Supporting information
Crystallographic Information File (CIF) https://doi.org/10.1107/S0108270112004386/ku3061sup1.cif | |
Structure factor file (CIF format) https://doi.org/10.1107/S0108270112004386/ku3061Isup2.hkl | |
Structure factor file (CIF format) https://doi.org/10.1107/S0108270112004386/ku3061IIsup3.hkl |
CCDC references: 873876; 873877
Cu(acac)2 (acac is acetylacetonate; 0.25 mmol) was dissolved in warm chloroform (5 ml) and pyridin-2-amine (0.25 mmol) for the preparation of (I) and pyrimidin-2-amine (0.25 mmol) for the preparation of (II) was added. The reaction mixture was stirred for 5 min and then allowed to stand at room temperature. Crystals suitable for X-ray analysis were obtained after slow evaporation of the solvent (yields: 50–55%).
All H atoms were initially located in difference Fourier maps and were subsequently treated as riding atoms in geometrically idealized positions, with C—H = 0.93 (aromatic and alkenyl) or 0.96 Å (CH3), and N—H = 0.86 Å and with Uiso(H) = kUeq(C,N), where k = 1.5 for amino and methyl groups, which were permitted to rotate but not to tilt, and 1.2 for all other H atoms. To improve the refinement results, two reflections in the case of (I) and eight reflections in the case of (II) with too high values of δ(F2)/e.s.d. and with Fo2 < Fc2 were deleted from the refinement.
For both compounds, data collection: COLLECT (Nonius, 1998); cell refinement: DENZO-SMN (Otwinowski & Minor, 1997); data reduction: DENZO-SMN (Otwinowski & Minor, 1997); program(s) used to solve structure: SIR97 (Altomare et al., 1999); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: ORTEP-3 (Farrugia, 1997) and DIAMOND (Brandenburg, 1999); software used to prepare material for publication: WinGX (Farrugia, 1999), PLATON (Spek, 2009) and publCIF (Westrip, 2010).
[Cu(C5H7O2)2(C5H6N2)] | F(000) = 740 |
Mr = 355.87 | Dx = 1.428 Mg m−3 |
Monoclinic, P21/n | Mo Kα radiation, λ = 0.71073 Å |
Hall symbol: -P 2yn | Cell parameters from 3433 reflections |
a = 7.5686 (1) Å | θ = 0.4–27.5° |
b = 8.2944 (2) Å | µ = 1.34 mm−1 |
c = 26.4250 (7) Å | T = 293 K |
β = 93.944 (1)° | Prism, blue |
V = 1654.95 (6) Å3 | 0.6 × 0.6 × 0.25 mm |
Z = 4 |
Nonius KappaCCD area-detector diffractometer | 3572 independent reflections |
Graphite monochromator | 3238 reflections with I > 2σ(I) |
Detector resolution: 0.055 pixels mm-1 | Rint = 0.026 |
ϕ scans + ω scans | θmax = 27.5°, θmin = 3.7° |
Absorption correction: multi-scan (SCALEPACK; Otwinowski & Minor, 1997) | h = −9→9 |
Tmin = 0.501, Tmax = 0.731 | k = −10→10 |
6316 measured reflections | l = −34→34 |
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)] = 0.037 | Hydrogen site location: inferred from neighbouring sites |
wR(F2) = 0.106 | H-atom parameters constrained |
S = 1.06 | w = 1/[σ2(Fo2) + (0.0543P)2 + 0.6509P] where P = (Fo2 + 2Fc2)/3 |
3572 reflections | (Δ/σ)max = 0.001 |
203 parameters | Δρmax = 0.27 e Å−3 |
0 restraints | Δρmin = −0.48 e Å−3 |
[Cu(C5H7O2)2(C5H6N2)] | V = 1654.95 (6) Å3 |
Mr = 355.87 | Z = 4 |
Monoclinic, P21/n | Mo Kα radiation |
a = 7.5686 (1) Å | µ = 1.34 mm−1 |
b = 8.2944 (2) Å | T = 293 K |
c = 26.4250 (7) Å | 0.6 × 0.6 × 0.25 mm |
β = 93.944 (1)° |
Nonius KappaCCD area-detector diffractometer | 3572 independent reflections |
Absorption correction: multi-scan (SCALEPACK; Otwinowski & Minor, 1997) | 3238 reflections with I > 2σ(I) |
Tmin = 0.501, Tmax = 0.731 | Rint = 0.026 |
6316 measured reflections |
R[F2 > 2σ(F2)] = 0.037 | 0 restraints |
wR(F2) = 0.106 | H-atom parameters constrained |
S = 1.06 | Δρmax = 0.27 e Å−3 |
3572 reflections | Δρmin = −0.48 e Å−3 |
203 parameters |
Experimental. 346 frames in 3 sets of ϕ scans + ω scans. Rotation/frame = 1.1 °. Crystal-detector distance = 40.0 mm. Measuring time = 60 s/°. |
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. |
x | y | z | Uiso*/Ueq | ||
Cu1 | 0.07784 (3) | 0.03893 (3) | 0.398789 (9) | 0.04405 (12) | |
N1 | 0.2271 (2) | −0.0879 (2) | 0.33569 (6) | 0.0409 (3) | |
N2 | 0.5020 (3) | 0.0000 (3) | 0.36643 (10) | 0.0702 (6) | |
H2A | 0.4516 | 0.061 | 0.3874 | 0.105* | |
H2B | 0.6156 | −0.0012 | 0.3662 | 0.105* | |
O1 | 0.22478 (18) | 0.23160 (17) | 0.40337 (6) | 0.0486 (3) | |
O2 | −0.10398 (19) | 0.1450 (2) | 0.35520 (6) | 0.0562 (4) | |
O3 | −0.09963 (19) | −0.1254 (2) | 0.40743 (7) | 0.0591 (4) | |
O4 | 0.23590 (19) | −0.04686 (18) | 0.45306 (6) | 0.0475 (3) | |
C1 | 0.3114 (4) | 0.5023 (3) | 0.39822 (12) | 0.0661 (6) | |
H1A | 0.3649 | 0.4906 | 0.432 | 0.099* | |
H1B | 0.2527 | 0.6048 | 0.3951 | 0.099* | |
H1C | 0.4013 | 0.4964 | 0.3744 | 0.099* | |
C2 | 0.1796 (3) | 0.3704 (2) | 0.38762 (8) | 0.0462 (4) | |
C3 | 0.0169 (3) | 0.4067 (3) | 0.36155 (11) | 0.0620 (6) | |
H3 | −0.0066 | 0.5145 | 0.3541 | 0.074* | |
C4 | −0.1107 (3) | 0.2957 (3) | 0.34605 (9) | 0.0550 (5) | |
C5 | −0.2744 (4) | 0.3510 (5) | 0.31499 (13) | 0.0878 (10) | |
H5A | −0.2748 | 0.3061 | 0.2815 | 0.132* | |
H5B | −0.2746 | 0.4666 | 0.3129 | 0.132* | |
H5C | −0.378 | 0.3156 | 0.3309 | 0.132* | |
C6 | −0.2640 (4) | −0.3218 (4) | 0.44775 (14) | 0.0815 (9) | |
H6A | −0.365 | −0.2609 | 0.4348 | 0.122* | |
H6B | −0.2785 | −0.3513 | 0.4823 | 0.122* | |
H6C | −0.2533 | −0.4175 | 0.4277 | 0.122* | |
C7 | −0.0995 (3) | −0.2211 (3) | 0.44522 (10) | 0.0529 (5) | |
C8 | 0.0367 (3) | −0.2384 (3) | 0.48251 (9) | 0.0546 (5) | |
H8 | 0.0203 | −0.3119 | 0.5084 | 0.065* | |
C9 | 0.1963 (3) | −0.1546 (2) | 0.48432 (7) | 0.0434 (4) | |
C10 | 0.3358 (4) | −0.1924 (3) | 0.52566 (9) | 0.0631 (6) | |
H10A | 0.3883 | −0.295 | 0.5191 | 0.095* | |
H10B | 0.283 | −0.1962 | 0.5576 | 0.095* | |
H10C | 0.4254 | −0.1104 | 0.5267 | 0.095* | |
C11 | 0.4032 (3) | −0.0939 (2) | 0.33389 (7) | 0.0439 (4) | |
C12 | 0.4844 (3) | −0.1913 (3) | 0.29876 (9) | 0.0603 (6) | |
H12 | 0.6072 | −0.1954 | 0.2986 | 0.072* | |
C13 | 0.3816 (4) | −0.2794 (4) | 0.26515 (11) | 0.0743 (8) | |
H13 | 0.4334 | −0.3441 | 0.2415 | 0.089* | |
C14 | 0.1996 (4) | −0.2728 (4) | 0.26605 (11) | 0.0743 (8) | |
H14 | 0.1267 | −0.3316 | 0.243 | 0.089* | |
C15 | 0.1296 (3) | −0.1771 (3) | 0.30193 (9) | 0.0551 (5) | |
H15 | 0.007 | −0.1738 | 0.3029 | 0.066* |
U11 | U22 | U33 | U12 | U13 | U23 | |
Cu1 | 0.02998 (15) | 0.04331 (17) | 0.05809 (19) | −0.00603 (8) | −0.00254 (10) | 0.00696 (10) |
N1 | 0.0365 (8) | 0.0398 (8) | 0.0454 (8) | −0.0034 (6) | −0.0043 (6) | 0.0003 (6) |
N2 | 0.0333 (9) | 0.0991 (16) | 0.0780 (14) | −0.0080 (10) | 0.0028 (9) | −0.0352 (13) |
O1 | 0.0395 (7) | 0.0381 (7) | 0.0674 (9) | −0.0044 (5) | −0.0025 (6) | 0.0033 (6) |
O2 | 0.0366 (7) | 0.0603 (9) | 0.0703 (10) | −0.0022 (6) | −0.0064 (6) | 0.0069 (8) |
O3 | 0.0374 (7) | 0.0594 (9) | 0.0795 (11) | −0.0148 (7) | −0.0036 (7) | 0.0116 (8) |
O4 | 0.0397 (7) | 0.0507 (8) | 0.0515 (8) | −0.0086 (6) | −0.0012 (6) | 0.0076 (6) |
C1 | 0.0698 (16) | 0.0430 (11) | 0.0854 (18) | −0.0112 (11) | 0.0058 (13) | 0.0021 (11) |
C2 | 0.0475 (10) | 0.0410 (10) | 0.0510 (10) | −0.0014 (8) | 0.0099 (8) | 0.0025 (8) |
C3 | 0.0555 (13) | 0.0522 (12) | 0.0782 (15) | 0.0071 (10) | 0.0036 (11) | 0.0167 (11) |
C4 | 0.0420 (11) | 0.0651 (14) | 0.0581 (12) | 0.0092 (9) | 0.0054 (9) | 0.0160 (10) |
C5 | 0.0573 (15) | 0.104 (2) | 0.099 (2) | 0.0172 (16) | −0.0144 (14) | 0.0322 (19) |
C6 | 0.0515 (14) | 0.0708 (17) | 0.123 (3) | −0.0235 (13) | 0.0128 (15) | 0.0149 (17) |
C7 | 0.0416 (10) | 0.0420 (10) | 0.0769 (14) | −0.0074 (8) | 0.0163 (10) | −0.0006 (10) |
C8 | 0.0545 (12) | 0.0484 (11) | 0.0620 (12) | −0.0066 (9) | 0.0134 (10) | 0.0077 (9) |
C9 | 0.0490 (10) | 0.0397 (9) | 0.0424 (9) | 0.0008 (8) | 0.0091 (8) | −0.0036 (7) |
C10 | 0.0707 (15) | 0.0657 (14) | 0.0515 (12) | −0.0064 (12) | −0.0051 (11) | 0.0078 (11) |
C11 | 0.0409 (10) | 0.0451 (10) | 0.0455 (9) | −0.0025 (8) | 0.0018 (7) | 0.0016 (8) |
C12 | 0.0574 (13) | 0.0620 (14) | 0.0636 (13) | 0.0038 (11) | 0.0178 (11) | −0.0036 (11) |
C13 | 0.094 (2) | 0.0662 (16) | 0.0643 (15) | 0.0007 (15) | 0.0157 (14) | −0.0183 (13) |
C14 | 0.091 (2) | 0.0650 (16) | 0.0643 (14) | −0.0118 (14) | −0.0108 (14) | −0.0220 (12) |
C15 | 0.0516 (12) | 0.0530 (12) | 0.0582 (12) | −0.0069 (9) | −0.0133 (9) | −0.0025 (10) |
Cu1—O3 | 1.9382 (15) | C5—H5A | 0.96 |
Cu1—O4 | 1.9385 (15) | C5—H5B | 0.96 |
Cu1—O2 | 1.9433 (15) | C5—H5C | 0.96 |
Cu1—O1 | 1.9460 (14) | C6—C7 | 1.505 (3) |
Cu1—N1 | 2.3287 (17) | C6—H6A | 0.96 |
N1—C11 | 1.337 (3) | C6—H6B | 0.96 |
N1—C15 | 1.341 (3) | C6—H6C | 0.96 |
N2—C11 | 1.348 (3) | C7—C8 | 1.383 (3) |
N2—H2A | 0.86 | C8—C9 | 1.392 (3) |
N2—H2B | 0.86 | C8—H8 | 0.93 |
O1—C2 | 1.263 (2) | C9—C10 | 1.499 (3) |
O2—C4 | 1.273 (3) | C10—H10A | 0.96 |
O3—C7 | 1.275 (3) | C10—H10B | 0.96 |
O4—C9 | 1.267 (2) | C10—H10C | 0.96 |
C1—C2 | 1.494 (3) | C11—C12 | 1.404 (3) |
C1—H1A | 0.96 | C12—C13 | 1.354 (4) |
C1—H1B | 0.96 | C12—H12 | 0.93 |
C1—H1C | 0.96 | C13—C14 | 1.380 (4) |
C2—C3 | 1.401 (3) | C13—H13 | 0.93 |
C3—C4 | 1.376 (4) | C14—C15 | 1.371 (4) |
C3—H3 | 0.93 | C14—H14 | 0.93 |
C4—C5 | 1.510 (3) | C15—H15 | 0.93 |
O3—Cu1—O4 | 92.98 (6) | H5A—C5—H5C | 109.5 |
O3—Cu1—O2 | 85.42 (7) | H5B—C5—H5C | 109.5 |
O4—Cu1—O2 | 168.65 (7) | C7—C6—H6A | 109.5 |
O3—Cu1—O1 | 165.46 (7) | C7—C6—H6B | 109.5 |
O4—Cu1—O1 | 86.24 (6) | H6A—C6—H6B | 109.5 |
O2—Cu1—O1 | 92.49 (7) | C7—C6—H6C | 109.5 |
O3—Cu1—N1 | 98.10 (7) | H6A—C6—H6C | 109.5 |
O4—Cu1—N1 | 93.37 (6) | H6B—C6—H6C | 109.5 |
O2—Cu1—N1 | 97.98 (7) | O3—C7—C8 | 125.66 (19) |
O1—Cu1—N1 | 96.45 (6) | O3—C7—C6 | 115.1 (2) |
C11—N1—C15 | 117.42 (19) | C8—C7—C6 | 119.2 (2) |
C11—N1—Cu1 | 125.14 (13) | C7—C8—C9 | 125.1 (2) |
C15—N1—Cu1 | 116.98 (15) | C7—C8—H8 | 117.5 |
C11—N2—H2A | 120 | C9—C8—H8 | 117.5 |
C11—N2—H2B | 120 | O4—C9—C8 | 125.0 (2) |
H2A—N2—H2B | 120 | O4—C9—C10 | 115.89 (19) |
C2—O1—Cu1 | 125.96 (14) | C8—C9—C10 | 119.1 (2) |
C4—O2—Cu1 | 125.07 (15) | C9—C10—H10A | 109.5 |
C7—O3—Cu1 | 124.51 (14) | C9—C10—H10B | 109.5 |
C9—O4—Cu1 | 125.43 (13) | H10A—C10—H10B | 109.5 |
C2—C1—H1A | 109.5 | C9—C10—H10C | 109.5 |
C2—C1—H1B | 109.5 | H10A—C10—H10C | 109.5 |
H1A—C1—H1B | 109.5 | H10B—C10—H10C | 109.5 |
C2—C1—H1C | 109.5 | N1—C11—N2 | 117.83 (19) |
H1A—C1—H1C | 109.5 | N1—C11—C12 | 121.8 (2) |
H1B—C1—H1C | 109.5 | N2—C11—C12 | 120.3 (2) |
O1—C2—C3 | 124.5 (2) | C13—C12—C11 | 119.1 (2) |
O1—C2—C1 | 116.3 (2) | C13—C12—H12 | 120.5 |
C3—C2—C1 | 119.2 (2) | C11—C12—H12 | 120.5 |
C4—C3—C2 | 125.3 (2) | C12—C13—C14 | 119.8 (2) |
C4—C3—H3 | 117.4 | C12—C13—H13 | 120.1 |
C2—C3—H3 | 117.4 | C14—C13—H13 | 120.1 |
O2—C4—C3 | 125.6 (2) | C15—C14—C13 | 117.9 (2) |
O2—C4—C5 | 115.0 (2) | C15—C14—H14 | 121 |
C3—C4—C5 | 119.4 (2) | C13—C14—H14 | 121 |
C4—C5—H5A | 109.5 | N1—C15—C14 | 123.9 (2) |
C4—C5—H5B | 109.5 | N1—C15—H15 | 118 |
H5A—C5—H5B | 109.5 | C14—C15—H15 | 118 |
C4—C5—H5C | 109.5 | ||
O3—Cu1—N1—C11 | −137.55 (16) | O1—C2—C3—C4 | −5.2 (4) |
O4—Cu1—N1—C11 | −44.05 (16) | C1—C2—C3—C4 | 175.0 (3) |
O2—Cu1—N1—C11 | 135.98 (16) | Cu1—O2—C4—C3 | 6.3 (4) |
O1—Cu1—N1—C11 | 42.55 (16) | Cu1—O2—C4—C5 | −174.41 (19) |
O3—Cu1—N1—C15 | 34.41 (16) | C2—C3—C4—O2 | 3.6 (4) |
O4—Cu1—N1—C15 | 127.91 (16) | C2—C3—C4—C5 | −175.7 (3) |
O2—Cu1—N1—C15 | −52.06 (16) | Cu1—O3—C7—C8 | −9.0 (3) |
O1—Cu1—N1—C15 | −145.50 (16) | Cu1—O3—C7—C6 | 171.34 (19) |
O3—Cu1—O1—C2 | −72.0 (3) | O3—C7—C8—C9 | −0.6 (4) |
O4—Cu1—O1—C2 | −159.40 (18) | C6—C7—C8—C9 | 179.1 (2) |
O2—Cu1—O1—C2 | 9.31 (18) | Cu1—O4—C9—C8 | 5.3 (3) |
N1—Cu1—O1—C2 | 107.63 (17) | Cu1—O4—C9—C10 | −175.27 (16) |
O3—Cu1—O2—C4 | 155.0 (2) | C7—C8—C9—O4 | 2.6 (4) |
O4—Cu1—O2—C4 | 72.7 (4) | C7—C8—C9—C10 | −176.8 (2) |
O1—Cu1—O2—C4 | −10.57 (19) | C15—N1—C11—N2 | 177.6 (2) |
N1—Cu1—O2—C4 | −107.44 (19) | Cu1—N1—C11—N2 | −10.5 (3) |
O4—Cu1—O3—C7 | 12.22 (19) | C15—N1—C11—C12 | −1.1 (3) |
O2—Cu1—O3—C7 | −156.52 (19) | Cu1—N1—C11—C12 | 170.87 (16) |
O1—Cu1—O3—C7 | −74.3 (3) | N1—C11—C12—C13 | 1.3 (4) |
N1—Cu1—O3—C7 | 106.05 (18) | N2—C11—C12—C13 | −177.3 (3) |
O3—Cu1—O4—C9 | −10.53 (17) | C11—C12—C13—C14 | −0.3 (4) |
O2—Cu1—O4—C9 | 71.0 (4) | C12—C13—C14—C15 | −0.7 (5) |
O1—Cu1—O4—C9 | 154.92 (17) | C11—N1—C15—C14 | −0.1 (4) |
N1—Cu1—O4—C9 | −108.83 (16) | Cu1—N1—C15—C14 | −172.7 (2) |
Cu1—O1—C2—C3 | −3.5 (3) | C13—C14—C15—N1 | 0.9 (4) |
Cu1—O1—C2—C1 | 176.35 (16) |
D—H···A | D—H | H···A | D···A | D—H···A |
N2—H2A···O1 | 0.86 | 2.29 | 3.054 (3) | 149 |
N2—H2B···O2i | 0.86 | 2.48 | 3.248 (3) | 149 |
N2—H2B···O3i | 0.86 | 2.56 | 3.301 (3) | 144 |
Symmetry code: (i) x+1, y, z. |
[Cu(C5H7O2)2(C4H5N3)] | F(000) = 740 |
Mr = 356.86 | Dx = 1.462 Mg m−3 |
Monoclinic, P21/n | Mo Kα radiation, λ = 0.71073 Å |
Hall symbol: -P 2yn | Cell parameters from 3870 reflections |
a = 7.5686 (3) Å | θ = 0.4–27.5° |
b = 8.3504 (3) Å | µ = 1.37 mm−1 |
c = 25.6871 (10) Å | T = 293 K |
β = 93.081 (1)° | Prism, blue |
V = 1621.10 (11) Å3 | 0.55 × 0.38 × 0.13 mm |
Z = 4 |
Nonius KappaCCD area-detector diffractometer | 3658 independent reflections |
Graphite monochromator | 3131 reflections with I > 2σ(I) |
Detector resolution: 0.055 pixels mm-1 | Rint = 0.021 |
ϕ scans + ω scans | θmax = 27.5°, θmin = 3.4° |
Absorption correction: multi-scan (SCALEPACK; Otwinowski & Minor, 1997) | h = −9→9 |
Tmin = 0.520, Tmax = 0.842 | k = −10→10 |
6985 measured reflections | l = −33→33 |
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)] = 0.033 | Hydrogen site location: inferred from neighbouring sites |
wR(F2) = 0.093 | H-atom parameters constrained |
S = 1.1 | w = 1/[σ2(Fo2) + (0.0371P)2 + 0.8686P] where P = (Fo2 + 2Fc2)/3 |
3658 reflections | (Δ/σ)max = 0.001 |
203 parameters | Δρmax = 0.25 e Å−3 |
0 restraints | Δρmin = −0.38 e Å−3 |
[Cu(C5H7O2)2(C4H5N3)] | V = 1621.10 (11) Å3 |
Mr = 356.86 | Z = 4 |
Monoclinic, P21/n | Mo Kα radiation |
a = 7.5686 (3) Å | µ = 1.37 mm−1 |
b = 8.3504 (3) Å | T = 293 K |
c = 25.6871 (10) Å | 0.55 × 0.38 × 0.13 mm |
β = 93.081 (1)° |
Nonius KappaCCD area-detector diffractometer | 3658 independent reflections |
Absorption correction: multi-scan (SCALEPACK; Otwinowski & Minor, 1997) | 3131 reflections with I > 2σ(I) |
Tmin = 0.520, Tmax = 0.842 | Rint = 0.021 |
6985 measured reflections |
R[F2 > 2σ(F2)] = 0.033 | 0 restraints |
wR(F2) = 0.093 | H-atom parameters constrained |
S = 1.1 | Δρmax = 0.25 e Å−3 |
3658 reflections | Δρmin = −0.38 e Å−3 |
203 parameters |
Experimental. 631 frames in 6 sets of ϕ scans + ω scans. Rotation/frame = 1.1 °. Crystal-detector distance = 55.0 mm. Measuring time = 20 s/°. |
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. |
x | y | z | Uiso*/Ueq | ||
Cu1 | 0.08123 (3) | 0.55022 (3) | 0.901115 (10) | 0.04168 (11) | |
N1 | 0.2227 (2) | 0.4135 (2) | 0.83418 (7) | 0.0411 (4) | |
N2 | 0.5038 (3) | 0.4901 (3) | 0.86093 (9) | 0.0643 (6) | |
H2B | 0.6168 | 0.4859 | 0.8588 | 0.096* | |
H2A | 0.4585 | 0.5525 | 0.8832 | 0.096* | |
N3 | 0.4779 (3) | 0.3046 (3) | 0.79559 (9) | 0.0611 (6) | |
O1 | 0.2359 (2) | 0.73558 (18) | 0.90285 (7) | 0.0465 (4) | |
O2 | −0.0965 (2) | 0.6569 (2) | 0.85606 (7) | 0.0521 (4) | |
O3 | −0.0968 (2) | 0.3882 (2) | 0.90995 (7) | 0.0525 (4) | |
O4 | 0.2403 (2) | 0.46119 (18) | 0.95510 (6) | 0.0444 (4) | |
C10 | 0.3427 (3) | 0.3062 (3) | 1.02684 (10) | 0.0564 (6) | |
H10A | 0.4301 | 0.3896 | 1.0292 | 0.085* | |
H10B | 0.3978 | 0.2071 | 1.018 | 0.085* | |
H10C | 0.2896 | 0.2952 | 1.0598 | 0.085* | |
C9 | 0.2033 (3) | 0.3480 (3) | 0.98569 (8) | 0.0400 (4) | |
C8 | 0.0440 (3) | 0.2632 (3) | 0.98319 (10) | 0.0494 (5) | |
H8 | 0.0295 | 0.1853 | 1.0085 | 0.059* | |
C7 | −0.0938 (3) | 0.2851 (3) | 0.94645 (10) | 0.0456 (5) | |
C6 | −0.2561 (3) | 0.1817 (4) | 0.94813 (14) | 0.0702 (8) | |
H6A | −0.2597 | 0.1084 | 0.9193 | 0.105* | |
H6B | −0.3598 | 0.248 | 0.946 | 0.105* | |
H6C | −0.2523 | 0.1225 | 0.9802 | 0.105* | |
C5 | −0.2585 (4) | 0.8629 (4) | 0.81288 (13) | 0.0775 (9) | |
H5A | −0.3641 | 0.8165 | 0.8255 | 0.116* | |
H5B | −0.2465 | 0.8313 | 0.7773 | 0.116* | |
H5C | −0.2657 | 0.9775 | 0.8149 | 0.116* | |
C4 | −0.1002 (3) | 0.8053 (3) | 0.84581 (9) | 0.0510 (6) | |
C3 | 0.0300 (3) | 0.9143 (3) | 0.86184 (11) | 0.0565 (6) | |
H3 | 0.0078 | 1.0222 | 0.8553 | 0.068* | |
C2 | 0.1921 (3) | 0.8742 (3) | 0.88710 (9) | 0.0437 (5) | |
C1 | 0.3282 (4) | 1.0027 (3) | 0.89787 (12) | 0.0620 (7) | |
H1A | 0.4112 | 1.0024 | 0.8709 | 0.093* | |
H1B | 0.3895 | 0.9828 | 0.9309 | 0.093* | |
H1C | 0.2707 | 1.1051 | 0.8987 | 0.093* | |
C11 | 0.3989 (3) | 0.3995 (3) | 0.82958 (8) | 0.0436 (5) | |
C12 | 0.3706 (5) | 0.2220 (4) | 0.76369 (12) | 0.0730 (8) | |
H12 | 0.4201 | 0.1549 | 0.7395 | 0.088* | |
C13 | 0.1878 (5) | 0.2299 (4) | 0.76421 (11) | 0.0712 (8) | |
H13 | 0.1151 | 0.1722 | 0.7407 | 0.085* | |
C14 | 0.1198 (4) | 0.3268 (3) | 0.80107 (10) | 0.0535 (6) | |
H14 | −0.0023 | 0.3325 | 0.8032 | 0.064* |
U11 | U22 | U33 | U12 | U13 | U23 | |
Cu1 | 0.03054 (14) | 0.04385 (17) | 0.04999 (17) | −0.00804 (10) | −0.00406 (10) | 0.00555 (12) |
N1 | 0.0420 (9) | 0.0396 (9) | 0.0409 (9) | −0.0046 (7) | −0.0052 (7) | −0.0008 (7) |
N2 | 0.0357 (10) | 0.0872 (16) | 0.0699 (14) | −0.0044 (11) | 0.0020 (9) | −0.0300 (13) |
N3 | 0.0691 (14) | 0.0596 (13) | 0.0560 (12) | −0.0023 (11) | 0.0183 (10) | −0.0119 (10) |
O1 | 0.0367 (8) | 0.0397 (8) | 0.0624 (10) | −0.0067 (6) | −0.0040 (7) | 0.0046 (7) |
O2 | 0.0353 (8) | 0.0595 (10) | 0.0603 (10) | −0.0040 (7) | −0.0071 (7) | 0.0078 (8) |
O3 | 0.0350 (8) | 0.0591 (10) | 0.0625 (10) | −0.0156 (7) | −0.0048 (7) | 0.0076 (8) |
O4 | 0.0375 (8) | 0.0496 (9) | 0.0455 (8) | −0.0111 (6) | −0.0031 (6) | 0.0067 (7) |
C10 | 0.0554 (14) | 0.0634 (16) | 0.0497 (13) | −0.0032 (12) | −0.0049 (11) | 0.0084 (12) |
C9 | 0.0422 (11) | 0.0389 (11) | 0.0395 (10) | 0.0012 (9) | 0.0060 (8) | −0.0050 (9) |
C8 | 0.0467 (12) | 0.0436 (12) | 0.0587 (13) | −0.0066 (10) | 0.0096 (10) | 0.0067 (10) |
C7 | 0.0358 (10) | 0.0398 (11) | 0.0623 (14) | −0.0069 (9) | 0.0119 (9) | −0.0037 (10) |
C6 | 0.0451 (14) | 0.0637 (17) | 0.102 (2) | −0.0209 (13) | 0.0083 (14) | 0.0072 (16) |
C5 | 0.0504 (15) | 0.096 (2) | 0.084 (2) | 0.0119 (16) | −0.0123 (14) | 0.0251 (18) |
C4 | 0.0374 (11) | 0.0663 (16) | 0.0493 (12) | 0.0061 (10) | 0.0037 (9) | 0.0132 (11) |
C3 | 0.0501 (13) | 0.0478 (13) | 0.0716 (16) | 0.0033 (11) | 0.0015 (12) | 0.0143 (12) |
C2 | 0.0433 (11) | 0.0411 (12) | 0.0473 (11) | −0.0028 (9) | 0.0072 (9) | 0.0026 (10) |
C1 | 0.0621 (16) | 0.0450 (13) | 0.0785 (18) | −0.0111 (12) | 0.0010 (14) | 0.0043 (13) |
C11 | 0.0455 (12) | 0.0448 (11) | 0.0405 (11) | −0.0013 (9) | 0.0033 (9) | 0.0012 (9) |
C12 | 0.097 (2) | 0.0664 (18) | 0.0566 (16) | −0.0075 (17) | 0.0158 (15) | −0.0204 (14) |
C13 | 0.093 (2) | 0.0628 (17) | 0.0561 (16) | −0.0135 (16) | −0.0094 (15) | −0.0192 (13) |
C14 | 0.0585 (14) | 0.0484 (13) | 0.0521 (13) | −0.0080 (11) | −0.0123 (11) | −0.0008 (11) |
Cu1—O3 | 1.9317 (16) | C8—H8 | 0.93 |
Cu1—O4 | 1.9352 (15) | C7—C6 | 1.504 (3) |
Cu1—O1 | 1.9397 (15) | C6—H6A | 0.96 |
Cu1—O2 | 1.9428 (16) | C6—H6B | 0.96 |
Cu1—N1 | 2.3672 (19) | C6—H6C | 0.96 |
N1—C14 | 1.335 (3) | C5—C4 | 1.508 (3) |
N1—C11 | 1.350 (3) | C5—H5A | 0.96 |
N2—C11 | 1.335 (3) | C5—H5B | 0.96 |
N2—H2B | 0.86 | C5—H5C | 0.96 |
N2—H2A | 0.86 | C4—C3 | 1.388 (4) |
N3—C12 | 1.317 (4) | C3—C2 | 1.397 (3) |
N3—C11 | 1.343 (3) | C3—H3 | 0.93 |
O1—C2 | 1.265 (3) | C2—C1 | 1.503 (3) |
O2—C4 | 1.267 (3) | C1—H1A | 0.96 |
O3—C7 | 1.272 (3) | C1—H1B | 0.96 |
O4—C9 | 1.270 (3) | C1—H1C | 0.96 |
C10—C9 | 1.494 (3) | C12—C13 | 1.385 (5) |
C10—H10A | 0.96 | C12—H12 | 0.93 |
C10—H10B | 0.96 | C13—C14 | 1.367 (4) |
C10—H10C | 0.96 | C13—H13 | 0.93 |
C9—C8 | 1.396 (3) | C14—H14 | 0.93 |
C8—C7 | 1.381 (3) | ||
O3—Cu1—O4 | 93.31 (7) | H6A—C6—H6B | 109.5 |
O3—Cu1—O1 | 168.59 (8) | C7—C6—H6C | 109.5 |
O4—Cu1—O1 | 86.48 (6) | H6A—C6—H6C | 109.5 |
O3—Cu1—O2 | 85.76 (7) | H6B—C6—H6C | 109.5 |
O4—Cu1—O2 | 170.76 (7) | C4—C5—H5A | 109.5 |
O1—Cu1—O2 | 92.61 (7) | C4—C5—H5B | 109.5 |
O3—Cu1—N1 | 95.35 (7) | H5A—C5—H5B | 109.5 |
O4—Cu1—N1 | 92.69 (7) | C4—C5—H5C | 109.5 |
O1—Cu1—N1 | 96.05 (7) | H5A—C5—H5C | 109.5 |
O2—Cu1—N1 | 96.55 (7) | H5B—C5—H5C | 109.5 |
C14—N1—C11 | 116.2 (2) | O2—C4—C3 | 124.9 (2) |
C14—N1—Cu1 | 116.94 (16) | O2—C4—C5 | 115.9 (2) |
C11—N1—Cu1 | 126.36 (14) | C3—C4—C5 | 119.2 (3) |
C11—N2—H2B | 120 | C4—C3—C2 | 124.9 (2) |
C11—N2—H2A | 120 | C4—C3—H3 | 117.5 |
H2B—N2—H2A | 120 | C2—C3—H3 | 117.5 |
C12—N3—C11 | 115.6 (2) | O1—C2—C3 | 125.2 (2) |
C2—O1—Cu1 | 125.15 (14) | O1—C2—C1 | 115.5 (2) |
C4—O2—Cu1 | 125.38 (16) | C3—C2—C1 | 119.3 (2) |
C7—O3—Cu1 | 125.12 (14) | C2—C1—H1A | 109.5 |
C9—O4—Cu1 | 125.45 (14) | C2—C1—H1B | 109.5 |
C9—C10—H10A | 109.5 | H1A—C1—H1B | 109.5 |
C9—C10—H10B | 109.5 | C2—C1—H1C | 109.5 |
H10A—C10—H10B | 109.5 | H1A—C1—H1C | 109.5 |
C9—C10—H10C | 109.5 | H1B—C1—H1C | 109.5 |
H10A—C10—H10C | 109.5 | N2—C11—N3 | 117.1 (2) |
H10B—C10—H10C | 109.5 | N2—C11—N1 | 117.2 (2) |
O4—C9—C8 | 124.6 (2) | N3—C11—N1 | 125.7 (2) |
O4—C9—C10 | 116.2 (2) | N3—C12—C13 | 123.5 (3) |
C8—C9—C10 | 119.3 (2) | N3—C12—H12 | 118.3 |
C7—C8—C9 | 125.6 (2) | C13—C12—H12 | 118.3 |
C7—C8—H8 | 117.2 | C14—C13—C12 | 116.6 (3) |
C9—C8—H8 | 117.2 | C14—C13—H13 | 121.7 |
O3—C7—C8 | 125.2 (2) | C12—C13—H13 | 121.7 |
O3—C7—C6 | 115.3 (2) | N1—C14—C13 | 122.3 (3) |
C8—C7—C6 | 119.5 (2) | N1—C14—H14 | 118.9 |
C7—C6—H6A | 109.5 | C13—C14—H14 | 118.9 |
C7—C6—H6B | 109.5 | ||
O3—Cu1—N1—C14 | 34.21 (17) | C10—C9—C8—C7 | −177.8 (2) |
O4—Cu1—N1—C14 | 127.80 (17) | Cu1—O3—C7—C8 | −5.7 (3) |
O1—Cu1—N1—C14 | −145.46 (17) | Cu1—O3—C7—C6 | 174.26 (18) |
O2—Cu1—N1—C14 | −52.12 (17) | C9—C8—C7—O3 | −1.4 (4) |
O3—Cu1—N1—C11 | −137.68 (18) | C9—C8—C7—C6 | 178.6 (2) |
O4—Cu1—N1—C11 | −44.10 (18) | Cu1—O2—C4—C3 | 5.4 (4) |
O1—Cu1—N1—C11 | 42.65 (19) | Cu1—O2—C4—C5 | −175.71 (19) |
O2—Cu1—N1—C11 | 135.98 (18) | O2—C4—C3—C2 | 6.7 (4) |
O3—Cu1—O1—C2 | −69.0 (4) | C5—C4—C3—C2 | −172.2 (3) |
O4—Cu1—O1—C2 | −158.34 (19) | Cu1—O1—C2—C3 | −5.7 (3) |
O2—Cu1—O1—C2 | 12.46 (19) | Cu1—O1—C2—C1 | 173.44 (17) |
N1—Cu1—O1—C2 | 109.33 (19) | C4—C3—C2—O1 | −6.6 (4) |
O3—Cu1—O2—C4 | 156.3 (2) | C4—C3—C2—C1 | 174.3 (3) |
O1—Cu1—O2—C4 | −12.4 (2) | C12—N3—C11—N2 | −177.2 (3) |
N1—Cu1—O2—C4 | −108.8 (2) | C12—N3—C11—N1 | 1.6 (4) |
O4—Cu1—O3—C7 | 8.6 (2) | C14—N1—C11—N2 | 177.4 (2) |
O1—Cu1—O3—C7 | −80.0 (4) | Cu1—N1—C11—N2 | −10.6 (3) |
O2—Cu1—O3—C7 | −162.1 (2) | C14—N1—C11—N3 | −1.3 (3) |
N1—Cu1—O3—C7 | 101.66 (19) | Cu1—N1—C11—N3 | 170.61 (18) |
O3—Cu1—O4—C9 | −7.73 (18) | C11—N3—C12—C13 | 0.0 (5) |
O1—Cu1—O4—C9 | 160.84 (18) | N3—C12—C13—C14 | −1.6 (5) |
N1—Cu1—O4—C9 | −103.26 (17) | C11—N1—C14—C13 | −0.5 (4) |
Cu1—O4—C9—C8 | 3.8 (3) | Cu1—N1—C14—C13 | −173.2 (2) |
Cu1—O4—C9—C10 | −175.92 (16) | C12—C13—C14—N1 | 1.8 (4) |
O4—C9—C8—C7 | 2.4 (4) |
Experimental details
(I) | (II) | |
Crystal data | ||
Chemical formula | [Cu(C5H7O2)2(C5H6N2)] | [Cu(C5H7O2)2(C4H5N3)] |
Mr | 355.87 | 356.86 |
Crystal system, space group | Monoclinic, P21/n | Monoclinic, P21/n |
Temperature (K) | 293 | 293 |
a, b, c (Å) | 7.5686 (1), 8.2944 (2), 26.4250 (7) | 7.5686 (3), 8.3504 (3), 25.6871 (10) |
β (°) | 93.944 (1) | 93.081 (1) |
V (Å3) | 1654.95 (6) | 1621.10 (11) |
Z | 4 | 4 |
Radiation type | Mo Kα | Mo Kα |
µ (mm−1) | 1.34 | 1.37 |
Crystal size (mm) | 0.6 × 0.6 × 0.25 | 0.55 × 0.38 × 0.13 |
Data collection | ||
Diffractometer | Nonius KappaCCD area-detector diffractometer | Nonius KappaCCD area-detector diffractometer |
Absorption correction | Multi-scan (SCALEPACK; Otwinowski & Minor, 1997) | Multi-scan (SCALEPACK; Otwinowski & Minor, 1997) |
Tmin, Tmax | 0.501, 0.731 | 0.520, 0.842 |
No. of measured, independent and observed [I > 2σ(I)] reflections | 6316, 3572, 3238 | 6985, 3658, 3131 |
Rint | 0.026 | 0.021 |
(sin θ/λ)max (Å−1) | 0.649 | 0.649 |
Refinement | ||
R[F2 > 2σ(F2)], wR(F2), S | 0.037, 0.106, 1.06 | 0.033, 0.093, 1.1 |
No. of reflections | 3572 | 3658 |
No. of parameters | 203 | 203 |
H-atom treatment | H-atom parameters constrained | H-atom parameters constrained |
Δρmax, Δρmin (e Å−3) | 0.27, −0.48 | 0.25, −0.38 |
Computer programs: COLLECT (Nonius, 1998), DENZO-SMN (Otwinowski & Minor, 1997), SIR97 (Altomare et al., 1999), SHELXL97 (Sheldrick, 2008), ORTEP-3 (Farrugia, 1997) and DIAMOND (Brandenburg, 1999), WinGX (Farrugia, 1999), PLATON (Spek, 2009) and publCIF (Westrip, 2010).
Cu1—O3 | 1.9382 (15) | Cu1—O1 | 1.9460 (14) |
Cu1—O4 | 1.9385 (15) | Cu1—N1 | 2.3287 (17) |
Cu1—O2 | 1.9433 (15) | ||
O3—Cu1—O4 | 92.98 (6) | O2—Cu1—O1 | 92.49 (7) |
O3—Cu1—O2 | 85.42 (7) | O3—Cu1—N1 | 98.10 (7) |
O4—Cu1—O2 | 168.65 (7) | O4—Cu1—N1 | 93.37 (6) |
O3—Cu1—O1 | 165.46 (7) | O2—Cu1—N1 | 97.98 (7) |
O4—Cu1—O1 | 86.24 (6) | O1—Cu1—N1 | 96.45 (6) |
D—H···A | D—H | H···A | D···A | D—H···A |
N2—H2A···O1 | 0.86 | 2.29 | 3.054 (3) | 148.9 |
N2—H2B···O2i | 0.86 | 2.48 | 3.248 (3) | 149.3 |
N2—H2B···O3i | 0.86 | 2.56 | 3.301 (3) | 144.4 |
Symmetry code: (i) x+1, y, z. |
Cu1—O3 | 1.9317 (16) | Cu1—O2 | 1.9428 (16) |
Cu1—O4 | 1.9352 (15) | Cu1—N1 | 2.3672 (19) |
Cu1—O1 | 1.9397 (15) | ||
O3—Cu1—O4 | 93.31 (7) | O1—Cu1—O2 | 92.61 (7) |
O3—Cu1—O1 | 168.59 (8) | O3—Cu1—N1 | 95.35 (7) |
O4—Cu1—O1 | 86.48 (6) | O4—Cu1—N1 | 92.69 (7) |
O3—Cu1—O2 | 85.76 (7) | O1—Cu1—N1 | 96.05 (7) |
O4—Cu1—O2 | 170.76 (7) | O2—Cu1—N1 | 96.55 (7) |
D—H···A | D—H | H···A | D···A | D—H···A |
N2—H2A···O1 | 0.86 | 2.35 | 3.116 (3) | 148.6 |
Metal β-diketonate compounds attract great interest, because metal complexes of β-diketonate derivatives can be used as good precursors in metal–organic chemical vapour deposition (MOCVD) (Kodas & Hampden-Smith, 1994), or as building blocks for the design of porous and supramolecular materials (Bray et al., 2007; Garibay et al., 2009). β-Diketonates and organic compounds containing an amino group are suitable starting materials for the formation of Schiff bases (Bourget-Merle et al., 2002; Holm et al., 1966). Pyridin-2-amine and pyrimidin-2-amine are close analogues of purine and pyrimidine nucleobases and are thus interesting as model compounds. They can act both as metal-coordinating ligands through the aromatic N atom and as hydrogen-bond donors through the amino group. Furthermore, pyrimidin-2-amine has an additional aromatic N atom that can serve as a second ligation centre or as a strong hydrogen-bond acceptor. When we examined the reactivity of bis(pentane-2,4-dionato-O,O')copper(II) with pyridin-2-amine and pyrimidin-2-amine, no Schiff base formation was observed under the applied reaction conditions; instead both compounds acted rather as a nitrogen-donor ligand, occupying the fifth coordination site via an aromatic N atom.
The title compounds, (pentane-2,4-dionato-κ2O,O')(pyridin-2-amine-κN1)copper(II), (I) (Fig. 1), and (pentane-2,4-dionato-κ2O,O')(pyrimidin-2-amine-κN1)copper(II), (II) (Fig. 2), have similar molecular structures. In the equatorial plane, the Cu atom is surrounded by four O atoms of two chelating pentane-2,4-dionate ligands. Selected bond distances and angles are listed in Tables 1 and 3. Bond distances and angles are typical for β-diketonate compounds (Gromilov & Baidina, 2004; Stabnikov et al., 2008; Germán-Acacio et al., 2009). The Cu atom lies above the plane formed by four acetylacetonate O atoms, by 0.219 Å in (I) and 0.174 Å in (II). The fifth coordination site is occupied by the additional ligand in the axial position. The geometry is square-pyramidal with only slight distortion. The distortion of a square-pyramid can be best described by the structural parameter τ = (β – α)/60°, where β and α are the largest angles in the coordination sphere (τ = 0 for a square-pyramid and τ = 1 for a trigonal-bipyramid; Addison et al., 1984), which in this case has values of 0.05 and 0.04 for (I) and (II), respectively. For five-coordinate β-diketonates, square-pyramidal geometry is more common (Bray et al., 2007; Garibay et al., 2009) than trigonal-bipyramidal. But still, the three closely related compounds (4-dimethylaminopyridine-κN)bis(pentane-2,4-dionato-κ2O,O')copper(II), (4-aminopyridine-κN)bis(pentane-2,4-dionato-κ2O,O')copper(II) and (4-dimethylaminopyridine-κN)bis(1,1,1,5,5,5-hexafluoropentane-2,4-dionato-κ2O,O')copper(II) have trigonal–bipyramidal geometry (Lindoy et al., 2006; Stabnikov et al., 2011). The Cu—N bond length is 2.3287 (17) Å in (I) and 2.3672 (19) Å in (II), significantly greater than in the above-mentioned trigonal–bipyramidal compounds (2.119, 2.008 and 1.978 Å, respectively; Lindoy et al., 2006; Stabnikov et al., 2011). However, they are similar to those in square-pyramidal copper(II) pentane-2,4-dionate complexes with adenine (Zaworotko et al., 2009), quinoline (Jose et al., 1969) and isonicotinamide (Germán-Acacio et al., 2009), where the bond lengths are 2.328, 2.357 and 2.384 Å, respectively. The molecular structure is by no means easy to predict. Coordination geometry can be influenced by electronic, steric and packing effects. Even small changes in noncovalent bonding, such as hydrogen-bonding and π–π interactions, might lead to different coordination geometry. Quantum-mechanical studies would be needed to understand the differences in geometries.
In both (I) and (II), the two acetylacetonate ligands are not coplanar. The angle formed between the Cu1/O1/C2–C4/O2 and Cu1/O3/C6–C8/O4 rings is 30.84 (8)° in (I) and 26.89 (8)° in (II). The pyridine and pyrimidine rings are not perpendicular to the O1/O2/O3/O4 plane, but form an angle of 81.72° in (I) and 81.35° in (II). Furthermore, the pyridine and pyrimidine rings are slightly rotated towards the O1 atom, as can be seen by comparing the O1—Cu1—N1—C11 and O4—Cu1—N1—C11 torsion angles [41.55 (16) and -44.05 (16)°, respectively, in (I), and 42.65 (19) and -44.10 (18)°, respectively, in (II)]. Owing to this rotation, the amino groups in both compounds form an intramolecular hydrogen bond with the O1 atom and not with the O4 atom (Tables 2 and 4). The graph-set motif is S(6) (Bernstein et al., 1995). In compound (I), a chain is formed due to the intermolecular bifurcated hydrogen bonds N2—H2b···O2(x+1, y, z) and N2—H2b···O3(x+1, y, z), with the graph-set motif C12(6)[R12(4)] (Fig. 3). Although the packing in (II) is similar, no intermolecular hydrogen bonding was observed owing to a somewhat larger separation between atom N2 and atoms O2 and O3 of an adjacent molecule, viz. 3.248 (3) and 3.301 (3) Å in (I), and 3.339 (3) Å and 3.322 (3) Å in (II). The H2b···O2(x+1, y, z) and H2b···O3(x+1, y, z) hydrogen-bond separations in (I) are 2.48 and 2.56 Å; the separations are, however, slightly longer in (II), where both contacts are 2.60 Å. The degree of similarity between crystals can be defined, for example, by the unit-cell similarity index (Π). In the event of great similarity of two unit cells, the index Π is practically zero (Kálmán et al., 1993), as can be observed also for (I) and (II) with Π = 0.016. Since the compounds are isostructural, the interactions should also be similar in both cases. The crystal packing in both compounds is similar also because the pyrimide atom N3 in compound (II), which could act as an electron donor, is not involved in the hydrogen bonding or in the metal coordination. For comparison, both N atoms of the pyrimidine ring are involved in the coordination to the copper metal centres in bis(1,1,1,5,5,5-hexafluoropentane-2,4-dionato)copper(II) adducts with pyrimidine and 4-methylpyrimidine (Yasui et al., 2001).
In both square-pyramidal compounds (I) and (II), there are π–π interactions between two parallel neighbouring Cu1/O3/C7–C9/O4 chelate rings, with a Cg1···Cg1(-x, -y, -z+1) centroid–centroid distance of 3.7106 (11) Å, a perpendicular distance from the centroid Cg1 to the plane of the other ring of 3.5682 (8) Å and a slippage between the centroids of 1.018 Å in compound (I). In compound (II), these values are even smaller, since two parallel neighbouring Cu1/O3/C7–C9/O4 rings have a Cg1···Cg1(-x, -y+1, -z+2) centroid–centroid distance of 3.5310 (11) Å, a perpendicular distance from the centroid Cg1 to the plane of the other ring of 3.4535 (8) Å and a slippage between the centroids of 0.736 Å. Such interactions would be consistent with well defined π–π stacking interactions in organic aromatic compounds (Hunter, 1994; Choudhury & Chitra, 2010; Malathy Sony & Ponnuswamy, 2006; Perdih & Perdih, 2011), although the interplanar separations are somewhat greater than the graphite spacing of 3.35 Å (Bacon, 1951). Janiak (2000) classified π–π interactions in nitrogen-containing heteroaromatic compounds where such values would indicate strong interactions, since strong interactions exhibit rather short centroid–centroid contacts (Cg···Cg < 3.8 Å), small slip angles (<25°) and vertical displacements (<1.5 Å), which translate into a sizeable overlap of the aromatic planes. In comparison, medium-to-weak interactions exhibit rather long centroid–centroid distances (>4.0 Å) together with large slip angles (>30°) and vertical displacements (>2.0 Å) (Janiak, 2000; Yang et al., 2005; Dorn et al., 2005). It is arguable whether aromatic π–π interactions are comparable with those observed in (I) and (II), since π-delocalized β-diketonate chelate rings have little or no aromatic character (Cotton et al., 1999). The necessity of the aromaticity for π–π interactions was questioned also by Bloom & Wheller (2011). Detailed analysis of XRD [X-ray diffraction?] data on copper β-diketonates and quantum-mechanical studies would be needed in order to study the nature as well as the factors influencing the π–π interactions in β-diketonates.
Strong π–π interactions are very common in square-planar bis(β-diketonato)copper(II) compounds. For example, in trans-bis(benzoylacetonato)copper(II), bis(pentane-2,4-dionato)copper(II) and bis(3-benzylpentane-2,4-dionato)copper(II), centroid–centroid contacts are 3.13, 3.14 and 3.22 Å, respectively, with parallel metallacycles or deviating from planarity by 0.02° (Hon et al., 1966; Lebrun et al., 1986; Judaš & Kaitner, 2006a). Strong π–π interactions are also present in some square-pyramidal compounds of copper(II) β-diketonates. The shortest interactions were found in catena-[3-cyanopentane-2,4-dionato-O,O',N)(3-cyanopentane-2,4-dionato-O,O')copper(II), with centroid–centroid contacts between two parallel metallacycles of 3.16 Å (Angelova et al., 1989). Centroid–centroid distances in the range 3.23–3.49 Å with parallel metallacycles or deviating from planarity by up to 0.03° were observed in several examples (Lee et al., 2001; Zaworotko et al., 2009; Delgado et al., 2007; Jose et al., 1969; Stabnikov et al., 2008; Caneschi et al., 1988; Song & Iyoda, 2009; Judaš & Kaitner, 2006b; Yoshida et al., 2008; Atienza et al., 2008). Interestingly, when searching the centroid–centroid distances in the range 3.50–4.00 Å, as observed in compounds (I) and (II), we found only two structures, viz. a tricopper complex where the centroid–centroid distance is 3.66 Å and the angle between metallacycles is 0.02° (Maxim et al., 2010), and (isonicotinamide-N)bis(pentane-2,4-dionato-O,O')copper(II), with a centroid–centroid distance of 3.90 Å and an angle between metallacycles of 6.97° (Germán-Acacio et al., 2009).