(Z)-N-(2,6-Diiso­propyl­phen­yl)-1-[(2-meth­oxyphen­yl)amino]­methanimine oxide

Juma, D.O.; Omondi, B.; Zamisa, S.J.; Munzeiwa, W.

doi:10.1107/S241431462400988X

organic compounds

IUCrDATA

ISSN: 2414-3146

Volume 9| Part 10| October 2024| x240988

https://doi.org/10.1107/S241431462400988X

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(Z)-N-(2,6-Diisopropylphenyl)-1-[(2-methoxyphenyl)amino]methanimine oxide

David O. Juma,^a Bernard Omondi,^a Sizwe J. Zamisa ^a ^* and Wisdom Munzeiwa ^b

^aSchool of Chemistry and Physics, University of KwaZulu Natal, Private Bag X54001, Westville, Durban, 4000, South Africa, and ^bChemistry Department, Bindura University of Science Education, Private Bag 1020, Bindura, Zimbabwe
^*Correspondence e-mail: zamisas@ukzn.ac.za

Edited by E. R. T. Tiekink, Universitat de lesIlles Balears, Palma de Mallorca, Spain (Received 1 October 2024; accepted 9 October 2024; online 21 October 2024)

The molecular structure of the title compound, C₂₀H₂₆N₂O₂ reveals non-co-planarity between the central formamidine backbone and each of the outer methoxy- and i-propyl- substituted benzene rings with dihedral angles of 7.88 (15) and 81.17 (15)°, respectively, indicating significant twists in the molecule. In the crystal, intermolecular C—H⋯O interactions, forming an R³₄(30) graph set, occur within a two-dimensional layer that extends along the ac plane.

Keywords: crystal structure; zwitterion; non-symmetric hydroxyformamidine.

CCDC reference: 2389590

Structure description

The tittle compound is a member of the formamidine class of compounds, which follow the general structure RN—C(R′)=NR′′, where R, R′ and R′′ can represent either hydrogen, alkyl or aryl groups (Zamisa et al., 2021 ; Barker & Kilner, 1994 ). Their varied structures have led to investigations into their potential medicinal uses, uncovering properties such as antimicrobial and anticancer activities (Clement, 2002 ; Stojak et al., 2014 ). Recently, we focused on the application of formamidine metal complexes as catalysts in ring-opening polymerization reactions (Munzeiwa et al., 2018 ). As part of our work to develop new derivatives with superior catalytic abilities, we synthesized the title compound and analysed its crystal structure.

The title crystal has one molecule in the asymmetric unit, as shown in Fig. 1. The molecular conformation of the title compound is described by a dihedral angle between the 2-methoxybenzene plane and the formamidine backbone of 7.88 (15)°, while that between the 2,6-diisopropylbenzene plane and the backbone measures 81.17 (15)°, suggesting a notable twist of this plane relative to the backbone. Furthermore, the dihedral angle between the two benzene planes is 78.17 (6)°. All other intramolecular bond parameters are comparable with those of (Z)-1-[(4-methoxyphenyl)amino]-N-phenylmethanimine oxide (CSD refcode: GIKFUB; Giumanini et al., 1999 ).

Figure 1
Molecular structure of the title compound showing the atom-numbering scheme and displacement ellipsoids drawn at the 50% probability level. All hydrogen atoms have been omitted for clarity.

Intermolecular C—H⋯O hydrogen bonds were found in the molecular packing of the title compound, Table 1. The oxygen atom is involved in bifurcated C14—H14C⋯O2 and C9—H9⋯O2 interactions with the hydrogen (H14C) atom of the isopropyl substituent and the hydrogen (H9) atom of the 2-methoxyphenyl ring, respectively. The former links neighbouring molecules along [100] whilst the latter joins neighbouring molecules along [001]. Collectively, the two types of C—H⋯O interactions can be described by an R₄³(30) graph set within a two-dimensional supramolecular arrangement that propagates along the ac plane (Fig. 2).

Table 1
Hydrogen-bond geometry (Å, °)

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
C9—H9⋯O2ⁱ	0.95	2.39	3.337 (2)	174
C14—H14C⋯O2ⁱⁱ	0.98	2.47	3.445 (2)	172
Symmetry codes: (i) ; (ii) .

Figure 2
Representation of intermolecular C—H⋯O interactions (red dotted bonds).

Synthesis and crystallization

The title compound was synthesized using a modified protocol (Munzeiwa et al., 2017 ). Thus, N-(2,6-diisopropylphenyl)-N′-(2-methoxyphenyl)formamidine (1 mmol) was dissolved in dichloromethane (6 ml) followed by the addition of solid sodium hydrogen carbonate (1 mmol). The mixture was cooled to 0°C. A slight excess of meta-chloroperoxybenzoic acid (1.2 mmol) in dichloromethane (6 ml) was then added dropwise, and the reaction mixture was allowed to gradually warm to room temperature while stirring for 1 h. The mixture was washed with 2 × 25 ml of 5% potassium carbonate solution. The combined organic layers were dried over anhydrous sodium sulfate, filtered and the solvent evaporated to yield a solid residue. The crude solid was subsequently recrystallized from its methanol solution to produce crystals suitable for X-ray diffraction.

Refinement

Crystallographic data and structure refinement details are summarized in Table 2.

Table 2
Experimental details

Crystal data
Chemical formula	C₂₀H₂₆N₂O₂
M_r	326.43
Crystal system, space group	Monoclinic, P2₁/c
Temperature (K)	100
a, b, c (Å)	10.1243 (4), 23.941 (1), 7.5053 (3)
β (°)	91.315 (3)
V (Å³)	1818.70 (13)
Z	4
Radiation type	Mo Kα
μ (mm⁻¹)	0.08
Crystal size (mm)	0.22 × 0.18 × 0.11

Data collection
Diffractometer	Bruker APEXII CCD
Absorption correction	Multi-scan (SADABS; Krause et al., 2015 )
T_min, T_max	0.984, 0.992
No. of measured, independent and observed [I > 2σ(I)] reflections	19835, 3268, 2304
R_int	0.050
(sin θ/λ)_max (Å⁻¹)	0.600

Refinement
R[F² > 2σ(F²)], wR(F²), S	0.044, 0.108, 1.03
No. of reflections	3268
No. of parameters	222
No. of restraints	1
H-atom treatment	H-atom parameters constrained
Δρ_max, Δρ_min (e Å⁻³)	0.17, −0.34
Computer programs: APEX2 and SAINT (Bruker, 2010 ), SHELXT (Sheldrick, 2015a ), SHELXL2018/3 (Sheldrick, 2015b ) and OLEX2 (Dolomanov et al., 2009 ).

Structural data

CCDC reference: 2389590

Crystal structure: contains datablock I. DOI: https://doi.org/10.1107/S241431462400988X/tk4110sup1.cif

Structure factors: contains datablock I. DOI: https://doi.org/10.1107/S241431462400988X/tk4110Isup2.hkl

Supporting information file. DOI: https://doi.org/10.1107/S241431462400988X/tk4110Isup3.cml

checkCIF report

Computing details top

(Z)-N-(2,6-Diisopropylphenyl)-1-[(2-methoxyphenyl)amino]methanimine oxide top

Crystal data top

C₂₀H₂₆N₂O₂	F(000) = 704
M_r = 326.43	D_x = 1.192 Mg m⁻³
Monoclinic, P2₁/c	Mo Kα radiation, λ = 0.71073 Å
a = 10.1243 (4) Å	Cell parameters from 3357 reflections
b = 23.941 (1) Å	θ = 2.6–26.1°
c = 7.5053 (3) Å	µ = 0.08 mm⁻¹
β = 91.315 (3)°	T = 100 K
V = 1818.70 (13) Å³	Block, colourless
Z = 4	0.22 × 0.18 × 0.11 mm

Data collection top

Bruker APEXII CCD diffractometer	2304 reflections with I > 2σ(I)
Graphite monochromator	R_int = 0.050
φ and ω scans	θ_max = 25.2°, θ_min = 1.7°
Absorption correction: multi-scan (SADABS; Krause et al., 2015)	h = −12→12
T_min = 0.984, T_max = 0.992	k = −26→28
19835 measured reflections	l = −6→9
3268 independent reflections

Refinement top

Refinement on F²	1 restraint
Least-squares matrix: full	Hydrogen site location: inferred from neighbouring sites
R[F² > 2σ(F²)] = 0.044	H-atom parameters constrained
wR(F²) = 0.108	w = 1/[σ²(F_o²) + (0.0455P)² + 0.5644P] where P = (F_o² + 2F_c²)/3
S = 1.03	(Δ/σ)_max = 0.001
3268 reflections	Δρ_max = 0.17 e Å⁻³
222 parameters	Δρ_min = −0.34 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	0.24618 (12)	0.68362 (5)	−0.12209 (16)	0.0240 (3)
O2	0.63374 (13)	0.64315 (6)	0.11780 (18)	0.0331 (4)
N1	0.58378 (14)	0.61829 (6)	0.25631 (19)	0.0170 (3)
N2	0.37631 (14)	0.64203 (6)	0.1547 (2)	0.0190 (4)
H2	0.413234	0.658969	0.064484	0.023*
C1	0.82344 (18)	0.54648 (8)	0.6549 (3)	0.0260 (5)
H1	0.874167	0.529441	0.748058	0.031*
C2	0.77386 (18)	0.59966 (8)	0.6781 (2)	0.0225 (4)
H2A	0.791133	0.618873	0.786910	0.027*
C3	0.69884 (16)	0.62541 (7)	0.5438 (2)	0.0180 (4)
C4	0.67049 (16)	0.59410 (7)	0.3911 (2)	0.0164 (4)
C5	0.45720 (17)	0.61710 (7)	0.2758 (2)	0.0182 (4)
H5	0.421147	0.598614	0.375576	0.022*
C6	0.23759 (17)	0.64312 (7)	0.1612 (2)	0.0170 (4)
C7	0.16819 (18)	0.62453 (8)	0.3053 (3)	0.0229 (4)
H7	0.214562	0.610891	0.407812	0.028*
C8	0.03063 (18)	0.62555 (8)	0.3021 (3)	0.0283 (5)
H8	−0.016409	0.612074	0.401349	0.034*
C9	−0.03726 (18)	0.64608 (8)	0.1551 (3)	0.0277 (5)
H9	−0.131108	0.646543	0.152560	0.033*
C10	0.1809 (2)	0.71154 (9)	−0.2667 (3)	0.0317 (5)
H10A	0.120039	0.685618	−0.327481	0.048*
H10B	0.246584	0.724767	−0.350876	0.048*
H10C	0.131282	0.743447	−0.221269	0.048*
C11	0.16860 (17)	0.66476 (7)	0.0128 (2)	0.0188 (4)
C12	0.65352 (17)	0.68551 (8)	0.5626 (2)	0.0210 (4)
H12	0.615423	0.697475	0.444555	0.025*
C13	0.76943 (19)	0.72415 (8)	0.6074 (3)	0.0305 (5)
H13A	0.805030	0.715203	0.726483	0.046*
H13B	0.739196	0.763030	0.604830	0.046*
H13C	0.838529	0.719026	0.519491	0.046*
C14	0.5452 (2)	0.69169 (9)	0.6997 (3)	0.0320 (5)
H14A	0.469131	0.668580	0.664185	0.048*
H14B	0.517834	0.730900	0.706103	0.048*
H14C	0.579024	0.679568	0.816829	0.048*
C15	0.80004 (18)	0.51781 (8)	0.4976 (3)	0.0239 (5)
H15	0.838574	0.482028	0.481773	0.029*
C16	0.72077 (17)	0.54058 (7)	0.3619 (2)	0.0195 (4)
C17	0.68975 (19)	0.50857 (8)	0.1912 (2)	0.0253 (5)
H17	0.652702	0.535657	0.101812	0.030*
C18	0.5848 (2)	0.46398 (9)	0.2228 (3)	0.0419 (6)
H18A	0.620523	0.435607	0.304729	0.063*
H18B	0.559595	0.446378	0.109107	0.063*
H18C	0.506945	0.481362	0.274722	0.063*
C19	0.03187 (17)	0.66612 (7)	0.0105 (3)	0.0233 (4)
H19	−0.014889	0.680792	−0.090184	0.028*
C22	0.8135 (2)	0.48265 (9)	0.1134 (3)	0.0371 (5)
H22A	0.881168	0.511530	0.100393	0.056*
H22B	0.791668	0.466460	−0.003513	0.056*
H22C	0.847068	0.453307	0.193454	0.056*

Atomic displacement parameters (Å²) top

	U¹¹	U²²	U³³	U¹²	U¹³	U²³
O1	0.0185 (7)	0.0334 (8)	0.0201 (7)	0.0049 (6)	−0.0014 (6)	0.0075 (6)
O2	0.0261 (8)	0.0423 (9)	0.0311 (8)	−0.0019 (6)	0.0022 (6)	0.0131 (7)
N1	0.0163 (8)	0.0197 (8)	0.0150 (8)	0.0004 (6)	−0.0011 (6)	0.0019 (6)
N2	0.0129 (8)	0.0246 (8)	0.0194 (8)	0.0007 (6)	−0.0006 (6)	0.0055 (7)
C1	0.0223 (10)	0.0292 (11)	0.0260 (11)	−0.0024 (9)	−0.0074 (9)	0.0109 (9)
C2	0.0215 (10)	0.0279 (11)	0.0179 (10)	−0.0056 (8)	−0.0036 (8)	0.0027 (8)
C3	0.0113 (9)	0.0228 (10)	0.0199 (10)	−0.0026 (7)	0.0003 (8)	0.0036 (8)
C4	0.0120 (9)	0.0208 (10)	0.0164 (10)	−0.0012 (7)	−0.0017 (8)	0.0046 (8)
C5	0.0182 (10)	0.0208 (10)	0.0155 (10)	0.0015 (8)	−0.0013 (8)	0.0006 (8)
C6	0.0133 (9)	0.0162 (9)	0.0215 (10)	0.0008 (7)	−0.0010 (8)	−0.0018 (8)
C7	0.0182 (10)	0.0260 (11)	0.0245 (11)	0.0037 (8)	−0.0011 (8)	0.0067 (9)
C8	0.0197 (10)	0.0308 (11)	0.0346 (12)	−0.0001 (9)	0.0042 (9)	0.0088 (10)
C9	0.0125 (10)	0.0282 (11)	0.0423 (13)	0.0000 (8)	0.0008 (9)	0.0037 (10)
C10	0.0286 (11)	0.0422 (13)	0.0240 (11)	0.0090 (10)	−0.0028 (9)	0.0111 (10)
C11	0.0177 (10)	0.0186 (10)	0.0201 (10)	−0.0001 (8)	0.0013 (8)	−0.0005 (8)
C12	0.0204 (10)	0.0236 (10)	0.0189 (10)	0.0001 (8)	−0.0027 (8)	0.0004 (8)
C13	0.0273 (11)	0.0256 (11)	0.0385 (13)	−0.0039 (9)	−0.0030 (10)	−0.0012 (9)
C14	0.0298 (12)	0.0307 (12)	0.0357 (12)	0.0017 (9)	0.0059 (10)	−0.0029 (10)
C15	0.0220 (10)	0.0213 (10)	0.0283 (11)	0.0034 (8)	−0.0003 (9)	0.0062 (9)
C16	0.0163 (9)	0.0205 (10)	0.0218 (10)	−0.0019 (8)	0.0007 (8)	0.0035 (8)
C17	0.0310 (11)	0.0215 (10)	0.0232 (11)	0.0036 (8)	−0.0031 (9)	−0.0002 (8)
C18	0.0421 (14)	0.0421 (14)	0.0414 (14)	−0.0123 (11)	0.0004 (11)	−0.0132 (11)
C19	0.0189 (10)	0.0223 (10)	0.0284 (11)	0.0018 (8)	−0.0066 (9)	−0.0004 (9)
C22	0.0416 (13)	0.0368 (13)	0.0331 (12)	0.0053 (10)	0.0054 (10)	−0.0065 (10)

Geometric parameters (Å, º) top

O1—C10	1.424 (2)	C10—H10B	0.9800
O1—C11	1.372 (2)	C10—H10C	0.9800
O2—N1	1.3095 (19)	C11—C19	1.384 (2)
N1—C4	1.445 (2)	C12—H12	1.0000
N1—C5	1.294 (2)	C12—C13	1.526 (3)
N2—H2	0.8800	C12—C14	1.529 (3)
N2—C5	1.349 (2)	C13—H13A	0.9800
N2—C6	1.407 (2)	C13—H13B	0.9800
C1—H1	0.9500	C13—H13C	0.9800
C1—C2	1.381 (3)	C14—H14A	0.9800
C1—C15	1.381 (3)	C14—H14B	0.9800
C2—H2A	0.9500	C14—H14C	0.9800
C2—C3	1.392 (2)	C15—H15	0.9500
C3—C4	1.394 (2)	C15—C16	1.394 (2)
C3—C12	1.518 (3)	C16—C17	1.519 (3)
C4—C16	1.398 (2)	C17—H17	1.0000
C5—H5	0.9500	C17—C18	1.529 (3)
C6—C7	1.377 (3)	C17—C22	1.526 (3)
C6—C11	1.401 (2)	C18—H18A	0.9800
C7—H7	0.9500	C18—H18B	0.9800
C7—C8	1.393 (3)	C18—H18C	0.9800
C8—H8	0.9500	C19—H19	0.9500
C8—C9	1.377 (3)	C22—H22A	0.9800
C9—H9	0.9500	C22—H22B	0.9800
C9—C19	1.390 (3)	C22—H22C	0.9800
C10—H10A	0.9800

C11—O1—C10	116.96 (14)	C3—C12—C13	111.26 (15)
O2—N1—C4	119.89 (14)	C3—C12—C14	112.18 (15)
C5—N1—O2	120.10 (15)	C13—C12—H12	107.5
C5—N1—C4	119.96 (15)	C13—C12—C14	110.69 (16)
C5—N2—H2	117.4	C14—C12—H12	107.5
C5—N2—C6	125.18 (15)	C12—C13—H13A	109.5
C6—N2—H2	117.4	C12—C13—H13B	109.5
C2—C1—H1	119.7	C12—C13—H13C	109.5
C2—C1—C15	120.67 (17)	H13A—C13—H13B	109.5
C15—C1—H1	119.7	H13A—C13—H13C	109.5
C1—C2—H2A	119.6	H13B—C13—H13C	109.5
C1—C2—C3	120.72 (18)	C12—C14—H14A	109.5
C3—C2—H2A	119.6	C12—C14—H14B	109.5
C2—C3—C4	117.11 (16)	C12—C14—H14C	109.5
C2—C3—C12	120.91 (16)	H14A—C14—H14B	109.5
C4—C3—C12	121.96 (15)	H14A—C14—H14C	109.5
C3—C4—N1	118.05 (15)	H14B—C14—H14C	109.5
C3—C4—C16	123.60 (16)	C1—C15—H15	119.5
C16—C4—N1	118.35 (15)	C1—C15—C16	121.01 (17)
N1—C5—N2	120.13 (16)	C16—C15—H15	119.5
N1—C5—H5	119.9	C4—C16—C17	121.73 (16)
N2—C5—H5	119.9	C15—C16—C4	116.70 (17)
C7—C6—N2	123.31 (16)	C15—C16—C17	121.57 (16)
C7—C6—C11	119.35 (16)	C16—C17—H17	107.8
C11—C6—N2	117.34 (16)	C16—C17—C18	110.65 (16)
C6—C7—H7	119.7	C16—C17—C22	111.84 (16)
C6—C7—C8	120.58 (17)	C18—C17—H17	107.8
C8—C7—H7	119.7	C22—C17—H17	107.8
C7—C8—H8	120.0	C22—C17—C18	110.80 (17)
C9—C8—C7	120.06 (18)	C17—C18—H18A	109.5
C9—C8—H8	120.0	C17—C18—H18B	109.5
C8—C9—H9	120.1	C17—C18—H18C	109.5
C8—C9—C19	119.84 (17)	H18A—C18—H18B	109.5
C19—C9—H9	120.1	H18A—C18—H18C	109.5
O1—C10—H10A	109.5	H18B—C18—H18C	109.5
O1—C10—H10B	109.5	C9—C19—H19	119.9
O1—C10—H10C	109.5	C11—C19—C9	120.24 (17)
H10A—C10—H10B	109.5	C11—C19—H19	119.9
H10A—C10—H10C	109.5	C17—C22—H22A	109.5
H10B—C10—H10C	109.5	C17—C22—H22B	109.5
O1—C11—C6	115.16 (15)	C17—C22—H22C	109.5
O1—C11—C19	124.93 (16)	H22A—C22—H22B	109.5
C19—C11—C6	119.91 (17)	H22A—C22—H22C	109.5
C3—C12—H12	107.5	H22B—C22—H22C	109.5

O1—C11—C19—C9	−179.71 (17)	C4—C3—C12—C14	109.98 (19)
O2—N1—C4—C3	97.35 (19)	C4—C16—C17—C18	−102.6 (2)
O2—N1—C4—C16	−83.0 (2)	C4—C16—C17—C22	133.38 (18)
O2—N1—C5—N2	−0.8 (3)	C5—N1—C4—C3	−80.2 (2)
N1—C4—C16—C15	−177.70 (15)	C5—N1—C4—C16	99.5 (2)
N1—C4—C16—C17	1.8 (2)	C5—N2—C6—C7	8.4 (3)
N2—C6—C7—C8	−178.56 (17)	C5—N2—C6—C11	−172.09 (16)
N2—C6—C11—O1	−1.2 (2)	C6—N2—C5—N1	179.54 (16)
N2—C6—C11—C19	179.04 (16)	C6—C7—C8—C9	−1.0 (3)
C1—C2—C3—C4	3.5 (3)	C6—C11—C19—C9	0.0 (3)
C1—C2—C3—C12	−175.00 (17)	C7—C6—C11—O1	178.31 (16)
C1—C15—C16—C4	2.0 (3)	C7—C6—C11—C19	−1.4 (3)
C1—C15—C16—C17	−177.53 (17)	C7—C8—C9—C19	−0.4 (3)
C2—C1—C15—C16	−3.1 (3)	C8—C9—C19—C11	0.9 (3)
C2—C3—C4—N1	175.00 (15)	C10—O1—C11—C6	−173.25 (16)
C2—C3—C4—C16	−4.7 (3)	C10—O1—C11—C19	6.5 (3)
C2—C3—C12—C13	53.0 (2)	C11—C6—C7—C8	1.9 (3)
C2—C3—C12—C14	−71.6 (2)	C12—C3—C4—N1	−6.5 (2)
C3—C4—C16—C15	2.0 (3)	C12—C3—C4—C16	173.79 (16)
C3—C4—C16—C17	−178.50 (16)	C15—C1—C2—C3	0.2 (3)
C4—N1—C5—N2	176.73 (15)	C15—C16—C17—C18	76.9 (2)
C4—C3—C12—C13	−125.41 (18)	C15—C16—C17—C22	−47.1 (2)

Hydrogen-bond geometry (Å, º) top

D—H···A	D—H	H···A	D···A	D—H···A
C9—H9···O2ⁱ	0.95	2.39	3.337 (2)	174
C14—H14C···O2ⁱⁱ	0.98	2.47	3.445 (2)	172

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

Acknowledgements

The authors would like to thank the University of KwaZulu Natal for the research facilities.

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