···Cg2^i	0.98	3.07	3.663	120

Symmetry codes: (i) −x, y, −z+1/2; (ii) −x+1/2, −y+1/2, −z+1; (iii) x, −y, z+1/2.