Bis{2-[(E)-benzyl­imino­meth­yl]-4-methyl­phenolato-κ² N,O}nickel(II)

Abstract

In the title complex, [Ni(C₁₅H₁₄NO)₂], the Ni^II atom is located on an inversion centre and is coordinated by two O and two N atoms from two symmetry-related bidentate Schiff base ligands in a slightly distorted square-planar geometry. The phenyl and benzene rings in the ligand mol­ecule form a dihedral angle of 72.79 (8)°.

Related literature

For the synthesis of 2-[(E)-(benzyl­imino)meth­yl]-4-methyl­phenol, see: Cohen et al. (1964 ▶). For the structure of a related Zn complex, see: Rodriguez de Barbarin et al. (1994 ▶).

Experimental

Crystal data

• [Ni(C₁₅H₁₄NO)₂]

• M _r = 507.26

• Monoclinic,

• a = 13.7182 (15) Å

• b = 10.5842 (11) Å

• c = 8.6716 (9) Å

• β = 107.593 (1)°

• V = 1200.2 (2) ų

• Z = 2

• Mo Kα radiation

• μ = 0.84 mm⁻¹

• T = 296 K

• 0.37 × 0.29 × 0.24 mm

Data collection

• Bruker SMART APEXII diffractometer

• Absorption correction: multi-scan (SADABS; Sheldrick, 2000 ▶) T _min = 0.751, T _max = 0.819

• 10296 measured reflections

• 2765 independent reflections

• 2303 reflections with I > 2σ(I)

• R _int = 0.029

Refinement

• R[F ² > 2σ(F ²)] = 0.030

• wR(F ²) = 0.081

• S = 1.04

• 2765 reflections

• 161 parameters

• H-atom parameters constrained

• Δρ_max = 0.35 e Å⁻³

• Δρ_min = −0.24 e Å⁻³

Data collection: APEX2 (Bruker, 2007 ▶); cell refinement: SAINT (Bruker, 2007 ▶); data reduction: SAINT; 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.

Supplementary Material

Additional supplementary materials: crystallographic information; 3D view; checkCIF report

Enhanced figure: interactive version of Fig. 1

Table 1. Selected geometric parameters (Å, °).

Ni1—O1	1.8294 (12)
Ni1—N1	1.9242 (14)

O1i—Ni1—N1	87.01 (6)
O1—Ni1—N1	92.99 (6)

Symmetry code: (i) .

supplementary crystallographic information

Comment

Schiff bases have played an important role in the development of coordination chemistry as they readily form stable complexes with most of the transition metals (Rodriguez de Barbarin et al., 1994). Salicylaldehyde and its derivatives are useful carbonyl precursors for the synthesis of a large variety of Schiff bases. Here we report on a new Ni(II) complex, (I).

The molecular structure of (I) as illustrated in Fig. 1 has the Ni²⁺ center in a square geometry as it its coordinated by two O atoms and two N atoms from two 2-[(E)-(benzylimino)methyl]-4-methylphenol bidentate chelating ligands. The bond lengths and bond angles in (I) are within normal ranges. The Ni1—O1 distance of 1.8294 (12) Å is shorter than the distance of Ni1—N1 [1.9242 (14) Å] (Table 1). The dihedral angle between the plane of O1/N1/Ni1 and the adjacent phenol ring is 10.91 (9)°.

Experimental

1 mmol of NiCl₂.6H₂O (0.240 g) were added to a 15 ml ethanol solution containing 2 mmol (0.450 g) 2-[(E)-(benzylimino)methyl]-4-methylphenol. The resulting mixture was stirred for about 0.5 h. The slow vaporization of the solvent yielded after about 6 d dark green single crystals. Yield: 70.2%. Calcd. for C₃₀H₂₈NiN₂O₂: C 71.03, H 5.56, N 5.52; Found: C 71.34, H 5.60, N 5.46%.

Synthesis of the ligand 2-[(E)-(benzylimino)methyl]-4-methylphenol: Phenylmethanamine and 5-methylsalicylaldehyde (1:1) were dissolved in ethanol and the solution was refluxed for 3 h. After evaporation, a crude product was recrystallized twice from ethanol to give a pure yellow product (Cohen et al., 1964).

Refinement

All H atoms were located in a difference Fourier map. H atoms of the C—H groups were then placed in geometrically idealized positions and constrained to ride on their parent atoms with C—H = 0.93, 0.96 or 0.97 Å, and with U_iso(H) = 1.2U_eq(C).

Figures

Fig. 1.

The structure of (I), showing displacement ellipsoids drawn at the 30% probability level [symmetry code: (A) -x + 2, -y + 1, -z].

Crystal data

[Ni(C15H14NO)2]	F(000) = 532.0
Mr = 507.26	Dx = 1.404 Mg m−3
Monoclinic, P21/c	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2ybc	Cell parameters from 3741 reflections
a = 13.7182 (15) Å	θ = 3.1–27.5°
b = 10.5842 (11) Å	µ = 0.84 mm−1
c = 8.6716 (9) Å	T = 296 K
β = 107.593 (1)°	Block, dark green
V = 1200.2 (2) Å3	0.37 × 0.28 × 0.24 mm
Z = 2

Data collection

Bruker SMART APEXII diffractometer	2765 independent reflections
Radiation source: fine-focus sealed tube	2303 reflections with I > 2σ(I)
graphite	Rint = 0.029
φ and ω scans	θmax = 27.5°, θmin = 2.5°
Absorption correction: multi-scan (SADABS; Sheldrick, 2000)	h = −16→17
Tmin = 0.751, Tmax = 0.819	k = −13→12
10296 measured reflections	l = −11→11

Refinement

Refinement on F2	Primary atom site location: structure-invariant direct methods
Least-squares matrix: full	Secondary atom site location: difference Fourier map
R[F2 > 2σ(F2)] = 0.030	Hydrogen site location: inferred from neighbouring sites
wR(F2) = 0.081	H-atom parameters constrained
S = 1.04	w = 1/[σ2(Fo2) + (0.0383P)2 + 0.6191P] where P = (Fo2 + 2Fc2)/3
2765 reflections	(Δ/σ)max = 0.001
161 parameters	Δρmax = 0.35 e Å−3
0 restraints	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.

Refinement. Refinement of F2 against ALL reflections. The weighted R-factor wR and goodness of fit S are based on F2, conventional R-factors R are based on F, with F set to zero for negative F2. The threshold expression of F2 > σ(F2) is used only for calculating R-factors(gt) etc. and is not relevant to the choice of reflections for refinement. R-factors based on F2 are statistically about twice as large as those based on F, and R- factors based on ALL data will be even larger.

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

	x	y	z	Uiso*/Ueq
Ni1	1.0000	0.5000	0.0000	0.01763 (10)
O1	1.13609 (9)	0.46366 (12)	0.08566 (15)	0.0256 (3)
N1	1.01028 (10)	0.65072 (13)	0.12801 (16)	0.0188 (3)
C1	1.31316 (14)	0.49471 (18)	0.1963 (2)	0.0264 (4)
H1A	1.3255	0.4178	0.1538	0.032*
C2	1.39446 (14)	0.56674 (19)	0.2854 (2)	0.0283 (4)
H2A	1.4606	0.5370	0.3017	0.034*
C3	1.38044 (13)	0.68377 (19)	0.3525 (2)	0.0282 (4)
C4	1.28159 (13)	0.72439 (18)	0.3268 (2)	0.0257 (4)
H4A	1.2704	0.8009	0.3714	0.031*
C5	1.19653 (12)	0.65377 (16)	0.23490 (19)	0.0205 (3)
C6	1.21133 (13)	0.53616 (17)	0.16842 (19)	0.0215 (3)
C7	1.47135 (16)	0.7606 (2)	0.4500 (3)	0.0432 (5)
H7A	1.4488	0.8236	0.5112	0.065*
H7B	1.5029	0.8009	0.3781	0.065*
H7C	1.5199	0.7058	0.5225	0.065*
C8	1.09560 (13)	0.70026 (16)	0.21563 (19)	0.0207 (3)
H8A	1.0906	0.7736	0.2718	0.025*
C9	0.91662 (12)	0.71815 (15)	0.13304 (19)	0.0200 (3)
H9A	0.8749	0.7359	0.0232	0.024*
H9B	0.9361	0.7984	0.1878	0.024*
C10	0.85332 (12)	0.64504 (15)	0.21800 (18)	0.0184 (3)
C11	0.89270 (13)	0.54673 (16)	0.3250 (2)	0.0211 (3)
H11A	0.9600	0.5209	0.3427	0.025*
C12	0.83210 (14)	0.48676 (17)	0.4056 (2)	0.0257 (4)
H12A	0.8592	0.4209	0.4766	0.031*
C13	0.73212 (15)	0.52398 (18)	0.3814 (2)	0.0288 (4)
H13A	0.6919	0.4838	0.4359	0.035*
C14	0.69245 (14)	0.6218 (2)	0.2752 (2)	0.0314 (4)
H14A	0.6252	0.6477	0.2584	0.038*
C15	0.75229 (13)	0.68172 (18)	0.1936 (2)	0.0258 (4)
H15A	0.7246	0.7470	0.1219	0.031*

Atomic displacement parameters (Ų)

	U11	U22	U33	U12	U13	U23
Ni1	0.01551 (16)	0.01832 (17)	0.01976 (15)	−0.00024 (12)	0.00637 (11)	−0.00090 (11)
O1	0.0169 (6)	0.0255 (7)	0.0320 (7)	0.0001 (5)	0.0037 (5)	−0.0069 (5)
N1	0.0184 (7)	0.0189 (7)	0.0210 (6)	0.0005 (5)	0.0087 (5)	0.0025 (5)
C1	0.0206 (9)	0.0296 (10)	0.0299 (9)	0.0024 (7)	0.0089 (7)	−0.0021 (7)
C2	0.0169 (8)	0.0387 (11)	0.0307 (9)	−0.0013 (8)	0.0092 (7)	0.0004 (8)
C3	0.0205 (9)	0.0366 (11)	0.0276 (9)	−0.0085 (8)	0.0073 (7)	−0.0024 (8)
C4	0.0247 (9)	0.0262 (10)	0.0278 (8)	−0.0048 (7)	0.0103 (7)	−0.0020 (7)
C5	0.0182 (8)	0.0229 (9)	0.0211 (7)	−0.0031 (6)	0.0072 (6)	0.0012 (6)
C6	0.0194 (8)	0.0247 (9)	0.0208 (8)	−0.0026 (6)	0.0066 (6)	0.0005 (6)
C7	0.0231 (10)	0.0525 (14)	0.0527 (12)	−0.0122 (10)	0.0094 (9)	−0.0174 (11)
C8	0.0239 (9)	0.0184 (8)	0.0222 (8)	−0.0025 (6)	0.0103 (7)	0.0003 (6)
C9	0.0195 (8)	0.0176 (8)	0.0240 (8)	0.0026 (6)	0.0082 (6)	0.0013 (6)
C10	0.0197 (8)	0.0184 (8)	0.0181 (7)	0.0005 (6)	0.0074 (6)	−0.0023 (6)
C11	0.0194 (8)	0.0215 (8)	0.0231 (8)	0.0034 (7)	0.0073 (6)	0.0012 (6)
C12	0.0301 (10)	0.0238 (9)	0.0247 (8)	0.0023 (7)	0.0105 (7)	0.0043 (7)
C13	0.0286 (10)	0.0333 (11)	0.0289 (9)	−0.0050 (8)	0.0153 (8)	0.0008 (7)
C14	0.0191 (9)	0.0446 (12)	0.0334 (9)	0.0053 (8)	0.0123 (7)	0.0035 (8)
C15	0.0230 (9)	0.0303 (10)	0.0248 (8)	0.0068 (7)	0.0084 (7)	0.0055 (7)

Geometric parameters (Å, °)

Ni1—O1i	1.8294 (12)	C7—H7A	0.9600
Ni1—O1	1.8294 (12)	C7—H7B	0.9600
Ni1—N1i	1.9242 (14)	C7—H7C	0.9600
Ni1—N1	1.9242 (14)	C8—H8A	0.9300
O1—C6	1.312 (2)	C9—C10	1.511 (2)
N1—C8	1.298 (2)	C9—H9A	0.9700
N1—C9	1.482 (2)	C9—H9B	0.9700
C1—C2	1.379 (3)	C10—C11	1.390 (2)
C1—C6	1.414 (2)	C10—C15	1.392 (2)
C1—H1A	0.9300	C11—C12	1.391 (2)
C2—C3	1.406 (3)	C11—H11A	0.9300
C2—H2A	0.9300	C12—C13	1.381 (3)
C3—C4	1.375 (3)	C12—H12A	0.9300
C3—C7	1.514 (3)	C13—C14	1.383 (3)
C4—C5	1.412 (2)	C13—H13A	0.9300
C4—H4A	0.9300	C14—C15	1.389 (2)
C5—C6	1.412 (2)	C14—H14A	0.9300
C5—C8	1.431 (2)	C15—H15A	0.9300
O1i—Ni1—O1	180.00 (8)	C3—C7—H7C	109.5
O1i—Ni1—N1i	92.99 (6)	H7A—C7—H7C	109.5
O1—Ni1—N1i	87.01 (6)	H7B—C7—H7C	109.5
O1i—Ni1—N1	87.01 (6)	N1—C8—C5	126.80 (16)
O1—Ni1—N1	92.99 (6)	N1—C8—H8A	116.6
N1i—Ni1—N1	180.00 (7)	C5—C8—H8A	116.6
C6—O1—Ni1	129.55 (12)	N1—C9—C10	113.51 (13)
C8—N1—C9	115.13 (14)	N1—C9—H9A	108.9
C8—N1—Ni1	124.64 (12)	C10—C9—H9A	108.9
C9—N1—Ni1	120.22 (10)	N1—C9—H9B	108.9
C2—C1—C6	120.95 (17)	C10—C9—H9B	108.9
C2—C1—H1A	119.5	H9A—C9—H9B	107.7
C6—C1—H1A	119.5	C11—C10—C15	118.58 (15)
C1—C2—C3	122.03 (17)	C11—C10—C9	122.97 (14)
C1—C2—H2A	119.0	C15—C10—C9	118.38 (15)
C3—C2—H2A	119.0	C10—C11—C12	120.43 (16)
C4—C3—C2	117.38 (17)	C10—C11—H11A	119.8
C4—C3—C7	121.88 (18)	C12—C11—H11A	119.8
C2—C3—C7	120.74 (17)	C13—C12—C11	120.70 (16)
C3—C4—C5	122.16 (17)	C13—C12—H12A	119.6
C3—C4—H4A	118.9	C11—C12—H12A	119.6
C5—C4—H4A	118.9	C12—C13—C14	119.18 (17)
C4—C5—C6	120.06 (16)	C12—C13—H13A	120.4
C4—C5—C8	119.30 (16)	C14—C13—H13A	120.4
C6—C5—C8	120.59 (15)	C13—C14—C15	120.46 (16)
O1—C6—C5	123.54 (16)	C13—C14—H14A	119.8
O1—C6—C1	119.03 (16)	C15—C14—H14A	119.8
C5—C6—C1	117.42 (16)	C14—C15—C10	120.65 (16)
C3—C7—H7A	109.5	C14—C15—H15A	119.7
C3—C7—H7B	109.5	C10—C15—H15A	119.7
H7A—C7—H7B	109.5

Symmetry codes: (i) −x+2, −y+1, −z.