On substituted pyrazole derivatives. II. (E)-1-(4-{[1-(4-Fluoro­phenyl)-3,5-dimethyl-1H-pyrazol-4-yl]diazenyl}phenyl)ethanone and (E)-1-(4-chloro­phenyl)-3,5-dimethyl-4-[2-(2-nitro­phenyl)diazenyl]-1H-pyrazole

The mol­ecular structures of (E)-1-(4-{[1-(4-fluoro­phenyl)-3,5-dimethyl-1H-pyrazol-4-yl]diazenyl}phenyl)ethanone, C₁₉H₁₇FN₄O, (III), and (E)-1-(4-chlorophenyl)-3,5-dimethyl-4-[2-(2-nitro­phenyl)diazenyl]-1H-pyrazole, C₁₇H₁₄ClN₅O₂, (IV), pre­pared by reaction of the corresponding β-diketo­hydrazones with substituted aryl­hydrazines in acid media, are nonplanar, with the planes of the lateral phenyl rings forming dihedral angles with that of the central pyrazole ring varying from 2.71 (7) to 45.22 (7)°. The crystal structures are supported by C—H...O, C—H...π and π–π weak intermolecular interactions together with some unusual trifurcated C—Cl...Cl—C contacts, which are discussed in detail.

S1. Introduction

Substituted β-diketohydrazones may be prepared by a coupling reaction between a β-diketonate anion and substituted diazo­nium salts (Yao, 1964; Bertolasi et al., 1999; Šimůnek et al., 2007). This type of compound can be used in the synthesis of a variety of heterocyclic derivatives (Greenhill et al., 1992) and in particular those containing a pyrazole ring (Bustos et al., 2009). In addition, pyrazole nuclei have been the target of extensive studies in such areas as biology, chemistry, pharmacology and medicine. As the result of the inter­est shown in this type of compound by the pharmaceutical industry, a number of relevant drugs such as Celebrex (Penning et al., 1997) and Viagra (Terrett et al., 1996) came to light. Pyrazole derivatives are also of pharmacological inter­est as anti-anxiety, anti­pyretic, analgesic, anti-inflamatory, anti­parasitic and anti­microbial drugs (Elguero et al., 2002), and some related compounds have been described as potent PDE4B inhibitors (Card et al., 2005). From the chemical side, pyrazole derivatives have been used as ligands for obtaining transition metal complexes, since the heterocycle may coordinate to the metal directly via one or both vicinal N atoms (Rojas et al., 2004).

Considering the synthetic route, we found it possible to obtain two types of molecules for substituted pyrazoles (Bustos et al., 2009), labelled a and b in Scheme 1.

We have recently reported the analysis of two pyrazole compounds corresponding to class a in this nomenclature, viz. (I) and (II) (Scheme 2) (Alvarez-Thon et al., 2014). A thorough introduction to the subject was given in that paper, and we refer the inter­ested reader to it for more detailed information. As a continuation of this work we shall discuss herein two further structures, this time of type b, viz. (E)-1-(4-{[1-(4-fluoro­phenyl)-3,5-di­methyl-1H-pyrazol-4-yl]diazenyl}phenyl)­ethanone, (III), and (E)-1-(4-chloro­phenyl)-3,5-di­methyl-4-[2-(2-nitro­phenyl)­diazenyl]-1H-pyrazole, (IV) (Scheme 2), prepared by reaction of the corresponding β-diketohydrazones with substituted aryl­hydrazine in acid media.

S2. Experimental

S2.1. Synthesis and crystallization

S2.1.1. Chemicals

Reagents [pentane-2,4-dione, sodium nitrite, sodium acetate, sodium hydroxide, 1-(4-amino­phenyl)­ethanone, 2-nitro­aniline, 4-fluoro­phenyl­hydrazine, 4-chloro­phenyl­hydrazine and glacial acetic acid] and solvents (methanol, ethanol and tetra­hydro­furan) were obtained from common commercial sources (Merck Chemical and Sigma–Aldrich) and used without purification. The precursors, 3-[2-(4-acetyl­phenyl)­hydrazinyl­idene]pentane-2,4-dione and 3-[2-(2-nitro­phenyl)­hydrazinyl­idene]pentane-2,4-dione, were prepared according to the method recommended in the literature (Yao, 1964; Bustos et al., 2007) and recrystallized from ethanol.

S2.1.2. Preparation of (III)

To a round-bottomed flask were added 3-[2-(4-acetyl­phenyl)­hydrazinyl­idene]pentane-2,4-dione (3.0 mmol, 0.739 g), 4-fluoro­phenyl­hydrazine hydro­chloride (97%, 3.0 mmol, 0.5039 g), acetic acid (5 ml) and ethanol (30 ml). The mixture was stirred and heated at reflux near the boiling point, and after 36 h a yellow–orange solid was obtained. The reaction mixture was then cooled at 263 K for 2 h, filtered by suction, washed with an abundant qu­antity of water (500 ml) and dried in a vacuum oven at 313 K for 12 h (yield 85% of crude product). Single crystals of (III) suitable for diffraction studies were obtained by slow crystallization from ethanol. Analysis: m.p. 435–436 K; elemental analysis for C₁₉H₁₇FN₄O (M_r 336.14), calculated: C 67.84, H 5.09, N 16.66%; found: C 67.87, H 5.12, N 16.81%.

S2.1.3. Preparation of (IV)

To a round bottomed flask were added 3-[2-(2-nitro­phenyl)­hydrazinyl­idene]pentane-2,4-dione (2.85 mmol, 0.702 g), 4-chloro­phenyl­hydrazine hydro­chloride (98%, 2.85 mmol, 0.521 g), acetic acid (5 ml) and ethanol (30 ml). The mixture was stirred and heated at reflux near the boiling point, and after 36 h a yellow–orange solid was obtained. The reaction mixture was then filtered by suction, washed with a 1:1 EtOH–H₂O mixture (100 ml) and dried in a vacuum oven at 313 K for 12 h (yield 99% of crude product). Single crystals of (IV) suitable for diffraction studies were obtained by crystallization from a 1:3:1 tetra­hydro­furan–EtOH–H₂O mixture. Analysis: m.p. 439–440 K; elemental analysis for C₁₇H₁₄ClN₅O₂ (M_r 355.08), calculated: C 57.39, H 3.97, N 19.68; found: C 57.26, H 4.16, N 19.60%.

S2.2. NMR data

Compound (III): ¹H NMR (400 MHz, CDCl₃): δ 8.06 (d, J = 8.5 Hz, 2H), 7.85 (d, J = 8.5 Hz, 2H), 7.51–7.42 (m, 2H), 7.19 (t, J = 8.5 Hz, 2H), 2.63 (s, 6H), 2.57 (s, 3H); ¹³C NMR (101 MHz, CDCl₃): δ 197.60, 162.24 (d, J = 248.7 Hz), 156.25, 144.22, 140.26, 137.37, 136.67, 135.13 (d, J = 3.1 Hz), 129.45, 126.89 (d, J = 8.7 Hz), 122.04, 116.37 (d, J = 23.0 Hz), 26.87, 14.24, 11.40.

Compound (IV): ¹H NMR (400 MHz, CDCl₃): δ 7.90–7.35 (m, 8H), 2.63 (s, 3H), 2.53 (s, 3H); ¹³ C NMR (101 MHz, CDCl₃): δ 147.36, 145.97, 145.29, 140.26, 137.32, 137.09, 134.23, 132.57, 129.52, 129.24, 126.05, 123.75, 118.23, 13.89, 11.46.

S2.3. Refinement

Crystal data, data collection and structure refinement details are summarized in Table 1. All H atoms were originally found in difference maps but treated differently in refinement. N-bound H atoms were refined with restrained N—H distances [0.85 (1) Å] and free U_iso. C-bound H atoms were repositioned in their expected positions and allowed to ride, with C—H_methyl = 0.96 Å and C—H_arom = 0.93 Å. In addition, the methyl groups were allowed to rotate around their C—C bond. Riding H atoms were assigned a U_iso(H) = xU_eq(C), x being 1.2 for C_arom and 1.5 for C_methyl.

S3. Results and discussion

Fig. 1 shows molecular views of the molecules of both (III) and (IV), with atom labelling and ring numbering. In both structures the nucleus is a type b pyrazol (Scheme 1), which in structure (III) includes as substituents a 4-substituted F atom on ring 2 and an ethanone group on ring 3, while in structure (IV) these roles are fulfilled by a 4-substituted Cl atom on phenyl 2 and a 2-nitro group on phenyl 3.

As shown in Table 1, the compounds crystallize in different space groups with diverse cell dimensions. The molecular geometries will not be discussed in depth, since the bond distances and angles in the two molecular structures do not depart from expected values. However, we include in Table 2, for comparison purposes, the single–double bond sequence in the pyrazole rings of compounds (I)–(IV). This clearly shows that the molecules of (III) and (IV) are consistent with type b nuclei rather than type a, the latter being the subject of our previous contribution (Alvarez-Thon et al., 2014).

Both molecules show marked departures from planarity. The dihedral angles made by the lateral rings 2 and 3 with the central pyrazole (ring 1) are 45.22 (7) and 2.71 (7)°, respectively, for (III), and 38.40 (8) and 23.06 (8)°, respectively, for (IV). These rather large values contrast with the almost planar structure found in (I) and (II), and confirm the role of the keto atom O1 at C7 in these latter compounds, which tends to make two intra­molecular hydrogen bonds, making a coplanar arrangement more favourable (Scheme 2). The absence of such inter­actions in the present structures eliminates the limitation for eventual rotations of phenyl ring 2 around the N1—C1 bond, and thus its rotational position is finally determined by the steric hindrance introduced by the bulky sustituents and weak inter­molecular inter­actions. These latter arguments are equally valid for ring 3, where the difference (in quality and location) of the substituent leads to an ~20° difference in relative rotation of the ring with respect to the core.

Since no conventional hydrogen-bonding donors are present in the structures of (III) and (IV), their supra­molecular dispositions are defined by weaker forces. An inter­esting aspect derived from this fact is the effect which the inter­play of these varied weak inter­molecular inter­actions (C—H···O, C—H···π, C—Cl···Cl—C etc.) has on their packing characteristics. Tables 3–7 present the most relevant inter­molecular inter­actions in (III) and (IV). In what follows and for the sake of brevity, we shall abbreviate the expression (Table `n', entry `m') by the shorthand (Tn,Em).

As stated above, both structures lack the intra­molecular N—H···O bonds characteristic of (I) and (II). In the case of (III), the inter­action scheme looks rather simple. The leading inter­actions (even though they are weak) are the π–π contacts presented as (T4,E1) and (T4,E2), and labelled A and B in Fig. 2, defining columnar arrays of phenyl rings along b, in ···2···2··· and ···3···3··· ring sequences (highlighted in Fig 2, at x ~0.25 and x ~0.75, respectively).These inter­actions serve to link the molecules into planar arrays parallel to (001), shown in Fig. 2. These two-dimensional arrays, in turn, are connected into a three-dimensional structure (Fig. 3) by C—H···O (T3,E1) and C—H···π (T3,E2) inter­actions (D and E in Fig. 3).

In contrast, the structure of (IV) is more complex. There is an elemental building block, a dimeric pair built up around an inversion centre (Fig. 4a), defined by a C—H···O bond (T5,E1; A in Fig. 4a) and a π–π one (T6,E1; B in the figure). These dimers, in turn, are linked into planar arrays parallel to (010) by a couple of C—H···π inter­actions (T5,E2 and T5,E3), shown in Fig. 4(b), where they labelled C and D, respectively. These broad two-dimensional structures (one full molecule in width) have a conspicuous characteristic, viz. they are externally padded by protruding Cl atoms which dispose in planes parallel to (010) at y ~0.25 and y ~0.75. Thus, adjacent two-dimensional structures defined by the dimers meet each other at these `chlorine boundaries', with adjacent planes inter­leaving their (oppositely oriented) C4—Cl1 groups, as shown in Fig. 5. This particular approach allows for a different type of inter­action, viz. C—Cl···Cl—C.

For a better understanding it is perhaps inter­esting at this stage to comment on the characteristics of the so-called C—X···X—C inter­actions (X = halogen), which according to their geometric disposition have historically been divided into types I and II (Scheme 3); those present in this structure correspond to the first type. Even though only type II contacts had originally been ascribed a stabilizing effect, further studies began to disclose a stabilizing character for many type I cases. For further details on the subject we refer, for instance, to Baker et al. (2012) and references therein.

Fig. 6 sketches the way in which the C4—Cl1 groups from one of the two-dimensional substructures (those depicted as solid circles) `protrude' into the voids left by their neighbouring analogues (those shown as open circles) in such a way that each Cl atom inter­acts with three different Cl atoms from the neighbouring plane. Table 7 presents the details of these type I inter­actions in (IV) (see Scheme 3 for nomenclature), which serve to link the planes to define the three-dimensional structure. A search of the Cambridge Structural Database (CSD, Version 5.3 updated to March 2014; Allen, 2002) showed this `trifurcated' type of halogen···halogen inter­action to be a rather unusual one, with only nine structures surveyed showing analogous contacts, up to a Cl···Cl distance of 3.8Å. Most of the entries found were tri­chloro­acetate complexes, and in all of them the spatial distribution of the halogen···halogen inter­actions appeared rather chaotic. The regular array observed in (IV) is thus esentially unique.

Summarizing, similar to their type a antecedants [(I) and (II)], these type b representatives [(III) and (IV)] are examples of molecular units having a common nucleus but presenting a whole palette of weak inter­molecular inter­actions (C—H···O, C—H···π, π–π, C—Cl···Cl—C etc.), mainly due to their different substituents which give rise to a rich diversity of supra­molecular organization.

Related literature

For related literature, see: Allen (2002); Alvarez-Thon, Bustos, Molins, Garland & Baggio (2014); Baker et al. (2012); Bertolasi et al. (1999); Bustos et al. (2007, 2009); Card et al. (2005); Elguero et al. (2002); Greenhill et al. (1992); Penning (1997); Rojas et al. (2004); Terrett et al. (1996); Yao (1964); Šimůnek et al. (2007).

Computing details

For both compounds, data collection: SMART (Bruker, 2001); cell refinement: SAINT (Bruker, 2002); data reduction: SAINT (Bruker, 2002); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 Sheldrick, 2008); molecular graphics: SHELXTL (Sheldrick, 2008); software used to prepare material for publication: SHELXTL (Sheldrick, 2008) and PLATON (Spek, 2009).

Figures

	Fig. 1. Molecular views of (III) and (IV), with the atom and ring numbering shown. Displacement ellipsoids are drawn at the 40% probability level.
	Fig. 2. A packing view of (III), projected down c, showing the way in which molecules interact via π–π interactions (dashed lines).
	Fig. 3. A packing view of (III), projected down b, showing the way in which the planes interact with each other via C—H···O and C—H···π interactions (dashed lines).
	Fig. 4. (a) The basic dimeric unit in (IV), with the responsible interactions drawn as double-dashed lines. (b) A packing view of (IV), projected down [010], showing as single-dashed lines the interactions between dimeric units already presented in (a), which define planar arrays parallel to (010). [Double-dashed lines indicate what here?] The purple shading highlights one of the dimeric units.
	Fig. 5. Two different packing views of (IV), (a) projected down [001] and (b) projected down [100], showing (double arrows [Not visible - please clarify]) the interaction zone between planes.
	Fig. 6. A detailed view of the interaction zone between the two-dimensional substructures in (IV). Details are to be found in Scheme 3 and Table 7. [Symmetry codes: (iii) -x + 1/2, -y + 1/2,z; (iv) x, -y + 1/2, z - 1/2; (v) x, -y + 1/2, z + 1/2.]

(III) (E)-1-(4-{[1-(4-Fluorophenyl)-3,5-dimethyl-1H-pyrazol-4-yl]diazenyl}phenyl)ethanone

Crystal data

C19H17FN4O	Dx = 1.342 Mg m^−3
Mr = 336.36	Mo Kα radiation, λ = 0.71073 Å
Orthorhombic, Pbcn	Cell parameters from 2886 reflections
a = 19.392 (4) Å	θ = 2.7–24.9°
b = 7.5431 (15) Å	µ = 0.09 mm^−1
c = 22.754 (5) Å	T = 294 K
V = 3328.5 (12) Å^3	Polyhedron, orange
Z = 8	0.37 × 0.25 × 0.12 mm
F(000) = 1408

Data collection

Bruker SMART CCD area-detector diffractometer	3805 independent reflections
Radiation source: fine-focus sealed tube	2287 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.062
CCD rotation images, thin slices scans	θmax = 27.9°, θmin = 1.8°
Absorption correction: multi-scan (SADABS in SAINT; Bruker, 2002)	h = −25→25
Tmin = 0.95, Tmax = 0.99	k = −9→9
25901 measured reflections	l = −29→29

Refinement

Refinement on F^2	0 restraints
Least-squares matrix: full	Hydrogen site location: inferred from neighbouring sites
R[F^2 > 2σ(F^2)] = 0.041	H-atom parameters constrained
wR(F^2) = 0.105	w = 1/[σ^2(Fo^2) + (0.059P)^2] where P = (Fo^2 + 2Fc^2)/3
S = 0.89	(Δ/σ)max < 0.001
3805 reflections	Δρmax = 0.27 e Å^−3
229 parameters	Δρmin = −0.19 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.

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Ų)

	x	y	z	Uiso*/Ueq
F1	0.11932 (4)	0.61557 (13)	0.37909 (4)	0.0770 (3)
O1	0.89377 (6)	0.42549 (18)	0.25877 (5)	0.0884 (4)
N1	0.40032 (5)	0.65350 (14)	0.41084 (5)	0.0454 (3)
N2	0.42475 (6)	0.71668 (15)	0.46412 (5)	0.0497 (3)
N3	0.57639 (6)	0.59827 (15)	0.37959 (5)	0.0487 (3)
N4	0.62858 (6)	0.64370 (15)	0.40935 (5)	0.0500 (3)
C1	0.32775 (6)	0.64360 (17)	0.40186 (6)	0.0424 (3)
C2	0.28662 (7)	0.57775 (17)	0.44661 (6)	0.0473 (3)
H2	0.3066	0.5385	0.4814	0.057*
C3	0.21604 (7)	0.57051 (18)	0.43950 (6)	0.0519 (4)
H3	0.1878	0.5283	0.4694	0.062*
C4	0.18846 (7)	0.62700 (19)	0.38722 (6)	0.0514 (4)
C5	0.22805 (7)	0.69197 (18)	0.34234 (6)	0.0518 (4)
H5	0.2078	0.7288	0.3074	0.062*
C6	0.29875 (7)	0.70194 (18)	0.34989 (6)	0.0485 (4)
H6	0.3265	0.7476	0.3202	0.058*
C7	0.45219 (7)	0.60313 (17)	0.37452 (6)	0.0451 (3)
C8	0.51261 (7)	0.63578 (17)	0.40509 (6)	0.0450 (3)
C9	0.49271 (7)	0.70737 (17)	0.46040 (6)	0.0472 (3)
C10	0.69240 (7)	0.60445 (16)	0.38109 (6)	0.0424 (3)
C11	0.69874 (7)	0.52932 (18)	0.32535 (6)	0.0475 (3)
H11	0.6596	0.5010	0.3037	0.057*
C12	0.76304 (7)	0.49736 (17)	0.30262 (6)	0.0469 (3)
H12	0.7668	0.4457	0.2657	0.056*
C13	0.82287 (7)	0.54027 (17)	0.33344 (6)	0.0429 (3)
C14	0.81624 (7)	0.61628 (17)	0.38880 (6)	0.0467 (3)
H14	0.8554	0.6461	0.4102	0.056*
C15	0.75156 (6)	0.64780 (17)	0.41225 (6)	0.0460 (3)
H15	0.7477	0.6986	0.4493	0.055*
C16	0.53649 (7)	0.7674 (2)	0.51056 (6)	0.0627 (4)
H16A	0.5610	0.8729	0.4995	0.094*
H16B	0.5689	0.6759	0.5205	0.094*
H16C	0.5078	0.7921	0.5439	0.094*
C17	0.44233 (8)	0.5245 (2)	0.31516 (6)	0.0596 (4)
H17A	0.4026	0.4484	0.3155	0.089*
H17B	0.4824	0.4568	0.3047	0.089*
H17C	0.4356	0.6175	0.2870	0.089*
C18	0.89117 (7)	0.50337 (19)	0.30552 (7)	0.0532 (4)
C19	0.95595 (8)	0.5613 (2)	0.33545 (7)	0.0706 (5)
H19A	0.9580	0.5098	0.3740	0.106*
H19B	0.9564	0.6882	0.3387	0.106*
H19C	0.9951	0.5231	0.3129	0.106*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
F1	0.0402 (5)	0.1152 (8)	0.0757 (6)	0.0006 (5)	−0.0003 (4)	−0.0060 (5)
O1	0.0568 (7)	0.1399 (11)	0.0686 (8)	0.0004 (7)	0.0113 (6)	−0.0356 (8)
N1	0.0410 (7)	0.0548 (7)	0.0405 (6)	0.0020 (5)	0.0040 (5)	−0.0016 (5)
N2	0.0476 (7)	0.0595 (8)	0.0419 (7)	−0.0006 (5)	0.0006 (5)	−0.0054 (6)
N3	0.0408 (7)	0.0551 (7)	0.0503 (7)	0.0011 (5)	0.0040 (5)	0.0056 (5)
N4	0.0428 (7)	0.0557 (7)	0.0514 (7)	−0.0006 (5)	0.0042 (5)	0.0017 (6)
C1	0.0391 (8)	0.0442 (7)	0.0438 (8)	0.0027 (6)	0.0036 (6)	−0.0025 (6)
C2	0.0471 (9)	0.0523 (8)	0.0424 (8)	0.0034 (6)	0.0052 (6)	0.0012 (6)
C3	0.0466 (9)	0.0583 (9)	0.0507 (9)	−0.0009 (7)	0.0118 (7)	−0.0020 (7)
C4	0.0381 (8)	0.0595 (9)	0.0567 (9)	0.0029 (6)	0.0024 (7)	−0.0112 (7)
C5	0.0489 (9)	0.0607 (9)	0.0458 (8)	0.0088 (7)	−0.0024 (6)	−0.0023 (7)
C6	0.0497 (9)	0.0529 (9)	0.0429 (8)	0.0030 (6)	0.0054 (6)	0.0041 (7)
C7	0.0437 (8)	0.0510 (8)	0.0405 (8)	0.0030 (6)	0.0060 (6)	0.0034 (6)
C8	0.0393 (8)	0.0508 (8)	0.0450 (8)	0.0009 (6)	0.0041 (6)	0.0039 (6)
C9	0.0447 (8)	0.0499 (8)	0.0471 (8)	0.0007 (6)	0.0018 (6)	0.0012 (7)
C10	0.0416 (8)	0.0417 (7)	0.0440 (8)	0.0018 (6)	0.0032 (6)	0.0056 (6)
C11	0.0419 (8)	0.0564 (9)	0.0440 (8)	−0.0019 (6)	−0.0046 (6)	0.0001 (7)
C12	0.0473 (8)	0.0537 (8)	0.0398 (7)	0.0009 (7)	0.0008 (6)	−0.0018 (6)
C13	0.0412 (8)	0.0443 (8)	0.0432 (8)	−0.0015 (6)	0.0011 (6)	0.0032 (6)
C14	0.0428 (8)	0.0522 (8)	0.0449 (8)	−0.0052 (6)	−0.0033 (6)	0.0012 (6)
C15	0.0493 (9)	0.0500 (8)	0.0387 (7)	−0.0019 (6)	0.0013 (6)	−0.0033 (6)
C16	0.0552 (9)	0.0764 (11)	0.0567 (10)	0.0006 (8)	−0.0042 (7)	−0.0110 (8)
C17	0.0525 (9)	0.0790 (11)	0.0472 (9)	0.0063 (8)	0.0049 (7)	−0.0065 (8)
C18	0.0467 (9)	0.0623 (10)	0.0505 (9)	−0.0006 (7)	0.0038 (7)	−0.0008 (8)
C19	0.0441 (9)	0.0897 (12)	0.0780 (12)	−0.0054 (8)	0.0021 (8)	−0.0074 (9)

Geometric parameters (Å, º)

F1—C4	1.3563 (15)	C9—C16	1.4930 (18)
O1—C18	1.2161 (16)	C10—C15	1.3877 (17)
N1—C7	1.3561 (16)	C10—C11	1.3946 (17)
N1—N2	1.3862 (15)	C11—C12	1.3713 (17)
N1—C1	1.4241 (16)	C11—H11	0.9300
N2—C9	1.3223 (16)	C12—C13	1.3938 (18)
N3—N4	1.2649 (15)	C12—H12	0.9300
N3—C8	1.3952 (16)	C13—C14	1.3900 (18)
N4—C10	1.4259 (16)	C13—C18	1.4953 (18)
C1—C6	1.3815 (17)	C14—C15	1.3837 (18)
C1—C2	1.3855 (17)	C14—H14	0.9300
C2—C3	1.3792 (18)	C15—H15	0.9300
C2—H2	0.9300	C16—H16A	0.9600
C3—C4	1.3722 (19)	C16—H16B	0.9600
C3—H3	0.9300	C16—H16C	0.9600
C4—C5	1.3685 (18)	C17—H17A	0.9600
C5—C6	1.3838 (18)	C17—H17B	0.9600
C5—H5	0.9300	C17—H17C	0.9600
C6—H6	0.9300	C18—C19	1.494 (2)
C7—C8	1.3848 (18)	C19—H19A	0.9600
C7—C17	1.4874 (19)	C19—H19B	0.9600
C8—C9	1.4229 (18)	C19—H19C	0.9600
C7—N1—N2	112.08 (11)	C12—C11—C10	119.64 (12)
C7—N1—C1	129.12 (11)	C12—C11—H11	120.2
N2—N1—C1	118.76 (10)	C10—C11—H11	120.2
C9—N2—N1	105.45 (10)	C11—C12—C13	121.76 (13)
N4—N3—C8	115.57 (12)	C11—C12—H12	119.1
N3—N4—C10	113.38 (11)	C13—C12—H12	119.1
C6—C1—C2	120.60 (12)	C14—C13—C12	118.35 (12)
C6—C1—N1	120.55 (11)	C14—C13—C18	122.94 (12)
C2—C1—N1	118.84 (11)	C12—C13—C18	118.71 (12)
C3—C2—C1	119.94 (13)	C15—C14—C13	120.27 (12)
C3—C2—H2	120.0	C15—C14—H14	119.9
C1—C2—H2	120.0	C13—C14—H14	119.9
C4—C3—C2	118.44 (13)	C14—C15—C10	120.79 (12)
C4—C3—H3	120.8	C14—C15—H15	119.6
C2—C3—H3	120.8	C10—C15—H15	119.6
F1—C4—C5	118.40 (13)	C9—C16—H16A	109.5
F1—C4—C3	118.94 (13)	C9—C16—H16B	109.5
C5—C4—C3	122.65 (13)	H16A—C16—H16B	109.5
C4—C5—C6	118.86 (13)	C9—C16—H16C	109.5
C4—C5—H5	120.6	H16A—C16—H16C	109.5
C6—C5—H5	120.6	H16B—C16—H16C	109.5
C1—C6—C5	119.49 (12)	C7—C17—H17A	109.5
C1—C6—H6	120.3	C7—C17—H17B	109.5
C5—C6—H6	120.3	H17A—C17—H17B	109.5
N1—C7—C8	105.76 (11)	C7—C17—H17C	109.5
N1—C7—C17	124.73 (12)	H17A—C17—H17C	109.5
C8—C7—C17	129.48 (12)	H17B—C17—H17C	109.5
C7—C8—N3	120.34 (12)	O1—C18—C19	120.34 (14)
C7—C8—C9	106.40 (11)	O1—C18—C13	119.88 (13)
N3—C8—C9	133.27 (12)	C19—C18—C13	119.78 (13)
N2—C9—C8	110.31 (12)	C18—C19—H19A	109.5
N2—C9—C16	120.11 (12)	C18—C19—H19B	109.5
C8—C9—C16	129.57 (12)	H19A—C19—H19B	109.5
C15—C10—C11	119.19 (12)	C18—C19—H19C	109.5
C15—C10—N4	115.99 (12)	H19A—C19—H19C	109.5
C11—C10—N4	124.82 (12)	H19B—C19—H19C	109.5

Hydrogen-bond geometry (Å, º)

Cg1 is the centroid of the N1/N2/C9/C8/C7 ring.

D—H···A	D—H	H···A	D···A	D—H···A
C6—H6···O1^i	0.93	2.58	3.515 (2)	170
C16—H16B···Cg1^ii	0.96	2.91	3.586 (2)	129

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

(IV) (E)-1-(4-Chlorophenyl)-3,5-dimethyl-4-[2-(2-nitrophenyl)diazenyl]-1H-pyrazole

Crystal data

C17H14ClN5O2	Dx = 1.458 Mg m^−3
Mr = 355.78	Mo Kα radiation, λ = 0.71073 Å
Orthorhombic, Pccn	Cell parameters from 3208 reflections
a = 14.076 (5) Å	θ = 2.9–25.1°
b = 30.549 (12) Å	µ = 0.26 mm^−1
c = 7.539 (3) Å	T = 150 K
V = 3242 (2) Å^3	Plate, yellow
Z = 8	0.43 × 0.35 × 0.05 mm
F(000) = 1472

Data collection

Bruker SMART CCD area-detector diffractometer	3710 independent reflections
Radiation source: fine-focus sealed tube	2412 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.086
CCD rotation images, thin slices scans	θmax = 27.9°, θmin = 1.6°
Absorption correction: multi-scan (SADABS in SAINT; Bruker, 2002)	h = −18→18
Tmin = 0.88, Tmax = 0.98	k = −39→39
25152 measured reflections	l = −9→9

Refinement

Refinement on F^2	0 restraints
Least-squares matrix: full	Hydrogen site location: inferred from neighbouring sites
R[F^2 > 2σ(F^2)] = 0.038	H-atom parameters constrained
wR(F^2) = 0.093	w = 1/[σ^2(Fo^2) + (0.0487P)^2] where P = (Fo^2 + 2Fc^2)/3
S = 0.88	(Δ/σ)max = 0.001
3710 reflections	Δρmax = 0.47 e Å^−3
228 parameters	Δρmin = −0.24 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.

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Ų)

	x	y	z	Uiso*/Ueq
Cl1	0.37814 (3)	0.24807 (2)	0.71131 (6)	0.03424 (14)
O1	0.50290 (10)	0.64203 (4)	0.75685 (17)	0.0439 (4)
O2	0.40551 (9)	0.69588 (4)	0.80209 (17)	0.0392 (3)
N1	0.36963 (9)	0.44197 (4)	0.68307 (18)	0.0231 (3)
N2	0.37066 (10)	0.46453 (4)	0.84302 (18)	0.0254 (3)
N3	0.38053 (9)	0.54756 (4)	0.49949 (18)	0.0234 (3)
N4	0.38129 (9)	0.58420 (4)	0.58077 (18)	0.0245 (3)
N5	0.43951 (10)	0.66668 (4)	0.70930 (19)	0.0281 (3)
C1	0.36813 (11)	0.39517 (5)	0.6903 (2)	0.0222 (4)
C2	0.41938 (11)	0.37431 (5)	0.8227 (2)	0.0238 (4)
H2	0.4539	0.3911	0.9070	0.029*
C3	0.42046 (11)	0.32906 (5)	0.8326 (2)	0.0250 (4)
H3	0.4546	0.3147	0.9243	0.030*
C4	0.37080 (11)	0.30491 (5)	0.7061 (2)	0.0242 (4)
C5	0.31740 (12)	0.32546 (5)	0.5765 (2)	0.0281 (4)
H5	0.2827	0.3086	0.4926	0.034*
C6	0.31486 (12)	0.37084 (5)	0.5698 (2)	0.0273 (4)
H6	0.2770	0.3852	0.4834	0.033*
C7	0.37428 (11)	0.46896 (5)	0.5407 (2)	0.0219 (4)
C8	0.37702 (11)	0.51114 (5)	0.6100 (2)	0.0225 (4)
C9	0.37459 (11)	0.50658 (5)	0.7986 (2)	0.0235 (4)
C10	0.37761 (11)	0.62078 (5)	0.4626 (2)	0.0222 (4)
C11	0.33988 (11)	0.61869 (5)	0.2919 (2)	0.0256 (4)
H11	0.3221	0.5912	0.2436	0.031*
C12	0.32817 (12)	0.65619 (5)	0.1925 (2)	0.0290 (4)
H12	0.3035	0.6541	0.0754	0.035*
C13	0.35197 (12)	0.69700 (6)	0.2614 (2)	0.0310 (4)
H13	0.3431	0.7226	0.1920	0.037*
C14	0.38828 (11)	0.70013 (5)	0.4302 (2)	0.0280 (4)
H14	0.4043	0.7278	0.4790	0.034*
C15	0.40113 (12)	0.66209 (5)	0.5281 (2)	0.0239 (4)
C16	0.37713 (13)	0.54081 (5)	0.9409 (2)	0.0313 (4)
H16A	0.3698	0.5268	1.0571	0.047*
H16B	0.3252	0.5617	0.9222	0.047*
H16C	0.4380	0.5563	0.9364	0.047*
C17	0.38089 (12)	0.45477 (5)	0.3520 (2)	0.0257 (4)
H17A	0.4168	0.4273	0.3448	0.039*
H17B	0.4134	0.4774	0.2826	0.039*
H17C	0.3169	0.4502	0.3043	0.039*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
Cl1	0.0494 (3)	0.0190 (2)	0.0343 (3)	−0.00075 (18)	−0.0020 (2)	0.00019 (18)
O1	0.0551 (9)	0.0365 (8)	0.0402 (8)	0.0106 (6)	−0.0181 (7)	−0.0058 (6)
O2	0.0572 (9)	0.0283 (7)	0.0320 (8)	−0.0003 (6)	0.0025 (6)	−0.0122 (6)
N1	0.0286 (8)	0.0190 (7)	0.0216 (8)	0.0001 (6)	−0.0004 (6)	−0.0020 (6)
N2	0.0321 (8)	0.0222 (7)	0.0219 (7)	0.0003 (6)	0.0000 (6)	−0.0032 (6)
N3	0.0254 (8)	0.0188 (7)	0.0260 (8)	0.0004 (6)	−0.0007 (6)	−0.0018 (6)
N4	0.0292 (8)	0.0203 (7)	0.0241 (8)	0.0008 (6)	0.0003 (6)	0.0001 (6)
N5	0.0386 (9)	0.0208 (7)	0.0249 (8)	−0.0044 (6)	−0.0008 (7)	−0.0022 (6)
C1	0.0251 (9)	0.0176 (8)	0.0238 (9)	−0.0012 (6)	0.0026 (7)	0.0004 (7)
C2	0.0247 (9)	0.0254 (9)	0.0213 (9)	−0.0022 (7)	−0.0003 (7)	−0.0013 (7)
C3	0.0283 (9)	0.0248 (9)	0.0220 (9)	0.0004 (7)	0.0005 (7)	0.0028 (7)
C4	0.0286 (9)	0.0186 (8)	0.0254 (9)	−0.0016 (7)	0.0035 (8)	0.0005 (7)
C5	0.0354 (11)	0.0231 (9)	0.0257 (10)	−0.0064 (7)	−0.0042 (8)	−0.0023 (7)
C6	0.0288 (10)	0.0268 (9)	0.0263 (10)	−0.0007 (7)	−0.0053 (8)	0.0012 (7)
C7	0.0212 (9)	0.0222 (8)	0.0224 (9)	0.0008 (7)	−0.0007 (7)	0.0004 (7)
C8	0.0246 (9)	0.0203 (8)	0.0225 (9)	0.0001 (7)	−0.0002 (7)	−0.0013 (7)
C9	0.0257 (9)	0.0221 (8)	0.0225 (9)	0.0013 (7)	−0.0006 (8)	0.0001 (7)
C10	0.0225 (9)	0.0209 (8)	0.0232 (9)	0.0019 (7)	0.0019 (7)	−0.0004 (7)
C11	0.0263 (9)	0.0255 (9)	0.0251 (9)	−0.0033 (7)	0.0005 (7)	−0.0021 (7)
C12	0.0270 (9)	0.0362 (10)	0.0239 (10)	−0.0015 (8)	−0.0013 (7)	0.0043 (8)
C13	0.0340 (10)	0.0259 (9)	0.0332 (11)	0.0009 (7)	0.0017 (8)	0.0094 (8)
C14	0.0322 (10)	0.0205 (8)	0.0314 (10)	−0.0015 (7)	0.0039 (8)	0.0005 (7)
C15	0.0267 (9)	0.0243 (9)	0.0208 (9)	0.0002 (7)	0.0013 (7)	−0.0004 (7)
C16	0.0464 (12)	0.0243 (9)	0.0231 (10)	0.0011 (8)	−0.0014 (8)	−0.0027 (7)
C17	0.0320 (10)	0.0227 (8)	0.0223 (9)	0.0010 (7)	−0.0013 (7)	−0.0018 (7)

Geometric parameters (Å, º)

Cl1—C4	1.7398 (17)	C7—C8	1.391 (2)
O1—N5	1.2214 (18)	C7—C17	1.490 (2)
O2—N5	1.2305 (17)	C8—C9	1.429 (2)
N1—C7	1.355 (2)	C9—C16	1.498 (2)
N1—N2	1.3889 (18)	C10—C11	1.394 (2)
N1—C1	1.431 (2)	C10—C15	1.395 (2)
N2—C9	1.329 (2)	C11—C12	1.379 (2)
N3—N4	1.2761 (18)	C11—H11	0.9500
N3—C8	1.391 (2)	C12—C13	1.392 (2)
N4—C10	1.430 (2)	C12—H12	0.9500
N5—C15	1.475 (2)	C13—C14	1.375 (2)
C1—C2	1.387 (2)	C13—H13	0.9500
C1—C6	1.393 (2)	C14—C15	1.388 (2)
C2—C3	1.384 (2)	C14—H14	0.9500
C2—H2	0.9500	C16—H16A	0.9800
C3—C4	1.394 (2)	C16—H16B	0.9800
C3—H3	0.9500	C16—H16C	0.9800
C4—C5	1.384 (2)	C17—H17A	0.9800
C5—C6	1.388 (2)	C17—H17B	0.9800
C5—H5	0.9500	C17—H17C	0.9800
C6—H6	0.9500
C7—N1—N2	112.66 (13)	N2—C9—C8	110.24 (14)
C7—N1—C1	129.71 (13)	N2—C9—C16	119.67 (15)
N2—N1—C1	117.56 (12)	C8—C9—C16	130.08 (14)
C9—N2—N1	105.15 (13)	C11—C10—C15	117.30 (14)
N4—N3—C8	114.47 (14)	C11—C10—N4	123.58 (14)
N3—N4—C10	112.72 (14)	C15—C10—N4	118.56 (15)
O1—N5—O2	124.35 (15)	C12—C11—C10	120.64 (15)
O1—N5—C15	118.73 (13)	C12—C11—H11	119.7
O2—N5—C15	116.92 (14)	C10—C11—H11	119.7
C2—C1—C6	120.28 (15)	C11—C12—C13	120.83 (17)
C2—C1—N1	118.64 (14)	C11—C12—H12	119.6
C6—C1—N1	121.07 (14)	C13—C12—H12	119.6
C3—C2—C1	120.23 (15)	C14—C13—C12	119.82 (16)
C3—C2—H2	119.9	C14—C13—H13	120.1
C1—C2—H2	119.9	C12—C13—H13	120.1
C2—C3—C4	119.11 (15)	C13—C14—C15	118.85 (16)
C2—C3—H3	120.4	C13—C14—H14	120.6
C4—C3—H3	120.4	C15—C14—H14	120.6
C5—C4—C3	121.03 (15)	C14—C15—C10	122.54 (16)
C5—C4—Cl1	120.06 (13)	C14—C15—N5	117.41 (14)
C3—C4—Cl1	118.90 (13)	C10—C15—N5	120.04 (14)
C4—C5—C6	119.53 (15)	C9—C16—H16A	109.5
C4—C5—H5	120.2	C9—C16—H16B	109.5
C6—C5—H5	120.2	H16A—C16—H16B	109.5
C5—C6—C1	119.70 (16)	C9—C16—H16C	109.5
C5—C6—H6	120.1	H16A—C16—H16C	109.5
C1—C6—H6	120.1	H16B—C16—H16C	109.5
N1—C7—C8	105.50 (14)	C7—C17—H17A	109.5
N1—C7—C17	125.62 (14)	C7—C17—H17B	109.5
C8—C7—C17	128.78 (14)	H17A—C17—H17B	109.5
N3—C8—C7	121.12 (15)	C7—C17—H17C	109.5
N3—C8—C9	132.44 (14)	H17A—C17—H17C	109.5
C7—C8—C9	106.44 (13)	H17B—C17—H17C	109.5

Hydrogen-bond geometry (Å, º)

Cg1 is the centroid of the N1/N2/C9/C8/C7 ring and Cg3 that of the C10–C15 ring.

D—H···A	D—H	H···A	D···A	D—H···A
C17—H17A···O1^i	0.98	2.52	3.478 (2)	165
C12—H12···Cg3^ii	0.93	2.87	3.689 (2)	145
C17—H17C···Cg1^ii	0.96	2.93	3.838 (2)	154

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