4-Fluoro­benzaldehyde [(E)-4-fluoro­benzyl­idene]hydrazone

The crystal structure of the title compound, C₁₄H₁₀F₂N₂, is stabilized by C—H...F inter­molecular hydrogen bonds, which generate edge-fused R₂¹(6)R₃²(15)R₂²(8)R₃²(17) ring motifs. The complete mol­ecule is centrosymmetric and almost planar.

Key indicators

• Single-crystal X-ray study
• T = 296 K
• Mean [sigma](C-C) = 0.003 Å
• R factor = 0.049
• wR factor = 0.143
• Data-to-parameter ratio = 11.0

checkCIF/PLATON results

No syntax errors found



Alert level C
PLAT063_ALERT_3_C Crystal Probably too Large for Beam Size .......       0.64 mm
PLAT480_ALERT_4_C Long H...A H-Bond Reported H4     ..  F1      ..       2.63 Ang.
PLAT480_ALERT_4_C Long H...A H-Bond Reported H7     ..  F1      ..       2.79 Ang.
PLAT481_ALERT_4_C Long D...A H-Bond Reported C7     ..  F1      ..       3.68 Ang.

Alert level G
FORMU01_ALERT_1_G  There is a discrepancy between the atom counts in the
            _chemical_formula_sum and _chemical_formula_moiety. This is
            usually due to the moiety formula being in the wrong format.
            Atom count from _chemical_formula_sum:   C14 H10 F2 N2
            Atom count from _chemical_formula_moiety:C14 H10 F2 N2 O1

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

   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
   1 ALERT type 3 Indicator that the structure quality may be low
   3 ALERT type 4 Improvement, methodology, query or suggestion
   0 ALERT type 5 Informative message, check

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S1. Comment

Hydrazones are known to possess antimicrobial, anticonvulsant, analgesic, anti-inflammatory, antiplatelet, antitubercular and antitumoral activities. For example, isonicotinoyl hydrazones are antitubercular; 4-hydroxybenzoic acid [(5-nitro-2-furyl)methylene]-hydrazide (nifuroxazide) is an intestinal antiseptic; 4-fluorobenzoic acid[(5-nitro-2-furyl)methylene]-hydrazide (Rollas et al., 2002) and 2,3,4-pentanetrione-3-[4-[[(5-nitro-2-furyl) methylene]hydrazino]carbonyl]phenyl]-hydrazone (Küçükgüzel et al., 1999) have antibacterial activity. A number of azine compounds containing both a diimine linkage and an N—N bond have been investigated in terms of their crystallography and coordination chemistry (Kundu et al., 2005; Kesslen & Euler, 1999; Armstrong et al., 1998; Xu et al., 1997). The crystal structures of N,N-bis(4-chlorobenzylidene)hydrazine (Zheng et al., 2005a), N,N'-bis (3-nitrobenzylidene)hydrazine (Zheng et al., 2005b), N,N'-bis(3-hydroxy-4- methoxybenzylidene)hydrazine (Duan et al., 2005), 1,2-bis[4-(trifluoromethyl) benzylidene]hydrazine (Xu & Hu, 2007) have been reported. A new hydrazone, (I), C₁₄H₁₀F₂N₂ was synthesized and its crystal structure is reported.

The N1═C1 bond length of 1.266 (2) Å is typical of a double bond and similar to the corresponding bond lengths in our previous works (Odabaşoğlu et al., 2005; Albayrak et al., 2005; Şahin et al., 2005; Kazak et al., 2004; Ersanlı, Odabaşoğlu et al.,2004, b; Yüce et al., 2004; Özek et al., 2007). The N—N bond length of 1.410 (3) Å is typical of a N_sp2—N_sp2 single bond.

The crystal structure of (I) is stabilized by three C—H···F intermolecular hydrogen bonds (Table 1). The C—H···F hydrogen bonds generate edge-fussed R₂¹(6)R₃²(15)R₂²(8)R₃²(17) ring motifs (Fig. 2) (Etter, 1990). The molecule is almost planar. There are no C—H···π and π···π interactions in crystal packing.

Related literature

For related literature, see: Albayrak et al. (2005); Armstrong et al. (1998); Duan et al. (2005); Ersanlı, Odabaşoğlu et al. (2004); Etter (1990); Kazak et al. (2004); Kesslen & Euler (1999); Küçükgüzel et al. (1999); Kundu et al. (2005); Odabaşoğlu et al. (2005); Rollas et al. (2002); Xu & Hu (2007); Xu et al. (1997); Yüce et al. (2004); Özek et al. (2007); Ersanlı, Albayrak et al. (2004); Şahin et al. (2005); Sarojini, Narayana et al. (2007); Sarojini, Yathirajan et al. (2007); Zheng et al. (2005a,b). Ersanli, Albayrak and Sarojini refs not cited elsewhere in CIF; OK to retain them here?

S2. Experimental

A mixture of 4-fluorobenzaldehyde (2.48 g, 0.02 mol) and hydrazine hydrate (0.5 ml, 0.01 mol) in 15 ml of absolute ethyl alcohol containing 2 drops of 4 M sulfuric acid was refluxed for about 3 h. On cooling, the solid separated was filtered and recrystallized from ethyl alcohol [m.p.: 439–441 K]. Analysis for C₁₄H₁₀F₂N₂: Found (calculated): C 68.65 (68.85), H 4.18 (4.13), N 11.35% (11.47%).

S3. Refinement

All H atoms were located in Fourier difference map and refined freely.

Computing details

Data collection: X-AREA (Stoe & Cie, 2002); cell refinement: X-AREA (Stoe & Cie, 2002); data reduction: X-RED32 (Stoe & Cie, 2002); program(s) used to solve structure: SHELXS97 (Sheldrick, 1997); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: ORTEP-3 for Windows (Farrugia, 1997); software used to prepare material for publication: WinGX (Farrugia, 1999).

Figures

	Fig. 1. A view of (I) with the atomic numbering scheme. Displacement ellipsoids are drawn at the 30% probability level. [Symmetry code: (i) -x, -y, -z].
	Fig. 2. Part of the crystal structure of (I), showing the formation of R2^1(6)R3^2(15)R2^2(8)R3^2(17) motifs. [Symmetry codes: (i) -x, -y, -z; (ii) 1 - x, -y, 1 - z; (iii) x - 1, 1/2 - y, z - 1/2].

4-Fluorobenzaldehyde [(E)-4-fluorobenzylidene]hydrazone

Crystal data

C14H10F2N2	F(000) = 252
Mr = 244.24	Dx = 1.397 Mg m^−3
Monoclinic, P21/c	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2ybc	Cell parameters from 2956 reflections
a = 3.8488 (18) Å	θ = 2.4–27.8°
b = 13.629 (5) Å	µ = 0.11 mm^−1
c = 11.083 (5) Å	T = 296 K
β = 93.17 (4)°	Prism, light yellow
V = 580.5 (4) Å^3	0.64 × 0.42 × 0.31 mm
Z = 2

Data collection

Stoe IPDSII diffractometer	1136 independent reflections
Radiation source: sealed X-ray tube, 12 x 0.4 mm long-fine focus	804 reflections with I > 2σ(I)
Plane graphite monochromator	Rint = 0.057
Detector resolution: 6.67 pixels mm^-1	θmax = 26.0°, θmin = 2.4°
ω scans	h = −4→4
Absorption correction: integration (X-RED32; Stoe & Cie, 2002)	k = −16→16
Tmin = 0.957, Tmax = 0.983	l = −9→13
2956 measured reflections

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)] = 0.049	All H-atom parameters refined
wR(F^2) = 0.143	w = 1/[σ^2(Fo^2) + (0.0881P)^2] where P = (Fo^2 + 2Fc^2)/3
S = 1.03	(Δ/σ)max < 0.001
1136 reflections	Δρmax = 0.15 e Å^−3
103 parameters	Δρmin = −0.19 e Å^−3
0 restraints	Extinction correction: SHELXL97 (Sheldrick, 1997), Fc^*=kFc[1+0.001xFc^2λ^3/sin(2θ)]^-1/4
Primary atom site location: structure-invariant direct methods	Extinction coefficient: 0.044 (11)

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	0.6680 (5)	0.41276 (12)	0.59066 (17)	0.0559 (5)
C2	0.7183 (4)	0.30733 (12)	0.60689 (16)	0.0499 (5)
C3	0.6028 (5)	0.24038 (13)	0.51855 (18)	0.0561 (5)
C4	0.6501 (5)	0.14112 (12)	0.53589 (19)	0.0620 (5)
C5	0.8109 (5)	0.10995 (12)	0.64283 (18)	0.0605 (5)
C6	0.9276 (5)	0.17279 (14)	0.73247 (19)	0.0618 (5)
C7	0.8812 (5)	0.27196 (13)	0.71346 (18)	0.0587 (5)
N1	0.5085 (4)	0.44837 (9)	0.49769 (14)	0.0590 (5)
F1	0.8551 (4)	0.01213 (8)	0.65970 (13)	0.0915 (6)
H1	0.775 (5)	0.4584 (15)	0.658 (2)	0.073 (6)*
H3	0.485 (5)	0.2631 (13)	0.445 (2)	0.060 (5)*
H4	0.577 (6)	0.0952 (18)	0.476 (2)	0.091 (7)*
H6	1.027 (6)	0.1472 (15)	0.804 (2)	0.083 (7)*
H7	0.965 (6)	0.3201 (19)	0.776 (2)	0.090 (7)*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
C1	0.0635 (10)	0.0470 (9)	0.0560 (10)	−0.0012 (7)	−0.0063 (9)	−0.0003 (8)
C2	0.0525 (9)	0.0453 (8)	0.0513 (9)	0.0006 (6)	−0.0031 (7)	0.0005 (7)
C3	0.0645 (10)	0.0492 (9)	0.0530 (10)	0.0010 (7)	−0.0115 (8)	0.0003 (7)
C4	0.0764 (12)	0.0471 (10)	0.0605 (12)	−0.0004 (8)	−0.0141 (10)	−0.0053 (8)
C5	0.0721 (11)	0.0426 (9)	0.0655 (12)	0.0026 (8)	−0.0088 (9)	0.0031 (8)
C6	0.0717 (11)	0.0550 (10)	0.0567 (11)	0.0026 (8)	−0.0150 (9)	0.0046 (8)
C7	0.0682 (11)	0.0507 (10)	0.0554 (11)	−0.0012 (8)	−0.0117 (8)	−0.0039 (8)
N1	0.0733 (10)	0.0393 (7)	0.0630 (10)	0.0023 (6)	−0.0098 (7)	−0.0005 (6)
F1	0.1328 (12)	0.0434 (6)	0.0940 (11)	0.0087 (6)	−0.0326 (8)	0.0052 (6)

Geometric parameters (Å, º)

C1—N1	1.266 (2)	C4—H4	0.94 (3)
C1—C2	1.460 (2)	C5—F1	1.356 (2)
C1—H1	1.04 (2)	C5—C6	1.368 (3)
C2—C7	1.392 (3)	C6—C7	1.378 (3)
C2—C3	1.393 (3)	C6—H6	0.93 (3)
C3—C4	1.377 (2)	C7—H7	1.00 (3)
C3—H3	0.96 (2)	N1—N1^i	1.410 (3)
C4—C5	1.374 (3)
N1—C1—C2	122.17 (16)	C3—C4—H4	121.5 (16)
N1—C1—H1	120.8 (12)	F1—C5—C6	118.79 (17)
C2—C1—H1	117.0 (12)	F1—C5—C4	118.04 (15)
C7—C2—C3	118.74 (17)	C6—C5—C4	123.16 (17)
C7—C2—C1	119.72 (15)	C5—C6—C7	117.92 (18)
C3—C2—C1	121.54 (16)	C5—C6—H6	119.2 (14)
C4—C3—C2	120.71 (18)	C7—C6—H6	122.9 (14)
C4—C3—H3	119.1 (11)	C6—C7—C2	121.18 (18)
C2—C3—H3	120.2 (11)	C6—C7—H7	120.3 (15)
C5—C4—C3	118.29 (17)	C2—C7—H7	118.5 (15)
C5—C4—H4	120.2 (15)	C1—N1—N1^i	111.98 (18)
N1—C1—C2—C7	−176.97 (19)	F1—C5—C6—C7	179.80 (18)
N1—C1—C2—C3	2.2 (3)	C4—C5—C6—C7	−0.2 (3)
C7—C2—C3—C4	−0.3 (3)	C5—C6—C7—C2	0.5 (3)
C1—C2—C3—C4	−179.46 (18)	C3—C2—C7—C6	−0.2 (3)
C2—C3—C4—C5	0.6 (3)	C1—C2—C7—C6	178.91 (18)
C3—C4—C5—F1	179.65 (18)	C2—C1—N1—N1^i	179.84 (17)
C3—C4—C5—C6	−0.4 (3)

Symmetry code: (i) −x+1, −y+1, −z+1.

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
C1—H1···F1^ii	1.04 (2)	2.52 (2)	3.507 (3)	159.36 (1)
C4—H4···F1^iii	0.94 (2)	2.63 (2)	3.518 (3)	157.98 (2)
C7—H7···F1^ii	1.00 (2)	2.79 (3)	3.683 (3)	149.43 (2)

Symmetry codes: (ii) −x+2, y+1/2, −z+3/2; (iii) −x+1, −y, −z+1.