2-Acetyl­pyrrole

The title mol­ecule, C₆H₇NO, forms centrosymmetric dimers in the solid state, through N—H...O hydrogen bonds involving amine and carbonyl groups. The resulting R₂²(10) hydrogen-bond pattern is close to that observed in 2-formyl-3-methyl­pyrrole, an isomeric pyrrole derivative.

Key indicators

• Single-crystal X-ray study
• T = 296 K
• Mean [sigma](C-C) = 0.002 Å
• R factor = 0.039
• wR factor = 0.111
• Data-to-parameter ratio = 11.8

checkCIF/PLATON results

No syntax errors found



Alert level C
PLAT245_ALERT_2_C U(iso) H82B    Smaller than U(eq) C8      by ...       0.01 AngSq

   0 ALERT level A = In general: serious problem
   0 ALERT level B = Potentially serious problem
   1 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
   1 ALERT type 2 Indicator that the structure model may be wrong or deficient
   0 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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Computing details

Data collection: XSCANS (Siemens, 1996); cell refinement: XSCANS; data reduction: XSCANS; program(s) used to solve structure: SHELXTL-Plus (Sheldrick, 1998); program(s) used to refine structure: SHELXTL-Plus; molecular graphics: Mercury (Macrae et al., 2006); software used to prepare material for publication: SHELXTL-Plus.

2-Acetylpyrrole

Crystal data

C6H7NO	F(000) = 232
Mr = 109.13	Dx = 1.224 Mg m^−3
Monoclinic, P21/n	Melting point: 362.97(2) K
Hall symbol: -P 2yn	Mo Kα radiation, λ = 0.71073 Å
a = 9.762 (2) Å	Cell parameters from 65 reflections
b = 5.172 (2) Å	θ = 4.8–15.9°
c = 11.731 (3) Å	µ = 0.09 mm^−1
β = 90.158 (5)°	T = 296 K
V = 592.3 (3) Å^3	Needle, colourless
Z = 4	0.60 × 0.18 × 0.12 mm

Data collection

Bruker P4 diffractometer	Rint = 0.028
Radiation source: fine-focus sealed tube, FN4	θmax = 27.5°, θmin = 2.7°
Graphite monochromator	h = −12→9
ω scans	k = −6→6
4203 measured reflections	l = −15→15
1362 independent reflections	3 standard reflections every 97 reflections
1002 reflections with I > 2σ(I)	intensity decay: 4.5%

Refinement

Refinement on F^2	Secondary atom site location: difference Fourier map
Least-squares matrix: full	Hydrogen site location: difference Fourier map
R[F^2 > 2σ(F^2)] = 0.039	All H-atom parameters refined
wR(F^2) = 0.111	w = 1/[σ^2(Fo^2) + (0.053P)^2 + 0.0572P] where P = (Fo^2 + 2Fc^2)/3
S = 1.04	(Δ/σ)max < 0.001
1362 reflections	Δρmax = 0.13 e Å^−3
115 parameters	Δρmin = −0.12 e Å^−3
0 restraints	Extinction correction: SHELXTL-Plus, Fc^*=kFc[1+0.001xFc^2λ^3/sin(2θ)]^-1/4
Primary atom site location: structure-invariant direct methods	Extinction coefficient: 0.156 (13)

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

	x	y	z	Uiso*/Ueq	Occ. (<1)
N1	0.52465 (11)	0.2206 (2)	0.84797 (9)	0.0565 (3)
H1	0.5503 (17)	0.084 (3)	0.8926 (13)	0.073 (5)*
C2	0.41314 (13)	0.3781 (2)	0.86168 (10)	0.0506 (3)
C3	0.41497 (17)	0.5544 (3)	0.77335 (13)	0.0665 (4)
H3	0.351 (2)	0.690 (3)	0.7615 (16)	0.086 (5)*
C4	0.52909 (17)	0.5001 (4)	0.70631 (14)	0.0756 (5)
H4	0.555 (2)	0.594 (4)	0.6370 (15)	0.098 (6)*
C5	0.59512 (16)	0.2945 (3)	0.75469 (13)	0.0668 (4)
H5	0.6772 (19)	0.200 (3)	0.7307 (15)	0.080 (5)*
C6	0.31839 (13)	0.3428 (3)	0.95483 (11)	0.0523 (3)
O7	0.33320 (11)	0.1686 (2)	1.02476 (9)	0.0717 (4)
C8	0.19909 (18)	0.5243 (4)	0.96365 (16)	0.0695 (5)
H81A	0.120 (3)	0.431 (7)	1.011 (3)	0.075 (12)*	0.61 (6)
H82A	0.228 (3)	0.689 (6)	0.994 (3)	0.069 (12)*	0.61 (6)
H83A	0.156 (3)	0.561 (6)	0.888 (3)	0.062 (11)*	0.61 (6)
H81B	0.170 (5)	0.546 (9)	1.046 (4)	0.066 (17)*	0.39 (6)
H82B	0.212 (4)	0.681 (9)	0.926 (5)	0.057 (15)*	0.39 (6)
H83B	0.108 (7)	0.426 (14)	0.922 (5)	0.11 (2)*	0.39 (6)

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
N1	0.0499 (6)	0.0603 (7)	0.0592 (7)	0.0044 (5)	0.0036 (5)	0.0068 (5)
C2	0.0442 (6)	0.0512 (7)	0.0563 (7)	−0.0004 (5)	−0.0046 (5)	0.0010 (5)
C3	0.0619 (9)	0.0648 (9)	0.0728 (9)	0.0007 (7)	−0.0048 (7)	0.0163 (7)
C4	0.0704 (10)	0.0887 (11)	0.0676 (9)	−0.0115 (8)	0.0064 (8)	0.0209 (9)
C5	0.0536 (8)	0.0814 (10)	0.0656 (8)	−0.0036 (8)	0.0106 (7)	0.0028 (8)
C6	0.0469 (7)	0.0546 (7)	0.0554 (7)	0.0018 (5)	−0.0043 (5)	−0.0025 (6)
O7	0.0644 (7)	0.0803 (7)	0.0706 (6)	0.0143 (5)	0.0127 (5)	0.0200 (5)
C8	0.0592 (9)	0.0757 (11)	0.0737 (10)	0.0160 (8)	0.0026 (8)	−0.0034 (9)

Geometric parameters (Å, º)

N1—C5	1.3495 (18)	C5—H5	0.981 (18)
N1—C2	1.3698 (17)	C6—O7	1.2267 (16)
N1—H1	0.912 (17)	C6—C8	1.499 (2)
C2—C3	1.3803 (19)	C8—H81A	1.06 (4)
C2—C6	1.4451 (18)	C8—H82A	0.97 (4)
C3—C4	1.394 (2)	C8—H83A	0.99 (3)
C3—H3	0.949 (19)	C8—H81B	1.01 (5)
C4—C5	1.366 (2)	C8—H82B	0.93 (5)
C4—H4	0.982 (18)	C8—H83B	1.13 (7)
C5—N1—C2	109.49 (13)	H81A—C8—H82A	115 (2)
C5—N1—H1	123.0 (10)	C6—C8—H83A	112.6 (15)
C2—N1—H1	127.5 (10)	H81A—C8—H83A	104 (2)
N1—C2—C3	107.03 (13)	H82A—C8—H83A	106 (2)
N1—C2—C6	121.61 (11)	C6—C8—H81B	111 (2)
C3—C2—C6	131.35 (13)	H81A—C8—H81B	49 (2)
C2—C3—C4	107.60 (14)	H82A—C8—H81B	69 (3)
C2—C3—H3	126.0 (12)	H83A—C8—H81B	135 (3)
C4—C3—H3	126.4 (12)	C6—C8—H82B	114 (2)
C5—C4—C3	107.43 (13)	H81A—C8—H82B	138 (3)
C5—C4—H4	127.2 (12)	H82A—C8—H82B	51 (3)
C3—C4—H4	125.4 (12)	H83A—C8—H82B	58 (3)
N1—C5—C4	108.45 (14)	H81B—C8—H82B	113 (4)
N1—C5—H5	120.7 (10)	C6—C8—H83B	107 (3)
C4—C5—H5	130.8 (10)	H81A—C8—H83B	57 (3)
O7—C6—C2	121.60 (12)	H82A—C8—H83B	142 (3)
O7—C6—C8	120.24 (13)	H83A—C8—H83B	51 (3)
C2—C6—C8	118.16 (13)	H81B—C8—H83B	104 (4)
C6—C8—H81A	108.5 (15)	H82B—C8—H83B	107 (4)
C6—C8—H82A	110.5 (18)
C5—N1—C2—C3	0.26 (16)	C3—C4—C5—N1	0.56 (19)
C5—N1—C2—C6	179.69 (12)	N1—C2—C6—O7	−0.75 (19)
N1—C2—C3—C4	0.09 (17)	C3—C2—C6—O7	178.52 (14)
C6—C2—C3—C4	−179.26 (14)	N1—C2—C6—C8	179.91 (14)
C2—C3—C4—C5	−0.40 (18)	C3—C2—C6—C8	−0.8 (2)
C2—N1—C5—C4	−0.52 (18)

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
N1—H1···O7^i	0.912 (17)	1.985 (18)	2.8628 (17)	161.0 (14)

Symmetry code: (i) −x+1, −y, −z+2.