Download citation
Download citation
link to html
In the title complex, [Cu(C12H13O2)2], the copper(II) ion lies on a crystallographic centre of symmetry and exhibits a square-planar coordination environment formed by four O atoms of two chelate β-diketonate ligands. The nearest neighbours of the copper(II) ion in the apical direction are two α-C atoms of β-diketonate ligands, 3.263 (2) Å away from the metal ion. Mol­ecules in the crystal are stacked face-to-face and held together by weak C—H...O hydrogen bonding and π–π stacking inter­actions.

Supporting information

cif

Crystallographic Information File (CIF) https://doi.org/10.1107/S1600536805042042/rz6151sup1.cif
Contains datablocks global, I

hkl

Structure factor file (CIF format) https://doi.org/10.1107/S1600536805042042/rz6151Isup2.hkl
Contains datablock I

CCDC reference: 296642

Key indicators

  • Single-crystal X-ray study
  • T = 293 K
  • Mean [sigma](C-C) = 0.004 Å
  • R factor = 0.030
  • wR factor = 0.088
  • Data-to-parameter ratio = 17.0

checkCIF/PLATON results

No syntax errors found



Alert level C PLAT063_ALERT_3_C Crystal Probably too Large for Beam Size ....... 0.80 mm PLAT199_ALERT_1_C Check the Reported _cell_measurement_temperature 293 K PLAT200_ALERT_1_C Check the Reported _diffrn_ambient_temperature . 293 K PLAT480_ALERT_4_C Long H...A H-Bond Reported H1B .. O1 .. 2.79 Ang. PLAT480_ALERT_4_C Long H...A H-Bond Reported H5C .. O2 .. 2.88 Ang. PLAT480_ALERT_4_C Long H...A H-Bond Reported H6B .. O1 .. 2.78 Ang. PLAT481_ALERT_4_C Long D...A H-Bond Reported C5 .. O2 .. 3.73 Ang.
0 ALERT level A = In general: serious problem 0 ALERT level B = Potentially serious problem 7 ALERT level C = Check and explain 0 ALERT level G = General alerts; check 2 ALERT type 1 CIF construction/syntax error, inconsistent or missing data 0 ALERT type 2 Indicator that the structure model may be wrong or deficient 1 ALERT type 3 Indicator that the structure quality may be low 4 ALERT type 4 Improvement, methodology, query or suggestion

Comment top

Copper(II) β-diketonate molecules are often planar and coordinationaly unsaturated. As a means to achieve coordination saturation the molecules readily self-assemble by way of weak intermolecular forces. Oligomers and polymers that form in such a way exhibit physical and chemical properties that render the compounds interesting in the context of materials science (Soldatov et al., 2003).

As a part of a study on the effects of weak interactions on the self-assembly properties of copper(II) β-diketonates, a series of β-diketonate ligands carrying sterically demanding groups in the α-position was prepared, including 3-benzylpentane-2,4-dione, H(αBzl)acac (Judaš & Kaitner, 2005).

In this paper we report the crystal and molecular structure of bis(3-benzylpentane-2,4-dionato)copper(II), Cu[(αBzl)acac]2, (I).

In the Cu[(αBzl)acac]2 complex molecule, which possesses a crystallographically imposed center of symmetry (Fig. 1), four O atoms of two β-diketonato ligands surround the copper(II) ion to form a coordination environment that is square-planar by symmetry. The six-membered chelate rings are folded at an angle of 2.5 (3)° about the O1···O2 line. The phenyl ring of the benzyl substituent is almost perpendicular to the chelate mean plane [dihedral angle 81.333 (6)°]. The significant distortion of the tetrahedral angle around atom C6, reflected in the value of the C3—C6—C7 angle of 114.06 (15)°, is most probably caused by the effects of molecular packing rather than intramolecular steric hindrances.

Molecules are linked together in the crystal by several weak cooperative C—H···O hydrogen bonds (Table 1). Specifically, the C1···O1i and C5···O2i hydrogen bonds [symmetry code: (i) 1 + x, y, z] are responsible for the bending of the carbon backbone of the molecule (Fig. 2), so as to tilt the atoms C1 and C5 out of the plane defined by atoms C2, C3, C4, O1, O2 and Cu by 0.142 (4) and 0.165 (4) Å, respectively.

The molecules in the crystal exhibit significant ππ stacking interactions involving chelate rings. In summary, self-assembly of copper complex molecules through C–H···O hydrogen bond and ππ stacking forces link the molecules into one-dimensional ribbons running parallel to the a axis (Fig. 3).

The comparison of crystal and molecular structures of the title compound and its analog bis(pentane-2,4-dionato)copper(II) (Starikova & Shugam, 1969; Lebrun et al., 1986) suggests that the introduction of a bulky benzyl substituent at the α-position of the ligand affects more the crystal than the molecular structure of the bis(chelato)copper(II) complex.

Experimental top

The ligand 3-benzylpentane-2,4-dione was prepared from sodium acetylacetonate and benzyl bromide by a previously described method (Morgan & Taylor, 1925) as a yellow oil. The title compound was prepared by the reaction of freshly prepared 3-benzylpentane-2,4-dione with copper(II) acetate in ethanol using triethylamine as a catalyst. Specifically, copper(II) acetate monohydrate (0.25 g, 1.3 mmol) was dissolved in hot ethanol (35 ml) containing a few drops of triethylamine. The ligand solution was prepared separately by dissolving 3-benzylpentane-2,4-dione (0.50 g, 2.6 mmol) in ethanol (10 ml). The hot solution of the ligand was added dropwise to the stirred hot solution of copper(II) acetate and catalyst until a precipitate of metallic gray colour separated. The solid was filtered off by suction and washed with one portion of cold ethanol, one portion of distiled water and one more portion of cold ethanol. The product was dried and recrystallized from benzene (yield 71%). Single crystals of the title compound were prepared by diffusion method. A warm ethanol solution (328 K) of the complex was overlayed with n-hexane (5 ml) to yield long and fragile needles of Cu[(αBzl)acac]2. Thermal analyses (TG and DSC) of purified Cu[(αBzl)acac]2 were performed using Mettler thermal analysis modules. The complex compound begins to melt with decomposition at 449 K in oxygen atmosphere. In a nitrogen atmosphere the complex melts at 482 K, ΔHfus = 47.3 kJ mol−1.

Refinement top

Coordinates of H atoms bonded to C atoms were calculated following the stereochemical rules with C—H distances of 0.93 Å for phenyl, 0.97 Å for methylene and 0.96 Å for methyl groups. The H atoms were included in the refinement using the riding-model approximation. Uiso(H) were defined as 1.2Ueq of the parent C atoms for phenyl and methylene residues and 1.5Ueq of the parent C atoms for the methyl groups.

Computing details top

Data collection: STADI4 (Stoe & Cie, 1995); cell refinement: STADI4; data reduction: X-RED (Stoe & Cie, 1995); program(s) used to solve structure: SHELXS97 (Sheldrick, 1997); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: ORTEP-3 for Windows (Farrugia, 1997), Mercury (Bruno et al., 2002), RasTop (Valadon, 2004) and POVRay (Persistence of Vision Pty, 2004); software used to prepare material for publication: WinGX (Farrugia, 1999).

Figures top
[Figure 1] Fig. 1. View of (I) showing 30% probability displacement ellipsoids. [Symmetry code: (ii) −x, −y, −z.]
[Figure 2] Fig. 2. Crystal packing diagram of (I) showing cooperative C—H···O hydrogen bonding (dashed lines) between the molecules.
[Figure 3] Fig. 3. Self-assembly of molecules of (I) through C—H···O hydrogen-bond and π···π-stacking forces (dashed lines) into one-dimensional ribbons parallel to the a axis.
bis(3-benzylpentane-2,4-dionato)copper(II) top
Crystal data top
[Cu(C12H13O2)2]Z = 1
Mr = 441.99F(000) = 231
Triclinic, P1Dx = 1.400 Mg m3
Dm = 1.38 Mg m3
Dm measured by flotation in what?
Hall symbol: -P 1Melting point: 480 K
a = 4.9124 (13) ÅMo Kα radiation, λ = 0.71073 Å
b = 9.9691 (2) ÅCell parameters from 40 reflections
c = 11.887 (3) Åθ = 11–17°
α = 110.970 (14)°µ = 1.07 mm1
β = 99.044 (12)°T = 293 K
γ = 98.254 (12)°Needle, black
V = 524.1 (2) Å30.80 × 0.17 × 0.13 mm
Data collection top
Philips PW1100
diffractometer
2132 reflections with I > 2σ(I)
Radiation source: fine-focus sealed tubeRint = 0.026
Planar Graphite monochromatorθmax = 27.0°, θmin = 2.2°
ω scanh = 66
Absorption correction: ψ scan
(North et al., 1968)
k = 1212
Tmin = 0.770, Tmax = 0.867l = 1515
4582 measured reflections4 standard reflections every 60 min
2291 independent reflections intensity decay: 2.8%
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) = 0.088H-atom parameters constrained
S = 1.11 w = 1/[σ2(Fo2) + (0.0507P)2 + 0.086P]
where P = (Fo2 + 2Fc2)/3
2291 reflections(Δ/σ)max < 0.001
135 parametersΔρmax = 0.35 e Å3
0 restraintsΔρmin = 0.37 e Å3
Crystal data top
[Cu(C12H13O2)2]γ = 98.254 (12)°
Mr = 441.99V = 524.1 (2) Å3
Triclinic, P1Z = 1
a = 4.9124 (13) ÅMo Kα radiation
b = 9.9691 (2) ŵ = 1.07 mm1
c = 11.887 (3) ÅT = 293 K
α = 110.970 (14)°0.80 × 0.17 × 0.13 mm
β = 99.044 (12)°
Data collection top
Philips PW1100
diffractometer
2132 reflections with I > 2σ(I)
Absorption correction: ψ scan
(North et al., 1968)
Rint = 0.026
Tmin = 0.770, Tmax = 0.8674 standard reflections every 60 min
4582 measured reflections intensity decay: 2.8%
2291 independent reflections
Refinement top
R[F2 > 2σ(F2)] = 0.0300 restraints
wR(F2) = 0.088H-atom parameters constrained
S = 1.11Δρmax = 0.35 e Å3
2291 reflectionsΔρmin = 0.37 e Å3
135 parameters
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
Cu0000.03732 (12)
O10.2361 (3)0.14317 (14)0.03318 (12)0.0417 (3)
O20.2634 (3)0.03449 (14)0.14820 (12)0.0425 (3)
C10.6190 (5)0.3141 (2)0.0296 (2)0.0516 (5)
H1A0.49470.29950.10580.077*
H1B0.79260.28660.0460.077*
H1C0.65750.41590.02510.077*
C20.4811 (4)0.22053 (18)0.02997 (17)0.0381 (4)
C30.6221 (4)0.22038 (19)0.14288 (17)0.0383 (4)
C40.5072 (4)0.12292 (19)0.19272 (16)0.0391 (4)
C50.6686 (5)0.1093 (2)0.30565 (19)0.0531 (5)
H5A0.54810.04580.33070.08*
H5B0.73110.20470.37160.08*
H5C0.82930.06860.28650.08*
C60.9049 (4)0.3295 (2)0.21052 (19)0.0444 (4)
H6A1.00320.29680.26990.053*
H6B1.01970.32830.15090.053*
C70.8776 (4)0.4865 (2)0.27776 (17)0.0426 (4)
C81.0167 (6)0.6012 (3)0.2557 (3)0.0652 (6)
H81.13140.58210.19910.078*
C90.9902 (7)0.7455 (3)0.3159 (3)0.0792 (8)
H91.08380.82090.29820.095*
C100.8274 (7)0.7757 (3)0.4005 (3)0.0725 (7)
H100.81070.87190.44170.087*
C110.6890 (7)0.6638 (3)0.4242 (3)0.0777 (8)
H110.57740.68420.48210.093*
C120.7118 (6)0.5201 (3)0.3635 (2)0.0640 (6)
H120.61430.44520.38070.077*
Atomic displacement parameters (Å2) top
U11U22U33U12U13U23
Cu0.03641 (18)0.03485 (17)0.04012 (18)0.00695 (11)0.00845 (12)0.01429 (12)
O10.0400 (6)0.0413 (6)0.0447 (7)0.0069 (5)0.0080 (5)0.0191 (5)
O20.0410 (6)0.0429 (7)0.0438 (7)0.0054 (5)0.0076 (5)0.0192 (5)
C10.0516 (11)0.0477 (10)0.0599 (12)0.0055 (9)0.0135 (9)0.0279 (9)
C20.0378 (8)0.0326 (8)0.0462 (9)0.0115 (7)0.0152 (7)0.0141 (7)
C30.0335 (8)0.0349 (8)0.0444 (9)0.0096 (6)0.0106 (7)0.0114 (7)
C40.0382 (8)0.0379 (8)0.0401 (8)0.0129 (7)0.0103 (7)0.0117 (7)
C50.0519 (11)0.0585 (12)0.0486 (11)0.0091 (9)0.0035 (9)0.0249 (9)
C60.0316 (8)0.0438 (10)0.0556 (11)0.0088 (7)0.0103 (7)0.0163 (8)
C70.0337 (8)0.0410 (9)0.0471 (9)0.0044 (7)0.0014 (7)0.0149 (8)
C80.0678 (15)0.0520 (12)0.0734 (15)0.0016 (11)0.0216 (12)0.0237 (11)
C90.091 (2)0.0455 (13)0.092 (2)0.0021 (12)0.0048 (16)0.0299 (13)
C100.0815 (18)0.0431 (11)0.0703 (15)0.0138 (11)0.0088 (13)0.0066 (11)
C110.088 (2)0.0585 (14)0.0759 (17)0.0224 (13)0.0295 (15)0.0070 (12)
C120.0712 (15)0.0484 (12)0.0722 (15)0.0108 (11)0.0313 (12)0.0177 (11)
Geometric parameters (Å, º) top
Cu—O11.8997 (13)C5—H5C0.96
Cu—O1i1.8997 (13)C6—C71.518 (3)
Cu—O21.9022 (13)C6—H6A0.97
Cu—O2i1.9022 (13)C6—H6B0.97
O1—C21.281 (2)C7—C81.375 (3)
O2—C41.286 (2)C7—C121.382 (3)
C1—C21.508 (3)C8—C91.394 (4)
C1—H1A0.96C8—H80.93
C1—H1B0.96C9—C101.359 (5)
C1—H1C0.96C9—H90.93
C2—C31.411 (3)C10—C111.362 (4)
C3—C41.405 (3)C10—H100.93
C3—C61.533 (2)C11—C121.385 (3)
C4—C51.509 (3)C11—H110.93
C5—H5A0.96C12—H120.93
C5—H5B0.96
O1—Cu—O1i180.00 (7)H5A—C5—H5C109.5
O1—Cu—O291.87 (6)H5B—C5—H5C109.5
O1i—Cu—O288.13 (6)C7—C6—C3114.06 (15)
O1—Cu—O2i88.13 (6)C7—C6—H6A108.7
O1i—Cu—O2i91.87 (6)C3—C6—H6A108.7
O2—Cu—O2i180.00 (6)C7—C6—H6B108.7
C2—O1—Cu127.70 (12)C3—C6—H6B108.7
C4—O2—Cu127.86 (12)H6A—C6—H6B107.6
C2—C1—H1A109.5C8—C7—C12117.2 (2)
C2—C1—H1B109.5C8—C7—C6121.35 (19)
H1A—C1—H1B109.5C12—C7—C6121.44 (18)
C2—C1—H1C109.5C7—C8—C9121.8 (2)
H1A—C1—H1C109.5C7—C8—H8119.1
H1B—C1—H1C109.5C9—C8—H8119.1
O1—C2—C3125.82 (16)C10—C9—C8119.8 (2)
O1—C2—C1113.36 (17)C10—C9—H9120.1
C3—C2—C1120.80 (17)C8—C9—H9120.1
C4—C3—C2121.10 (16)C9—C10—C11119.3 (2)
C4—C3—C6120.47 (16)C9—C10—H10120.3
C2—C3—C6118.43 (16)C11—C10—H10120.3
O2—C4—C3125.44 (17)C10—C11—C12121.0 (3)
O2—C4—C5112.61 (17)C10—C11—H11119.5
C3—C4—C5121.92 (17)C12—C11—H11119.5
C4—C5—H5A109.5C7—C12—C11120.8 (2)
C4—C5—H5B109.5C7—C12—H12119.6
H5A—C5—H5B109.5C11—C12—H12119.6
C4—C5—H5C109.5
O2—Cu—O1—C21.87 (15)C2—C3—C4—C5173.16 (17)
O2i—Cu—O1—C2178.13 (15)C6—C3—C4—C56.9 (3)
O1—Cu—O2—C42.20 (15)C4—C3—C6—C7103.5 (2)
O1i—Cu—O2—C4177.80 (15)C2—C3—C6—C776.4 (2)
Cu—O1—C2—C33.5 (3)C3—C6—C7—C8125.1 (2)
Cu—O1—C2—C1174.97 (12)C3—C6—C7—C1254.8 (3)
O1—C2—C3—C44.7 (3)C12—C7—C8—C90.7 (4)
C1—C2—C3—C4173.65 (17)C6—C7—C8—C9179.2 (2)
O1—C2—C3—C6175.22 (15)C7—C8—C9—C101.2 (4)
C1—C2—C3—C66.4 (2)C8—C9—C10—C110.8 (5)
Cu—O2—C4—C34.2 (3)C9—C10—C11—C120.0 (5)
Cu—O2—C4—C5174.19 (12)C8—C7—C12—C110.1 (4)
C2—C3—C4—O25.1 (3)C6—C7—C12—C11180.0 (2)
C6—C3—C4—O2174.90 (16)C10—C11—C12—C70.5 (5)
Symmetry code: (i) x, y, z.
Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
C1—H1B···O1ii0.962.793.684 (3)156
C5—H5C···O2ii0.962.883.734 (3)149
C6—H6B···O1ii0.972.783.604 (2)143
Symmetry code: (ii) x+1, y, z.

Experimental details

Crystal data
Chemical formula[Cu(C12H13O2)2]
Mr441.99
Crystal system, space groupTriclinic, P1
Temperature (K)293
a, b, c (Å)4.9124 (13), 9.9691 (2), 11.887 (3)
α, β, γ (°)110.970 (14), 99.044 (12), 98.254 (12)
V3)524.1 (2)
Z1
Radiation typeMo Kα
µ (mm1)1.07
Crystal size (mm)0.80 × 0.17 × 0.13
Data collection
DiffractometerPhilips PW1100
diffractometer
Absorption correctionψ scan
(North et al., 1968)
Tmin, Tmax0.770, 0.867
No. of measured, independent and
observed [I > 2σ(I)] reflections
4582, 2291, 2132
Rint0.026
(sin θ/λ)max1)0.639
Refinement
R[F2 > 2σ(F2)], wR(F2), S 0.030, 0.088, 1.11
No. of reflections2291
No. of parameters135
H-atom treatmentH-atom parameters constrained
Δρmax, Δρmin (e Å3)0.35, 0.37

Computer programs: STADI4 (Stoe & Cie, 1995), STADI4, X-RED (Stoe & Cie, 1995), SHELXS97 (Sheldrick, 1997), SHELXL97 (Sheldrick, 1997), ORTEP-3 for Windows (Farrugia, 1997), Mercury (Bruno et al., 2002), RasTop (Valadon, 2004) and POVRay (Persistence of Vision Pty, 2004), WinGX (Farrugia, 1999).

Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
C1—H1B···O1i0.962.793.684 (3)156
C5—H5C···O2i0.962.883.734 (3)149
C6—H6B···O1i0.972.783.604 (2)143
Symmetry code: (i) x+1, y, z.
 

Follow Acta Cryst. E
Sign up for e-alerts
Follow Acta Cryst. on Twitter
Follow us on facebook
Sign up for RSS feeds