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lr2071 scheme

Acta Cryst. (2012). E68, m1165    [ doi:10.1107/S1600536812032187 ]

Bis(2-hydroxyiminomethyl-6-methoxyphenolato-[kappa]2N,O1)copper(II)

S. R. Petrusenko, Y. I. Belozub, V. N. Kokozay and I. V. Omelchenko

Abstract top

In the title compound, [Cu(C8H8NO3)2], the nearly planar molecule (r.m.s. deviation = 0.037 Å) is centrosymmetric with the CuII atom lying on an inversion center. The CuII atom is tetracoordinated, displaying a slightly distorted square-planar geometry. The main deviation from the ideal geometry is seen in the differences in the Cu-O [1.8833 (10) Å] and Cu-N [1.9405 (13) Å] bond lengths, while angular deviations are less than 3°. Intramolecular O-H...O and intermolecular Csp2-H...O hydrogen bonds form S(5) and R22(8) ring motifs, respectively. The latter interaction results in chains of molecules along [100].

Comment top

Aiming to prepare Cu/Mn heterometallic complexes with an ONO donor Shiff base (H2L = 2-hydroxyiminomethyl-6-methoxyphenol) the following system based on "direct synthesis" methodology (Makhankova, 2011) has been investigated: Cu0 – Mn0o-vianillin– NH2OH.HCl – NH4X – solv (in open air), where o-vainillin = 2-hydroxy-3-methoxybenzaldehyde; X = Cl, Br, I; solv = CH3OH, dymethylformamide(dmf), dymethylsulfoxide(dmso).

In all cases the total dissolution of copper and manganese powders was observed within 5 - 6 h resulting into intensive dark green solutions. X-ray quality crystalls were obtained from the systems with NH4Br in dmso and NH4Cl in dmf, but in the former one the yield was some better.

The asymmetric unit of [Cu(HL)2] includes one-half of the molecule with Cu atom occupying the (1/2 1/2 1/2) special position of multiplicity 2. The coordination geometry of the metal atom is square-planar, with the CuN2O2 chromophore, formed by means of two imine nitrogen atoms and two phenolate oxygen atoms of the two monodeptotonated Schiff base ligands realising their bidentate chelate function, [1.11110] by Harris notation (Coxall et al., 2000) (Fig. 1). Difference between Cu–O and Cu–N bond lengths (Table 1) causes significant linear distortion of the square. Deviations in bond angles at the Cu atom are less than 3°. The bond valence sum analysis applied to the appropriate bond lengths supports the +2 oxidation state for copper, BVS(Cu) = 2.003 (Brown & Altermatt, 1985).

Hydrogen bonds(HBs) play the principal role in the crystal structure of [Cu(HL)2]. The N–OH group takes part in simultaneous formation of a strong intramolecular O(3)–H(3O)···O(1) hydrogen bond with Ophenolate of the second ligand and a weak inter-molecular C(7)–H(7)···O(3)' hydrogen bond with C(sp2)–H group of the neighboring molecule (Fig. 2, Table 2). As a result, two ligands being coordinated to the CuII ion form some analogue of a macrocyclic ligand [R14] based on HBs which binds to the copper center generating two 6-membered (with only covalent bonds) and two 5-membered (with covalent and hydrogen bonds) rings (Fig. 1). It is worth noting that all known structures with H2L, namely Co(HL)2 (Zhang et al., 2008), Ni(HL)2 (Li et al., 2009) and VO(HL)2 (Li et al., 2004), are built in the same manner demonstrating high thermodynamic stability of such structure.

The adjacent molecules join through complementary C–H···O HBs, [R22(8)] synthon, forming one-dimentional stair-like ribbons along (100) direction (Fig. 2).

Related literature top

For related structures, see: Zhang et al. (2008); Li et al. (2004), 2009). For bond-valence-sum calculations, see: Brown & Altermatt (1985). For in situ formation of polydentate ligands, see: Coxall et al. (2000). For background to direct synthesis, see: Makhankova (2011).

Experimental top

Copper powder (0.06 g, 1 mmol), manganese powder (0.05 g, 1 mmol), o-vainillin (0.46 g, 3 mmol), hydroxylamine hydrochloride (0.21 g, mmol) and NH4Br (0.20 g, 2 mmol) were added to 10 ml of dimethylsulfoxide. The mixture was stirred magnetically at 323 – 333 K until total dissolution of metal powders was observed (ca5 h). Goldish-green needle crystals that precipitated after 1 day, were collected by filtration, washed with methanol and dried in air; yield 32% based on Cu. IR(KBr, cm-1): 3080(m), 3057(m), 3006(m), 2959(m), 2936(m), 2834(m), 1649(m), 1598(m), 1554(w), 1510(m), 1468(s), 1451(s), 1353(w), 1332(m), 1302(s), 1247(s), 1216(s), 1195(m), 1101(m), 1081(m), 1018(m), 969(s), 932(w), 863(m), 778(m), 755(m), 735(s), 712(s), 624(m), 575(w), 546(w), 502(w).

Refinement top

Structure was solved by direct method and refined against F2 within anisotropic approximation for all non-hydrogen atoms. All hydrogen atoms were located from difference Fourier map and refined isotropically, except phenyl (H(3) - H(5)) and hydroxyl (H(3O)) H atoms that were allowed to ride on their attached atoms with C—H = 0.93 (1) Å and Uiso(H)= 1.2Ueq(C) for phenyl, and C—H = 0.82 (1) Å and Uiso(H)= 1.5Ueq(C) for hydroxyl H atoms. Coordinates of Cu(1) were constrained to special position (x=0.5000, y=0.5000, z=0.5000).

Computing details top

Data collection: CrysAlis CCD (Oxford Diffraction, 2010); cell refinement: CrysAlis CCD (Oxford Diffraction, 2010); data reduction: CrysAlis RED (Oxford Diffraction, 2010); program(s) used to solve structure: SHELXTL (Sheldrick, 2008); program(s) used to refine structure: SHELXTL (Sheldrick, 2008); molecular graphics: SHELXTL (Sheldrick, 2008); software used to prepare material for publication: publCIF (Westrip, 2010).

Figures top
[Figure 1] Fig. 1. Molecular structure of [Cu(HL)2] with 70% probability displacement elipsoids for non-H atoms. The dashed lines denote hydrogen bonds.
[Figure 2] Fig. 2. Fragment of chain-like alignment of [Cu(HL)2] viewed along the [100] direction.
Bis(2-hydroxyiminomethyl-6-methoxyphenolato-κ2N,O1)copper(II) top
Crystal data top
[Cu(C8H8NO3)2]F(000) = 406
Mr = 395.85Dx = 1.675 Mg m3
Monoclinic, P21/nMo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2ynCell parameters from 2721 reflections
a = 8.4906 (4) Åθ = 3.1–32.2°
b = 4.8997 (2) ŵ = 1.43 mm1
c = 18.9309 (9) ÅT = 293 K
β = 94.906 (4)°Needle, gold–green
V = 784.67 (6) Å30.50 × 0.20 × 0.10 mm
Z = 2
Data collection top
Oxford Diffraction Xcalibur/Sapphire3
diffractometer
2245 independent reflections
Radiation source: Enhance (Mo) X-ray Source1816 reflections with I > 2σ(I)
Graphite monochromatorRint = 0.020
Detector resolution: 16.1827 pixels mm-1θmax = 30.0°, θmin = 3.9°
ω scansh = 1111
Absorption correction: multi-scan
(CrysAlis RED; Oxford Diffraction, 2010)
k = 66
Tmin = 0.535, Tmax = 0.763l = 2626
8497 measured reflections
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)] = 0.028Hydrogen site location: difference Fourier map
wR(F2) = 0.077H atoms treated by a mixture of independent and constrained refinement
S = 1.01 w = 1/[σ2(Fo2) + (0.0486P)2]
where P = (Fo2 + 2Fc2)/3
2245 reflections(Δ/σ)max = 0.001
132 parametersΔρmax = 0.39 e Å3
0 restraintsΔρmin = 0.19 e Å3
11 constraints
Crystal data top
[Cu(C8H8NO3)2]V = 784.67 (6) Å3
Mr = 395.85Z = 2
Monoclinic, P21/nMo Kα radiation
a = 8.4906 (4) ŵ = 1.43 mm1
b = 4.8997 (2) ÅT = 293 K
c = 18.9309 (9) Å0.50 × 0.20 × 0.10 mm
β = 94.906 (4)°
Data collection top
Oxford Diffraction Xcalibur/Sapphire3
diffractometer
2245 independent reflections
Absorption correction: multi-scan
(CrysAlis RED; Oxford Diffraction, 2010)
1816 reflections with I > 2σ(I)
Tmin = 0.535, Tmax = 0.763Rint = 0.020
8497 measured reflectionsθmax = 30.0°
Refinement top
R[F2 > 2σ(F2)] = 0.028H atoms treated by a mixture of independent and constrained refinement
wR(F2) = 0.077Δρmax = 0.39 e Å3
S = 1.01Δρmin = 0.19 e Å3
2245 reflectionsAbsolute structure: ?
132 parametersFlack parameter: ?
0 restraintsRogers parameter: ?
Special details top

Experimental. CrysAlis RED, Oxford Diffraction Ltd., 2010. Empirical absorption correction using spherical harmonics, implemented in SCALE3 ABSPACK scaling algorithm.

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 (Å2) top
xyzUiso*/Ueq
Cu10.50000.50000.50000.03633 (10)
N10.27576 (15)0.5566 (3)0.50728 (7)0.0398 (3)
C10.60680 (18)0.0698 (3)0.59715 (8)0.0378 (3)
O10.49066 (12)0.2223 (2)0.56829 (5)0.0446 (2)
O20.41409 (14)0.1275 (2)0.66227 (6)0.0541 (3)
C20.56941 (19)0.1252 (3)0.64921 (7)0.0416 (3)
O30.20159 (13)0.3924 (3)0.55453 (6)0.0518 (3)
H3O0.26650.28790.57450.078*
C30.6860 (2)0.2899 (3)0.68168 (8)0.0488 (4)
H30.66030.41640.71550.059*
C40.8415 (2)0.2687 (3)0.66435 (8)0.0512 (4)
H40.91890.38140.68650.061*
C50.8809 (2)0.0838 (4)0.61520 (9)0.0467 (3)
H50.98530.07000.60430.056*
C60.76430 (18)0.0881 (3)0.58031 (8)0.0393 (3)
C70.81554 (18)0.2753 (3)0.52815 (8)0.0420 (3)
H70.920 (2)0.279 (4)0.5214 (9)0.054 (5)*
C80.3647 (3)0.3339 (4)0.70831 (10)0.0572 (4)
H8A0.392 (3)0.514 (4)0.6925 (12)0.050 (6)*
H8B0.418 (3)0.314 (4)0.7595 (12)0.072 (6)*
H8C0.255 (3)0.322 (4)0.7053 (10)0.064 (6)*
Atomic displacement parameters (Å2) top
U11U22U33U12U13U23
Cu10.03102 (14)0.03680 (14)0.04131 (15)0.00245 (9)0.00388 (9)0.00387 (9)
N10.0332 (6)0.0452 (6)0.0413 (6)0.0056 (5)0.0060 (5)0.0017 (5)
C10.0405 (7)0.0349 (6)0.0379 (7)0.0014 (6)0.0017 (6)0.0020 (5)
O10.0358 (5)0.0457 (5)0.0525 (5)0.0010 (4)0.0052 (4)0.0134 (5)
O20.0521 (7)0.0494 (6)0.0621 (7)0.0034 (5)0.0118 (5)0.0163 (6)
C20.0463 (8)0.0360 (7)0.0422 (7)0.0041 (6)0.0021 (6)0.0008 (6)
O30.0370 (5)0.0640 (7)0.0550 (6)0.0058 (6)0.0083 (5)0.0176 (6)
C30.0611 (10)0.0393 (7)0.0451 (7)0.0020 (7)0.0013 (7)0.0044 (6)
C40.0554 (9)0.0464 (8)0.0499 (8)0.0099 (7)0.0072 (7)0.0004 (7)
C50.0402 (8)0.0483 (7)0.0505 (8)0.0060 (7)0.0024 (7)0.0055 (7)
C60.0391 (7)0.0369 (6)0.0410 (7)0.0000 (6)0.0009 (6)0.0049 (6)
C70.0320 (7)0.0477 (8)0.0463 (7)0.0020 (6)0.0033 (6)0.0023 (6)
C80.0656 (12)0.0517 (9)0.0560 (10)0.0083 (9)0.0151 (9)0.0089 (8)
Geometric parameters (Å, º) top
Cu1—O1i1.8833 (10)C3—C41.392 (3)
Cu1—O11.8833 (10)C3—H30.9300
Cu1—N11.9405 (13)C4—C51.361 (2)
Cu1—N1i1.9405 (13)C4—H40.9300
N1—C7i1.281 (2)C5—C61.419 (2)
N1—O31.3928 (17)C5—H50.9300
C1—O11.3179 (17)C6—C71.442 (2)
C1—C61.404 (2)C7—N1i1.281 (2)
C1—C21.428 (2)C7—H70.903 (19)
O2—C21.362 (2)C8—H8A0.965 (18)
O2—C81.422 (2)C8—H8B1.04 (2)
C2—C31.380 (2)C8—H8C0.93 (2)
O3—H3O0.8200
O1i—Cu1—O1180.0C4—C3—H3119.7
O1i—Cu1—N192.56 (5)C5—C4—C3120.27 (15)
O1—Cu1—N187.44 (5)C5—C4—H4119.9
O1i—Cu1—N1i87.44 (5)C3—C4—H4119.9
O1—Cu1—N1i92.56 (5)C4—C5—C6120.76 (16)
N1—Cu1—N1i180.00 (8)C4—C5—H5119.6
C7i—N1—O3114.91 (13)C6—C5—H5119.6
C7i—N1—Cu1127.46 (11)C1—C6—C5119.77 (15)
O3—N1—Cu1117.60 (10)C1—C6—C7123.03 (14)
O1—C1—C6124.28 (14)C5—C6—C7117.20 (15)
O1—C1—C2117.57 (14)N1i—C7—C6124.28 (14)
C6—C1—C2118.15 (14)N1i—C7—H7117.8 (12)
C1—O1—Cu1128.33 (10)C6—C7—H7117.8 (12)
C2—O2—C8117.25 (14)O2—C8—H8A111.8 (14)
O2—C2—C3125.65 (14)O2—C8—H8B112.2 (12)
O2—C2—C1113.99 (13)H8A—C8—H8B106.2 (18)
C3—C2—C1120.35 (15)O2—C8—H8C105.2 (13)
N1—O3—H3O109.5H8A—C8—H8C107.6 (19)
C2—C3—C4120.69 (15)H8B—C8—H8C113.9 (17)
C2—C3—H3119.7
O1i—Cu1—N1—C7i2.42 (14)C6—C1—C2—C30.0 (2)
O1—Cu1—N1—C7i177.58 (14)O2—C2—C3—C4179.65 (14)
O1i—Cu1—N1—O3179.73 (11)C1—C2—C3—C40.1 (2)
O1—Cu1—N1—O30.27 (11)C2—C3—C4—C50.3 (2)
C6—C1—O1—Cu10.8 (2)C3—C4—C5—C60.6 (2)
C2—C1—O1—Cu1178.82 (10)O1—C1—C6—C5179.24 (14)
N1—Cu1—O1—C1177.96 (12)C2—C1—C6—C50.4 (2)
N1i—Cu1—O1—C12.04 (12)O1—C1—C6—C71.0 (2)
C8—O2—C2—C36.2 (2)C2—C1—C6—C7179.38 (13)
C8—O2—C2—C1174.03 (14)C4—C5—C6—C10.7 (2)
O1—C1—C2—O20.10 (19)C4—C5—C6—C7179.06 (14)
C6—C1—C2—O2179.74 (13)C1—C6—C7—N1i0.6 (2)
O1—C1—C2—C3179.64 (13)C5—C6—C7—N1i179.65 (15)
Symmetry code: (i) x+1, y+1, z+1.
Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
O3—H3O···O10.821.942.5840 (16)134
C7—H7···O3ii0.903 (19)2.49 (2)3.3231 (19)154.3 (15)
Symmetry code: (ii) x+1, y, z.
Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
O3—H3O···O10.821.942.5840 (16)134.3
C7—H7···O3i0.903 (19)2.49 (2)3.3231 (19)154.3 (15)
Symmetry code: (i) x+1, y, z.
references
References top

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Coxall, R. A., Harris, S. G., Henderson, D. K., Parsons, S., Tasker, P. A. & Winpenny, R. E. P. (2000). J. Chem. Soc. Dalton Trans. pp. 2349–2356.

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Makhankova, V. G. (2011). Glob. J. Inorg. Chem. 2, 265–285.

Oxford Diffraction (2010). CrysAlis CCD and CrysAlis RED. Oxford Diffraction Ltd, Yarnton, England.

Sheldrick, G. M. (2008). Acta Cryst. A64, 112–122.

Westrip, S. P. (2010). J. Appl. Cryst. 43, 920–925.

Zhang, S. H., Ge, C. M. & Feng, C. (2008). Acta Cryst. E64, m1627.