N-(4-Methyl­phen­yl)formamide

Abstract

In the title compound, C₈H₉NO, the amide group makes a dihedral of 32.35 (1)° with the benzene ring. In the crystal, pairs of strong N—H⋯O hydrogen bonds link the mol­ecules into inversion dimers. Weak C—H⋯O inter­actions further connect the mol­ecules into chains along the a axis.

Related literature  

For the structures and properties of related compounds, see: Tam et al. (2003 ▶); Omondi et al. (2005 ▶).

Experimental  

Crystal data  

• C₈H₉NO

• M _r = 135.16

• Triclinic,

• a = 6.5511 (11) Å

• b = 6.9192 (12) Å

• c = 8.0265 (17) Å

• α = 93.730 (1)°

• β = 102.780 (1)°

• γ = 91.769 (1)°

• V = 353.68 (11) ų

• Z = 2

• Mo Kα radiation

• μ = 0.09 mm⁻¹

• T = 153 K

• 0.10 × 0.05 × 0.05 mm

Data collection  

• Rigaku Mercury2 diffractometer

• Absorption correction: multi-scan (CrystalClear; Rigaku, 2005 ▶) T _min = 0.910, T _max = 1.000

• 2597 measured reflections

• 1570 independent reflections

• 943 reflections with I > 2σ(I)

• R _int = 0.030

Refinement  

• R[F ² > 2σ(F ²)] = 0.046

• wR(F ²) = 0.127

• S = 0.90

• 1570 reflections

• 92 parameters

• H-atom parameters constrained

• Δρ_max = 0.24 e Å⁻³

• Δρ_min = −0.21 e Å⁻³

Data collection: CrystalClear (Rigaku, 2005 ▶); cell refinement: CrystalClear; data reduction: CrystalClear; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008 ▶); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008 ▶); molecular graphics: SHELXTL (Sheldrick, 2008 ▶); software used to prepare material for publication: SHELXTL.

Supplementary Material

Supplementary material file. DOI: 10.1107/S1600536812024300/pv2549Isup3.cml

Additional supplementary materials: crystallographic information; 3D view; checkCIF report

Table 1. Hydrogen-bond geometry (Å, °).

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
N1—H1B⋯O1i	0.86	1.99	2.849 (2)	172
C7—H7A⋯O1ii	0.93	2.63	3.546 (2)	171

Symmetry codes: (i) ; (ii) .

supplementary crystallographic information

Comment

N-(4-Chlorophenyl)formamide and N-(2,6-dichlorophenyl)formamide exhibit phase transitions under different thermal conditions from disordered model to ordered model (Tam et al., 2003; Omondi et al., 2005). Therefore, with the purpose of obtaining phase transition crystals of organic compounds, various similar organic molecules have been studied. The title compound has been synthesized to determine its crystal structure and dielectric properties. In this article, the synthesis and crystal structure of the title compound are reported.

In the title compound (Fig. 1), the amide group (O1/N1/C1) makes a dihedral of 32.35 (1)° with the benzene ring (C2–C7). In the crystal structure, the H atom bonded to the N atom is involved in a strong intermolecular N1—H1B···O1 hydrogen bond. In addition, weak C7—H7A···O1 further stabilize the crystal structure. These H-bonding interactions connect the molecules into a 1D chain along the a-axis (Fig. 2 and Table 1). The bond lengths and bond angles in the title molecule agree very well with the corresponding bond distances and bond angles reported in closely related compounds (Tam et al., 2003; Omondi et al., 2005)

Experimental

A mixture of formic acid (30 mmol), 4-toluidine (10 mmol), H₂SO₄ (0.5 ml, molar concentration 98%) and ethanol (50 mL) in a 100 ml flask was stirred at 333 K for 10 h. Colourless crystals suitable for X-ray diffraction were obtained by slow evaporation of the solution.

Refinement

All H atoms were positioned geometrically and refined using a riding model, with distances N—H = 0.86 Å and C—H = 0.93 and 0.96 Å, for aryl and methyl H-atoms, respectively. The U_iso(H) were allowed at 1.5U_eq(C methyl) or 1.2U_eq(N/C non-methyl).

Figures

Fig. 1.

The molecular structure of the title compound with the atom numbering scheme. Displacement ellipsoids are drawn at the 50% probability level. H atoms are presented as small spheres of arbitrary radius.

Fig. 2.

A view of the N—H···O and C—-H···O hydrogen bonds (dotted lines) in the crystal structure of the title compound. H atoms non-participating in hydrogen-bonding were omitted for clarity.

Crystal data

C8H9NO	Z = 2
Mr = 135.16	F(000) = 144
Triclinic, P1	Dx = 1.269 Mg m−3
Hall symbol: -P 1	Mo Kα radiation, λ = 0.71073 Å
a = 6.5511 (11) Å	Cell parameters from 1570 reflections
b = 6.9192 (12) Å	θ = 3.6–27.5°
c = 8.0265 (17) Å	µ = 0.09 mm−1
α = 93.730 (1)°	T = 153 K
β = 102.780 (1)°	Block, colorless
γ = 91.769 (1)°	0.10 × 0.05 × 0.05 mm
V = 353.68 (11) Å3

Data collection

Rigaku Mercury2 diffractometer	1570 independent reflections
Radiation source: fine-focus sealed tube	943 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.030
Detector resolution: 13.6612 pixels mm-1	θmax = 27.5°, θmin = 3.6°
CCD profile fitting scans	h = −8→8
Absorption correction: multi-scan (CrystalClear; Rigaku, 2005)	k = −7→8
Tmin = 0.910, Tmax = 1.000	l = −10→10
2597 measured reflections

Refinement

Refinement on F2	Primary atom site location: structure-invariant direct methods
Least-squares matrix: full	Secondary atom site location: difference Fourier map
R[F2 > 2σ(F2)] = 0.046	Hydrogen site location: inferred from neighbouring sites
wR(F2) = 0.127	H-atom parameters constrained
S = 0.90	w = 1/[σ2(Fo2) + (0.0693P)2] where P = (Fo2 + 2Fc2)/3
1570 reflections	(Δ/σ)max < 0.001
92 parameters	Δρmax = 0.24 e Å−3
0 restraints	Δρmin = −0.21 e Å−3

Special details

Geometry. All esds (except the esd in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell esds are taken into account individually in the estimation of esds in distances, angles and torsion angles; correlations between esds in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell esds is used for estimating esds 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 > 2sigma(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
O1	0.23436 (18)	1.02875 (15)	0.39355 (14)	0.0308 (3)
N1	0.3558 (2)	0.80633 (18)	0.58427 (17)	0.0232 (3)
H1B	0.4814	0.8558	0.6014	0.028*
C7	0.1344 (3)	0.6126 (2)	0.7268 (2)	0.0247 (4)
H7A	0.0295	0.7011	0.7049	0.030*
C3	0.4782 (2)	0.5127 (2)	0.7131 (2)	0.0238 (4)
H3A	0.6044	0.5333	0.6805	0.029*
C2	0.3215 (2)	0.6435 (2)	0.67500 (19)	0.0210 (4)
C4	0.4474 (3)	0.3510 (2)	0.7997 (2)	0.0249 (4)
H4A	0.5542	0.2648	0.8251	0.030*
C1	0.2053 (3)	0.8876 (2)	0.4739 (2)	0.0251 (4)
H1A	0.0695	0.8344	0.4562	0.030*
C6	0.1060 (3)	0.4493 (2)	0.8112 (2)	0.0261 (4)
H6A	−0.0204	0.4285	0.8434	0.031*
C5	0.2602 (3)	0.3151 (2)	0.8494 (2)	0.0251 (4)
C8	0.2248 (3)	0.1390 (2)	0.9420 (2)	0.0359 (5)
H8A	0.0850	0.0854	0.8973	0.054*
H8B	0.2434	0.1753	1.0620	0.054*
H8C	0.3236	0.0439	0.9255	0.054*

Atomic displacement parameters (Ų)

	U11	U22	U33	U12	U13	U23
O1	0.0283 (7)	0.0289 (7)	0.0364 (7)	0.0013 (5)	0.0065 (5)	0.0132 (6)
N1	0.0220 (7)	0.0227 (7)	0.0251 (7)	−0.0013 (5)	0.0053 (6)	0.0054 (6)
C7	0.0244 (9)	0.0237 (8)	0.0267 (9)	0.0018 (7)	0.0075 (7)	0.0018 (7)
C3	0.0231 (8)	0.0263 (9)	0.0226 (8)	−0.0012 (7)	0.0066 (7)	0.0017 (7)
C2	0.0258 (9)	0.0177 (8)	0.0189 (8)	−0.0014 (6)	0.0043 (6)	0.0011 (6)
C4	0.0268 (9)	0.0234 (9)	0.0238 (9)	0.0030 (7)	0.0039 (7)	0.0027 (7)
C1	0.0226 (9)	0.0255 (9)	0.0279 (9)	0.0018 (7)	0.0066 (7)	0.0029 (7)
C6	0.0251 (9)	0.0295 (9)	0.0248 (9)	−0.0042 (7)	0.0087 (7)	0.0013 (7)
C5	0.0322 (10)	0.0215 (8)	0.0202 (8)	−0.0045 (7)	0.0041 (7)	0.0015 (7)
C8	0.0412 (12)	0.0317 (10)	0.0355 (11)	−0.0041 (8)	0.0087 (9)	0.0111 (8)

Geometric parameters (Å, º)

O1—C1	1.2369 (18)	C4—C5	1.391 (2)
N1—C1	1.3364 (19)	C4—H4A	0.9300
N1—C2	1.4189 (19)	C1—H1A	0.9300
N1—H1B	0.8600	C6—C5	1.391 (2)
C7—C6	1.383 (2)	C6—H6A	0.9300
C7—C2	1.393 (2)	C5—C8	1.506 (2)
C7—H7A	0.9300	C8—H8A	0.9600
C3—C2	1.387 (2)	C8—H8B	0.9600
C3—C4	1.387 (2)	C8—H8C	0.9600
C3—H3A	0.9300
C1—N1—C2	124.15 (14)	O1—C1—N1	124.50 (15)
C1—N1—H1B	117.9	O1—C1—H1A	117.8
C2—N1—H1B	117.9	N1—C1—H1A	117.8
C6—C7—C2	119.50 (15)	C7—C6—C5	122.15 (15)
C6—C7—H7A	120.3	C7—C6—H6A	118.9
C2—C7—H7A	120.3	C5—C6—H6A	118.9
C2—C3—C4	120.16 (15)	C6—C5—C4	117.38 (14)
C2—C3—H3A	119.9	C6—C5—C8	120.91 (15)
C4—C3—H3A	119.9	C4—C5—C8	121.71 (15)
C3—C2—C7	119.37 (14)	C5—C8—H8A	109.5
C3—C2—N1	119.07 (14)	C5—C8—H8B	109.5
C7—C2—N1	121.56 (14)	H8A—C8—H8B	109.5
C3—C4—C5	121.42 (15)	C5—C8—H8C	109.5
C3—C4—H4A	119.3	H8A—C8—H8C	109.5
C5—C4—H4A	119.3	H8B—C8—H8C	109.5

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
N1—H1B···O1i	0.86	1.99	2.849 (2)	172
C7—H7A···O1ii	0.93	2.63	3.546 (2)	171

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