supplementary materials


hg5344 scheme

Acta Cryst. (2013). E69, m551-m552    [ doi:10.1107/S1600536813025105 ]

Bis{[mu]-2-methoxy-6-[(methylimino)methyl]phenolato}bis({2-methoxy-6-[(methylimino)methyl]phenolato}copper(II))

T. V. Sydoruk, E. A. Buvaylo, V. N. Kokozay, O. Y. Vassilyeva and B. W. Skelton

Abstract top

The title compound, [Cu2(C9H10NO2)4], is built of discrete centrosymmetric dimers. The CuII atoms are each five coordinated by two deprotonated Schiff base ligands that are bonded differently to the metal atoms. Of the two phenolate O atoms, one is coordinated to one CuII atom, whereas another bridges the two metal atoms. The basal plane of the square pyramid around CuII atoms is formed by the imino N and phenolate O atoms of the bidentate and the monodentate/bidentate Schiff base ligands. The bridging phenolate oxygen occupies the apical position of the coordination sphere with a considerably longer Cu-O bond length. In the crystal, the dimeric molecules pack relative to each other in such a way that the Cu2O2 planes of adjacent dimers are orthogonal.

Comment top

The Schiff base ligand 2-methoxy-6-iminomethylphenol (HL) (Chatziefthimiou et al. 2006) with various connectivity fashions is usually used as a multidentate linker between several metal centres thus affording electronic and magnetic exchanges. [Ni7], [Zn7] (Meally et al., 2010), [Co7] (Meally et al., 2012) and [Mn7] (Zhang et al., 2010) complexes of HL (singly deprotonated at the phenolate site) with planar hexagonal disc-like cores which possess double-bowl metallocalix[6]arene topologies have shown to act as host cavities accommodating numerous guest solvent molecules.

The Schiff base, a bright yellow crystalline solid, is usually obtained by the standard method of condensation of the substituted salicylaldehyde with aqueous solution of methylamine in methanol (Meally et al., 2010). In the present work, we used a mixture of 2-hydroxy-3-methoxy-benzaldehyde and methylamine hydrochloride to react with copper powder and transition metal salt, NiCl2.6H2O, in an attempt to prepare a heterometallic complex with HL ligand. Details of the used synthetic approach as well as its applications were given by Chygorin et al. (2012a) and Chygorin et al. (2012b). However, the monometallic [Cu2L4] 1 was isolated instead. As there is no evidence of the influence of NiCl2.6H2O on the formation of 1 it can be presumed that the given copper complex may be synthesized starting from metallic copper or copper salt as well. To the best of our knowledge no copper complexes of HL have been structurally characterized.

The molecular structure of 1 consists of discrete centrosymmetric dimers [Cu2L4] (Fig. 1). The copper atoms are five coordinated each by two deprotonated Schiff base ligands that are bonded differently to the metal centres. Of the two phenolate oxygen atoms, O21 is coordinated to one copper atom, whereas O11 bridges the two metal centres. The basal plane of the square pyramid around copper atoms is formed by the coordination of the imino nitrogen, N27, and phenolate oxygen, O21, atoms of the bidentate Schiff base ligand and N17 and O11 donor atoms of the tridentate L with Cu–O/N distances in the range 1.9044 (7)–2.0032 (8) Å (Table 1). The bridging phenolate oxygen O11{-x + 1,-y + 1,-z + 1} occupies the apical position of the coordination sphere with the bond distance of 2.4329 (8) Å. The elongation of the apical contact is typical for copper (II) complexes. The trans angles at the metal atom are equal to 169.53 (3) and 175.12 (3)°, the cis angles vary from 79.17 (3) to 105.57 (3)°. The deviation of the copper(II) ion from the basal plane is 0.13 Å. The bridge angle Cu1–O11–Cu1{-x + 1,-y + 1,-z + 1} involving the phenolate oxygen is 100.8 (2)°, the separation between the metal centres is about 3.37 Å.

In the crystal lattice, the dimeric molecules pack relative to each other in such a way that Cu2O2 planes of the adjacent dimers are orthogonal (Fig. 2).

Related literature top

For direct synthesis using metal powders and Schiff base ligands, see: Chygorin et al. (2012a,b) and references therein. For the structure of the Schiff base ligand 2-methoxy-6-iminomethylphenol, see: Chatziefthimiou et al. (2006). For structures of metal complexes of the Schiff base ligand, see: Meally et al. (2010, 2012); Zhang & Feng (2010).

Experimental top

2-Hydroxy-3-methoxy-benzaldehyde (0.30 g, 2 mmol), CH3NH2.HCl (0.14 g, 2 mmol), NEt3 (0.3 ml, 2 mmol) were added to 20 ml of methanol and stirred magnetically for 30 min. After that copper powder (0.06 g, 1 mmol) and NiCl2.6H2O (0.23 g, 1 mmol) were added to the yellow solution and the mixture was heated to 323 K under stirring for an hour. The resulting green solution was filtered and allowed to stand at room temperature. Dark-green rhombic plates of the title compound were formed next day. They were collected by filter-suction, washed with dry PriOH and finally dried in vacuo (yield: 32%).

Refinement top

Hydrogen atoms were placed at idealized positions (C–H = 0.95 Å, UisoH = 1.2Ueq C for CH, 0.98 Å, 1.5Ueq C for CH3) and refined as part of riding models.

Computing details top

Data collection: CrysAlis PRO (Agilent, 2011); cell refinement: CrysAlis PRO (Agilent, 2011); data reduction: CrysAlis PRO (Agilent, 2011); program(s) used to solve structure: SIR92 (Altomare et al., 1994); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: ORTEPII (Johnson, 1976); software used to prepare material for publication: WinGX (Farrugia, 2012).

Figures top
[Figure 1] Fig. 1. Molecular structure of the complex with the numbering scheme (the non-hydrogen atoms shown as 30% thermal ellipsoids). Symmetry code: (i) -x + 1, -y + 1, -z + 1.
[Figure 2] Fig. 2. Packing diagram viewed down the c axis (CH and CH3 hydrogen atoms were omitted for clarity).
Bis{µ-2-methoxy-6-[(methylimino)methyl]phenolato}bis({2-methoxy-6-[(methylimino)methyl]phenolato}copper(II)) top
Crystal data top
[Cu2(C9H10NO2)4]F(000) = 1624
Mr = 783.8Dx = 1.554 Mg m3
Orthorhombic, PbcaMo Kα radiation, λ = 0.71073 Å
Hall symbol: -p 2ac 2abCell parameters from 25414 reflections
a = 10.1889 (12) Åθ = 3.7–37.4°
b = 15.2033 (5) ŵ = 1.33 mm1
c = 21.6254 (9) ÅT = 100 K
V = 3349.9 (4) Å3Plate, dark green
Z = 40.59 × 0.47 × 0.10 mm
Data collection top
Oxford Diffraction Gemini
diffractometer
8673 independent reflections
Graphite monochromator7021 reflections with I > 2σ(I)
Detector resolution: 10.4738 pixels mm-1Rint = 0.045
ω scansθmax = 37.5°, θmin = 3.7°
Absorption correction: analytical
[CrysAlis PRO (Agilent, 2011) based on Clark & Reid (1995)]
h = 1717
Tmin = 0.597, Tmax = 0.88k = 2525
110425 measured reflectionsl = 3636
Refinement top
Refinement on F2Primary atom site location: structure-invariant direct methods
Least-squares matrix: fullSecondary atom site location: difference Fourier map
R[F2 > 2σ(F2)] = 0.031Hydrogen site location: inferred from neighbouring sites
wR(F2) = 0.084H-atom parameters constrained
S = 1.05 w = 1/[σ2(Fo2) + (0.0415P)2 + 0.9858P]
where P = (Fo2 + 2Fc2)/3
8673 reflections(Δ/σ)max = 0.004
231 parametersΔρmax = 0.64 e Å3
0 restraintsΔρmin = 0.37 e Å3
Crystal data top
[Cu2(C9H10NO2)4]V = 3349.9 (4) Å3
Mr = 783.8Z = 4
Orthorhombic, PbcaMo Kα radiation
a = 10.1889 (12) ŵ = 1.33 mm1
b = 15.2033 (5) ÅT = 100 K
c = 21.6254 (9) Å0.59 × 0.47 × 0.10 mm
Data collection top
Oxford Diffraction Gemini
diffractometer
8673 independent reflections
Absorption correction: analytical
[CrysAlis PRO (Agilent, 2011) based on Clark & Reid (1995)]
7021 reflections with I > 2σ(I)
Tmin = 0.597, Tmax = 0.88Rint = 0.045
110425 measured reflectionsθmax = 37.5°
Refinement top
R[F2 > 2σ(F2)] = 0.031H-atom parameters constrained
wR(F2) = 0.084Δρmax = 0.64 e Å3
S = 1.05Δρmin = 0.37 e Å3
8673 reflectionsAbsolute structure: ?
231 parametersAbsolute structure parameter: ?
0 restraintsRogers parameter: ?
Special details top

Geometry. All s.u.'s (except the s.u. in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell s.u.'s are taken into account individually in the estimation of s.u.'s in distances, angles and torsion angles; correlations between s.u.'s in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell s.u.'s is used for estimating s.u.'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 > 2σ(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 (Å2) top
xyzUiso*/Ueq
Cu10.402856 (11)0.587478 (7)0.514407 (5)0.01235 (3)
C110.32361 (9)0.46134 (6)0.42192 (4)0.01446 (14)
O110.42030 (7)0.50521 (5)0.44728 (3)0.01630 (12)
C120.33769 (10)0.43410 (6)0.35910 (4)0.01654 (15)
O120.45029 (8)0.46267 (6)0.33152 (3)0.02223 (15)
C1210.47672 (13)0.43092 (8)0.27121 (5)0.0262 (2)
H12A0.48140.36650.2720.039*
H12B0.56060.45480.25670.039*
H12C0.40640.44940.24310.039*
C130.24123 (11)0.38471 (7)0.33053 (5)0.02007 (17)
H130.25220.36680.28880.024*
C140.12726 (12)0.36098 (7)0.36284 (5)0.02237 (19)
H140.06140.32690.3430.027*
C150.11093 (10)0.38700 (7)0.42308 (5)0.01978 (17)
H150.03370.37050.44480.024*
C160.20753 (9)0.43801 (6)0.45312 (4)0.01527 (15)
C170.18368 (9)0.46319 (6)0.51653 (4)0.01637 (15)
H170.11140.43620.53670.02*
N170.25120 (8)0.51886 (5)0.54829 (4)0.01518 (13)
C180.21142 (10)0.53316 (7)0.61269 (4)0.01945 (17)
H18A0.13790.49420.62280.029*
H18B0.18430.59450.61810.029*
H18C0.28550.52040.64020.029*
C210.44917 (9)0.73470 (6)0.59567 (4)0.01441 (14)
O210.37172 (7)0.67187 (5)0.57781 (4)0.01810 (13)
C220.41886 (9)0.78000 (6)0.65201 (4)0.01576 (15)
O220.30820 (7)0.75006 (5)0.68125 (3)0.01921 (13)
C2210.25933 (13)0.80269 (8)0.73029 (5)0.0256 (2)
H22A0.32140.80150.76490.038*
H22B0.17430.77960.7440.038*
H22C0.24850.86340.71590.038*
C230.49660 (11)0.84784 (6)0.67335 (5)0.01998 (17)
H230.47450.87670.71090.024*
C240.60788 (11)0.87448 (7)0.64016 (5)0.0236 (2)
H240.66150.92090.65520.028*
C250.63872 (11)0.83310 (7)0.58585 (5)0.02131 (18)
H250.71410.85130.56340.026*
C260.56052 (9)0.76367 (6)0.56242 (4)0.01585 (15)
C270.58954 (9)0.73111 (7)0.50142 (5)0.01682 (16)
H270.66030.75820.48010.02*
N270.52864 (8)0.66860 (5)0.47287 (4)0.01607 (14)
C280.56176 (12)0.65605 (7)0.40743 (5)0.02199 (19)
H28A0.63560.69430.39640.033*
H28B0.48560.6710.38180.033*
H28C0.58620.59450.40030.033*
Atomic displacement parameters (Å2) top
U11U22U33U12U13U23
Cu10.01144 (5)0.01349 (5)0.01214 (5)0.00031 (3)0.00112 (3)0.00053 (3)
C110.0148 (3)0.0148 (3)0.0138 (3)0.0015 (3)0.0024 (3)0.0005 (3)
O110.0141 (3)0.0204 (3)0.0145 (3)0.0013 (2)0.0003 (2)0.0039 (2)
C120.0177 (4)0.0175 (4)0.0145 (4)0.0035 (3)0.0022 (3)0.0015 (3)
O120.0198 (3)0.0319 (4)0.0149 (3)0.0009 (3)0.0021 (3)0.0060 (3)
C1210.0323 (6)0.0315 (5)0.0147 (4)0.0057 (4)0.0027 (4)0.0042 (4)
C130.0247 (4)0.0186 (4)0.0169 (4)0.0022 (3)0.0059 (3)0.0037 (3)
C140.0264 (5)0.0189 (4)0.0218 (4)0.0045 (4)0.0071 (4)0.0014 (3)
C150.0209 (4)0.0183 (4)0.0201 (4)0.0050 (3)0.0040 (3)0.0008 (3)
C160.0156 (4)0.0148 (3)0.0153 (4)0.0013 (3)0.0022 (3)0.0011 (3)
C170.0159 (4)0.0165 (4)0.0167 (4)0.0024 (3)0.0003 (3)0.0023 (3)
N170.0148 (3)0.0170 (3)0.0137 (3)0.0011 (3)0.0009 (2)0.0004 (3)
C180.0201 (4)0.0232 (4)0.0151 (4)0.0040 (3)0.0041 (3)0.0008 (3)
C210.0138 (3)0.0128 (3)0.0166 (4)0.0005 (3)0.0003 (3)0.0008 (3)
O210.0164 (3)0.0173 (3)0.0206 (3)0.0037 (2)0.0050 (2)0.0050 (2)
C220.0177 (4)0.0136 (3)0.0160 (4)0.0016 (3)0.0013 (3)0.0010 (3)
O220.0204 (3)0.0189 (3)0.0183 (3)0.0008 (3)0.0036 (2)0.0030 (2)
C2210.0350 (6)0.0231 (5)0.0187 (4)0.0054 (4)0.0062 (4)0.0026 (4)
C230.0256 (5)0.0150 (4)0.0193 (4)0.0008 (3)0.0057 (3)0.0003 (3)
C240.0269 (5)0.0191 (4)0.0248 (5)0.0074 (4)0.0070 (4)0.0022 (4)
C250.0197 (4)0.0198 (4)0.0244 (5)0.0064 (3)0.0025 (3)0.0046 (3)
C260.0145 (3)0.0147 (3)0.0184 (4)0.0011 (3)0.0010 (3)0.0028 (3)
C270.0145 (4)0.0166 (4)0.0194 (4)0.0007 (3)0.0023 (3)0.0042 (3)
N270.0162 (3)0.0158 (3)0.0162 (3)0.0018 (3)0.0034 (3)0.0028 (3)
C280.0268 (5)0.0220 (4)0.0172 (4)0.0019 (4)0.0078 (4)0.0030 (3)
Geometric parameters (Å, º) top
Cu1—O211.9044 (7)C18—H18A0.98
Cu1—O111.9243 (7)C18—H18B0.98
Cu1—N271.9925 (8)C18—H18C0.98
Cu1—N172.0032 (8)C21—O211.2979 (11)
Cu1—O11i2.4329 (8)C21—C261.4135 (13)
C11—O111.3101 (11)C21—C221.4333 (13)
C11—C161.4071 (13)C22—O221.3705 (12)
C11—C121.4274 (13)C22—C231.3799 (14)
O11—Cu1i2.4329 (8)O22—C2211.4187 (13)
C12—O121.3640 (13)C221—H22A0.98
C12—C131.3825 (14)C221—H22B0.98
O12—C1211.4165 (13)C221—H22C0.98
C121—H12A0.98C23—C241.4017 (16)
C121—H12B0.98C23—H230.95
C121—H12C0.98C24—C251.3689 (17)
C13—C141.4026 (16)C24—H240.95
C13—H130.95C25—C261.4163 (14)
C14—C151.3716 (15)C25—H250.95
C14—H140.95C26—C271.4396 (14)
C15—C161.4115 (14)C27—N271.2922 (14)
C15—H150.95C27—H270.95
C16—C171.4444 (14)N27—C281.4673 (13)
C17—N171.2890 (12)C28—H28A0.98
C17—H170.95C28—H28B0.98
N17—C181.4667 (13)C28—H28C0.98
O21—Cu1—O11175.12 (3)N17—C18—H18A109.5
O21—Cu1—N2790.84 (3)N17—C18—H18B109.5
O11—Cu1—N2790.16 (3)H18A—C18—H18B109.5
O21—Cu1—N1787.65 (3)N17—C18—H18C109.5
O11—Cu1—N1790.50 (3)H18A—C18—H18C109.5
N27—Cu1—N17169.53 (3)H18B—C18—H18C109.5
O21—Cu1—O11i105.57 (3)O21—C21—C26124.47 (9)
O11—Cu1—O11i79.17 (3)O21—C21—C22118.40 (8)
N27—Cu1—O11i92.04 (3)C26—C21—C22117.11 (8)
N17—Cu1—O11i98.34 (3)C21—O21—Cu1127.51 (6)
O11—C11—C16124.03 (8)O22—C22—C23124.49 (9)
O11—C11—C12118.08 (9)O22—C22—C21114.20 (8)
C16—C11—C12117.89 (8)C23—C22—C21121.32 (9)
C11—O11—Cu1125.26 (6)C22—O22—C221116.50 (8)
C11—O11—Cu1i113.86 (6)O22—C221—H22A109.5
Cu1—O11—Cu1i100.84 (3)O22—C221—H22B109.5
O12—C12—C13125.13 (9)H22A—C221—H22B109.5
O12—C12—C11114.10 (8)O22—C221—H22C109.5
C13—C12—C11120.76 (9)H22A—C221—H22C109.5
C12—O12—C121117.00 (9)H22B—C221—H22C109.5
O12—C121—H12A109.5C22—C23—C24120.60 (10)
O12—C121—H12B109.5C22—C23—H23119.7
H12A—C121—H12B109.5C24—C23—H23119.7
O12—C121—H12C109.5C25—C24—C23119.49 (10)
H12A—C121—H12C109.5C25—C24—H24120.3
H12B—C121—H12C109.5C23—C24—H24120.3
C12—C13—C14120.37 (9)C24—C25—C26121.35 (10)
C12—C13—H13119.8C24—C25—H25119.3
C14—C13—H13119.8C26—C25—H25119.3
C15—C14—C13119.97 (10)C21—C26—C25120.12 (9)
C15—C14—H14120C21—C26—C27121.59 (9)
C13—C14—H14120C25—C26—C27117.94 (9)
C14—C15—C16120.73 (10)N27—C27—C26126.30 (9)
C14—C15—H15119.6N27—C27—H27116.8
C16—C15—H15119.6C26—C27—H27116.8
C11—C16—C15120.26 (9)C27—N27—C28116.49 (9)
C11—C16—C17122.00 (8)C27—N27—Cu1123.28 (7)
C15—C16—C17117.72 (9)C28—N27—Cu1120.15 (7)
N17—C17—C16126.16 (9)N27—C28—H28A109.5
N17—C17—H17116.9N27—C28—H28B109.5
C16—C17—H17116.9H28A—C28—H28B109.5
C17—N17—C18117.11 (8)N27—C28—H28C109.5
C17—N17—Cu1123.97 (7)H28A—C28—H28C109.5
C18—N17—Cu1118.90 (6)H28B—C28—H28C109.5
Symmetry code: (i) x+1, y+1, z+1.

Experimental details

Crystal data
Chemical formula[Cu2(C9H10NO2)4]
Mr783.8
Crystal system, space groupOrthorhombic, Pbca
Temperature (K)100
a, b, c (Å)10.1889 (12), 15.2033 (5), 21.6254 (9)
V3)3349.9 (4)
Z4
Radiation typeMo Kα
µ (mm1)1.33
Crystal size (mm)0.59 × 0.47 × 0.10
Data collection
DiffractometerOxford Diffraction Gemini
diffractometer
Absorption correctionAnalytical
[CrysAlis PRO (Agilent, 2011) based on Clark & Reid (1995)]
Tmin, Tmax0.597, 0.88
No. of measured, independent and
observed [I > 2σ(I)] reflections
110425, 8673, 7021
Rint0.045
(sin θ/λ)max1)0.856
Refinement
R[F2 > 2σ(F2)], wR(F2), S 0.031, 0.084, 1.05
No. of reflections8673
No. of parameters231
No. of restraints0
H-atom treatmentH-atom parameters constrained
Δρmax, Δρmin (e Å3)0.64, 0.37

Computer programs: CrysAlis PRO (Agilent, 2011), SIR92 (Altomare et al., 1994), SHELXL97 (Sheldrick, 2008), ORTEPII (Johnson, 1976), WinGX (Farrugia, 2012).

Selected geometric parameters (Å, º) top
Cu1—O211.9044 (7)Cu1—N172.0032 (8)
Cu1—O111.9243 (7)Cu1—O11i2.4329 (8)
Cu1—N271.9925 (8)
O21—Cu1—O11175.12 (3)N27—Cu1—N17169.53 (3)
O21—Cu1—N2790.84 (3)O21—Cu1—O11i105.57 (3)
O11—Cu1—N2790.16 (3)O11—Cu1—O11i79.17 (3)
O21—Cu1—N1787.65 (3)N27—Cu1—O11i92.04 (3)
O11—Cu1—N1790.50 (3)N17—Cu1—O11i98.34 (3)
Symmetry code: (i) x+1, y+1, z+1.
Acknowledgements top

This work was partly supported by the State Fund for Fundamental Researches of Ukraine (project 54.3/005). The authors acknowledge the facilities, scientific and technical assistance of the Australian Microscopy & Microanalysis Research Facility at the Centre for Microscopy, Characterization & Analysis, the University of Western Australia, a facility funded by the University, State and Commonwealth Governments.

references
References top

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