Supporting information
Crystallographic Information File (CIF) https://doi.org/10.1107/S1600536803014399/ac6048sup1.cif | |
Structure factor file (CIF format) https://doi.org/10.1107/S1600536803014399/ac6048Isup2.hkl |
CCDC reference: 217431
A solution containing 68 mg of CuCl2·2H2O, 25 mg of oxalic acid and 74 mg of dpk in 30 ml of water and 10 ml of methanol was added to a solution of 667 mg of K4SiW12O40 in 50 ml of water and a violet precipitate was formed. The title compound was obtained upon recrystallization of the precipitate in a 2:1 mixture of an acetate buffer and DMF. Elemental analysis(%): found (C, H, N) 46.76, 5.16, 8.42; calculated for C26CuH26N4O8·4H2O: 47.45, 5.21, 8.51. IR (cm−1): 1523, 1427, 1230, 1217, 1032.
The H atoms of the water molecules and hydroxyl groups of the dpkdiol ligand were located in a Fourier difference map. The positions of all remaining H atoms were calculated geometrically. Water molecule H atoms were refined with the O—H distance constrained to 0.85 (1) Å. All remaining H atoms were refined as riding, with isotropic displacement parameters fixed at 1.2 (aromatic C) or 1.5 (methyl and hydroxyl groups) times the equivalent isotropic displacement parameters of their parent atoms.
Data collection: CrysAlis CCD (Oxford Diffraction, 2002); cell refinement: CrysAlis RED (Oxford Diffraction, 2002); data reduction: CrysAlis RED; program(s) used to solve structure: DIRDIF99.2 (Beurskens et al., 1999); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: ORTEP-3 for Windows (Farrugia, 1997); software used to prepare material for publication: WinGX (Farrugia, 1999).
[Cu(C11H10N2O2)2](C2H3O2)2·4H2O | F(000) = 686 |
Mr = 658.11 | Dx = 1.408 Mg m−3 |
Monoclinic, P21/n | Mo Kα radiation, λ = 0.71073 Å |
Hall symbol: -P 2yn | Cell parameters from 6500 reflections |
a = 8.617 (1) Å | θ = 3.5–25° |
b = 7.8765 (9) Å | µ = 0.77 mm−1 |
c = 23.103 (3) Å | T = 293 K |
β = 98.00 (1)° | Prism, purple |
V = 1552.8 (3) Å3 | 0.37 × 0.23 × 0.10 mm |
Z = 2 |
Xcalibur diffractometer | 4484 independent reflections |
Radiation source: fine-focus sealed tube | 2765 reflections with I > 2σ(I) |
Graphite monochromator | Rint = 0.044 |
Detector resolution: 1024 × 1024 with blocks 2 × 2 pixels mm-1 | θmax = 30°, θmin = 3.5° |
ω scans | h = −12→12 |
Absorption correction: analytical (CrysAlis RED; Oxford Diffraction, 2002) | k = −11→8 |
Tmin = 0.793, Tmax = 0.931 | l = −32→32 |
12971 measured reflections |
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)] = 0.049 | H atoms treated by a mixture of independent and constrained refinement |
wR(F2) = 0.115 | w = 1/[σ2(Fo2) + (0.0588P)2] where P = (Fo2 + 2Fc2)/3 |
S = 0.96 | (Δ/σ)max = 0.001 |
4480 reflections | Δρmax = 0.47 e Å−3 |
211 parameters | Δρmin = −0.34 e Å−3 |
4 restraints |
[Cu(C11H10N2O2)2](C2H3O2)2·4H2O | V = 1552.8 (3) Å3 |
Mr = 658.11 | Z = 2 |
Monoclinic, P21/n | Mo Kα radiation |
a = 8.617 (1) Å | µ = 0.77 mm−1 |
b = 7.8765 (9) Å | T = 293 K |
c = 23.103 (3) Å | 0.37 × 0.23 × 0.10 mm |
β = 98.00 (1)° |
Xcalibur diffractometer | 4484 independent reflections |
Absorption correction: analytical (CrysAlis RED; Oxford Diffraction, 2002) | 2765 reflections with I > 2σ(I) |
Tmin = 0.793, Tmax = 0.931 | Rint = 0.044 |
12971 measured reflections |
R[F2 > 2σ(F2)] = 0.049 | 4 restraints |
wR(F2) = 0.115 | H atoms treated by a mixture of independent and constrained refinement |
S = 0.96 | Δρmax = 0.47 e Å−3 |
4480 reflections | Δρmin = −0.34 e Å−3 |
211 parameters |
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. |
x | y | z | Uiso*/Ueq | ||
Cu1 | 0.0000 | 0.0000 | 0.0000 | 0.03418 (12) | |
O14 | −0.03830 (18) | 0.26003 (18) | −0.05417 (6) | 0.0367 (3) | |
H14 | −0.0435 | 0.2576 | −0.0899 | 0.055* | |
O15 | −0.2598 (2) | 0.43429 (19) | −0.06184 (7) | 0.0479 (4) | |
H15 | −0.2623 | 0.4341 | −0.0975 | 0.072* | |
N1 | −0.2177 (2) | −0.0169 (2) | −0.04184 (7) | 0.0342 (4) | |
N13 | −0.0808 (2) | 0.1706 (2) | 0.05422 (7) | 0.0362 (4) | |
C2 | −0.2932 (3) | −0.1636 (3) | −0.05549 (11) | 0.0448 (6) | |
H2 | −0.2429 | −0.2654 | −0.0445 | 0.054* | |
C3 | −0.4424 (3) | −0.1677 (3) | −0.08517 (13) | 0.0568 (7) | |
H3 | −0.4919 | −0.2708 | −0.0949 | 0.068* | |
C4 | −0.5179 (3) | −0.0169 (3) | −0.10027 (13) | 0.0607 (7) | |
H4 | −0.6198 | −0.0171 | −0.1198 | 0.073* | |
C5 | −0.4416 (3) | 0.1343 (3) | −0.08622 (11) | 0.0479 (6) | |
H5 | −0.4909 | 0.2372 | −0.0964 | 0.058* | |
C6 | −0.2907 (2) | 0.1307 (3) | −0.05680 (9) | 0.0339 (5) | |
C7 | −0.1888 (3) | 0.2873 (2) | −0.03881 (9) | 0.0352 (5) | |
C8 | −0.1650 (2) | 0.2981 (2) | 0.02719 (10) | 0.0356 (5) | |
C9 | −0.2239 (3) | 0.4264 (3) | 0.05854 (11) | 0.0462 (6) | |
H9 | −0.2825 | 0.5141 | 0.0394 | 0.055* | |
C10 | −0.1942 (3) | 0.4222 (3) | 0.11879 (12) | 0.0547 (7) | |
H10 | −0.2319 | 0.5080 | 0.1407 | 0.066* | |
C11 | −0.1092 (3) | 0.2917 (3) | 0.14599 (11) | 0.0563 (7) | |
H11 | −0.0891 | 0.2868 | 0.1866 | 0.068* | |
C12 | −0.0535 (3) | 0.1673 (3) | 0.11248 (10) | 0.0458 (6) | |
H12 | 0.0047 | 0.0784 | 0.1310 | 0.055* | |
C20 | −0.1655 (3) | 0.3480 (3) | −0.19680 (11) | 0.0532 (7) | |
C21 | −0.1604 (5) | 0.3642 (5) | −0.26154 (13) | 0.0883 (11) | |
H21A | −0.1804 | 0.2554 | −0.2798 | 0.132* | |
H21B | −0.0588 | 0.4037 | −0.2679 | 0.132* | |
H21C | −0.2387 | 0.4437 | −0.2781 | 0.132* | |
O1 | −0.0614 (2) | 0.2591 (2) | −0.16774 (8) | 0.0582 (5) | |
O2 | −0.2713 (2) | 0.4210 (3) | −0.17510 (8) | 0.0656 (5) | |
O10 | −0.5910 (3) | 0.3908 (3) | −0.21450 (10) | 0.0762 (6) | |
O11 | 0.2041 (3) | 0.1290 (3) | −0.20391 (11) | 0.0742 (6) | |
H10A | −0.4931 (14) | 0.409 (5) | −0.2079 (14) | 0.089* | |
H10B | −0.619 (4) | 0.473 (3) | −0.2368 (13) | 0.089* | |
H11A | 0.124 (3) | 0.184 (4) | −0.1972 (15) | 0.089* | |
H11B | 0.263 (3) | 0.210 (3) | −0.2101 (16) | 0.089* |
U11 | U22 | U33 | U12 | U13 | U23 | |
Cu1 | 0.0351 (2) | 0.03151 (19) | 0.0341 (2) | −0.00007 (17) | −0.00151 (13) | −0.00008 (16) |
O14 | 0.0406 (8) | 0.0370 (8) | 0.0332 (8) | −0.0042 (6) | 0.0071 (6) | 0.0024 (6) |
O15 | 0.0667 (12) | 0.0307 (7) | 0.0457 (10) | 0.0103 (8) | 0.0053 (8) | 0.0059 (7) |
N1 | 0.0376 (9) | 0.0291 (9) | 0.0349 (9) | −0.0042 (8) | 0.0014 (7) | 0.0009 (7) |
N13 | 0.0378 (10) | 0.0400 (9) | 0.0295 (9) | −0.0066 (8) | 0.0006 (7) | −0.0005 (7) |
C2 | 0.0480 (15) | 0.0339 (11) | 0.0522 (15) | −0.0091 (10) | 0.0058 (11) | 0.0009 (10) |
C3 | 0.0493 (16) | 0.0505 (15) | 0.0685 (18) | −0.0192 (13) | 0.0010 (13) | −0.0020 (13) |
C4 | 0.0362 (13) | 0.0736 (19) | 0.0683 (18) | −0.0137 (13) | −0.0067 (11) | 0.0014 (14) |
C5 | 0.0363 (13) | 0.0512 (13) | 0.0540 (15) | 0.0065 (11) | −0.0016 (11) | 0.0078 (12) |
C6 | 0.0347 (12) | 0.0349 (11) | 0.0317 (11) | 0.0006 (9) | 0.0032 (9) | 0.0019 (9) |
C7 | 0.0424 (12) | 0.0280 (10) | 0.0350 (11) | 0.0023 (9) | 0.0044 (9) | 0.0017 (8) |
C8 | 0.0372 (12) | 0.0296 (10) | 0.0405 (12) | −0.0068 (9) | 0.0076 (9) | −0.0005 (9) |
C9 | 0.0524 (15) | 0.0362 (11) | 0.0523 (15) | −0.0028 (11) | 0.0149 (11) | −0.0056 (11) |
C10 | 0.0648 (18) | 0.0510 (14) | 0.0527 (16) | −0.0167 (13) | 0.0234 (13) | −0.0190 (13) |
C11 | 0.0663 (18) | 0.0675 (17) | 0.0356 (13) | −0.0176 (15) | 0.0087 (12) | −0.0078 (12) |
C12 | 0.0486 (14) | 0.0538 (14) | 0.0339 (12) | −0.0072 (11) | 0.0023 (10) | 0.0008 (10) |
C20 | 0.0591 (18) | 0.0570 (15) | 0.0418 (14) | −0.0085 (13) | 0.0009 (13) | 0.0054 (12) |
C21 | 0.109 (3) | 0.111 (3) | 0.0429 (17) | 0.022 (2) | 0.0045 (17) | 0.0133 (17) |
O1 | 0.0571 (11) | 0.0771 (12) | 0.0400 (10) | 0.0093 (10) | 0.0057 (8) | 0.0055 (9) |
O2 | 0.0598 (12) | 0.0834 (13) | 0.0515 (11) | 0.0163 (11) | 0.0007 (9) | 0.0118 (10) |
O10 | 0.0565 (13) | 0.0928 (16) | 0.0798 (16) | 0.0000 (13) | 0.0111 (12) | 0.0166 (12) |
O11 | 0.0554 (14) | 0.0713 (14) | 0.0963 (16) | 0.0008 (10) | 0.0124 (12) | −0.0062 (12) |
Cu1—N1i | 1.9918 (17) | C6—C7 | 1.537 (3) |
Cu1—N1 | 1.9918 (17) | C7—C8 | 1.512 (3) |
Cu1—N13i | 2.0257 (18) | C8—C9 | 1.381 (3) |
Cu1—N13 | 2.0257 (18) | C9—C10 | 1.380 (4) |
Cu1—O14i | 2.3990 (14) | C9—H9 | 0.9300 |
O14—C7 | 1.408 (3) | C10—C11 | 1.364 (4) |
O14—H14 | 0.8200 | C10—H10 | 0.9300 |
O15—C7 | 1.381 (2) | C11—C12 | 1.376 (4) |
O15—H15 | 0.8200 | C11—H11 | 0.9300 |
N1—C2 | 1.342 (3) | C12—H12 | 0.9300 |
N1—C6 | 1.344 (3) | C20—O2 | 1.240 (3) |
N13—C12 | 1.334 (3) | C20—O1 | 1.257 (3) |
N13—C8 | 1.341 (3) | C20—C21 | 1.508 (4) |
C2—C3 | 1.371 (3) | C21—H21A | 0.9600 |
C2—H2 | 0.9300 | C21—H21B | 0.9600 |
C3—C4 | 1.375 (4) | C21—H21C | 0.9600 |
C3—H3 | 0.9300 | O10—H10A | 0.848 (10) |
C4—C5 | 1.377 (3) | O10—H10B | 0.845 (10) |
C4—H4 | 0.9300 | O11—H11A | 0.848 (10) |
C5—C6 | 1.381 (3) | O11—H11B | 0.842 (10) |
C5—H5 | 0.9300 | ||
N1i—Cu1—N1 | 180.00 (14) | O15—C7—O14 | 113.88 (17) |
N1i—Cu1—N13i | 87.86 (7) | O15—C7—C8 | 109.37 (17) |
N1—Cu1—N13i | 92.14 (7) | O14—C7—C8 | 105.19 (17) |
N1i—Cu1—N13 | 92.14 (7) | O15—C7—C6 | 111.29 (17) |
N1—Cu1—N13 | 87.86 (7) | O14—C7—C6 | 108.72 (16) |
N13i—Cu1—N13 | 180.00 (11) | C8—C7—C6 | 108.08 (16) |
N1i—Cu1—O14i | 75.63 (6) | N13—C8—C9 | 121.2 (2) |
N1—Cu1—O14i | 104.37 (6) | N13—C8—C7 | 114.58 (18) |
N13i—Cu1—O14i | 73.86 (6) | C9—C8—C7 | 124.2 (2) |
N13—Cu1—O14i | 106.14 (6) | C10—C9—C8 | 118.8 (2) |
C7—O14—H14 | 109.5 | C10—C9—H9 | 120.6 |
C7—O15—H15 | 109.5 | C8—C9—H9 | 120.6 |
C2—N1—C6 | 119.38 (18) | C11—C10—C9 | 119.7 (2) |
C2—N1—Cu1 | 124.37 (15) | C11—C10—H10 | 120.2 |
C6—N1—Cu1 | 116.25 (13) | C9—C10—H10 | 120.2 |
C12—N13—C8 | 119.5 (2) | C10—C11—C12 | 119.0 (2) |
C12—N13—Cu1 | 125.69 (16) | C10—C11—H11 | 120.5 |
C8—N13—Cu1 | 114.77 (14) | C12—C11—H11 | 120.5 |
N1—C2—C3 | 121.9 (2) | N13—C12—C11 | 121.8 (2) |
N1—C2—H2 | 119.1 | N13—C12—H12 | 119.1 |
C3—C2—H2 | 119.1 | C11—C12—H12 | 119.1 |
C2—C3—C4 | 118.9 (2) | O2—C20—O1 | 123.5 (2) |
C2—C3—H3 | 120.5 | O2—C20—C21 | 119.1 (3) |
C4—C3—H3 | 120.5 | O1—C20—C21 | 117.4 (3) |
C3—C4—C5 | 119.6 (2) | C20—C21—H21A | 109.5 |
C3—C4—H4 | 120.2 | C20—C21—H21B | 109.5 |
C5—C4—H4 | 120.2 | H21A—C21—H21B | 109.5 |
C4—C5—C6 | 119.0 (2) | C20—C21—H21C | 109.5 |
C4—C5—H5 | 120.5 | H21A—C21—H21C | 109.5 |
C6—C5—H5 | 120.5 | H21B—C21—H21C | 109.5 |
N1—C6—C5 | 121.25 (19) | H10A—O10—H10B | 100 (3) |
N1—C6—C7 | 113.31 (18) | H11A—O11—H11B | 100 (3) |
C5—C6—C7 | 125.43 (19) | ||
N13i—Cu1—N1—C2 | 49.06 (18) | N1—C6—C7—O15 | 171.84 (18) |
N13—Cu1—N1—C2 | −130.94 (18) | C5—C6—C7—O15 | −7.2 (3) |
O14i—Cu1—N1—C2 | −24.82 (19) | N1—C6—C7—O14 | 45.6 (2) |
N13i—Cu1—N1—C6 | −130.93 (15) | C5—C6—C7—O14 | −133.4 (2) |
N13—Cu1—N1—C6 | 49.07 (15) | N1—C6—C7—C8 | −68.0 (2) |
O14i—Cu1—N1—C6 | 155.19 (14) | C5—C6—C7—C8 | 112.9 (2) |
N1i—Cu1—N13—C12 | −49.05 (18) | C12—N13—C8—C9 | 0.1 (3) |
N1—Cu1—N13—C12 | 130.95 (18) | Cu1—N13—C8—C9 | −178.18 (16) |
O14i—Cu1—N13—C12 | 26.61 (19) | C12—N13—C8—C7 | −179.62 (19) |
N1i—Cu1—N13—C8 | 129.10 (15) | Cu1—N13—C8—C7 | 2.1 (2) |
N1—Cu1—N13—C8 | −50.90 (15) | O15—C7—C8—N13 | −172.77 (18) |
O14i—Cu1—N13—C8 | −155.24 (14) | O14—C7—C8—N13 | −50.1 (2) |
C6—N1—C2—C3 | 1.0 (3) | C6—C7—C8—N13 | 65.9 (2) |
Cu1—N1—C2—C3 | −179.0 (2) | O15—C7—C8—C9 | 7.5 (3) |
N1—C2—C3—C4 | −1.4 (4) | O14—C7—C8—C9 | 130.2 (2) |
C2—C3—C4—C5 | 1.1 (4) | C6—C7—C8—C9 | −113.8 (2) |
C3—C4—C5—C6 | −0.4 (4) | N13—C8—C9—C10 | 0.3 (3) |
C2—N1—C6—C5 | −0.3 (3) | C7—C8—C9—C10 | 180.0 (2) |
Cu1—N1—C6—C5 | 179.67 (17) | C8—C9—C10—C11 | −0.6 (4) |
C2—N1—C6—C7 | −179.4 (2) | C9—C10—C11—C12 | 0.6 (4) |
Cu1—N1—C6—C7 | 0.6 (2) | C8—N13—C12—C11 | −0.1 (3) |
C4—C5—C6—N1 | 0.0 (4) | Cu1—N13—C12—C11 | 177.93 (18) |
C4—C5—C6—C7 | 179.0 (2) | C10—C11—C12—N13 | −0.2 (4) |
Symmetry code: (i) −x, −y, −z. |
D—H···A | D—H | H···A | D···A | D—H···A |
O14—H14···O1 | 0.82 | 1.78 | 2.603 (2) | 178 |
O15—H15···O2 | 0.82 | 1.79 | 2.607 (3) | 177 |
O10—H10A···O2 | 0.85 (1) | 1.96 (1) | 2.788 (3) | 166 (3) |
O10—H10B···O11ii | 0.85 (1) | 1.91 (1) | 2.741 (3) | 169 (3) |
O11—H11A···O1 | 0.85 (1) | 1.92 (1) | 2.741 (3) | 164 (3) |
O11—H11B···O10iii | 0.84 (1) | 1.91 (1) | 2.748 (3) | 173 (4) |
Symmetry codes: (ii) −x−1/2, y+1/2, −z−1/2; (iii) x+1, y, z. |
Experimental details
Crystal data | |
Chemical formula | [Cu(C11H10N2O2)2](C2H3O2)2·4H2O |
Mr | 658.11 |
Crystal system, space group | Monoclinic, P21/n |
Temperature (K) | 293 |
a, b, c (Å) | 8.617 (1), 7.8765 (9), 23.103 (3) |
β (°) | 98.00 (1) |
V (Å3) | 1552.8 (3) |
Z | 2 |
Radiation type | Mo Kα |
µ (mm−1) | 0.77 |
Crystal size (mm) | 0.37 × 0.23 × 0.10 |
Data collection | |
Diffractometer | Xcalibur diffractometer |
Absorption correction | Analytical (CrysAlis RED; Oxford Diffraction, 2002) |
Tmin, Tmax | 0.793, 0.931 |
No. of measured, independent and observed [I > 2σ(I)] reflections | 12971, 4484, 2765 |
Rint | 0.044 |
(sin θ/λ)max (Å−1) | 0.703 |
Refinement | |
R[F2 > 2σ(F2)], wR(F2), S | 0.049, 0.115, 0.96 |
No. of reflections | 4480 |
No. of parameters | 211 |
No. of restraints | 4 |
H-atom treatment | H atoms treated by a mixture of independent and constrained refinement |
Δρmax, Δρmin (e Å−3) | 0.47, −0.34 |
Computer programs: CrysAlis CCD (Oxford Diffraction, 2002), CrysAlis RED (Oxford Diffraction, 2002), CrysAlis RED, DIRDIF99.2 (Beurskens et al., 1999), SHELXL97 (Sheldrick, 1997), ORTEP-3 for Windows (Farrugia, 1997), WinGX (Farrugia, 1999).
Cu1—N1i | 1.9918 (17) | O14—C7 | 1.408 (3) |
Cu1—N13i | 2.0257 (18) | O15—C7 | 1.381 (2) |
Cu1—O14i | 2.3990 (14) | ||
N1i—Cu1—N13i | 87.86 (7) | N13—Cu1—O14i | 106.14 (6) |
N1i—Cu1—N13 | 92.14 (7) | C2—N1—Cu1 | 124.37 (15) |
N1—Cu1—N13 | 87.86 (7) | C6—N1—Cu1 | 116.25 (13) |
N1i—Cu1—O14i | 75.63 (6) | C12—N13—Cu1 | 125.69 (16) |
N1—Cu1—O14i | 104.37 (6) | C8—N13—Cu1 | 114.77 (14) |
N13i—Cu1—O14i | 73.86 (6) |
Symmetry code: (i) −x, −y, −z. |
D—H···A | D—H | H···A | D···A | D—H···A |
O14—H14···O1 | 0.82 | 1.78 | 2.603 (2) | 178 |
O15—H15···O2 | 0.82 | 1.79 | 2.607 (3) | 177 |
O10—H10A···O2 | 0.848 (10) | 1.958 (13) | 2.788 (3) | 166 (3) |
O10—H10B···O11ii | 0.845 (10) | 1.906 (12) | 2.741 (3) | 169 (3) |
O11—H11A···O1 | 0.848 (10) | 1.915 (14) | 2.741 (3) | 164 (3) |
O11—H11B···O10iii | 0.842 (10) | 1.910 (11) | 2.748 (3) | 173 (4) |
Symmetry codes: (ii) −x−1/2, y+1/2, −z−1/2; (iii) x+1, y, z. |
The di-2-pyridyl-ketone ligand (dpk) has been observed to undergo hydration of the ketocarbonyl group, forming a gem-diol after initial N,N'-coordination to a transition metal (Wang et al., 1986). This gem-diol ligand (dpkdiol) can coordinate both as a N,N'-bidentate ligand (Parker et al., 2000) or as an N,O,N'-tridentate ligand, either protonated (Sommerer et al., 1993; Tangoulis et al., 1997; Yang et al., 1998; Serna et al., 1999) or deprotonated (Sommerer et al., 1990; Breeze et al., 1996; Tong et al., 1998; Hemmert et al., 1999; Woltz et al., 2002). The title complex, (I), which was obtained in the attempt to prepare a copper-dpk-Keggin complex, consists of [Cu(N,O,N'-dpkdiol)2]2+ complex cations, acetate anions and hydration water molecules.
The Cu atom lies in a distorted elongated octahedral CuN4O2 environment. The equatorial coordination positions are occupied by the N atoms of the dpkdiol ligands, while two hydroxyl groups occupy the axial ones. The two hydroxyl groups of the ligands and the acetate anions are forming two strong face-to-face carboxylate–diol hydrogen bonds, leading to trimeric entities built up of one cationic complex and two acetate anions (Fig. 1). These entities are placed in layers parallel to the (001) plane which are connected by an extented O—H···O hydrogen-bond network between the O atoms of the acetate anions and helicoidal chains of hydration water running parallel to the b axis (Fig. 2).