supplementary materials


bv2221 scheme

Acta Cryst. (2013). E69, m412-m413    [ doi:10.1107/S1600536813016802 ]

Bis{2-[(5-hydroxypentyl)iminomethyl]phenolato-[kappa]2N,O1}copper(II)

R. Modak, S. Patra, S. Mandal, Y. Sikdar and S. Goswami

Abstract top

In the title compound, [Cu(C12H16NO2)2], the CuII ion, located on a center of inversion, is coordinated by two singly deprotonated Schiff base ligands derived from condensation of salicyldehyde and 1-aminopentan-5-ol. The imino N and phenol O atoms from both ligands offer a square-planar arrangement around the metal ion. The Cu-N and Cu-O bond lengths are 2.0146 (15) and 1.8870 (12) Å, respectively. Since the Cu-O and Cu-N bond lengths are different, it can be concluded that the resulting geometry of the complex is distorted. The aliphatic -OH group of the ligand is not coordinated and points away from the metal coordination zone and actively participates in hydrogen bonding connecting two other units and thus stabilizing the crystal lattice. This results in a two-dimensional extended array parallel to (201).

Comment top

Coordination chemistry of copper complexes of chelating ligands is a subject of continuing importance in connection with their structural, spectral, and redox properties in general and from the standpoint of their relevance to copper-containing metalloproteins in particular (Solomon et al., 2001; Hatcher & Karlin, 2004; Kaim & Rall, 1996). Copper ions are found in the active sites of a large number of metalloproteins involved in important biological electron-transfer reactions, as well as in redox processes of molecular oxygen (Reedijk & Bouwman, 1999).

Crystallographic analysis reveals that the asymmetric unit of the title mononuclear complex consists of one CuII ion, which is located on a center of inversion, and two singly deprotonated ligands, HL-, with the phenolic O atom being deprotonated. The phenolic O atoms (O2 and O2_a; symmetry code: (a) 2-x, 1-y, 1-z) and the imine N atoms (N1 and N1_a; symmetry code: (a) 2-x, 1-y, 1-z) from both the ligands coordinate to the same CuII center in the trans disposition to each other. The aliphatic –OH group remains as a pendant arm and is pointing away from the metal coordination zone. This uncoordinated oxygen atom, O1, is 8.083 Å away from the CuII ion. The complex has a τ4 value of 0 (α = O2 - Cu1 - O2_a = 180.00 and β = N1 - Cu1 - N1_a = 180.00) as a consequence of the Cu lying on a center of inversion thus supporting an assignment of distorted square planar geometry around the central metal ion (Yang et al. 2007). The complex exhibits a Cu1 – N1 bond length of 2.0146 (16) Å. In a perfectly square planar CuN4 moiety, the average CuII – N distance lies in the range of 1.980 (9) and 2.018 (9) Å (Maeda et al.,2003, Akimova et al., 2001). The Cu – N bond length value is comparable to the previously reported nearly planar CuII porphyrins (2.020 Å, 2.065 Å, 1.977 Å) (Pawlicki et al. 2007). It agrees well with the CuN2O2 monomer (τ4 = 1/5) having average CuII – N bond length range of 2.071 Å (Verma et al., 2011). The Cu1 – O2 bond distance in the complex is 1.8871 (11) Å. It is well established in the literature that in a nearly square planar geometry, the CuII – phenolic oxygen bond length lies in the range of 1.84 Å to 1.93 Å (Khandar & Nejati, 2000; Sundaravel et al., 2009). Since the Cu - O and Cu - N bond lengths are different, therefore, it can be concluded that the resultant geometry is a distorted square planar one. The pendant –OH group actively participates in H-bonding and connects two other units stabilizing the crystal lattice. As a result we have a two-dimensional extended array parallel to 201 plane with O1 - H1 - - - O1 length 2.864 (2) Å.

Related literature top

For the participation of the copper ion in the active sites of a large number of metalloproteins involved in important biological electron-transfer reactions, see: Reedijk & Bouwman (1999); Solomon et al. (2001); Hatcher & Karlin (2004); Kaim & Rall (1996). For references regarding the t4 value, see: Yang et al. (2007). For similar Cu—N and Cu—O bond lengths, see: Maeda et al. (2003); Akimova et al. (2001); Pawlicki et al. (2007); Verma et al. (2011); Khandar & Nejati (2000); Sundaravel et al. (2009).

Experimental top

The solution of 5-amino-1-pentanol (3 mmol, 650.8 mg) in methanol (20 mL) was added to the solution of salicylaldehyde (3 mmol, 366.36 mg) in methanol (20 ml) under vigorous stirring condition. The resulting reaction mixture was subsequently refluxed with stirring for 4 h. Completion of the reaction checked by thin layer chromatography (TLC). After reaction was complete, the solution was dried over Na2SO4, followed by filtration and the solvent was removed under reduced pressure to get the ligand. Now a solution of Cu(OAc)2.H2O (1.5 mmol, 299.47 mg) in methanol (20 ml) was added to the solution of the prepared crude ligand (3 mmol, 621.84 mg) in methanol(20 ml) with constant stirring. The resulting mixture was stirred for 3 h at room temperature and then filtered. The resulting dark brown solution on slow evaporation gave a brown amorphous solid which was washed with diethyl ether properly and dried in vacuum desiccator containing anhydrous CaCl2. X-ray quality single crystals were grown from acetonitrile by the slow evaporation method.

Refinement top

The H atoms were placed in calculated positions and refined as riding atoms, with C—H = 0.93 Å, aliphatic C – H = 0.97 Å and O – H = 0.82 Å.

Computing details top

Data collection: APEX2 (Bruker, 2004); cell refinement: SAINT (Bruker, 2004); data reduction: SAINT (Bruker, 2004); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: ORTEP-3 for Windows (Farrugia, 2012); software used to prepare material for publication: Mercury (Macrae et al., 2008).

Figures top
[Figure 1] Fig. 1. The structure of (I), showing the atom-labelling scheme. H atoms omitted for clarity. Displacement ellipsoids are drawn at the 50% probability level.
[Figure 2] Fig. 2. A view of the two-dimensional hydrogen-bonded framework viewed along the b axis. Hydrogen bonding interactions are shown by dashed lines.
Bis{2-[(5-hydroxypentyl)iminomethyl]phenolato-κ2N,O1}copper(II) top
Crystal data top
[Cu(C12H16NO2)2]F(000) = 502.0
Mr = 476.07Dx = 1.385 Mg m3
Monoclinic, P21/cMo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2ybcCell parameters from 13343 reflections
a = 11.8815 (8) Åθ = 1.8–27.5°
b = 5.2219 (3) ŵ = 0.99 mm1
c = 18.9588 (12) ÅT = 296 K
β = 102.876 (2)°Block, dark green
V = 1146.70 (12) Å30.8 × 0.6 × 0.4 mm
Z = 2
Data collection top
Bruker APEXII SMART CCD
diffractometer
2549 independent reflections
Radiation source: fine-focus sealed tube2174 reflections with I > 2σ(I)
Graphite monochromatorRint = 0.027
φ and ω scansθmax = 27.5°, θmin = 1.8°
Absorption correction: multi-scan
(SADABS; Sheldrick, 1996)
h = 1414
Tmin = 0.497, Tmax = 0.674k = 66
13343 measured reflectionsl = 2424
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)] = 0.030Hydrogen site location: inferred from neighbouring sites
wR(F2) = 0.096H-atom parameters constrained
S = 0.95 w = 1/[σ2(Fo2) + (0.0695P)2 + 0.3017P]
where P = (Fo2 + 2Fc2)/3
2549 reflections(Δ/σ)max = 0.015
143 parametersΔρmax = 0.27 e Å3
0 restraintsΔρmin = 0.30 e Å3
Crystal data top
[Cu(C12H16NO2)2]V = 1146.70 (12) Å3
Mr = 476.07Z = 2
Monoclinic, P21/cMo Kα radiation
a = 11.8815 (8) ŵ = 0.99 mm1
b = 5.2219 (3) ÅT = 296 K
c = 18.9588 (12) Å0.8 × 0.6 × 0.4 mm
β = 102.876 (2)°
Data collection top
Bruker APEXII SMART CCD
diffractometer
2549 independent reflections
Absorption correction: multi-scan
(SADABS; Sheldrick, 1996)
2174 reflections with I > 2σ(I)
Tmin = 0.497, Tmax = 0.674Rint = 0.027
13343 measured reflectionsθmax = 27.5°
Refinement top
R[F2 > 2σ(F2)] = 0.030H-atom parameters constrained
wR(F2) = 0.096Δρmax = 0.27 e Å3
S = 0.95Δρmin = 0.30 e Å3
2549 reflectionsAbsolute structure: ?
143 parametersAbsolute structure parameter: ?
0 restraintsRogers parameter: ?
Special details top

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
Cu11.00000.50000.50000.03217 (12)
O10.50800 (15)0.8210 (3)0.72046 (8)0.0640 (4)
H10.49710.94760.74360.096*
O21.04519 (10)0.2230 (2)0.44865 (7)0.0440 (3)
N10.83417 (13)0.4686 (3)0.44597 (8)0.0338 (3)
C10.74512 (14)0.6417 (3)0.46237 (9)0.0372 (4)
H1A0.67940.64530.42150.045*
H1B0.77610.81400.46970.045*
C20.70561 (16)0.5564 (3)0.52942 (10)0.0389 (4)
H2A0.66280.39750.51910.047*
H2B0.77270.52360.56800.047*
C30.63016 (16)0.7546 (4)0.55460 (10)0.0420 (4)
H3A0.56210.78290.51630.050*
H3B0.67220.91500.56290.050*
C40.59209 (16)0.6804 (4)0.62336 (10)0.0422 (4)
H4A0.53460.54570.61220.051*
H4B0.65790.61270.65810.051*
C50.5428 (2)0.8995 (5)0.65661 (12)0.0571 (5)
H5A0.60011.03420.66850.068*
H5B0.47680.96790.62220.068*
C60.79987 (14)0.3133 (3)0.39297 (9)0.0375 (4)
H60.72300.32770.36870.045*
C70.86641 (14)0.1202 (3)0.36685 (8)0.0362 (4)
C80.98489 (15)0.0831 (3)0.39729 (9)0.0357 (3)
C91.04061 (17)0.1203 (3)0.36855 (10)0.0437 (4)
H91.11870.15000.38730.052*
C100.98222 (18)0.2730 (4)0.31404 (10)0.0485 (5)
H101.02120.40490.29670.058*
C110.86595 (19)0.2348 (4)0.28419 (10)0.0502 (5)
H110.82700.33920.24690.060*
C120.80936 (19)0.0411 (4)0.31035 (11)0.0452 (4)
H120.73130.01490.29040.054*
Atomic displacement parameters (Å2) top
U11U22U33U12U13U23
Cu10.02804 (18)0.03330 (18)0.03728 (18)0.00376 (10)0.01180 (12)0.00224 (10)
O10.0847 (11)0.0657 (9)0.0553 (8)0.0084 (8)0.0448 (8)0.0046 (7)
O20.0337 (6)0.0444 (7)0.0535 (7)0.0065 (5)0.0088 (5)0.0123 (6)
N10.0299 (7)0.0393 (8)0.0358 (7)0.0058 (5)0.0146 (6)0.0026 (5)
C10.0309 (8)0.0425 (9)0.0405 (8)0.0106 (7)0.0131 (6)0.0037 (7)
C20.0356 (9)0.0362 (8)0.0498 (10)0.0068 (7)0.0203 (7)0.0052 (7)
C30.0427 (9)0.0422 (9)0.0471 (9)0.0112 (7)0.0226 (8)0.0079 (7)
C40.0442 (10)0.0426 (9)0.0444 (9)0.0038 (7)0.0198 (7)0.0042 (7)
C50.0746 (15)0.0529 (12)0.0562 (12)0.0147 (11)0.0415 (11)0.0116 (10)
C60.0312 (8)0.0467 (9)0.0359 (8)0.0016 (7)0.0103 (6)0.0029 (7)
C70.0402 (9)0.0369 (9)0.0350 (8)0.0010 (7)0.0158 (7)0.0006 (7)
C80.0400 (9)0.0318 (8)0.0386 (8)0.0028 (7)0.0161 (7)0.0015 (7)
C90.0481 (10)0.0371 (9)0.0486 (10)0.0099 (8)0.0167 (8)0.0001 (8)
C100.0693 (13)0.0356 (9)0.0464 (10)0.0071 (9)0.0252 (9)0.0032 (8)
C110.0651 (13)0.0474 (10)0.0399 (9)0.0069 (9)0.0156 (8)0.0066 (8)
C120.0459 (11)0.0537 (11)0.0369 (9)0.0038 (8)0.0110 (8)0.0025 (7)
Geometric parameters (Å, º) top
Cu1—O2i1.8870 (12)C4—C51.488 (3)
Cu1—O21.8870 (12)C4—H4A0.9700
Cu1—N1i2.0146 (15)C4—H4B0.9700
Cu1—N12.0146 (15)C5—H5A0.9700
O1—C51.424 (2)C5—H5B0.9700
O1—H10.8200C6—C71.436 (2)
O2—C81.298 (2)C6—H60.9300
N1—C61.285 (2)C7—C81.411 (2)
N1—C11.476 (2)C7—C121.411 (3)
C1—C21.517 (2)C8—C91.423 (2)
C1—H1A0.9700C9—C101.366 (3)
C1—H1B0.9700C9—H90.9300
C2—C31.514 (2)C10—C111.386 (3)
C2—H2A0.9700C10—H100.9300
C2—H2B0.9700C11—C121.368 (3)
C3—C41.522 (2)C11—H110.9300
C3—H3A0.9700C12—H120.9300
C3—H3B0.9700
O2i—Cu1—O2179.999 (1)C3—C4—H4A109.0
O2i—Cu1—N1i91.94 (5)C5—C4—H4B109.0
O2—Cu1—N1i88.06 (5)C3—C4—H4B109.0
O2i—Cu1—N188.06 (5)H4A—C4—H4B107.8
O2—Cu1—N191.94 (5)O1—C5—C4110.77 (17)
N1i—Cu1—N1179.998 (1)O1—C5—H5A109.5
C5—O1—H1109.5C4—C5—H5A109.5
C8—O2—Cu1130.21 (11)O1—C5—H5B109.5
C6—N1—C1115.71 (15)C4—C5—H5B109.5
C6—N1—Cu1123.56 (12)H5A—C5—H5B108.1
C1—N1—Cu1120.58 (11)N1—C6—C7127.59 (15)
N1—C1—C2111.53 (13)N1—C6—H6116.2
N1—C1—H1A109.3C7—C6—H6116.2
C2—C1—H1A109.3C8—C7—C12119.69 (16)
N1—C1—H1B109.3C8—C7—C6122.08 (15)
C2—C1—H1B109.3C12—C7—C6118.20 (16)
H1A—C1—H1B108.0O2—C8—C7124.29 (15)
C3—C2—C1112.27 (14)O2—C8—C9118.78 (16)
C3—C2—H2A109.2C7—C8—C9116.92 (16)
C1—C2—H2A109.2C10—C9—C8121.64 (18)
C3—C2—H2B109.2C10—C9—H9119.2
C1—C2—H2B109.2C8—C9—H9119.2
H2A—C2—H2B107.9C9—C10—C11121.12 (17)
C2—C3—C4113.92 (15)C9—C10—H10119.4
C2—C3—H3A108.8C11—C10—H10119.4
C4—C3—H3A108.8C12—C11—C10118.98 (18)
C2—C3—H3B108.8C12—C11—H11120.5
C4—C3—H3B108.8C10—C11—H11120.5
H3A—C3—H3B107.7C11—C12—C7121.66 (19)
C5—C4—C3112.76 (15)C11—C12—H12119.2
C5—C4—H4A109.0C7—C12—H12119.2
Symmetry code: (i) x+2, y+1, z+1.
Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
O1—H1···O1ii0.822.072.864 (2)163
C1—H1B···O2i0.972.342.771 (2)106
Symmetry codes: (i) x+2, y+1, z+1; (ii) x+1, y+1/2, z+3/2.

Experimental details

Crystal data
Chemical formula[Cu(C12H16NO2)2]
Mr476.07
Crystal system, space groupMonoclinic, P21/c
Temperature (K)296
a, b, c (Å)11.8815 (8), 5.2219 (3), 18.9588 (12)
β (°) 102.876 (2)
V3)1146.70 (12)
Z2
Radiation typeMo Kα
µ (mm1)0.99
Crystal size (mm)0.8 × 0.6 × 0.4
Data collection
DiffractometerBruker APEXII SMART CCD
diffractometer
Absorption correctionMulti-scan
(SADABS; Sheldrick, 1996)
Tmin, Tmax0.497, 0.674
No. of measured, independent and
observed [I > 2σ(I)] reflections
13343, 2549, 2174
Rint0.027
(sin θ/λ)max1)0.650
Refinement
R[F2 > 2σ(F2)], wR(F2), S 0.030, 0.096, 0.95
No. of reflections2549
No. of parameters143
No. of restraints0
H-atom treatmentH-atom parameters constrained
Δρmax, Δρmin (e Å3)0.27, 0.30

Computer programs: APEX2 (Bruker, 2004), SAINT (Bruker, 2004), SHELXS97 (Sheldrick, 2008), SHELXL97 (Sheldrick, 2008), ORTEP-3 for Windows (Farrugia, 2012), Mercury (Macrae et al., 2008).

Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
O1—H1···O1i0.82002.07002.864 (2)163.00
C1—H1B···O2ii0.97002.34002.771 (2)106.00
Symmetry codes: (i) x+1, y+1/2, z+3/2; (ii) x+2, y+1, z+1.
Acknowledgements top

Financial support from the University Grants Commission for a junior research fellowship to SM [Sanction No. UGC/749/Jr. Fellow(Sc.)] and an RFSMS fellowship (Sanction No. UGC/740/RFSMS) to RM is gratefully acknowledged. We thank the DST for a junior research fellowship to YS (Sanction No. SERB/F/1585/2012–13). DST–FIST is acknowledged for providing the X-ray diffraction facility at the Department of Chemistry, University of Calcutta.

references
References top

Akimova, E. V. R., Nazarenko, A. Y., Chen, L., Krieger, P. W., Herrera, A. M., Tarasov, V. V. & Robinson, P. D. (2001). Inorg. Chim. Acta, 324, 1–15.

Bruker (2004). APEX2 and SAINT. Bruker–Nonius AXS Inc., Madison, Wisconsin, USA.

Farrugia, L. J. (2012). J. Appl. Cryst. 45, 849–854.

Hatcher, L. Q. & Karlin, K. D. (2004). J. Biol. Inorg. Chem. 9, 669–683.

Kaim, W. & Rall, J. (1996). Angew. Chem. Int. Ed. 35, 43–60.

Khandar, A. A. & Nejati, M. (2000). Polyhedron, 19, 607–613.

Macrae, C. F., Bruno, I. J., Chisholm, J. A., Edgington, P. R., McCabe, P., Pidcock, E., Rodriguez-Monge, L., Taylor, R., van de Streek, J. & Wood, P. A. (2008). J. Appl. Cryst. 41, 466–470.

Maeda, H., Osuka, A., Ishikawa, Y., Aritome, I., Hisaeda, Y. & Furuta, H. (2003). Org. Lett. 5, 1293–1296.

Pawlicki, M., Kanska, I. & Latos-Grazynski, L. (2007). Inorg. Chem. 46, 6575–6584.

Reedijk, J. & Bouwman, E. (1999). In Bioinorganic Catalysis, 2nd ed. New York: Marcel Dekker.

Sheldrick, G. M. (1996). SADABS. University of Göttingen, Germany.

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

Solomon, E. I., Chen, P., Metz, M., Lee, S.-K. & Palmer, A. E. (2001). Angew. Chem. Int. Ed. 40, 4570–4590.

Sundaravel, K., Suresh, E. & Palaniandavar, M. (2009). Inorg. Chim. Acta, 362, 199–207.

Verma, P., Weir, J., Mirica, L., Stack, T. & Daniel, P. (2011). Inorg. Chem. 50, 9816–9825.

Yang, L., Powell, D. R. & Houser, R. P. (2007). Dalton Trans. pp. 955–964.