metal-organic compounds
Bis[N′-(2-methylpropylidene)-4-(prop-2-en-1-yloxy)benzohydrazidato-κ2N′,O]nickel(II)
aDepartment of Pharmacy, Pabna University of Science and Technology, Pabna-6600, Bangladesh, bDepartment of Chemistry, Rajshahi University, Rajshahi-6205, Bangladesh, cDivision of Applied Chemistry, Graduate School of Natural Science and Technology, Okayama University, 1-1 Tsushima-naka, 3-Chome, Okayama, 700-8530, Japan, dCenter for Environmental Conservation and Research Safety, University of Toyama, 3190 Gofuku, Toyama, 930-8555, Japan, and eDepartment of Chemical and Pharmaceutical Science, University of Trieste, Italy
*Correspondence e-mail: [email protected]
In the mononuclear title complex, [Ni(C14H17N2O2)2], the nickel(II) atom exhibits a slightly distorted square-planar coordination environment with the metal located on a crystallographic center of symmetry that induces a trans configuration of the N,O chelating ligands. In the crystal, weak C—H⋯O and C—H⋯π interactions consolidate the packing.
Keywords: crystal structure; nickel(II) complex; aroylhydrazone ligand.
CCDC reference: 2335124
Structure description
Hydrazone ligands have attracted special attention for their chelating capabilities. The corresponding nickel(II) complexes are of considerable interest since they exhibit a broad spectrum of structure-dependent physiological and pharmacological activities (Al-Qadsy et al., 2021
; Neethu et al., 2021
; Krishnamoorthy et al., 2012
; Yang et al., 2020
).
The title nickel(II) complex crystallizes in the monoclinic space group P21/c with the metal located on an inversion center, so that the comprises a half molecule (Fig. 1
). The NiII atom exhibits a slightly distorted square-planar coordination environment with the chelating ligands in a trans configuration imposed by symmetry. The coordinating enolizable O atom and the azomethine N atom of the deprotonated ligand form a five-membered nearly planar chelate ring (r.m.s. deviation from planarity = 0.0084 Å). The Ni—N1 and Ni—O1 bond lengths of 1.8671 (13) and 1.8382 (11) Å and the chelate angle of 83.64 (5)° are in agreement with those of previously reported complexes (Al-Qadsy et al., 2021
; Khan et al., 2023
, 2025
; Krishnamoorthy et al., 2012
; Neethu et al., 2021
; Yang et al., 2020
), irrespective of the substituents present in the ligand. The C5—O1 bond length of 1.3080 (18) Å lies in between a C—O single and a C=O double bond. The bond lengths N1—C4 of 1.285 (2) Å and N2—C5 of 1.308 (2) Å are indicative of a conjugated system within the —CH=N—N=C—O fragment, even after the deprotonation of its enolized carbonyl O atom. The benzylidene entity (C5–C11) is practically co-planar with the N2O2 coordination plane [dihedral angle of 3.09 (5)°] and also to the allyloxy fragment [7.73 (14)°]. An intramolecular hydrogen bond between a methine group (C4—H4) and the chelating O atom (Table 1
) stabilizes the molecular conformation.
| |||||||||||||||||||||||||||
| Figure 1 The molecular structure of the title complex with displacement ellipsoids drawn at the 50% probability level. Atoms marked with a prime character and all non-labelled atoms are generated by inversion symmetry. [Symmetry code: −x + 1, −y + 1, −z.] |
The packing of the complex molecules is consolidated by a weak intermolecular hydrogen bond between a methylene group (C12—H12A) and the ligating O atom of a neighbouring complex. C—H⋯π interactions between the second H atom of this methylene group and the centroid (Cg3) of the benzyl ring are also observed (Table 1
), while no apparent π–π interactions are present. In the crystal packing (Fig. 2
) the shortest separation of NiII atoms is 8.5593 (2) Å.
| Figure 2 Crystal packing of the title complex with H atoms removed for clarity. |
Synthesis and crystallization
Isobutyraldehyde (0.216 g, 3.0 mmol) in 10 ml of ethanol was added to a 30 ml ethanolic solution of 4-(allyloxy)benzoylhydrazine (0.576 g, 3.0 mmol), followed by refluxing for one h. To this mixture Ni(CH3COO)2·4H2O (0.373 g, 1.5 mmol, in 30 ml) was introduced, and refluxing was prolonged for additional three h. The yellow precipitate formed was then filtered off while hot. Finally, the product was dried and stored in a vacuum desiccator containing anhydrous CaCl2. Single crystals of the nickel(II) complex, suitable for X-ray diffraction, were obtained through gradual evaporation from a mixture of chloroform and toluene (3:1, v/v) over a period of 3 weeks. Yellow crystals, yield: 0.604 g (73%); melting point: 485–487 K. IR data (KBr disc, cm−1): 1606 ν(C=N), 1587 ν(C=C), 997 ν(N—N), 596 ν(M—N), 465 ν(M—O). 1H NMR (CDCl3, 400 MHz), δ: 7.82 (d, 2×2H, C-6, 8, J = 8.8 Hz), 6.85 (d, 2×2H, C-5, 9, J = 8.8 Hz), 6.50 (d, 2×1H, C-11, CH=N, J = 8.0 Hz), 6.4–6.0 (m, 2×1H, C-2, Hc), 5.41 (d, 2×1H, C-1, Ha, J = 17.6 Hz), 5.29 (d, 2×1H, C-1, Hb, J = 10.4 Hz), 4.56 (d, 2×2H, C-3, OCH2, J = 5.6 Hz,), 3.72–3.63 (m, 2×1H, C-12), 1.16 (d, 2×6H, C-13,14, J = 8.4 Hz). HRMS (FAB) calculated for C28H34N4NiO4, [M+H]+: 549.20086, found [M+H]+: 549.20062.
Refinement
Crystal data, data collection, and structure details are summarized in Table 2
.
|
Structural data
CCDC reference: 2335124
contains datablocks I, global. DOI: https://doi.org/10.1107/S2414314625009885/wm4238sup1.cif
Structure factors: contains datablock I. DOI: https://doi.org/10.1107/S2414314625009885/wm4238Isup2.hkl
| [Ni(C14H17N2O2)2] | F(000) = 580 |
| Mr = 549.30 | Dx = 1.343 Mg m−3 |
| Monoclinic, P21/c | Mo Kα radiation, λ = 0.71075 Å |
| a = 12.5241 (3) Å | Cell parameters from 10492 reflections |
| b = 13.4196 (4) Å | θ = 2.3–27.5° |
| c = 8.5593 (2) Å | µ = 0.75 mm−1 |
| β = 109.274 (8)° | T = 173 K |
| V = 1357.91 (9) Å3 | Prism, yellow |
| Z = 2 | 0.22 × 0.11 × 0.07 mm |
| Rigaku R-AXIS RAPID diffractometer | 2678 reflections with I > 2σ(I) |
| ω scans | Rint = 0.031 |
| Absorption correction: multi-scan (ABSCOR; Rigaku, 1995) | θmax = 27.5°, θmin = 2.3° |
| Tmin = 0.722, Tmax = 0.949 | h = −16→16 |
| 12824 measured reflections | k = −17→17 |
| 3106 independent reflections | l = −11→11 |
| Refinement on F2 | 0 restraints |
| Least-squares matrix: full | Hydrogen site location: inferred from neighbouring sites |
| R[F2 > 2σ(F2)] = 0.032 | H-atom parameters constrained |
| wR(F2) = 0.081 | w = 1/[σ2(Fo2) + (0.0388P)2 + 0.5845P] where P = (Fo2 + 2Fc2)/3 |
| S = 1.04 | (Δ/σ)max < 0.001 |
| 3106 reflections | Δρmax = 0.43 e Å−3 |
| 171 parameters | Δρmin = −0.21 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 | ||
| Ni1 | 0.500000 | 0.500000 | 0.000000 | 0.02365 (9) | |
| O1 | 0.40545 (9) | 0.48867 (8) | 0.12389 (13) | 0.0272 (2) | |
| O2 | 0.18732 (9) | 0.38385 (9) | 0.66963 (13) | 0.0302 (3) | |
| N1 | 0.59615 (11) | 0.42033 (10) | 0.16621 (15) | 0.0251 (3) | |
| N2 | 0.55099 (11) | 0.39157 (10) | 0.28959 (16) | 0.0265 (3) | |
| C1 | 0.89710 (15) | 0.35433 (15) | 0.3488 (3) | 0.0423 (4) | |
| H1A | 0.913977 | 0.331595 | 0.250634 | 0.051* | |
| H1B | 0.945166 | 0.318522 | 0.446480 | 0.051* | |
| H1C | 0.911834 | 0.426013 | 0.363773 | 0.051* | |
| C2 | 0.74500 (17) | 0.22294 (14) | 0.3009 (2) | 0.0411 (4) | |
| H2A | 0.798169 | 0.184695 | 0.390729 | 0.049* | |
| H2B | 0.750983 | 0.201381 | 0.194659 | 0.049* | |
| H2C | 0.667728 | 0.211635 | 0.300996 | 0.049* | |
| C3 | 0.77329 (14) | 0.33389 (12) | 0.3261 (2) | 0.0290 (3) | |
| H3 | 0.758739 | 0.355730 | 0.428933 | 0.035* | |
| C4 | 0.69787 (14) | 0.39313 (12) | 0.18425 (19) | 0.0274 (3) | |
| H4 | 0.727860 | 0.412281 | 0.100237 | 0.033* | |
| C5 | 0.45128 (13) | 0.43305 (11) | 0.25439 (18) | 0.0245 (3) | |
| C6 | 0.38466 (13) | 0.41678 (11) | 0.36654 (18) | 0.0239 (3) | |
| C7 | 0.42822 (13) | 0.36377 (12) | 0.51408 (19) | 0.0264 (3) | |
| H7 | 0.502209 | 0.336480 | 0.543159 | 0.032* | |
| C8 | 0.36562 (13) | 0.35007 (12) | 0.61932 (19) | 0.0268 (3) | |
| H8 | 0.396352 | 0.313752 | 0.719449 | 0.032* | |
| C9 | 0.25697 (13) | 0.39030 (11) | 0.57628 (18) | 0.0247 (3) | |
| C10 | 0.21195 (14) | 0.44225 (12) | 0.42783 (19) | 0.0278 (3) | |
| H10 | 0.137429 | 0.468481 | 0.397653 | 0.033* | |
| C11 | 0.27520 (13) | 0.45567 (12) | 0.32482 (19) | 0.0264 (3) | |
| H11 | 0.244144 | 0.491699 | 0.224447 | 0.032* | |
| C12 | 0.22916 (14) | 0.33458 (12) | 0.82672 (19) | 0.0289 (3) | |
| H12A | 0.301977 | 0.364646 | 0.894171 | 0.035* | |
| H12B | 0.242193 | 0.263153 | 0.810353 | 0.035* | |
| C13 | 0.14474 (17) | 0.34507 (15) | 0.9136 (2) | 0.0416 (4) | |
| H13 | 0.160758 | 0.310432 | 1.015534 | 0.050* | |
| C14 | 0.05119 (18) | 0.39645 (17) | 0.8655 (3) | 0.0511 (5) | |
| H14A | 0.030867 | 0.432590 | 0.764502 | 0.061* | |
| H14B | 0.003345 | 0.397763 | 0.931571 | 0.061* |
| U11 | U22 | U33 | U12 | U13 | U23 | |
| Ni1 | 0.02442 (15) | 0.02543 (15) | 0.02219 (15) | 0.00068 (11) | 0.00916 (10) | 0.00268 (11) |
| O1 | 0.0265 (5) | 0.0313 (6) | 0.0251 (5) | 0.0021 (5) | 0.0102 (4) | 0.0048 (4) |
| O2 | 0.0293 (6) | 0.0368 (6) | 0.0278 (6) | 0.0051 (5) | 0.0139 (5) | 0.0085 (5) |
| N1 | 0.0277 (6) | 0.0259 (6) | 0.0237 (6) | 0.0000 (5) | 0.0111 (5) | 0.0009 (5) |
| N2 | 0.0291 (7) | 0.0281 (7) | 0.0253 (6) | 0.0002 (5) | 0.0130 (5) | 0.0033 (5) |
| C1 | 0.0313 (9) | 0.0417 (10) | 0.0533 (11) | 0.0065 (8) | 0.0132 (8) | 0.0076 (9) |
| C2 | 0.0491 (11) | 0.0308 (9) | 0.0409 (10) | 0.0014 (8) | 0.0114 (8) | 0.0049 (8) |
| C3 | 0.0296 (8) | 0.0293 (8) | 0.0288 (8) | 0.0042 (7) | 0.0107 (6) | 0.0013 (6) |
| C4 | 0.0301 (8) | 0.0282 (8) | 0.0263 (7) | 0.0005 (6) | 0.0127 (6) | 0.0008 (6) |
| C5 | 0.0275 (7) | 0.0226 (7) | 0.0234 (7) | −0.0035 (6) | 0.0086 (6) | −0.0016 (6) |
| C6 | 0.0251 (7) | 0.0233 (7) | 0.0240 (7) | −0.0029 (6) | 0.0091 (6) | −0.0001 (6) |
| C7 | 0.0232 (7) | 0.0290 (8) | 0.0268 (7) | 0.0017 (6) | 0.0079 (6) | 0.0013 (6) |
| C8 | 0.0286 (8) | 0.0271 (8) | 0.0243 (7) | 0.0016 (6) | 0.0083 (6) | 0.0044 (6) |
| C9 | 0.0271 (8) | 0.0229 (7) | 0.0260 (7) | −0.0015 (6) | 0.0114 (6) | −0.0002 (6) |
| C10 | 0.0265 (8) | 0.0281 (8) | 0.0292 (8) | 0.0047 (6) | 0.0099 (6) | 0.0042 (6) |
| C11 | 0.0299 (8) | 0.0242 (7) | 0.0251 (7) | 0.0020 (6) | 0.0088 (6) | 0.0042 (6) |
| C12 | 0.0347 (9) | 0.0279 (8) | 0.0251 (7) | 0.0009 (7) | 0.0111 (6) | 0.0040 (6) |
| C13 | 0.0523 (11) | 0.0428 (10) | 0.0383 (10) | 0.0070 (9) | 0.0265 (9) | 0.0117 (8) |
| C14 | 0.0483 (12) | 0.0591 (13) | 0.0584 (13) | 0.0099 (10) | 0.0345 (10) | 0.0159 (10) |
| Ni1—O1i | 1.8382 (11) | C4—H4 | 0.9500 |
| Ni1—O1 | 1.8382 (11) | C5—C6 | 1.481 (2) |
| Ni1—N1i | 1.8671 (13) | C6—C7 | 1.394 (2) |
| Ni1—N1 | 1.8671 (13) | C6—C11 | 1.399 (2) |
| O1—C5 | 1.3080 (18) | C7—C8 | 1.388 (2) |
| O2—C9 | 1.3663 (18) | C7—H7 | 0.9500 |
| O2—C12 | 1.4334 (18) | C8—C9 | 1.396 (2) |
| N1—C4 | 1.285 (2) | C8—H8 | 0.9500 |
| N1—N2 | 1.4065 (17) | C9—C10 | 1.395 (2) |
| N2—C5 | 1.308 (2) | C10—C11 | 1.378 (2) |
| C1—C3 | 1.523 (2) | C10—H10 | 0.9500 |
| C1—H1A | 0.9800 | C11—H11 | 0.9500 |
| C1—H1B | 0.9800 | C12—C13 | 1.486 (2) |
| C1—H1C | 0.9800 | C12—H12A | 0.9900 |
| C2—C3 | 1.529 (2) | C12—H12B | 0.9900 |
| C2—H2A | 0.9800 | C13—C14 | 1.304 (3) |
| C2—H2B | 0.9800 | C13—H13 | 0.9500 |
| C2—H2C | 0.9800 | C14—H14A | 0.9500 |
| C3—C4 | 1.497 (2) | C14—H14B | 0.9500 |
| C3—H3 | 1.0000 | ||
| O1i—Ni1—O1 | 180.0 | O1—C5—N2 | 123.77 (14) |
| O1i—Ni1—N1i | 83.64 (5) | O1—C5—C6 | 117.08 (13) |
| O1—Ni1—N1i | 96.36 (5) | N2—C5—C6 | 119.15 (13) |
| O1i—Ni1—N1 | 96.36 (5) | C7—C6—C11 | 118.63 (14) |
| O1—Ni1—N1 | 83.64 (5) | C7—C6—C5 | 121.78 (14) |
| N1i—Ni1—N1 | 180.0 | C11—C6—C5 | 119.59 (14) |
| C5—O1—Ni1 | 110.80 (10) | C8—C7—C6 | 121.30 (14) |
| C9—O2—C12 | 118.13 (12) | C8—C7—H7 | 119.4 |
| C4—N1—N2 | 117.41 (13) | C6—C7—H7 | 119.4 |
| C4—N1—Ni1 | 128.23 (11) | C7—C8—C9 | 119.21 (14) |
| N2—N1—Ni1 | 114.28 (10) | C7—C8—H8 | 120.4 |
| C5—N2—N1 | 107.47 (12) | C9—C8—H8 | 120.4 |
| C3—C1—H1A | 109.5 | O2—C9—C10 | 114.85 (13) |
| C3—C1—H1B | 109.5 | O2—C9—C8 | 125.18 (13) |
| H1A—C1—H1B | 109.5 | C10—C9—C8 | 119.97 (14) |
| C3—C1—H1C | 109.5 | C11—C10—C9 | 120.22 (14) |
| H1A—C1—H1C | 109.5 | C11—C10—H10 | 119.9 |
| H1B—C1—H1C | 109.5 | C9—C10—H10 | 119.9 |
| C3—C2—H2A | 109.5 | C10—C11—C6 | 120.66 (14) |
| C3—C2—H2B | 109.5 | C10—C11—H11 | 119.7 |
| H2A—C2—H2B | 109.5 | C6—C11—H11 | 119.7 |
| C3—C2—H2C | 109.5 | O2—C12—C13 | 108.98 (13) |
| H2A—C2—H2C | 109.5 | O2—C12—H12A | 109.9 |
| H2B—C2—H2C | 109.5 | C13—C12—H12A | 109.9 |
| C4—C3—C1 | 110.55 (14) | O2—C12—H12B | 109.9 |
| C4—C3—C2 | 110.35 (14) | C13—C12—H12B | 109.9 |
| C1—C3—C2 | 111.84 (15) | H12A—C12—H12B | 108.3 |
| C4—C3—H3 | 108.0 | C14—C13—C12 | 127.31 (17) |
| C1—C3—H3 | 108.0 | C14—C13—H13 | 116.3 |
| C2—C3—H3 | 108.0 | C12—C13—H13 | 116.3 |
| N1—C4—C3 | 125.70 (14) | C13—C14—H14A | 120.0 |
| N1—C4—H4 | 117.1 | C13—C14—H14B | 120.0 |
| C3—C4—H4 | 117.1 | H14A—C14—H14B | 120.0 |
| N1i—Ni1—O1—C5 | 179.15 (10) | N2—C5—C6—C7 | 4.2 (2) |
| N1—Ni1—O1—C5 | −0.84 (10) | O1—C5—C6—C11 | 3.6 (2) |
| O1i—Ni1—N1—C4 | 4.90 (15) | N2—C5—C6—C11 | −176.09 (14) |
| O1—Ni1—N1—C4 | −175.10 (15) | C11—C6—C7—C8 | −0.6 (2) |
| O1i—Ni1—N1—N2 | −178.37 (10) | C5—C6—C7—C8 | 179.14 (14) |
| O1—Ni1—N1—N2 | 1.63 (10) | C6—C7—C8—C9 | 0.0 (2) |
| C4—N1—N2—C5 | 175.12 (14) | C12—O2—C9—C10 | −177.85 (14) |
| Ni1—N1—N2—C5 | −1.98 (15) | C12—O2—C9—C8 | 1.9 (2) |
| N2—N1—C4—C3 | −0.5 (2) | C7—C8—C9—O2 | −178.80 (14) |
| Ni1—N1—C4—C3 | 176.19 (12) | C7—C8—C9—C10 | 0.9 (2) |
| C1—C3—C4—N1 | −154.63 (17) | O2—C9—C10—C11 | 178.54 (14) |
| C2—C3—C4—N1 | 81.1 (2) | C8—C9—C10—C11 | −1.2 (2) |
| Ni1—O1—C5—N2 | −0.14 (19) | C9—C10—C11—C6 | 0.6 (2) |
| Ni1—O1—C5—C6 | −179.85 (10) | C7—C6—C11—C10 | 0.3 (2) |
| N1—N2—C5—O1 | 1.4 (2) | C5—C6—C11—C10 | −179.43 (14) |
| N1—N2—C5—C6 | −178.90 (12) | C9—O2—C12—C13 | 174.40 (14) |
| O1—C5—C6—C7 | −176.10 (14) | O2—C12—C13—C14 | −5.0 (3) |
| Symmetry code: (i) −x+1, −y+1, −z. |
| Cg3 is the centroid of the benzyl ring. |
| D—H···A | D—H | H···A | D···A | D—H···A |
| C4—H4···O1i | 0.95 | 2.47 | 2.9822 (19) | 114 |
| C12—H12A···O1ii | 0.99 | 2.58 | 3.451 (2) | 148 |
| C12—H12B···Cg3iii | 0.99 | 2.64 | 3.4762 (17) | 143 |
| Symmetry codes: (i) −x+1, −y+1, −z; (ii) x, y, z+1; (iii) x, −y+1/2, z+1/2. |
Acknowledgements
MBHH, and SSK are grateful to the Department of Chemistry, Rajshahi University, Rajshahi-6205, Bangladesh for providing laboratory facilities. MCS and RM acknowledge the Center for Environmental Conservation and Research Safety, University of Toyama, for providing facilities for single-crystal X-ray analyses.
References
Al-Qadsy, I., Al-Odayni, A.-B., Saeed, W. S., Alrabie, A., Al-Adhreai, A., Al-Faqeeh, L. A. S., Lama, P., Alghamdi, A. A. & Farooqui, M. (2021). Crystals 11, 110. Google Scholar
Brandenburg, K. & Putz, H. (1999). DIAMOND. Crystal Impact GbR, Bonn, Germany. Google Scholar
Farrugia, L. J. (2012). J. Appl. Cryst. 45, 849–854. Web of Science CrossRef CAS IUCr Journals Google Scholar
Khan, S. S., Howlader, M. B. H., Sheikh, M. C., Miyatake, R. & Zangrando, E. (2023). Acta Cryst. E79, 465–468. Web of Science CSD CrossRef IUCr Journals Google Scholar
Khan, S. S., Howlader, Md. B. H., Sheikh, Md. C., Miyatake, R. & Zangrando, E. (2025). IUCrData 10, x250120. Google Scholar
Krishnamoorthy, P., Sathyadevi, P., Butorac, R. R., Cowley, A. H., Bhuvanesh, N. S. P. & Dharmaraj, N. (2012). Dalton Trans. 41, 4423–4436. Web of Science CSD CrossRef CAS PubMed Google Scholar
Neethu, K. S., Sivaselvam, S., Theetharappan, M., Ranjitha, J., Bhuvanesh, N. S. P., Ponpandian, N., Neelakantan, M. A. & Kaveri, M. V. (2021). Inorg. Chim. Acta 524, 120419. Web of Science CSD CrossRef Google Scholar
Rigaku (1995). ABSCOR. Rigaku Corporation, Tokyo, Japan. Google Scholar
Rigaku (2019). RAPID-AUTO. Rigaku Corporation, Tokyo, Japan. Google Scholar
Sheldrick, G. M. (2015a). Acta Cryst. A71, 3–8. Web of Science CrossRef IUCr Journals Google Scholar
Sheldrick, G. M. (2015b). Acta Cryst. C71, 3–8. Web of Science CrossRef IUCr Journals Google Scholar
Yang, P., Chen, H., Wang, Z.-Z., Zhang, L.-L., Zhang, D.-D., Shi, Q.-S. & Xie, X.-B. (2020). J. Inorg. Biochem. 213, 111248. Web of Science CSD CrossRef PubMed Google Scholar
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