N′-[1-(2-Thien­yl)ethyl­idene]aceto­hydrazide

The title compound, C₈H₁₀N₂OS, was prepared by the reaction of 1-(thio­phen-2-yl)ethanone and acetohydrazide. The mol­ecules form a dimer, in which two N—H...O hydrogen bonds generate an inter­molecular R₂²(8) ring. There is also an inter­molecular C—H...O hydrogen-bonding inter­action.

Key indicators

• Single-crystal X-ray study
• T = 294 K
• Mean [sigma](C-C) = 0.003 Å
• R factor = 0.044
• wR factor = 0.132
• Data-to-parameter ratio = 16.2

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S1. Comment

Schiff bases have received considerable attention in the literature. They are attractive from several points of view, such as the possibility of analytical application (Cimerman, et al., 1997). As part of our search for new schiff base compounds we synthesized the title compound (I), and describe its structure here.

The molecular structure of the title compund (I) is shown in Fig. 1. The values of all the geometric parameters in (I) are normal. The structure is stabilized by the N—H···O hydrogen bonds form a dimer structure, generating an intermolecular R₂²(8) ring, and intramolecular C—H···O hydrogen bonding interactions.

Related literature

For related literature, see: Cimerman et al. (1997); Sutherland & Hoy (1968); Tucker et al. (1975)

S2. Experimental

A mixture of the 1-(thiophen-2-yl)ethanone (0.1 mol), and acetohydrazide (0.1 mol) was stirred in refluxing ethanol (30 ml) for 5 h to afford the title compound (0.087 mol, yield 87%). Single crystals (I) of suitable for X-ray measurements were obtained by recrystallization from ethanol at room temperature.

S3. Refinement

NH H atom was found from difference Fourier map and refined freely. H atoms bonded to C atoms were fixed geometrically and allowed to ride on their attached atoms, with C—H = 0.93 - 0.96 Å, and with U_iso(H) = 1.2–1.5U_eq(C).

Computing details

Data collection: SMART (Bruker, 1997); cell refinement: SMART; data reduction: SAINT (Bruker, 1997); program(s) used to solve structure: SHELXS97 (Sheldrick, 1997); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: SHELXTL (Bruker, 1997); software used to prepare material for publication: SHELXTL.

Figures

Fig. 1. An ORTEP view of the title compound (I), showing 30% probability displacement ellipsoids and the atom-numbering scheme.

N'-[1-(2-Thienyl)ethylidene]acetohydrazide

Crystal data

C8H10N2OS	Z = 4
Mr = 182.24	F(000) = 384
Monoclinic, P21/n	Dx = 1.344 Mg m^−3
Hall symbol: -P 2yn	Mo Kα radiation, λ = 0.71073 Å
a = 5.2903 (11) Å	θ = 2.3–26.4°
b = 9.788 (2) Å	µ = 0.31 mm^−1
c = 17.435 (4) Å	T = 294 K
β = 94.102 (3)°	Block, colourless
V = 900.5 (3) Å^3	0.24 × 0.16 × 0.14 mm

Data collection

Bruker SMART CCD area detector diffractometer	1847 independent reflections
Radiation source: fine-focus sealed tube	1435 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.026
φ and ω scans	θmax = 26.4°, θmin = 2.3°
Absorption correction: multi-scan (SADABS; Bruker, 1997)	h = −5→6
Tmin = 0.929, Tmax = 0.958	k = −7→12
5012 measured reflections	l = −21→17

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)] = 0.044	Hydrogen site location: inferred from neighbouring sites
wR(F^2) = 0.132	H atoms treated by a mixture of independent and constrained refinement
S = 1.06	w = 1/[σ^2(Fo^2) + (0.0625P)^2 + 0.4879P] where P = (Fo^2 + 2Fc^2)/3
1847 reflections	(Δ/σ)max < 0.001
114 parameters	Δρmax = 0.31 e Å^−3
1 restraint	Δρmin = −0.33 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
S1	0.22200 (12)	0.44789 (7)	0.06956 (4)	0.0566 (3)
O1	0.8443 (4)	0.0201 (2)	−0.09105 (9)	0.0601 (5)
N1	0.5822 (3)	0.23827 (19)	0.03934 (10)	0.0405 (4)
N2	0.7406 (3)	0.1420 (2)	0.01056 (10)	0.0433 (5)
C1	0.0993 (5)	0.5464 (3)	0.13844 (17)	0.0590 (7)
H1	−0.0331	0.6078	0.1284	0.071*
C2	0.2152 (5)	0.5258 (3)	0.20932 (16)	0.0542 (6)
H2	0.1716	0.5718	0.2531	0.065*
C3	0.4117 (4)	0.4255 (2)	0.20935 (14)	0.0445 (5)
H3	0.5104	0.3982	0.2529	0.053*
C4	0.4369 (4)	0.3738 (2)	0.13575 (12)	0.0382 (5)
C5	0.6116 (4)	0.2692 (2)	0.11116 (12)	0.0363 (5)
C6	0.8019 (4)	0.2087 (3)	0.16943 (13)	0.0464 (6)
H6A	0.8417	0.1173	0.1545	0.070*
H6B	0.7325	0.2071	0.2188	0.070*
H6C	0.9532	0.2632	0.1723	0.070*
C7	0.7020 (4)	0.1030 (2)	−0.06398 (12)	0.0428 (5)
C8	0.4802 (5)	0.1646 (3)	−0.11048 (14)	0.0525 (6)
H8A	0.4804	0.1339	−0.1628	0.079*
H8B	0.4932	0.2624	−0.1089	0.079*
H8C	0.3256	0.1367	−0.0894	0.079*
H2A	0.871 (3)	0.104 (3)	0.0379 (14)	0.058 (8)*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
S1	0.0562 (4)	0.0665 (5)	0.0460 (4)	0.0183 (3)	−0.0035 (3)	0.0045 (3)
O1	0.0651 (11)	0.0742 (13)	0.0402 (9)	0.0259 (10)	−0.0033 (8)	−0.0083 (9)
N1	0.0392 (9)	0.0452 (11)	0.0365 (9)	0.0038 (8)	−0.0006 (7)	−0.0007 (8)
N2	0.0438 (10)	0.0493 (11)	0.0357 (10)	0.0107 (9)	−0.0042 (8)	−0.0010 (8)
C1	0.0520 (14)	0.0568 (16)	0.0684 (17)	0.0152 (12)	0.0066 (13)	0.0005 (13)
C2	0.0512 (14)	0.0573 (16)	0.0549 (15)	0.0008 (11)	0.0096 (11)	−0.0119 (12)
C3	0.0402 (11)	0.0487 (14)	0.0443 (12)	−0.0032 (10)	0.0008 (9)	−0.0083 (10)
C4	0.0344 (10)	0.0418 (12)	0.0377 (11)	−0.0032 (9)	−0.0022 (8)	0.0013 (9)
C5	0.0331 (10)	0.0401 (12)	0.0352 (10)	−0.0040 (9)	−0.0010 (8)	0.0013 (9)
C6	0.0456 (12)	0.0532 (14)	0.0394 (11)	0.0072 (10)	−0.0048 (9)	−0.0012 (10)
C7	0.0437 (11)	0.0475 (13)	0.0365 (11)	0.0027 (10)	−0.0020 (9)	0.0022 (10)
C8	0.0533 (14)	0.0624 (16)	0.0403 (12)	0.0073 (12)	−0.0079 (10)	−0.0002 (11)

Geometric parameters (Å, º)

S1—C1	1.704 (3)	C3—C4	1.394 (3)
S1—C4	1.721 (2)	C3—H3	0.9300
O1—C7	1.224 (3)	C4—C5	1.464 (3)
N1—C5	1.287 (3)	C5—C6	1.500 (3)
N1—N2	1.379 (3)	C6—H6A	0.9600
N2—C7	1.356 (3)	C6—H6B	0.9600
N2—H2A	0.889 (10)	C6—H6C	0.9600
C1—C2	1.355 (4)	C7—C8	1.504 (3)
C1—H1	0.9300	C8—H8A	0.9600
C2—C3	1.430 (3)	C8—H8B	0.9600
C2—H2	0.9300	C8—H8C	0.9600
C1—S1—C4	91.85 (12)	N1—C5—C6	126.5 (2)
C5—N1—N2	118.70 (18)	C4—C5—C6	119.00 (18)
C7—N2—N1	119.20 (18)	C5—C6—H6A	109.5
C7—N2—H2A	117.1 (18)	C5—C6—H6B	109.5
N1—N2—H2A	123.7 (18)	H6A—C6—H6B	109.5
C2—C1—S1	112.9 (2)	C5—C6—H6C	109.5
C2—C1—H1	123.6	H6A—C6—H6C	109.5
S1—C1—H1	123.6	H6B—C6—H6C	109.5
C1—C2—C3	112.6 (2)	O1—C7—N2	120.1 (2)
C1—C2—H2	123.7	O1—C7—C8	122.4 (2)
C3—C2—H2	123.7	N2—C7—C8	117.5 (2)
C4—C3—C2	111.5 (2)	C7—C8—H8A	109.5
C4—C3—H3	124.3	C7—C8—H8B	109.5
C2—C3—H3	124.3	H8A—C8—H8B	109.5
C3—C4—C5	128.82 (19)	C7—C8—H8C	109.5
C3—C4—S1	111.24 (17)	H8A—C8—H8C	109.5
C5—C4—S1	119.93 (15)	H8B—C8—H8C	109.5
N1—C5—C4	114.48 (18)
C5—N1—N2—C7	176.3 (2)	N2—N1—C5—C4	179.08 (18)
C4—S1—C1—C2	0.3 (2)	N2—N1—C5—C6	−1.2 (3)
S1—C1—C2—C3	−0.4 (3)	C3—C4—C5—N1	177.0 (2)
C1—C2—C3—C4	0.4 (3)	S1—C4—C5—N1	−1.9 (3)
C2—C3—C4—C5	−179.1 (2)	C3—C4—C5—C6	−2.7 (3)
C2—C3—C4—S1	−0.2 (2)	S1—C4—C5—C6	178.39 (17)
C1—S1—C4—C3	−0.04 (19)	N1—N2—C7—O1	178.3 (2)
C1—S1—C4—C5	179.01 (19)	N1—N2—C7—C8	−2.0 (3)

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
N2—H2A···O1^i	0.89 (2)	2.10 (2)	2.978 (3)	169 (3)
C6—H6A···O1^i	0.96	2.46	3.279 (3)	143

Symmetry code: (i) −x+2, −y, −z.