Crystal structure, Hirshfeld surface analysis and DFT studies of 6-[(E)-2-(thio-phen-2-yl)ethenyl]-4,5-di-hydro-pyridazin-3(2H)-one.

In the title compound, C10H10N2OS, the five atoms of the thio-phene ring are essentially coplanar (r.m.s. deviation = 0.0037 Å) and the pyridazine ring is non-planar. In the crystal, pairs of N-H⋯O hydrogen bonds link the mol-ecules into dimers with an R 2 2(8) ring motif. The dimers are linked by C-H⋯O inter-actions, forming layers parallel to the bc plane. The theoretical geometric parameters are in good agreement with XRD results. The inter-molecular inter-actions were investigated using a Hirshfeld surface analysis and two-dimensional fingerprint plots. The Hirshfeld surface analysis of the title compound suggests that the most significant contributions to the crystal packing are by H⋯H (39.7%), C⋯H/H⋯C (17.3%) and O⋯H/H⋯O (16.8%) contacts. © Daoui et al. 2019.

Chemical context

Pyridazinone derivatives have been tested for their chemical and biological properties and achieved an increased inter­est in recent years (Akhtar et al., 2016 ▸). The pyridazinone moiety is known as a ‘wonder nucleus’ as it can form diverse derivatives with many types of pharmacological activities such as anti­depressant (Boukharsa et al., 2016 ▸), anti-HIV (Livermore et al., 1993 ▸), anti-inflammatory (Barberot et al., 2018 ▸), anti­convulsant (Partap et al., 2018 ▸), anti­histaminic (Tao et al. 2012 ▸) and glucan synthase inhibition (Zhou et al., 2011 ▸) as well as acting as herbicidal agents (Asif, 2013 ▸). We report the synthesis and the crystal and mol­ecular structure of the title compound (Fig. 1 ▸), as well as an analysis of its Hirshfeld surface and DFT studies.

Figure 1

Mol­ecular structure of the title compound showing the atom labelling and displacement ellipsoids drawn at the 50% probability level.

Structural commentary

Selected geometrical parameters are given in Table 1 ▸. The five atoms of the thio­phene ring are essentially coplanar (r.m.s. deviation = 0.0037 Å) while the pyridazine ring is non-planar with atom C2 furthest from the mean mol­ecular plane at a distance of 0.610 (5) Å.

Table 1

Selected bond lengths, angles and torsion angles (Å, °)

	X-ray	DFT/B3LYP/LANL2DZ
S1—C10	1.691 (3)	1.734 (7)
O1—C1	1.227 (3)	1.219 (9)
N2—C4	1.283 (3)	1.300 (2)
N2—N1	1.385 (2)	1.375 (6)
N1—C1	1.345 (3)	1.353 (0)
C10—S1—C7	92.31 (13)	91.705 (6)
O1—C1—N1	121.4 (2)	121.412 (2)
C7—C6—C5—C4	179.0 (2)	178.857 (8)
N2—C4—C5—C6	−179.4 (2)	179.554 (8)

Supra­molecular features

In the crystal, the mol­ecules are connected pairwise through N—H⋯O hydrogen bonds (Table 2 ▸), forming dimers with an (8) graph set motif. The dimers are linked by C—H⋯O hydrogen bonds, forming layers parallel to the bc plane (Fig. 2 ▸). A packing diagram is shown in Fig. 2 ▸.

Table 2

Hydrogen-bond geometry (Å, °)

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
N1—H1⋯O1i	0.83 (3)	2.07 (3)	2.899 (3)	175 (2)
C10—H10⋯O1ii	0.93	2.61	3.505 (3)	161

Symmetry codes: (i) ; (ii) .

Figure 2

Inversion dimers with (8) ring motifs formed by N—H⋯O hydrogen bonds (red dashed lines; Table 2 ▸). C—H⋯O inter­actions are shown as black dashed lines.

Database survey

A search of the Cambridge Structural Database (CSD, version 5.40, update November 2018; Groom et al., 2016 ▸) using (E)-6-(thio­phen-2-yl)hex-5-enal and 6-vinyl-4,5-di­hydro­pyridazin-3(2H)-one as the main skeleton found two structures similar to the title compound containing the pyridazine moiety with different substituents: 4-chloro-2-[(5-eth­oxy-1,3,4-thia­diazol-2-yl)meth­yl]-5-(piperidin-1-yl)pyridazin-3(2H)-one (DOP­ZAL; Li et al., 2014 ▸) and 4-[(tert-butyl­diphenyl­sil­yloxy)meth­yl]pyridazin-3(2H)-one (CISPAX; Costas-Lago et al., 2013 ▸). In DOPZAL, the six atoms of the 1,6-di­hydro­pyridazine ring are essentially coplanar (r.m.s. deviation = 0.008 Å), and the dihedral angle between this and the 1,3,4-thia­diazole ring is 62.06 (10)°. In CISPAX, pyridazinone moieties are anti-oriented across the Si—O bond [torsion angle = 168.44 (19)°]. In the crystal, mol­ecules are assembled into inversion dimers through co-operative N—H⋯O hydrogen bonds between the NH groups and O atoms of the pyridazinone rings of neighbouring mol­ecules.

Surface Analysis (SA)

The Hirshfeld surface analysis (Spackman & Jayatilaka, 2009 ▸) and the associated fingerprint plots were performed with CrystalExplorer17.5 (Turner et al., 2017 ▸). This software was used to analyse the inter­molecular inter­actions in the crystal and to generate fingerprint plots mapped over d norm, shape index and curvedness (Fig. 3 ▸). The Hirshfeld surface was calculated using a standard (high) surface resolution with the three-dimensional d norm surface plotted over a fixed colour scale of −0.532 (red) to 1.345 (blue) a.u. The pale-red spots symbolize short contacts and negative d norm values on the surface correspond to the N—H⋯O and C—H⋯O inter­actions (Table 2 ▸). The overall fingerprint plot and those delin­eated into H⋯H, H⋯C/ C⋯H, H⋯O/O⋯H, N⋯H/H⋯N and N⋯·C/C⋯·N contacts are shown in Fig. 4 ▸ along with their relative contributions to the Hirshfeld surface. The largest contribution is from H⋯H inter­actions (40.0%). The shape-index map of the title complex was generated in the range −1 to 1 Å, with the convex blue regions indicating hydrogen-donor groups and the concave red regions hydrogen-acceptor groups. The curvedness map, generated in the range −4 to 0.4 Å, shows large regions of green which denote a relatively flat surface area (planar), while the blue regions denote areas of curvature.

Figure 3

The Hirshfeld surfaces of the title compound mapped over d norm, shape-index and curvedness.

Figure 4

Two-dimensional fingerprint plots for the title compound, with a d norm view and the relative contributions of the atom pairs to the Hirshfeld surface.

A view of the mol­ecular electrostatic potential, in the range − 0.084 to 0.084 a.u. generated by the DFT method using the 6-31G(d,p) basis set is shown in Fig. 5 ▸. Here the N—H⋯O hydrogen-bond donors and acceptors are shown as blue and red areas around the atoms related with positive (hydrogen-bond donors) and negative (hydrogen-bond acceptors) electrostatic potentials, respectively.

Figure 5

A view of the mol­ecular electrostatic potential for the title compound in the range −0.084 to 0.084 a.u. generated by DFT using the 6–31G(d,p) basis set.

The theoretical calculations were performed using GAUSSIAN03 (Frisch et al., 2004 ▸). The initial geometry was taken from the X-ray coordinates and this geometry was optimized using the DFT/B3LYP (Becke, 1993 ▸) method with LANL2DZ as the basis set. The theoretical geometrical parameters are in good agreement with XRD results (Table 1 ▸).

Frontier mol­ecular orbitals

The highest occupied mol­ecular orbitals (HOMO) and the lowest unoccupied mol­ecular orbitals (LUMO) are known as frontier mol­ecular orbitals (FMOs). The FMOs play an important role in the optical and electric properties. The frontier orbital gap can indicate the chemical reactivity and the kinetic stability of the mol­ecule. If the energy gap is small then the mol­ecule is highly polarizable and has high chemical reactivity. A mol­ecule with a small frontier orbital gap is generally associated with a high chemical reactivity, low kinetic stability and is termed a soft mol­ecule. Fig. 6 ▸ illustrates the HOMO and LUMO energy levels of the title compound. The small HOMO–LUMO energy gap of 2.41 eV in this compound indicates the chemical reactivity is strong and the kinetic stability is weak. A map of the electron density is shown in Fig. 7 ▸.

Figure 6

The electron distribution of the HOMO and LUMO energy gaps of the title compound.

Figure 7

The total electron density three-dimensional surface mapped for the compound with the electrostatic potential calculated at the B3LYP/6–31G(d,p) level.

Synthesis and crystallization

To a solution of 4-oxo-6-(thio­phen-2-yl)hex-5-enoic acid (0.21 g, 1 mmol) in 20 mL of ethanol, it was added an equimolar amount of hydrazine hydrate. The mixture was maintained under reflux for 4h, until TLC indicated the end of the reaction. The reaction mixture was poured into cold water, and the precipitate formed was filtered out, washed with ethanol and recrystallized from ethanol. Slow evaporation at room temperature led to formation of single crystals.

Refinement

Crystal data, data collection and structure refinement details are summarized in Table 3 ▸. Hydrogen atoms were fixed geometrically and treated as riding, the C-bound H atoms were placed in idealized positions and refined as riding: C—H = 0.93 Å for methyl­ene U iso(H) = 1.5U eq(C) and C—H = 0.97 Å for the other C atoms with U iso(H) = 1.2U eq(C). The NH H atom was located in a difference-Fourier map and freely refined.

Table 3

Experimental details

Crystal data
Chemical formula	C10H10N2OS
M r	206.26
Crystal system, space group	Monoclinic, P21/c
Temperature (K)	296
a, b, c (Å)	6.9932 (5), 16.2916 (9), 9.3544 (7)
β (°)	110.168 (6)
V (Å3)	1000.40 (12)
Z	4
Radiation type	Mo Kα
μ (mm−1)	0.29
Crystal size (mm)	0.78 × 0.43 × 0.25
Data collection
Diffractometer	Stoe IPDS 2
Absorption correction	Integration (X-RED32; Stoe & Cie, 2002 ▸)
T min, T max	0.767, 0.932
No. of measured, independent and observed [I > 2σ(I)] reflections	6292, 1971, 1394
R int	0.043
(sin θ/λ)max (Å−1)	0.617
Refinement
R[F 2 > 2σ(F 2)], wR(F 2), S	0.045, 0.135, 1.02
No. of reflections	1971
No. of parameters	131
No. of restraints	19
H-atom treatment	H atoms treated by a mixture of independent and constrained refinement
Δρmax, Δρmin (e Å−3)	0.24, −0.34

Computer programs: X-AREA and X-RED32 (Stoe & Cie, 2002 ▸), SHELXT2015 (Sheldrick, 2015a ▸), SHELXL2015 (Sheldrick, 2015b ▸), Mercury (Macrae et al., 2008 ▸), WinGX (Farrugia, 2012 ▸) and PLATON (Spek, 2009 ▸).

Crystal structure: contains datablock(s) I. DOI: 10.1107/S2056989019015147/mw2150sup1.cif

Structure factors: contains datablock(s) I. DOI: 10.1107/S2056989019015147/mw2150Isup2.hkl

CCDC references: 1964913, 1964910, 1964910

Additional supporting information: crystallographic information; 3D view; checkCIF report

C10H10N2OS	F(000) = 432
Mr = 206.26	Dx = 1.369 Mg m−3
Monoclinic, P21/c	Mo Kα radiation, λ = 0.71073 Å
a = 6.9932 (5) Å	Cell parameters from 6992 reflections
b = 16.2916 (9) Å	θ = 2.3–30.0°
c = 9.3544 (7) Å	µ = 0.29 mm−1
β = 110.168 (6)°	T = 296 K
V = 1000.40 (12) Å3	Stick, orange
Z = 4	0.78 × 0.43 × 0.25 mm

Stoe IPDS 2 diffractometer	1971 independent reflections
Radiation source: sealed X-ray tube, 12 x 0.4 mm long-fine focus	1394 reflections with I > 2σ(I)
Plane graphite monochromator	Rint = 0.043
Detector resolution: 6.67 pixels mm-1	θmax = 26.0°, θmin = 2.5°
rotation method scans	h = −8→8
Absorption correction: integration (X-RED32; Stoe & Cie, 2002)	k = −20→19
Tmin = 0.767, Tmax = 0.932	l = −11→11
6292 measured reflections

Refinement on F2	19 restraints
Least-squares matrix: full	Hydrogen site location: mixed
R[F2 > 2σ(F2)] = 0.045	H atoms treated by a mixture of independent and constrained refinement
wR(F2) = 0.135	w = 1/[σ2(Fo2) + (0.079P)2] where P = (Fo2 + 2Fc2)/3
S = 1.02	(Δ/σ)max < 0.001
1971 reflections	Δρmax = 0.24 e Å−3
131 parameters	Δρmin = −0.34 e Å−3

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.

	x	y	z	Uiso*/Ueq
S1	0.23031 (12)	0.42526 (4)	0.98925 (7)	0.0768 (3)
O1	0.8844 (3)	0.41724 (11)	0.36257 (19)	0.0752 (5)
N2	0.6910 (3)	0.45665 (12)	0.66000 (19)	0.0559 (5)
N1	0.8097 (3)	0.45451 (13)	0.5682 (2)	0.0581 (5)
C4	0.5618 (3)	0.39839 (14)	0.6440 (2)	0.0521 (5)
C7	0.1949 (3)	0.34895 (13)	0.8563 (2)	0.0517 (5)
C6	0.3065 (3)	0.34666 (13)	0.7517 (2)	0.0535 (5)
H6	0.277544	0.303662	0.682065	0.064*
C5	0.4468 (3)	0.40054 (14)	0.7461 (2)	0.0549 (5)
H5	0.473561	0.443933	0.814790	0.066*
C8	0.0484 (4)	0.29384 (15)	0.8660 (2)	0.0607 (6)
H8	0.005051	0.248100	0.803758	0.073*
C1	0.7734 (3)	0.41133 (14)	0.4389 (2)	0.0568 (6)
C2	0.5880 (4)	0.35925 (15)	0.3960 (2)	0.0640 (6)
H2A	0.607918	0.311934	0.339710	0.077*
H2B	0.473610	0.390273	0.329261	0.077*
C3	0.5376 (4)	0.33001 (16)	0.5325 (3)	0.0681 (6)
H3A	0.398564	0.309944	0.499271	0.082*
H3B	0.627316	0.285060	0.581438	0.082*
C10	0.0570 (4)	0.38383 (19)	1.0572 (3)	0.0739 (7)
H10	0.023862	0.405884	1.137400	0.089*
C9	−0.0260 (4)	0.31634 (18)	0.9828 (3)	0.0713 (6)
H9	−0.124891	0.286306	1.005625	0.086*
H1	0.902 (4)	0.4897 (15)	0.593 (2)	0.058 (7)*

	U11	U22	U33	U12	U13	U23
S1	0.0979 (5)	0.0736 (5)	0.0729 (4)	−0.0147 (4)	0.0476 (4)	−0.0139 (3)
O1	0.0895 (12)	0.0816 (12)	0.0746 (10)	−0.0144 (10)	0.0540 (9)	−0.0103 (8)
N2	0.0594 (11)	0.0619 (11)	0.0527 (9)	−0.0040 (9)	0.0272 (8)	−0.0029 (8)
N1	0.0604 (11)	0.0644 (12)	0.0580 (10)	−0.0108 (10)	0.0312 (9)	−0.0065 (9)
C4	0.0534 (11)	0.0535 (12)	0.0522 (11)	0.0012 (10)	0.0216 (9)	−0.0007 (9)
C7	0.0521 (11)	0.0561 (13)	0.0465 (10)	0.0032 (10)	0.0165 (9)	0.0054 (9)
C6	0.0573 (12)	0.0530 (13)	0.0542 (11)	0.0002 (10)	0.0242 (10)	−0.0016 (9)
C5	0.0610 (12)	0.0565 (13)	0.0525 (11)	−0.0034 (11)	0.0261 (9)	−0.0043 (9)
C8	0.0651 (13)	0.0659 (14)	0.0543 (11)	−0.0087 (11)	0.0249 (9)	0.0049 (9)
C1	0.0655 (13)	0.0554 (13)	0.0550 (11)	0.0023 (11)	0.0279 (10)	0.0014 (9)
C2	0.0696 (14)	0.0668 (15)	0.0599 (12)	−0.0052 (12)	0.0281 (11)	−0.0118 (10)
C3	0.0757 (15)	0.0639 (15)	0.0798 (15)	−0.0133 (12)	0.0459 (13)	−0.0150 (12)
C10	0.0869 (17)	0.0885 (19)	0.0583 (13)	0.0085 (16)	0.0403 (12)	0.0062 (13)
C9	0.0686 (14)	0.0910 (18)	0.0624 (12)	−0.0097 (13)	0.0329 (10)	0.0097 (12)

S1—C10	1.691 (3)	C5—H5	0.9300
S1—C7	1.715 (2)	C8—C9	1.411 (3)
O1—C1	1.227 (3)	C8—H8	0.9300
N2—C4	1.283 (3)	C1—C2	1.484 (3)
N2—N1	1.385 (2)	C2—C3	1.515 (3)
N1—C1	1.345 (3)	C2—H2A	0.9700
N1—H1	0.83 (2)	C2—H2B	0.9700
C4—C5	1.446 (3)	C3—H3A	0.9700
C4—C3	1.495 (3)	C3—H3B	0.9700
C7—C8	1.388 (3)	C10—C9	1.323 (4)
C7—C6	1.448 (3)	C10—H10	0.9300
C6—C5	1.331 (3)	C9—H9	0.9300
C6—H6	0.9300
C10—S1—C7	92.31 (13)	O1—C1—C2	123.8 (2)
C4—N2—N1	117.21 (18)	N1—C1—C2	114.77 (19)
C1—N1—N2	127.1 (2)	C1—C2—C3	112.76 (18)
C1—N1—H1	119.6 (16)	C1—C2—H2A	109.0
N2—N1—H1	112.7 (16)	C3—C2—H2A	109.0
N2—C4—C5	115.76 (19)	C1—C2—H2B	109.0
N2—C4—C3	122.57 (19)	C3—C2—H2B	109.0
C5—C4—C3	121.6 (2)	H2A—C2—H2B	107.8
C8—C7—C6	127.6 (2)	C4—C3—C2	110.5 (2)
C8—C7—S1	110.28 (16)	C4—C3—H3A	109.5
C6—C7—S1	122.15 (16)	C2—C3—H3A	109.5
C5—C6—C7	125.9 (2)	C4—C3—H3B	109.5
C5—C6—H6	117.1	C2—C3—H3B	109.5
C7—C6—H6	117.1	H3A—C3—H3B	108.1
C6—C5—C4	126.5 (2)	C9—C10—S1	112.02 (19)
C6—C5—H5	116.7	C9—C10—H10	124.0
C4—C5—H5	116.7	S1—C10—H10	124.0
C7—C8—C9	111.1 (2)	C10—C9—C8	114.3 (2)
C7—C8—H8	124.4	C10—C9—H9	122.9
C9—C8—H8	124.4	C8—C9—H9	122.9
O1—C1—N1	121.4 (2)
C4—N2—N1—C1	18.1 (3)	S1—C7—C8—C9	−0.6 (2)
N1—N2—C4—C5	177.40 (18)	N2—N1—C1—O1	176.4 (2)
N1—N2—C4—C3	0.3 (3)	N2—N1—C1—C2	−1.9 (3)
C10—S1—C7—C8	0.74 (18)	O1—C1—C2—C3	152.4 (2)
C10—S1—C7—C6	−179.65 (18)	N1—C1—C2—C3	−29.5 (3)
C8—C7—C6—C5	−179.7 (2)	N2—C4—C3—C2	−30.2 (3)
S1—C7—C6—C5	0.8 (3)	C5—C4—C3—C2	152.9 (2)
C7—C6—C5—C4	179.0 (2)	C1—C2—C3—C4	43.3 (3)
N2—C4—C5—C6	−179.4 (2)	C7—S1—C10—C9	−0.7 (2)
C3—C4—C5—C6	−2.3 (4)	S1—C10—C9—C8	0.5 (3)
C6—C7—C8—C9	179.8 (2)	C7—C8—C9—C10	0.1 (3)

D—H···A	D—H	H···A	D···A	D—H···A
N1—H1···O1i	0.83 (3)	2.07 (3)	2.899 (3)	175 (2)
C10—H10···O1ii	0.93	2.61	3.505 (3)	161