4-Acetyl-N-methyl­aniline

Mol­ecules of the title compound, C₉H₁₁NO, are connected into infinite chains by inter­molecular N—H...O hydrogen bonds of length 2.893 (3) Å between the N-methyl­amino and carbonyl functions.

Key indicators

• Single-crystal X-ray study
• T = 294 K
• Mean [sigma](C-C)= 0.004 Å
• R factor = 0.063
• wR factor = 0.141
• Data-to-parameter ratio = 14.2

checkCIF/PLATON results

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Computing details

Data collection: R3m/V (Siemens, 1989); cell refinement: R3m/V; data reduction: XDISK (Siemens, 1989); program(s) used to solve structure: SHELXS97 (Sheldrick, 1997); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: SHELXTL-Plus (Sheldrick, 1995); software used to prepare material for publication: SHELXL97.

4-Acetyl-N-methylaniline

Crystal data

C9H11NO	F(000) = 320
Mr = 149.19	Dx = 1.194 Mg m^−3
Monoclinic, P21/c	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2ybc	Cell parameters from 18 reflections
a = 6.286 (4) Å	θ = 7.3–16.0°
b = 7.6675 (16) Å	µ = 0.08 mm^−1
c = 17.358 (5) Å	T = 294 K
β = 97.33 (4)°	Prism, light yellow
V = 829.8 (6) Å^3	0.54 × 0.52 × 0.35 mm
Z = 4

Data collection

Siemens P4 four-circle diffractometer	733 reflections with I > 2σ(I)
Radiation source: fine-focus sealed tube	Rint = 0.043
Graphite monochromator	θmax = 25.0°, θmin = 2.4°
Profile fitted scans	h = −1→7
Absorption correction: ψ scan (XPREP in SHELXTL; Sheldrick, 1995)	k = −1→9
Tmin = 0.937, Tmax = 0.981	l = −20→20
2178 measured reflections	3 standard reflections every 100 reflections
1462 independent reflections	intensity decay: none

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)] = 0.063	H-atom parameters constrained
wR(F^2) = 0.141	w = 1/[σ^2(Fo^2) + (0.0537P)^2] where P = (Fo^2 + 2Fc^2)/3
S = 0.99	(Δ/σ)max = 0.016
1462 reflections	Δρmax = 0.15 e Å^−3
103 parameters	Δρmin = −0.14 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: 0.010 (3)

Special details

Experimental. The IR spectrum of (I) (KBr pellet) exhibits a characteristic sharp strong band for ν(NH). The strong band at 3321 cm^-1 (Raman, crystalline powder) is likewise assigned to stretching of the NH group. In CCl₄ the IR frequency of this group lies at 3319 cm^-1 and in CHCl₃ at 3335 cm^-1, coinciding with the literature data. Three weak bands at 3094, 3062 and 3021 cm^-1 are assigned to ν(CH) of the substituted benzene ring and those at 2983, 2933, 2904, 2888, 2857 and 2823 cm^-1 to ν(CH) of two methyl groups. The strong band at 1653 cm^-1(IR) results from the stretching vibration of the carbonyl group and its Raman counterpart is observed at 1650 cm^-1 at high intensity. Other prominent bands at 1589 and 1560 cm^-1 (IR) and 1589 and 1562 cm^-1 (Raman) are attributed to radial vibrations 8a and 8 b of the aromatic ring. It is known that a strong donating group in the 4-position lowers the frequencies of these modes and increases their intensities. Because of the relative strong charge-transfer character of (I), the frequencies of these modes are downshifted. The bands at 1532 and 1449 cm^-1 belong also to the radial vibration of the phenyl ring. A strong band at 1279 cm^-1(IR) and a weak Raman band at 1281 cm^-1 were attributed to ν[Ph–C(O)CH₃] vibration. The moderate intensity bands at 1160, 1115 and 1082 cm^-1 were assigned to in-plane deformation vibrations of the aromatic nucleus. Out-of-plane modes appear at 994, 959, 828 and 815 cm^-1.

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
C1	0.2271 (5)	0.8305 (4)	0.26566 (15)	0.0495 (8)
N1	0.1680 (4)	0.8358 (3)	0.33870 (12)	0.0627 (8)
H1	0.2529	0.7900	0.3760	0.075*
C11	−0.0283 (5)	0.9137 (5)	0.35692 (16)	0.0736 (10)
H111	−0.0391	0.8982	0.4112	0.110*
H112	−0.1484	0.8587	0.3267	0.110*
H113	−0.0282	1.0360	0.3451	0.110*
C2	0.4085 (5)	0.7390 (4)	0.25213 (16)	0.0572 (8)
H2	0.4885	0.6813	0.2932	0.069*
C3	0.4736 (5)	0.7314 (4)	0.17948 (16)	0.0579 (8)
H3	0.5971	0.6699	0.1723	0.070*
O4	0.2898 (4)	0.8564 (3)	−0.01906 (11)	0.0771 (8)
C4	0.3557 (4)	0.8152 (4)	0.11616 (15)	0.0496 (8)
C41	0.4128 (5)	0.8021 (4)	0.03667 (17)	0.0578 (8)
C42	0.6242 (5)	0.7218 (5)	0.02328 (18)	0.0772 (11)
H421	0.6317	0.7140	−0.0315	0.116*
H422	0.6357	0.6072	0.0457	0.116*
H423	0.7397	0.7932	0.0472	0.116*
C5	0.1747 (5)	0.9081 (4)	0.12999 (15)	0.0537 (8)
H5	0.0949	0.9656	0.0888	0.064*
C6	0.1095 (4)	0.9178 (4)	0.20275 (15)	0.0539 (8)
H6	−0.0119	0.9818	0.2102	0.065*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
C1	0.057 (2)	0.0412 (17)	0.0480 (17)	−0.0037 (17)	−0.0019 (15)	0.0001 (14)
N1	0.0675 (18)	0.0696 (19)	0.0503 (15)	0.0045 (16)	0.0041 (12)	0.0054 (13)
C11	0.073 (2)	0.082 (3)	0.068 (2)	−0.003 (2)	0.0156 (17)	0.0033 (18)
C2	0.057 (2)	0.055 (2)	0.0561 (18)	0.0070 (18)	−0.0070 (15)	0.0080 (15)
C3	0.0508 (19)	0.057 (2)	0.0640 (19)	0.0090 (17)	−0.0003 (15)	0.0009 (16)
O4	0.0889 (17)	0.0893 (17)	0.0502 (12)	0.0007 (15)	−0.0021 (11)	−0.0041 (12)
C4	0.0506 (19)	0.0474 (19)	0.0495 (16)	−0.0007 (16)	0.0010 (14)	−0.0007 (14)
C41	0.067 (2)	0.050 (2)	0.0569 (18)	−0.0090 (19)	0.0086 (17)	−0.0043 (16)
C42	0.075 (2)	0.082 (3)	0.078 (2)	0.001 (2)	0.0208 (19)	−0.0053 (19)
C5	0.055 (2)	0.054 (2)	0.0489 (16)	−0.0015 (17)	−0.0049 (14)	0.0054 (14)
C6	0.0533 (19)	0.0518 (19)	0.0553 (17)	0.0061 (17)	0.0019 (15)	0.0017 (15)

Geometric parameters (Å, º)

C1—N1	1.367 (3)	C3—H3	0.9300
C1—C2	1.384 (4)	O4—C41	1.231 (3)
C1—C6	1.407 (3)	C4—C5	1.389 (4)
N1—C11	1.442 (4)	C4—C41	1.473 (4)
N1—H1	0.8600	C41—C42	1.509 (4)
C11—H111	0.9600	C42—H421	0.9600
C11—H112	0.9600	C42—H422	0.9600
C11—H113	0.9600	C42—H423	0.9600
C2—C3	1.376 (4)	C5—C6	1.379 (4)
C2—H2	0.9300	C5—H5	0.9300
C3—C4	1.401 (4)	C6—H6	0.9300
N1—C1—C2	120.0 (3)	C5—C4—C3	117.6 (3)
N1—C1—C6	121.8 (3)	C5—C4—C41	120.0 (3)
C2—C1—C6	118.2 (3)	C3—C4—C41	122.4 (3)
C1—N1—C11	123.9 (3)	O4—C41—C4	120.6 (3)
C1—N1—H1	118.1	O4—C41—C42	119.6 (3)
C11—N1—H1	118.1	C4—C41—C42	119.8 (3)
N1—C11—H111	109.5	C41—C42—H421	109.5
N1—C11—H112	109.5	C41—C42—H422	109.5
H111—C11—H112	109.5	H421—C42—H422	109.5
N1—C11—H113	109.5	C41—C42—H423	109.5
H111—C11—H113	109.5	H421—C42—H423	109.5
H112—C11—H113	109.5	H422—C42—H423	109.5
C3—C2—C1	121.6 (3)	C6—C5—C4	122.1 (3)
C3—C2—H2	119.2	C6—C5—H5	118.9
C1—C2—H2	119.2	C4—C5—H5	118.9
C2—C3—C4	120.7 (3)	C5—C6—C1	119.8 (3)
C2—C3—H3	119.7	C5—C6—H6	120.1
C4—C3—H3	119.7	C1—C6—H6	120.1

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
N1—H1···O4^i	0.86	2.13	2.893 (3)	148

Symmetry code: (i) x, −y+3/2, z+1/2.