Crystal structure of 2-(4-methyl­benzyl­idene)malono­nitrile

The mol­ecule of the title compound, C₁₁H₈N₂, is approximately planar (r.m.s.deviation for all non-H atoms = 0.023 Å). The malono­nitrile C—C—C angle is 113.54 (13)°. In the crystal, mol­ecules stack head-to-tail along [010]. There are no significant inter­molecular inter­actions present.

Key indicators

• Single-crystal X-ray study
• T = 296 K
• Mean [sigma](C-C) = 0.002 Å
• R factor = 0.046
• wR factor = 0.132
• Data-to-parameter ratio = 16.3

checkCIF/PLATON results

No syntax errors found



Alert level C
PLAT029_ALERT_3_C _diffrn_measured_fraction_theta_full Low .......      0.968 Note
PLAT905_ALERT_3_C Negative K value in the Analysis of Variance ...     -0.513 Report
PLAT911_ALERT_3_C Missing # FCF Refl Between THmin & STh/L=  0.600         53 Report
PLAT913_ALERT_3_C Missing # of Very Strong Reflections in FCF ....          1 Note

Alert level G
PLAT005_ALERT_5_G No _iucr_refine_instructions_details  in the CIF     Please Do !
PLAT154_ALERT_1_G The su's on the Cell Angles are Equal ..........    0.00400 Degree
PLAT899_ALERT_4_G SHELXL97   is Deprecated and Succeeded by SHELXL       2014 Note
PLAT910_ALERT_3_G Missing # of FCF Reflections Below Th(Min) .....          1 Report
PLAT912_ALERT_4_G Missing # of FCF Reflections Above STh/L=  0.600         22 Note

   0 ALERT level A = Most likely a serious problem - resolve or explain
   0 ALERT level B = A potentially serious problem, consider carefully
   4 ALERT level C = Check. Ensure it is not caused by an omission or oversight
   5 ALERT level G = General information/check it is not something unexpected

   1 ALERT type 1 CIF construction/syntax error, inconsistent or missing data
   0 ALERT type 2 Indicator that the structure model may be wrong or deficient
   5 ALERT type 3 Indicator that the structure quality may be low
   2 ALERT type 4 Improvement, methodology, query or suggestion
   1 ALERT type 5 Informative message, check

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S1. Comment

Pharmacological effects of benzylidenemalononitrile (BMN) compounds have been examined since the 1990's when several of their derivatives, referred to as tyrphostins, were recognized as specific inhibitors of epidermal growth factor tyrosine kinase (Gazit, et al., 1989). Subsequent design and testing of a series of BMNs revealed new specific inhibitors of various protein tyrosine kinases (Levitzki & Mishani, 2006). It is well known that the benzylidenemalononitrile derivatives are very useful reagents for the preparation of heterocyclic compounds (Kolla & Lee, 2011; Gao & Du, 2012; Li et al., 2006).

The title molecule is almost planar, Fig. 1, with an r.m.s. devation = 0.023 Å; the maximum deviation of -0.037 (2) Å was observed for atom C5. The malononitrile angle C10–C9–C11 is 113.58 (12)°.

In the crystal, molecules stack head-to-tail along [010]. There are no significant intermolecular interactions present.

Related literature

For the pharmacological activity of benzylidenemalononitriles, see: Gazit et al. (1989); Levitzki & Mishani (2006). For the use of benzylidenemalononitrile derivatives in the preparation of heterocyclic compounds, see: Kolla & Lee (2011); Gao & Du (2012); Li et al. (2006).

S2. Experimental

In a 250 ml round bottom flask, 4-methylbenzaldehyde (10 mmol), malononitrile (10 mmol) and phosphorus pentoxide (3.54 mmol) have stirred mechanically for ten minutes in 25 ml absolute ethanol. The resulting reaction mixture was heated at reflux using a water bath. The reaction mixture was poured onto crushed ice after the completion of the reaction monitored by TLC. On stirring separation of the desired product took place. The solid was filtered, washed with petroleum ether, dried and recrystallized from ethanol (yield: 68%, m.p.: 404 K), yielding block-like colourless crystals.

S3. Refinement

H atoms were located in a difference Fourier map and treated as riding: C–H = 0.93 - 0.96 Å with U_iso(H) = 1.5U_e(C) for methyl H atoms and = 1.2U_eq(C) for other H atoms.

Computing details

Data collection: APEX2 (Bruker, 2009); cell refinement: SAINT (Bruker, 2009); data reduction: SAINT (Bruker, 2009); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: ORTEP-3 for Windows (Farrugia, 2012); software used to prepare material for publication: PLATON (Spek, 2009) and publCIF (Westrip, 2010).

Figures

The molecular structure of the title compound, with atom labelling. Displacement ellipsoids are drawn at the 50% probability level.

2-(4-Methylbenzylidene)malononitrile

Crystal data

C11H8N2	F(000) = 176
Mr = 168.19	Dx = 1.229 Mg m^−3
Triclinic, P1	Melting point: 404 K
a = 7.0043 (5) Å	Mo Kα radiation, λ = 0.71073 Å
b = 7.5270 (5) Å	Cell parameters from 1923 reflections
c = 9.5396 (6) Å	θ = 3.0–27.1°
α = 106.757 (4)°	µ = 0.08 mm^−1
β = 96.592 (4)°	T = 296 K
γ = 105.204 (4)°	Block, colourless
V = 454.75 (5) Å^3	0.40 × 0.34 × 0.30 mm
Z = 2

Data collection

Bruker X8 APEX diffractometer	1923 independent reflections
Radiation source: fine-focus sealed tube	1535 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.022
ϕ and ω scans	θmax = 27.1°, θmin = 3.0°
Absorption correction: multi-scan (SADABS; Bruker, 2009)	h = −8→8
Tmin = 0.637, Tmax = 0.746	k = −9→9
7629 measured reflections	l = −12→12

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)] = 0.046	Hydrogen site location: inferred from neighbouring sites
wR(F^2) = 0.132	H-atom parameters constrained
S = 1.06	w = 1/[σ^2(Fo^2) + (0.0567P)^2 + 0.1308P] where P = (Fo^2 + 2Fc^2)/3
1923 reflections	(Δ/σ)max < 0.001
118 parameters	Δρmax = 0.20 e Å^−3
0 restraints	Δρmin = −0.18 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
C1	0.3051 (2)	−0.0064 (2)	0.22452 (16)	0.0427 (4)
C2	0.1662 (3)	0.0403 (2)	0.30984 (17)	0.0488 (4)
H2	0.0285	−0.0170	0.2695	0.059*
C3	0.2306 (2)	0.1710 (2)	0.45410 (17)	0.0461 (4)
H3	0.1352	0.2004	0.5095	0.055*
C4	0.4357 (2)	0.25984 (19)	0.51829 (15)	0.0365 (3)
C5	0.5753 (2)	0.2128 (2)	0.43179 (17)	0.0448 (4)
H5	0.7131	0.2701	0.4714	0.054*
C6	0.5089 (2)	0.0816 (2)	0.28791 (17)	0.0476 (4)
H6	0.6036	0.0516	0.2321	0.057*
C7	0.2353 (3)	−0.1472 (3)	0.06642 (17)	0.0555 (4)
H7A	0.3430	−0.1963	0.0365	0.083*
H7B	0.1977	−0.0811	0.0006	0.083*
H7C	0.1209	−0.2539	0.0615	0.083*
C8	0.4888 (2)	0.3945 (2)	0.67091 (15)	0.0389 (3)
H8	0.3790	0.4133	0.7126	0.047*
C9	0.6697 (2)	0.4962 (2)	0.76167 (15)	0.0386 (3)
C10	0.6819 (2)	0.6205 (2)	0.91126 (16)	0.0435 (4)
C11	0.8637 (2)	0.4944 (2)	0.72682 (17)	0.0476 (4)
N1	0.6955 (2)	0.7184 (2)	1.03069 (15)	0.0601 (4)
N2	1.0205 (2)	0.4968 (3)	0.70532 (18)	0.0734 (5)

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
C1	0.0507 (9)	0.0391 (7)	0.0347 (7)	0.0136 (7)	0.0069 (7)	0.0079 (6)
C2	0.0390 (9)	0.0520 (9)	0.0436 (8)	0.0077 (7)	0.0051 (7)	0.0059 (7)
C3	0.0398 (9)	0.0523 (9)	0.0417 (8)	0.0131 (7)	0.0140 (7)	0.0080 (7)
C4	0.0388 (8)	0.0379 (7)	0.0320 (7)	0.0119 (6)	0.0091 (6)	0.0098 (6)
C5	0.0381 (9)	0.0524 (9)	0.0377 (8)	0.0135 (7)	0.0090 (6)	0.0061 (6)
C6	0.0467 (10)	0.0570 (9)	0.0368 (8)	0.0210 (8)	0.0132 (7)	0.0060 (7)
C7	0.0619 (12)	0.0541 (9)	0.0381 (8)	0.0160 (8)	0.0038 (8)	0.0012 (7)
C8	0.0406 (8)	0.0428 (7)	0.0331 (7)	0.0139 (6)	0.0128 (6)	0.0096 (6)
C9	0.0419 (9)	0.0405 (7)	0.0326 (7)	0.0146 (6)	0.0110 (6)	0.0083 (6)
C10	0.0412 (9)	0.0464 (8)	0.0384 (8)	0.0118 (7)	0.0102 (7)	0.0084 (6)
C11	0.0442 (10)	0.0522 (9)	0.0367 (8)	0.0146 (7)	0.0066 (7)	0.0014 (6)
N1	0.0602 (10)	0.0649 (9)	0.0403 (7)	0.0147 (7)	0.0136 (7)	−0.0016 (6)
N2	0.0460 (9)	0.0935 (13)	0.0613 (10)	0.0225 (9)	0.0134 (7)	−0.0043 (8)

Geometric parameters (Å, º)

C1—C6	1.384 (2)	C6—H6	0.9300
C1—C2	1.389 (2)	C7—H7A	0.9600
C1—C7	1.508 (2)	C7—H7B	0.9600
C2—C3	1.382 (2)	C7—H7C	0.9600
C2—H2	0.9300	C8—C9	1.341 (2)
C3—C4	1.395 (2)	C8—H8	0.9300
C3—H3	0.9300	C9—C11	1.438 (2)
C4—C5	1.3998 (19)	C9—C10	1.4419 (18)
C4—C8	1.4535 (18)	C10—N1	1.1420 (19)
C5—C6	1.381 (2)	C11—N2	1.137 (2)
C5—H5	0.9300
C6—C1—C2	118.20 (14)	C5—C6—H6	119.1
C6—C1—C7	121.04 (14)	C1—C6—H6	119.1
C2—C1—C7	120.75 (15)	C1—C7—H7A	109.5
C3—C2—C1	120.64 (15)	C1—C7—H7B	109.5
C3—C2—H2	119.7	H7A—C7—H7B	109.5
C1—C2—H2	119.7	C1—C7—H7C	109.5
C2—C3—C4	121.29 (14)	H7A—C7—H7C	109.5
C2—C3—H3	119.4	H7B—C7—H7C	109.5
C4—C3—H3	119.4	C9—C8—C4	130.79 (13)
C3—C4—C5	117.90 (13)	C9—C8—H8	114.6
C3—C4—C8	117.33 (12)	C4—C8—H8	114.6
C5—C4—C8	124.77 (14)	C8—C9—C11	126.43 (13)
C6—C5—C4	120.21 (15)	C8—C9—C10	120.02 (13)
C6—C5—H5	119.9	C11—C9—C10	113.54 (13)
C4—C5—H5	119.9	N1—C10—C9	178.50 (17)
C5—C6—C1	121.76 (14)	N2—C11—C9	177.20 (17)