Crystal structure, Hirshfeld surface analysis and DFT studies of 4-amino-N′-[(1E)-1-(3-hy­droxyphen­yl)ethyl­idene]benzohydrazide

Maheswari, S.U.; Senthilkumar, S.; Selvanayagam, S.

doi:10.1107/S205698902500297X

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Volume 81| Part 5| May 2025|

https://doi.org/10.1107/S205698902500297X

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Crystal structure, Hirshfeld surface analysis and DFT studies of 4-amino-N′-[(1E)-1-(3-hydroxyphenyl)ethylidene]benzohydrazide

Subramani Uma Maheswari,^a,^b Srinivasan Senthilkumar ^a ^* and Sivashanmugam Selvanayagam ^c ^*

^aDepartment of Chemistry, Annamalai University, Annamalainagar, Chidambaram 608 002, India, ^bDepartment of Science and Humanities, Dhaanish Ahmed Institute of Technology, Coimbatore 641 042, India, and ^cPG & Research Department of Physics, Government Arts College, Melur 625 106, India
^*Correspondence e-mail: senraj05@gmail.com, sselvanayagam@gmail.com

Edited by M. Weil, Vienna University of Technology, Austria (Received 10 March 2025; accepted 2 April 2025; online 8 April 2025)

In the title compound, C₁₅H₁₅N₃O₂, (I), the aniline and phenol rings form a dihedral angle of 62.1 (1)°. Intermolecular N—H⋯O and O—H⋯O hydrogen bonds lead to the formation of sheets extending parallel to (010). Intermolecular interactions were quantified and analysed using Hirshfeld surface analysis, revealing that H⋯H interactions contribute most to the crystal packing (42.2%). The molecular structure was optimized by density functional theory (DFT) at the B3LYP/6–31 G(d,p) level and was compared with the experimentally determined molecular structure in the solid state.

Keywords: crystal structure; benzohydrazide derivative; N—H⋯O and O—H⋯O intermolecular hydrogen bonds; Hirshfeld surface analysis; DFT analysis.

CCDC reference: 2203541

1. Chemical context

Hydrazones have been found to show various biological properties, including antioxidant (Belkheiri et al., 2010 ), anti-inflammatory (Radwan et al., 2007 ) and anticancer (Kumar et al., 2012 ) effects.

In the present work, the synthesis, structural and computational studies of another hydrozone, 4-amino-N′-[(1E)-1-(3-hydroxyphenyl)ethylidene]benzohydrazide, (I), is reported.

2. Structural commentary

The molecular structure of (I) is displayed in Fig. 1. The aniline ring (C1–C6/N1) is planar with a maximum deviation of 0.023 (1) Å for atom N1. Likewise, the phenol ring (C10–C15/O2) is planar with a maximum deviation of 0.003 (2) Å for atom C12. These two rings are oriented at a dihedral angle of 62.1 (1)°. The least-squares plane calculation of the N′-[(1E)-ethylidene]formohydrazide moiety (C7/O1/N2/N3/C8/C9) reveals that this part of the molecule is nearly planar with a maximum deviation of −0.223 (1) Å for atom O1. This moiety forms dihedral angles of 36.5 (1) and 25.6 (1)°, respectively, with respect to the aniline and phenol rings.

Figure 1
The molecular structure of (I) with displacement ellipsoids drawn at the 30% probability level.

3. Supramolecular features

In the crystal, molecules associate pairwise via O2—H2⋯O1ⁱ hydrogen bonds (Table 1) into inversion dimers with an R₂² (20) graph-set motif (Etter et al., 1990 ), as shown in Fig. 2. Molecules are further linked into a C(14) chain motif by N1—H1A⋯O2ⁱⁱⁱ hydrogen bonds running parallel to [100], and by N1—H1B⋯O1ⁱⁱ hydrogen bonds into a C(8) chain motif running along [102] (Table 1; Fig. 3). Taken together, these interactions lead to a layered arrangement parallel to (010). It is interesting to note that the amine function (N2—H2A) is not involved in any intermolecular interactions.

Table 1
Hydrogen-bond geometry (Å, °)

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
O2—H2⋯O1ⁱ	0.82	1.88	2.694 (2)	171
N1—H1B⋯O1ⁱⁱ	0.86	2.13	2.958 (2)	162
N1—H1A⋯O2ⁱⁱⁱ	0.86	2.37	3.119 (2)	146
Symmetry codes: (i) ; (ii) ; (iii) .

Figure 2
The formation of a centrosymmetric dimer in the crystal structure of (I) through O—H⋯O hydrogen bonds. [Symmetry code: (b) −x + 1, −y + 2, −z.]

Figure 3
Intermolecular N—H⋯O and O—H⋯O hydrogen bonds in (I) shown as dashed lines. For clarity, H atoms not involved in these hydrogen bonds have been omitted.

4. Hirshfeld surface analysis

To further characterize the intermolecular interactions in (I), a Hirshfeld surface (HS) analysis (Spackman & Jayatilaka, 2009 ) was carried out using CrystalExplorer (Spackman et al., 2021 ). The HS mapped over d_norm is illustrated in Fig. 4, showing the aforementioned hydrogen-bonding interactions as red-colored areas.

Figure 4
The Hirshfeld surface mapped for (I) over d_norm.

The associated two-dimensional fingerprint plots (McKinnon et al., 2007 ) provide quantitative information about the non-covalent interactions in the crystal packing in terms of the percentage contribution of the interatomic contacts (Spackman & McKinnon, 2002 ). The overall two-dimensional fingerprint plot is shown in Fig. 5a. The HS analysis reveals that H⋯H and H⋯C/C⋯H contacts are the main contributors to the crystal packing, followed by H⋯O/O⋯H, N⋯H/H⋯N and C⋯N/N⋯C contacts; see Fig. 5b–f. The HS analysis confirms the importance of H-atom contacts in establishing the packing (Hathwar et al., 2015 ).

Figure 5
Two-dimensional fingerprint plots for (I), showing (a) all interactions, and delineated into (b) H⋯H, (c) H⋯C/C⋯H, (d) H⋯O/O⋯H, (e) H⋯N/N⋯H and (f) N⋯C/C⋯N interactions with their relative contributions. The d_i and d_e values are the closest internal and external distances (in Å) from given points on the Hirshfeld surface.

5. DFT Studies

The optimized structure of (I) in the gas phase was computed with Gaussian09W using the B3LYP/6–31G (d, p) basis set and generated by GaussView5.0 (Frisch et al., 2009 ). Comparison of experimentally determined bond lengths and angles (present single-crystal X-ray study) with those of theoretical values from the optimized structure showed good agreement [electronic supporting information (ESI), Table S1; the optimized molecular structure of (I) is shown in ESI as Fig. S1].

HOMO and LUMO (Fig. 6) were generated and their energies were evaluated from the optimized structure. The biological activity may also be comprehended by using the value of ΔE (Gulsevensidir et al., 2011 ), which can be used to correlate and understand a decreased toxicity, longer half-life, and sustained activity. Therefore, it is anticipated that molecule (I) with ΔE = 4.395 eV might have a strong biological influence with low adverse effects.

Figure 6
The HOMO/LUMO energy diagram of (I).

The molecular electrostatic potential surface (MEPS; Fig. 7) is used to find the positive and negative electrostatic potential of the molecule, which provides possible information about its reactive sites with regard to chemical processes and binding sites for certain biological entities. The red-colored areas on the MEPS of (I) above the carbonyl oxygen atom of the azonitrile nitrogen moiety, which is likely to undergo electrophilic attack, indicate the electron-rich portion with a partial negative charge. The mild-blue coloration of (I) suggests that there are slight electron-deficient regions. The lack of a bright-blue area on the MEPS indicates that the molecule has no potential nucleophilic attack sites. The pale-blue color of the phenyl rings indicate weak electrophilic sites.

Figure 7
The molecular electrostatic potential surface (MEPS) of (I).

6. Synthesis and crystallization

4-Aminobenzohydrazide (2 mmol) and the corresponding substituted aromatic ketone (2 mmol) were dissolved in 25 ml of methanol, along with a few drops of acetic acid, to give a clear solution. The reaction mixture was filled in a round bottom flask and refluxed on a water bath for about 4 h. The progress of the reaction was monitored by thin layer chromatography (TLC). After completion of the reaction, methanol was removed by vacuum distillation. The solid product was collected, washed, and recrystallized from methanol to obtain a pure product of (I).

7. Refinement

Crystal data, data collection and structure refinement details are summarized in Table 2. Atom H2A was located from a difference-Fourier map; all other H atoms were placed in idealized positions and allowed to ride on their parent atoms with O—H = 0.82, N—H = 0.86 and C—H = 0.93–0.96 Å, respectively, and with U_iso(H) = 1.5U_eq(C) for methyl H atoms and U_iso(H) = 1.2U_eq(C)(C or N or O).

Table 2
Experimental details

Crystal data
Chemical formula	C₁₅H₁₅N₃O₂
M_r	269.30
Crystal system, space group	Triclinic, P $[\overline{1}]$
Temperature (K)	298
a, b, c (Å)	8.3562 (4), 9.2666 (4), 9.9151 (4)
α, β, γ (°)	76.685 (2), 65.316 (1), 84.909 (2)
V (Å³)	678.83 (5)
Z	2
Radiation type	Mo Kα
μ (mm⁻¹)	0.09
Crystal size (mm)	0.33 × 0.29 × 0.17

Data collection
Diffractometer	Bruker D8 Quest XRD
No. of measured, independent and observed [I > 2σ(I)] reflections	13112, 3420, 2620
R_int	0.026
(sin θ/λ)_max (Å⁻¹)	0.707

Refinement
R[F² > 2σ(F²)], wR(F²), S	0.050, 0.134, 1.05
No. of reflections	3420
No. of parameters	186
No. of restraints	1
H-atom treatment	H atoms treated by a mixture of independent and constrained refinement
Δρ_max, Δρ_min (e Å⁻³)	0.25, −0.15
Computer programs: APEX3 and SAINT (Bruker, 2017 ), SHELXT (Sheldrick, 2015a ), ORTEP-3 for Windows (Farrugia, 2012 ) and PLATON (Spek, 2020 ), SHELXL (Sheldrick, 2015b ).

Supporting information

CCDC reference: 2203541

Crystal structure: contains datablocks I, global. DOI: https://doi.org/10.1107/S205698902500297X/wm5754sup1.cif

Structure factors: contains datablock I. DOI: https://doi.org/10.1107/S205698902500297X/wm5754Isup2.hkl

Table S1. DOI: https://doi.org/10.1107/S205698902500297X/wm5754sup3.docx

Figure S1. DOI: https://doi.org/10.1107/S205698902500297X/wm5754sup4.tif

Supporting information file. DOI: https://doi.org/10.1107/S205698902500297X/wm5754Isup5.cml

checkCIF report

Computing details top

4-Amino-N'-[(1E)-1-(3-hydroxyphenyl)ethylidene]benzohydrazide top

Crystal data top

C₁₅H₁₅N₃O₂	Z = 2
M_r = 269.30	F(000) = 284
Triclinic, P1	D_x = 1.318 Mg m⁻³
a = 8.3562 (4) Å	Mo Kα radiation, λ = 0.71073 Å
b = 9.2666 (4) Å	Cell parameters from 5917 reflections
c = 9.9151 (4) Å	θ = 2.7–29.3°
α = 76.685 (2)°	µ = 0.09 mm⁻¹
β = 65.316 (1)°	T = 298 K
γ = 84.909 (2)°	Block, colorless
V = 678.83 (5) Å³	0.33 × 0.29 × 0.17 mm

Data collection top

Bruker D8 Quest XRD diffractometer	R_int = 0.026
Detector resolution: 7.3910 pixels mm^-1	θ_max = 30.2°, θ_min = 2.7°
ω and Phi Scans scans	h = −11→11
13112 measured reflections	k = −12→13
3420 independent reflections	l = −13→13
2620 reflections with I > 2σ(I)

Refinement top

Refinement on F²	1 restraint
Least-squares matrix: full	Hydrogen site location: mixed
R[F² > 2σ(F²)] = 0.050	H atoms treated by a mixture of independent and constrained refinement
wR(F²) = 0.134	w = 1/[σ²(F_o²) + (0.0511P)² + 0.2093P] where P = (F_o² + 2F_c²)/3
S = 1.05	(Δ/σ)_max < 0.001
3420 reflections	Δρ_max = 0.25 e Å⁻³
186 parameters	Δρ_min = −0.15 e Å⁻³

Special details top

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.

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å²) top

	x	y	z	U_iso*/U_eq
O1	0.15425 (14)	0.90009 (13)	0.19913 (13)	0.0525 (3)
O2	0.99259 (14)	0.84728 (15)	−0.28575 (16)	0.0642 (4)
H2	0.939270	0.922396	−0.261740	0.096*
N1	−0.67521 (18)	0.83831 (19)	0.41445 (18)	0.0646 (4)
H1A	−0.730474	0.838506	0.509568	0.078*
H1B	−0.733195	0.836403	0.360773	0.078*
N2	0.14917 (16)	0.77285 (15)	0.03196 (16)	0.0470 (3)
N3	0.33033 (15)	0.76091 (14)	−0.03496 (14)	0.0449 (3)
C1	−0.22296 (19)	0.83740 (17)	0.12941 (16)	0.0432 (3)
H1	−0.164218	0.833788	0.027285	0.052*
C2	−0.4043 (2)	0.83844 (17)	0.19445 (17)	0.0456 (3)
H2B	−0.466420	0.837429	0.135719	0.055*
C3	−0.49542 (19)	0.84101 (17)	0.34866 (18)	0.0449 (3)
C4	−0.3979 (2)	0.84413 (19)	0.43329 (17)	0.0490 (4)
H4	−0.456202	0.844926	0.536114	0.059*
C5	−0.2173 (2)	0.84603 (18)	0.36659 (17)	0.0465 (4)
H5	−0.155097	0.850317	0.424490	0.056*
C6	−0.12531 (18)	0.84166 (16)	0.21355 (16)	0.0395 (3)
C7	0.06932 (19)	0.84259 (16)	0.14849 (17)	0.0413 (3)
C8	0.38915 (19)	0.66826 (16)	−0.12234 (17)	0.0430 (3)
C9	0.2747 (2)	0.5749 (3)	−0.1523 (3)	0.0787 (7)
H9A	0.347537	0.514173	−0.221098	0.118*
H9B	0.199464	0.512823	−0.058500	0.118*
H9C	0.204057	0.638171	−0.196627	0.118*
C10	0.58360 (19)	0.65143 (16)	−0.19348 (16)	0.0406 (3)
C11	0.69503 (19)	0.76129 (16)	−0.20501 (16)	0.0417 (3)
H11	0.647841	0.846282	−0.168357	0.050*
C12	0.87624 (19)	0.74403 (17)	−0.27108 (17)	0.0449 (3)
C13	0.9479 (2)	0.61656 (19)	−0.32493 (18)	0.0488 (4)
H13	1.069377	0.604830	−0.368656	0.059*
C14	0.8379 (2)	0.50825 (18)	−0.31303 (19)	0.0507 (4)
H14	0.885554	0.422900	−0.348736	0.061*
C15	0.6570 (2)	0.52448 (17)	−0.24861 (19)	0.0495 (4)
H15	0.584065	0.450565	−0.242003	0.059*
H2A	0.082 (2)	0.730 (2)	0.005 (2)	0.068 (6)*

Atomic displacement parameters (Å²) top

	U¹¹	U²²	U³³	U¹²	U¹³	U²³
O1	0.0408 (6)	0.0658 (7)	0.0606 (7)	0.0009 (5)	−0.0226 (5)	−0.0283 (6)
O2	0.0385 (6)	0.0698 (8)	0.0813 (9)	−0.0062 (5)	−0.0078 (6)	−0.0407 (7)
N1	0.0364 (7)	0.0989 (12)	0.0575 (9)	−0.0049 (7)	−0.0141 (6)	−0.0225 (8)
N2	0.0338 (6)	0.0549 (7)	0.0551 (8)	−0.0020 (5)	−0.0144 (6)	−0.0237 (6)
N3	0.0333 (6)	0.0503 (7)	0.0497 (7)	−0.0023 (5)	−0.0125 (5)	−0.0159 (6)
C1	0.0427 (8)	0.0501 (8)	0.0379 (7)	−0.0027 (6)	−0.0150 (6)	−0.0128 (6)
C2	0.0427 (8)	0.0545 (9)	0.0457 (8)	−0.0019 (6)	−0.0219 (6)	−0.0139 (7)
C3	0.0369 (7)	0.0491 (8)	0.0473 (8)	−0.0025 (6)	−0.0150 (6)	−0.0108 (7)
C4	0.0442 (8)	0.0635 (10)	0.0363 (7)	0.0002 (7)	−0.0132 (6)	−0.0110 (7)
C5	0.0429 (8)	0.0586 (9)	0.0420 (8)	0.0002 (7)	−0.0201 (6)	−0.0128 (7)
C6	0.0361 (7)	0.0415 (7)	0.0411 (7)	−0.0018 (5)	−0.0146 (6)	−0.0108 (6)
C7	0.0381 (7)	0.0416 (7)	0.0448 (8)	−0.0014 (6)	−0.0169 (6)	−0.0100 (6)
C8	0.0406 (7)	0.0448 (7)	0.0455 (8)	−0.0011 (6)	−0.0173 (6)	−0.0133 (6)
C9	0.0488 (10)	0.0951 (15)	0.1132 (18)	0.0044 (10)	−0.0324 (11)	−0.0646 (14)
C10	0.0405 (7)	0.0435 (7)	0.0380 (7)	−0.0002 (6)	−0.0148 (6)	−0.0114 (6)
C11	0.0403 (7)	0.0446 (7)	0.0395 (7)	0.0009 (6)	−0.0121 (6)	−0.0163 (6)
C12	0.0403 (8)	0.0535 (8)	0.0409 (7)	−0.0024 (6)	−0.0120 (6)	−0.0181 (7)
C13	0.0397 (8)	0.0589 (9)	0.0464 (8)	0.0053 (7)	−0.0122 (6)	−0.0210 (7)
C14	0.0525 (9)	0.0457 (8)	0.0519 (9)	0.0074 (7)	−0.0159 (7)	−0.0198 (7)
C15	0.0503 (9)	0.0441 (8)	0.0542 (9)	−0.0023 (6)	−0.0176 (7)	−0.0168 (7)

Geometric parameters (Å, º) top

O1—C7	1.2360 (17)	C5—C6	1.394 (2)
O2—C12	1.3656 (18)	C5—H5	0.9300
O2—H2	0.8200	C6—C7	1.4782 (19)
N1—C3	1.3652 (19)	C8—C10	1.487 (2)
N1—H1A	0.8600	C8—C9	1.501 (2)
N1—H1B	0.8600	C9—H9A	0.9600
N2—C7	1.3496 (19)	C9—H9B	0.9600
N2—N3	1.3818 (17)	C9—H9C	0.9600
N2—H2A	0.864 (9)	C10—C11	1.394 (2)
N3—C8	1.2811 (19)	C10—C15	1.395 (2)
C1—C2	1.377 (2)	C11—C12	1.387 (2)
C1—C6	1.397 (2)	C11—H11	0.9300
C1—H1	0.9300	C12—C13	1.392 (2)
C2—C3	1.400 (2)	C13—C14	1.373 (2)
C2—H2B	0.9300	C13—H13	0.9300
C3—C4	1.399 (2)	C14—C15	1.383 (2)
C4—C5	1.371 (2)	C14—H14	0.9300
C4—H4	0.9300	C15—H15	0.9300

C12—O2—H2	109.5	N2—C7—C6	115.58 (12)
C3—N1—H1A	120.0	N3—C8—C10	116.54 (13)
C3—N1—H1B	120.0	N3—C8—C9	124.22 (14)
H1A—N1—H1B	120.0	C10—C8—C9	119.22 (13)
C7—N2—N3	121.26 (12)	C8—C9—H9A	109.5
C7—N2—H2A	117.2 (13)	C8—C9—H9B	109.5
N3—N2—H2A	121.4 (13)	H9A—C9—H9B	109.5
C8—N3—N2	115.54 (12)	C8—C9—H9C	109.5
C2—C1—C6	121.41 (13)	H9A—C9—H9C	109.5
C2—C1—H1	119.3	H9B—C9—H9C	109.5
C6—C1—H1	119.3	C11—C10—C15	119.07 (14)
C1—C2—C3	120.25 (14)	C11—C10—C8	120.63 (13)
C1—C2—H2B	119.9	C15—C10—C8	120.30 (13)
C3—C2—H2B	119.9	C12—C11—C10	120.09 (13)
N1—C3—C4	121.19 (14)	C12—C11—H11	120.0
N1—C3—C2	120.41 (14)	C10—C11—H11	120.0
C4—C3—C2	118.39 (14)	O2—C12—C11	123.02 (13)
C5—C4—C3	120.85 (14)	O2—C12—C13	116.66 (13)
C5—C4—H4	119.6	C11—C12—C13	120.32 (14)
C3—C4—H4	119.6	C14—C13—C12	119.50 (14)
C4—C5—C6	121.19 (14)	C14—C13—H13	120.3
C4—C5—H5	119.4	C12—C13—H13	120.2
C6—C5—H5	119.4	C13—C14—C15	120.83 (14)
C5—C6—C1	117.89 (13)	C13—C14—H14	119.6
C5—C6—C7	118.67 (13)	C15—C14—H14	119.6
C1—C6—C7	123.44 (13)	C14—C15—C10	120.19 (14)
O1—C7—N2	121.81 (13)	C14—C15—H15	119.9
O1—C7—C6	122.59 (13)	C10—C15—H15	119.9

C7—N2—N3—C8	166.52 (15)	N2—N3—C8—C10	−178.92 (13)
C6—C1—C2—C3	−1.2 (2)	N2—N3—C8—C9	−0.7 (2)
C1—C2—C3—N1	−178.36 (15)	N3—C8—C10—C11	−20.1 (2)
C1—C2—C3—C4	0.7 (2)	C9—C8—C10—C11	161.65 (17)
N1—C3—C4—C5	179.65 (16)	N3—C8—C10—C15	159.42 (15)
C2—C3—C4—C5	0.6 (2)	C9—C8—C10—C15	−18.9 (2)
C3—C4—C5—C6	−1.4 (3)	C15—C10—C11—C12	0.3 (2)
C4—C5—C6—C1	0.9 (2)	C8—C10—C11—C12	179.74 (13)
C4—C5—C6—C7	−179.44 (14)	C10—C11—C12—O2	−179.94 (15)
C2—C1—C6—C5	0.4 (2)	C10—C11—C12—C13	−0.6 (2)
C2—C1—C6—C7	−179.23 (14)	O2—C12—C13—C14	179.78 (15)
N3—N2—C7—O1	0.9 (2)	C11—C12—C13—C14	0.4 (2)
N3—N2—C7—C6	−177.49 (13)	C12—C13—C14—C15	0.2 (3)
C5—C6—C7—O1	−27.6 (2)	C13—C14—C15—C10	−0.5 (3)
C1—C6—C7—O1	152.05 (15)	C11—C10—C15—C14	0.3 (2)
C5—C6—C7—N2	150.74 (15)	C8—C10—C15—C14	−179.20 (14)
C1—C6—C7—N2	−29.6 (2)

Hydrogen-bond geometry (Å, º) top

D—H···A	D—H	H···A	D···A	D—H···A
O2—H2···O1ⁱ	0.82	1.88	2.694 (2)	171
N1—H1B···O1ⁱⁱ	0.86	2.13	2.958 (2)	162
N1—H1A···O2ⁱⁱⁱ	0.86	2.37	3.119 (2)	146

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

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