4-Methyl-3-nitro­benzaldehyde

In the crystal structure of the title compound, C₈H₇NO₃, mol­ecules are linked through weak inter­molecular C—H...O hydrogen bonding.

Key indicators

• Single-crystal X-ray study
• T = 293 K
• Mean [sigma](C-C) = 0.002 Å
• R factor = 0.039
• wR factor = 0.114
• Data-to-parameter ratio = 12.3

checkCIF/PLATON results

No syntax errors found



Alert level C
PLAT242_ALERT_2_C Check Low       Ueq as Compared to Neighbors for         N1

Alert level G
PLAT199_ALERT_1_G Check the Reported _cell_measurement_temperature        293 K
PLAT200_ALERT_1_G Check the Reported   _diffrn_ambient_temperature        293 K

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

   2 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

---

S1. Comment

The title compound is an important intermediate for preparing supramolecular electron transfer materials (Yagi et al., 2003; Ezoe et al., 2006) and it has been utilized to synthesize medicinal compounds with biological activities. Herein we report the crystal structure of the title compound (Fig. 1).

The title compound crystallizes in the monoclinic space group P2₁/c, the unit cell is consists of four molecules. In the title compound, the bond distances and bond angles are similar to those of the reported compound (Zhang et al., 2009). The crystal packing (Fig. 2) is stabilized by a weak intermolecular C—H···O hydrogen bond between the benzene H atom and the oxygen of the aldehyde group(Table 1).

Related literature

For the preparation, see: Johnson et al. (1991). For general background to supramolecular electron-transfer materials, see: Yagi et al. (2003); Ezoe et al. (2006); Normand-Bayle et al. (2005); Ward et al. (2005). For a related structure, see: Zhang et al. (2009).

S2. Experimental

The title compound was obtained according to the literature method (Johnson et al., 1991). Single crystals suitable for X–ray diffraction were prepared by slow evaporation of a solution of the title compound in diethyl ether at room temperature.

S3. Refinement

The H atoms were placed in calculated positions, with C—H = 0.93–0.96 Å and refined as riding modrl, with U_iso(H) = 1.2–1.5 times U_eq(C).

Computing details

Data collection: SMART (Bruker, 2002); cell refinement: SAINT-Plus (Bruker, 2003); data reduction: SAINT-Plus (Bruker, 2003); program(s) used to solve structure: SHELXTL (Sheldrick, 2008); program(s) used to refine structure: SHELXTL (Sheldrick, 2008); molecular graphics: ORTEP-3 (Farrugia, 1997); software used to prepare material for publication: WinGX (Farrugia, 1999).

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 a small spheres of arbitrary radius.
	Fig. 2. C—H···O interaction (dotted lines) in the crystal structure of the title compound.

4-Methyl-3-nitrobenzaldehyde

Crystal data

C8H7NO3	F(000) = 344
Mr = 165.15	Dx = 1.435 Mg m^−3
Monoclinic, P21/c	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2ybc	Cell parameters from 1083 reflections
a = 3.9052 (6) Å	θ = 2.2–23.9°
b = 17.841 (3) Å	µ = 0.11 mm^−1
c = 11.0663 (15) Å	T = 293 K
β = 97.647 (2)°	Block, colorless
V = 764.14 (19) Å^3	0.32 × 0.20 × 0.12 mm
Z = 4

Data collection

Bruker APEX CCD area-detector diffractometer	1353 independent reflections
Radiation source: fine-focus sealed tube	1012 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.018
φ and ω scans	θmax = 25.0°, θmin = 2.2°
Absorption correction: multi-scan (SADABS; Bruker, 2003)	h = −4→4
Tmin = 0.745, Tmax = 1.000	k = −21→18
4088 measured reflections	l = −13→13

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)] = 0.039	Hydrogen site location: inferred from neighbouring sites
wR(F^2) = 0.114	H-atom parameters constrained
S = 1.05	w = 1/[σ^2(Fo^2) + (0.0555P)^2 + 0.1376P] where P = (Fo^2 + 2Fc^2)/3
1353 reflections	(Δ/σ)max < 0.001
110 parameters	Δρmax = 0.13 e Å^−3
0 restraints	Δρmin = −0.16 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
O1	1.3758 (4)	0.60008 (9)	1.06104 (12)	0.0824 (5)
O2	1.0886 (5)	0.70092 (9)	1.05565 (14)	0.0976 (6)
O3	0.8183 (5)	0.42460 (9)	0.60139 (14)	0.0937 (6)
N1	1.1695 (4)	0.64374 (9)	1.00814 (13)	0.0537 (4)
C1	0.7588 (6)	0.75833 (11)	0.8424 (2)	0.0680 (6)
H1A	0.6294	0.7831	0.7740	0.102*
H1B	0.9756	0.7835	0.8638	0.102*
H1C	0.6300	0.7594	0.9105	0.102*
C2	0.8234 (4)	0.67836 (9)	0.80931 (16)	0.0479 (4)
C3	0.6869 (5)	0.65315 (10)	0.69353 (16)	0.0549 (5)
H3	0.5619	0.6866	0.6403	0.066*
C4	0.7290 (5)	0.58141 (10)	0.65495 (15)	0.0546 (5)
H4	0.6312	0.5669	0.5772	0.065*
C5	0.9177 (4)	0.52988 (10)	0.73139 (14)	0.0483 (4)
C6	0.9618 (5)	0.45197 (11)	0.69313 (17)	0.0640 (5)
H6	1.1124	0.4217	0.7440	0.077*
C7	1.0625 (4)	0.55297 (9)	0.84592 (14)	0.0458 (4)
H7	1.1943	0.5197	0.8975	0.055*
C8	1.0119 (4)	0.62533 (9)	0.88392 (14)	0.0440 (4)

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
O1	0.0988 (12)	0.0828 (11)	0.0565 (9)	0.0162 (9)	−0.0233 (8)	−0.0012 (7)
O2	0.1323 (15)	0.0757 (11)	0.0757 (11)	0.0201 (10)	−0.0198 (10)	−0.0281 (9)
O3	0.1213 (14)	0.0757 (11)	0.0727 (10)	0.0141 (9)	−0.0293 (9)	−0.0225 (8)
N1	0.0589 (9)	0.0527 (9)	0.0476 (8)	−0.0074 (7)	0.0000 (7)	−0.0003 (7)
C1	0.0713 (13)	0.0501 (11)	0.0811 (14)	0.0055 (9)	0.0046 (11)	0.0069 (10)
C2	0.0438 (9)	0.0461 (10)	0.0540 (10)	−0.0021 (7)	0.0074 (8)	0.0087 (7)
C3	0.0530 (10)	0.0593 (12)	0.0504 (10)	0.0036 (8)	−0.0001 (8)	0.0172 (8)
C4	0.0554 (11)	0.0646 (12)	0.0412 (9)	−0.0009 (9)	−0.0028 (8)	0.0046 (8)
C5	0.0472 (10)	0.0536 (10)	0.0429 (9)	−0.0010 (7)	0.0011 (7)	0.0010 (7)
C6	0.0730 (13)	0.0625 (13)	0.0527 (11)	0.0082 (10)	−0.0063 (9)	−0.0047 (9)
C7	0.0439 (9)	0.0480 (10)	0.0438 (9)	0.0007 (7)	0.0000 (7)	0.0072 (7)
C8	0.0427 (9)	0.0488 (10)	0.0396 (9)	−0.0064 (7)	0.0028 (7)	0.0046 (7)

Geometric parameters (Å, º)

O1—N1	1.2135 (19)	C3—C4	1.366 (3)
O2—N1	1.209 (2)	C3—H3	0.9300
O3—C6	1.197 (2)	C4—C5	1.392 (2)
N1—C8	1.467 (2)	C4—H4	0.9300
C1—C2	1.503 (2)	C5—C7	1.380 (2)
C1—H1A	0.9600	C5—C6	1.470 (3)
C1—H1B	0.9600	C6—H6	0.9300
C1—H1C	0.9600	C7—C8	1.380 (2)
C2—C3	1.395 (2)	C7—H7	0.9300
C2—C8	1.399 (2)
O2—N1—O1	121.80 (16)	C3—C4—C5	120.32 (16)
O2—N1—C8	119.68 (16)	C3—C4—H4	119.8
O1—N1—C8	118.51 (15)	C5—C4—H4	119.8
C2—C1—H1A	109.5	C7—C5—C4	118.69 (17)
C2—C1—H1B	109.5	C7—C5—C6	119.82 (16)
H1A—C1—H1B	109.5	C4—C5—C6	121.49 (16)
C2—C1—H1C	109.5	O3—C6—C5	124.79 (18)
H1A—C1—H1C	109.5	O3—C6—H6	117.6
H1B—C1—H1C	109.5	C5—C6—H6	117.6
C3—C2—C8	115.51 (16)	C5—C7—C8	120.08 (15)
C3—C2—C1	118.29 (16)	C5—C7—H7	120.0
C8—C2—C1	126.21 (16)	C8—C7—H7	120.0
C4—C3—C2	122.81 (16)	C7—C8—C2	122.57 (15)
C4—C3—H3	118.6	C7—C8—N1	115.84 (14)
C2—C3—H3	118.6	C2—C8—N1	121.59 (15)
C8—C2—C3—C4	0.8 (3)	C5—C7—C8—N1	178.59 (14)
C1—C2—C3—C4	−179.54 (18)	C3—C2—C8—C7	0.4 (2)
C2—C3—C4—C5	−0.7 (3)	C1—C2—C8—C7	−179.27 (16)
C3—C4—C5—C7	−0.5 (3)	C3—C2—C8—N1	−179.79 (14)
C3—C4—C5—C6	178.88 (17)	C1—C2—C8—N1	0.5 (3)
C7—C5—C6—O3	172.0 (2)	O2—N1—C8—C7	−167.19 (17)
C4—C5—C6—O3	−7.4 (3)	O1—N1—C8—C7	11.8 (2)
C4—C5—C7—C8	1.6 (2)	O2—N1—C8—C2	13.0 (3)
C6—C5—C7—C8	−177.77 (16)	O1—N1—C8—C2	−167.98 (17)
C5—C7—C8—C2	−1.6 (3)

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
C4—H4···O3^i	0.93	2.47	3.319 (2)	152

Symmetry code: (i) −x+1, −y+1, −z+1.