
Acta Cryst. (2013). E69, m89 [ doi:10.1107/S160053681205177X ]
3O,N,O')nickel(II) dinitrate tetrahydrateIn the title compound, [Ni(C6H12N4O3)2](NO3)2·4H2O, the NiII cation is located on an inversion center and is N,O,O'-chelated by two nitrilotris(acetamide) molecules in a distorted octahedral geometry. The complex cations, nitrate anions and lattice water molecules are connected by O-H
O and N-H
O hydrogen bonds, forming a three-dimensional supramolecular structure.
The synthesis of nitrilotriacetamide was carried out according to US patent 3799981 (Donald & George, 1974). The title compound was synthesized by adding solid Ni(NO3)2.6H2O (291 mg, 1 mmol) to a solution of ligands (376 mg, 2 mmol) in ethanol/water (2:1, 20 ml), then the mixture was stirred for 2 h at room temperature. The solution was filtered and the filtrate was allowed to stand in air for 1 d, and blue crystals were formed at the bottom of the vessel on slow evaporation of the solvent at room temperature.Yield: 73%.
Water H atoms were located in a difference Fourier map and the positional parameters were refined, Uiso(H) = 1.5Ueq(O). Other H atoms were included in calculated positions with C—H = 0.93 or 0.97 and N—H = 0.86 Å, and refined using a riding-model with Uiso(H) = 1.2Ueq(C,N).
Data collection: SMART (Bruker, 2007); cell refinement: SAINT (Bruker, 2007); data reduction: SAINT (Bruker, 2007); 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: SHELXTL (Sheldrick, 2008).
| [Ni(C6H12N4O3)2](NO3)2·4H2O | Z = 1 |
| Mr = 631.17 | F(000) = 330 |
| Triclinic, P1 | Dx = 1.534 Mg m−3 |
| Hall symbol: -P 1 | Mo Kα radiation, λ = 0.71073 Å |
| a = 8.557 (7) Å | Cell parameters from 2322 reflections |
| b = 9.212 (8) Å | θ = 2.4–28.2° |
| c = 9.367 (8) Å | µ = 0.80 mm−1 |
| α = 91.180 (14)° | T = 296 K |
| β = 96.215 (14)° | Block, blue |
| γ = 111.136 (14)° | 0.42 × 0.38 × 0.33 mm |
| V = 683.2 (10) Å3 |
| Bruker SMART 1000 CCD area-detector diffractometer | 2352 independent reflections |
| Radiation source: fine-focus sealed tube | 2219 reflections with I > 2σ(I) |
| Graphite monochromator | Rint = 0.014 |
| phi and ω scans | θmax = 25.0°, θmin = 2.2° |
| Absorption correction: multi-scan (SADABS; Bruker, 2001) | h = −10→10 |
| Tmin = 0.731, Tmax = 0.779 | k = −10→10 |
| 3732 measured reflections | l = −11→9 |
| 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)] = 0.032 | Hydrogen site location: inferred from neighbouring sites |
| wR(F2) = 0.088 | H atoms treated by a mixture of independent and constrained refinement |
| S = 1.05 | w = 1/[σ2(Fo2) + (0.0494P)2 + 0.3085P] where P = (Fo2 + 2Fc2)/3 |
| 2352 reflections | (Δ/σ)max < 0.001 |
| 190 parameters | Δρmax = 0.31 e Å−3 |
| 6 restraints | Δρmin = −0.24 e Å−3 |
| [Ni(C6H12N4O3)2](NO3)2·4H2O | γ = 111.136 (14)° |
| Mr = 631.17 | V = 683.2 (10) Å3 |
| Triclinic, P1 | Z = 1 |
| a = 8.557 (7) Å | Mo Kα radiation |
| b = 9.212 (8) Å | µ = 0.80 mm−1 |
| c = 9.367 (8) Å | T = 296 K |
| α = 91.180 (14)° | 0.42 × 0.38 × 0.33 mm |
| β = 96.215 (14)° |
| Bruker SMART 1000 CCD area-detector diffractometer | 2352 independent reflections |
| Absorption correction: multi-scan (SADABS; Bruker, 2001) | 2219 reflections with I > 2σ(I) |
| Tmin = 0.731, Tmax = 0.779 | Rint = 0.014 |
| 3732 measured reflections | θmax = 25.0° |
| R[F2 > 2σ(F2)] = 0.032 | H atoms treated by a mixture of independent and constrained refinement |
| wR(F2) = 0.088 | Δρmax = 0.31 e Å−3 |
| S = 1.05 | Δρmin = −0.24 e Å−3 |
| 2352 reflections | Absolute structure: ? |
| 190 parameters | Flack parameter: ? |
| 6 restraints | Rogers parameter: ? |
Experimental. Selected IR data (cm-1): 3315 (s), 3192 (s), 2935(w), 2783(w), 1666(s), 1596(s), 1276(m), 1134(m), 997(m), 867(m), 729(w), 561(s). |
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. |
| x | y | z | Uiso*/Ueq | ||
| Ni1 | 1.0000 | 0.5000 | 1.0000 | 0.02392 (14) | |
| O1 | 1.0488 (2) | 0.43473 (17) | 1.20851 (16) | 0.0346 (4) | |
| O3 | 0.7111 (2) | −0.06864 (18) | 0.86966 (18) | 0.0445 (4) | |
| O2 | 0.78448 (19) | 0.51673 (16) | 1.05845 (18) | 0.0341 (4) | |
| O4 | 0.3921 (3) | 0.3138 (2) | 0.7047 (3) | 0.0796 (8) | |
| O5 | 0.3643 (3) | 0.0742 (3) | 0.7446 (3) | 0.0766 (7) | |
| O6 | 0.1436 (3) | 0.1309 (3) | 0.6829 (3) | 0.0760 (7) | |
| O8 | 0.1390 (3) | 0.4509 (2) | 0.58844 (19) | 0.0503 (5) | |
| H8A | 0.070 (4) | 0.467 (4) | 0.640 (3) | 0.075* | |
| H8B | 0.188 (4) | 0.396 (4) | 0.635 (3) | 0.075* | |
| O7 | 0.6156 (3) | 0.2788 (2) | 0.5043 (2) | 0.0618 (6) | |
| H7A | 0.563 (4) | 0.311 (4) | 0.564 (4) | 0.093* | |
| H7B | 0.685 (4) | 0.361 (3) | 0.470 (4) | 0.093* | |
| N4 | 0.6721 (3) | −0.0015 (2) | 0.6398 (2) | 0.0488 (6) | |
| H4A | 0.6150 | −0.0964 | 0.6083 | 0.059* | |
| H4B | 0.6905 | 0.0722 | 0.5816 | 0.059* | |
| N1 | 0.8516 (2) | 0.25706 (19) | 0.97289 (18) | 0.0255 (4) | |
| N3 | 0.5292 (2) | 0.3768 (2) | 1.1244 (2) | 0.0383 (5) | |
| H3A | 0.5150 | 0.4598 | 1.1533 | 0.046* | |
| H3B | 0.4526 | 0.2868 | 1.1308 | 0.046* | |
| N2 | 1.0204 (3) | 0.2211 (2) | 1.3335 (2) | 0.0504 (6) | |
| H2A | 1.0547 | 0.2765 | 1.4138 | 0.060* | |
| H2B | 0.9931 | 0.1216 | 1.3325 | 0.060* | |
| N5 | 0.3008 (3) | 0.1727 (3) | 0.7132 (3) | 0.0495 (6) | |
| C4 | 0.6690 (3) | 0.3874 (2) | 1.0699 (2) | 0.0278 (4) | |
| C1 | 0.9486 (3) | 0.1859 (2) | 1.0730 (2) | 0.0301 (5) | |
| H1A | 1.0441 | 0.1794 | 1.0299 | 0.036* | |
| H1B | 0.8767 | 0.0813 | 1.0920 | 0.036* | |
| C6 | 0.7323 (3) | 0.0313 (2) | 0.7789 (2) | 0.0313 (5) | |
| C2 | 1.0099 (3) | 0.2884 (2) | 1.2128 (2) | 0.0316 (5) | |
| C5 | 0.8390 (3) | 0.2040 (2) | 0.8193 (2) | 0.0322 (5) | |
| H5A | 0.9522 | 0.2242 | 0.7956 | 0.039* | |
| H5B | 0.7918 | 0.2669 | 0.7599 | 0.039* | |
| C3 | 0.6822 (3) | 0.2338 (2) | 1.0189 (3) | 0.0346 (5) | |
| H3C | 0.6623 | 0.1635 | 1.0963 | 0.041* | |
| H3D | 0.5953 | 0.1855 | 0.9388 | 0.041* |
| U11 | U22 | U33 | U12 | U13 | U23 | |
| Ni1 | 0.0223 (2) | 0.0156 (2) | 0.0283 (2) | 0.00044 (14) | 0.00210 (14) | 0.00082 (14) |
| O1 | 0.0430 (9) | 0.0214 (8) | 0.0311 (8) | 0.0035 (7) | −0.0013 (7) | 0.0001 (6) |
| O3 | 0.0518 (11) | 0.0231 (8) | 0.0437 (9) | −0.0027 (7) | 0.0006 (8) | 0.0012 (7) |
| O2 | 0.0284 (8) | 0.0193 (7) | 0.0515 (9) | 0.0033 (6) | 0.0110 (7) | 0.0018 (6) |
| O4 | 0.0941 (18) | 0.0344 (11) | 0.1007 (18) | 0.0035 (11) | 0.0446 (15) | −0.0048 (11) |
| O5 | 0.0583 (14) | 0.0618 (14) | 0.109 (2) | 0.0227 (12) | 0.0036 (13) | 0.0220 (13) |
| O6 | 0.0538 (13) | 0.0572 (13) | 0.123 (2) | 0.0250 (11) | 0.0171 (13) | 0.0198 (13) |
| O8 | 0.0604 (13) | 0.0489 (11) | 0.0404 (10) | 0.0185 (10) | 0.0068 (9) | 0.0036 (8) |
| O7 | 0.0663 (14) | 0.0445 (11) | 0.0573 (13) | −0.0015 (10) | 0.0122 (10) | −0.0014 (9) |
| N4 | 0.0606 (14) | 0.0304 (11) | 0.0401 (11) | 0.0019 (10) | −0.0052 (10) | −0.0068 (9) |
| N1 | 0.0240 (9) | 0.0187 (8) | 0.0296 (9) | 0.0033 (7) | 0.0013 (7) | −0.0007 (7) |
| N3 | 0.0323 (10) | 0.0231 (9) | 0.0577 (13) | 0.0052 (8) | 0.0156 (9) | 0.0004 (9) |
| N2 | 0.0761 (16) | 0.0300 (11) | 0.0355 (11) | 0.0115 (11) | −0.0064 (10) | 0.0045 (9) |
| N5 | 0.0567 (15) | 0.0376 (12) | 0.0546 (13) | 0.0139 (11) | 0.0196 (11) | 0.0053 (10) |
| C4 | 0.0258 (10) | 0.0242 (11) | 0.0303 (11) | 0.0062 (9) | 0.0010 (8) | 0.0019 (8) |
| C1 | 0.0325 (11) | 0.0195 (10) | 0.0342 (11) | 0.0060 (9) | −0.0007 (9) | 0.0019 (8) |
| C6 | 0.0305 (11) | 0.0234 (11) | 0.0358 (11) | 0.0050 (9) | 0.0040 (9) | −0.0054 (9) |
| C2 | 0.0307 (11) | 0.0252 (11) | 0.0332 (11) | 0.0050 (9) | −0.0017 (9) | 0.0021 (9) |
| C5 | 0.0372 (12) | 0.0216 (10) | 0.0292 (11) | 0.0011 (9) | 0.0024 (9) | −0.0001 (8) |
| C3 | 0.0247 (11) | 0.0211 (10) | 0.0529 (14) | 0.0017 (9) | 0.0079 (10) | −0.0008 (9) |
| Ni1—O2 | 2.036 (2) | N1—C5 | 1.490 (3) |
| Ni1—O2i | 2.036 (2) | N1—C3 | 1.499 (3) |
| Ni1—O1i | 2.098 (2) | N1—C1 | 1.499 (3) |
| Ni1—O1 | 2.098 (2) | N3—C4 | 1.323 (3) |
| Ni1—N1 | 2.131 (2) | N3—H3A | 0.8600 |
| Ni1—N1i | 2.131 (2) | N3—H3B | 0.8600 |
| O1—C2 | 1.270 (3) | N2—C2 | 1.311 (3) |
| O3—C6 | 1.244 (3) | N2—H2A | 0.8600 |
| O2—C4 | 1.259 (3) | N2—H2B | 0.8600 |
| O4—N5 | 1.262 (3) | C4—C3 | 1.530 (3) |
| O5—N5 | 1.239 (3) | C1—C2 | 1.525 (3) |
| O6—N5 | 1.256 (3) | C1—H1A | 0.9700 |
| O8—H8A | 0.856 (17) | C1—H1B | 0.9700 |
| O8—H8B | 0.859 (17) | C6—C5 | 1.537 (3) |
| O7—H7A | 0.868 (18) | C5—H5A | 0.9700 |
| O7—H7B | 0.866 (18) | C5—H5B | 0.9700 |
| N4—C6 | 1.335 (3) | C3—H3C | 0.9700 |
| N4—H4A | 0.8600 | C3—H3D | 0.9700 |
| N4—H4B | 0.8600 | ||
| O2—Ni1—O2i | 180.0 | C2—N2—H2B | 120.0 |
| O2—Ni1—O1i | 92.01 (7) | H2A—N2—H2B | 120.0 |
| O2i—Ni1—O1i | 87.99 (7) | O5—N5—O6 | 119.8 (2) |
| O2—Ni1—O1 | 87.99 (7) | O5—N5—O4 | 121.1 (3) |
| O2i—Ni1—O1 | 92.01 (7) | O6—N5—O4 | 119.1 (3) |
| O1i—Ni1—O1 | 180.000 (1) | O2—C4—N3 | 122.14 (19) |
| O2—Ni1—N1 | 83.50 (8) | O2—C4—C3 | 121.45 (19) |
| O2i—Ni1—N1 | 96.50 (7) | N3—C4—C3 | 116.40 (18) |
| O1i—Ni1—N1 | 99.63 (7) | N1—C1—C2 | 108.21 (17) |
| O1—Ni1—N1 | 80.37 (7) | N1—C1—H1A | 110.1 |
| O2—Ni1—N1i | 96.50 (7) | C2—C1—H1A | 110.1 |
| O2i—Ni1—N1i | 83.50 (8) | N1—C1—H1B | 110.1 |
| O1i—Ni1—N1i | 80.37 (7) | C2—C1—H1B | 110.1 |
| O1—Ni1—N1i | 99.63 (7) | H1A—C1—H1B | 108.4 |
| N1—Ni1—N1i | 180.0 | O3—C6—N4 | 123.8 (2) |
| C2—O1—Ni1 | 112.16 (13) | O3—C6—C5 | 121.5 (2) |
| C4—O2—Ni1 | 114.27 (14) | N4—C6—C5 | 114.6 (2) |
| H8A—O8—H8B | 109 (2) | O1—C2—N2 | 122.5 (2) |
| H7A—O7—H7B | 107 (2) | O1—C2—C1 | 119.24 (18) |
| C6—N4—H4A | 120.0 | N2—C2—C1 | 118.3 (2) |
| C6—N4—H4B | 120.0 | N1—C5—C6 | 115.90 (17) |
| H4A—N4—H4B | 120.0 | N1—C5—H5A | 108.3 |
| C5—N1—C3 | 112.27 (17) | C6—C5—H5A | 108.3 |
| C5—N1—C1 | 112.83 (17) | N1—C5—H5B | 108.3 |
| C3—N1—C1 | 111.36 (17) | C6—C5—H5B | 108.3 |
| C5—N1—Ni1 | 108.65 (12) | H5A—C5—H5B | 107.4 |
| C3—N1—Ni1 | 107.87 (12) | N1—C3—C4 | 112.21 (16) |
| C1—N1—Ni1 | 103.32 (13) | N1—C3—H3C | 109.2 |
| C4—N3—H3A | 120.0 | C4—C3—H3C | 109.2 |
| C4—N3—H3B | 120.0 | N1—C3—H3D | 109.2 |
| H3A—N3—H3B | 120.0 | C4—C3—H3D | 109.2 |
| C2—N2—H2A | 120.0 | H3C—C3—H3D | 107.9 |
| O2—Ni1—O1—C2 | 100.65 (16) | O1i—Ni1—N1—C1 | 147.65 (13) |
| O2i—Ni1—O1—C2 | −79.35 (16) | O1—Ni1—N1—C1 | −32.35 (13) |
| O1i—Ni1—O1—C2 | 177 (100) | N1i—Ni1—N1—C1 | −136 (100) |
| N1—Ni1—O1—C2 | 16.91 (15) | Ni1—O2—C4—N3 | 171.21 (17) |
| N1i—Ni1—O1—C2 | −163.09 (15) | Ni1—O2—C4—C3 | −9.8 (3) |
| O2i—Ni1—O2—C4 | 178 (100) | C5—N1—C1—C2 | 159.20 (17) |
| O1i—Ni1—O2—C4 | 106.73 (15) | C3—N1—C1—C2 | −73.5 (2) |
| O1—Ni1—O2—C4 | −73.27 (15) | Ni1—N1—C1—C2 | 42.05 (18) |
| N1—Ni1—O2—C4 | 7.27 (15) | Ni1—O1—C2—N2 | −175.82 (19) |
| N1i—Ni1—O2—C4 | −172.73 (15) | Ni1—O1—C2—C1 | 4.2 (3) |
| O2—Ni1—N1—C5 | 118.55 (14) | N1—C1—C2—O1 | −33.3 (3) |
| O2i—Ni1—N1—C5 | −61.45 (14) | N1—C1—C2—N2 | 146.7 (2) |
| O1i—Ni1—N1—C5 | 27.60 (14) | C3—N1—C5—C6 | −59.4 (2) |
| O1—Ni1—N1—C5 | −152.40 (14) | C1—N1—C5—C6 | 67.4 (2) |
| N1i—Ni1—N1—C5 | 103 (100) | Ni1—N1—C5—C6 | −178.62 (15) |
| O2—Ni1—N1—C3 | −3.40 (13) | O3—C6—C5—N1 | −25.7 (3) |
| O2i—Ni1—N1—C3 | 176.60 (13) | N4—C6—C5—N1 | 157.0 (2) |
| O1i—Ni1—N1—C3 | −94.34 (14) | C5—N1—C3—C4 | −119.78 (19) |
| O1—Ni1—N1—C3 | 85.66 (14) | C1—N1—C3—C4 | 112.6 (2) |
| N1i—Ni1—N1—C3 | −18 (100) | Ni1—N1—C3—C4 | −0.1 (2) |
| O2—Ni1—N1—C1 | −121.40 (14) | O2—C4—C3—N1 | 6.6 (3) |
| O2i—Ni1—N1—C1 | 58.60 (14) | N3—C4—C3—N1 | −174.31 (19) |
| Symmetry code: (i) −x+2, −y+1, −z+2. |
| D—H···A | D—H | H···A | D···A | D—H···A |
| N2—H2A···O8ii | 0.86 | 2.14 | 2.988 (3) | 169 |
| N2—H2B···O6iii | 0.86 | 2.19 | 3.027 (4) | 165 |
| N3—H3A···O4iv | 0.86 | 2.28 | 3.056 (4) | 150 |
| N3—H3B···O3iii | 0.86 | 1.99 | 2.848 (3) | 173 |
| N4—H4A···O7v | 0.86 | 2.22 | 3.002 (3) | 152 |
| N4—H4B···O7 | 0.86 | 2.32 | 3.068 (4) | 145 |
| O7—H7A···O4 | 0.87 (2) | 2.08 (2) | 2.913 (4) | 162 (3) |
| O7—H7B···O8vi | 0.87 (2) | 1.98 (2) | 2.843 (3) | 174 (4) |
| O8—H8A···O1iv | 0.86 (2) | 2.18 (2) | 3.018 (3) | 165 (3) |
| O8—H8B···O4 | 0.86 (2) | 2.19 (2) | 2.999 (4) | 157 (3) |
| O8—H8B···O6 | 0.86 (2) | 2.40 (3) | 3.107 (4) | 141 (3) |
| Symmetry codes: (ii) x+1, y, z+1; (iii) −x+1, −y, −z+2; (iv) −x+1, −y+1, −z+2; (v) −x+1, −y, −z+1; (vi) −x+1, −y+1, −z+1. |
| D—H···A | D—H | H···A | D···A | D—H···A |
| N2—H2A···O8i | 0.86 | 2.14 | 2.988 (3) | 168.8 |
| N2—H2B···O6ii | 0.86 | 2.19 | 3.027 (4) | 164.9 |
| N3—H3A···O4iii | 0.86 | 2.28 | 3.056 (4) | 149.6 |
| N3—H3B···O3ii | 0.86 | 1.99 | 2.848 (3) | 173.4 |
| N4—H4A···O7iv | 0.86 | 2.22 | 3.002 (3) | 151.6 |
| N4—H4B···O7 | 0.86 | 2.32 | 3.068 (4) | 145.3 |
| O7—H7A···O4 | 0.868 (18) | 2.075 (19) | 2.913 (4) | 162 (3) |
| O7—H7B···O8v | 0.866 (18) | 1.980 (19) | 2.843 (3) | 174 (4) |
| O8—H8A···O1iii | 0.856 (17) | 2.18 (2) | 3.018 (3) | 165 (3) |
| O8—H8B···O4 | 0.859 (17) | 2.188 (19) | 2.999 (4) | 157 (3) |
| O8—H8B···O6 | 0.859 (17) | 2.40 (3) | 3.107 (4) | 141 (3) |
| Symmetry codes: (i) x+1, y, z+1; (ii) −x+1, −y, −z+2; (iii) −x+1, −y+1, −z+2; (iv) −x+1, −y, −z+1; (v) −x+1, −y+1, −z+1. |
This research was supported by the International Cooperation Special Fund of the Ministry of Science and Technology, China (No. 2011DFB31620). We are grateful to Professor Dr S.-M. Qiu of Hubei Academy of Agricultural Science for his valuable suggestions.
Ben Amor, F., Bourguiba, N., Driss, A. & Jouini, T. (1998). Acta Cryst. C54, 197–199.
Biswajit, D., Somnath, R. C., Eringathodi, S., Atish, D. J. & Subrata, M. (2009). J. Mol. Struct. 921, 268–273.
Bruker (2001). SADABS. Bruker AXS Inc., Madison, Wisconsin, USA.
Bruker (2007). SMART and SAINT. Bruker AXS Inc., Madison, Wisconsin, USA.
Donald, H. T. & George, C. H. (1974). US patent No. 3799981.
Niraj, K., Benzamin, D. W., Sanjib, K. & Lallan, M. (2012). Polyhedron, 33, 425–434.
Sheldrick, G. M. (2008). Acta Cryst. A64, 112–122.
Coordination chemistry of nitrilotriacetic acid with metal ions is explored extensively owing to their flexible coordinating nature, but nitrilotriacetamide (H3NTA) is hardly studied (Niraj et al., 2012; Biswajit et al., 2009; Ben Amor et al., 1998). This is the first report of a bis(H3NTA)–nickel(II) structure in which only H3NTA acts as a tridentate ligand.
Complex I consists of a Ni(H3NTA)2 cation, two nitrate anions and four solvent water molecules (Scheme). Ni(II) has an octahedral coordination environment which is centrosymmetric as Ni(II) occupies an inversion center. The Ni atom is coordinated in a planar geometry by the nitrilotriacetamide N and O atoms. Two trans axial sites of this coordination environment is occupied by O2 and its symmetry related O2' oxygen atoms from ligands(Fig. 1). In the equatorial plane the Ni—N1 distance is 2.131 (2) Å and the Ni—O1 distance is 2.098 (2) Å. The axial Ni—O2 bond is appreciably shortented which is 2.036 (2) Å. A few more selected bond distances and bond angles are presented in Table 1. The molecules are stacked along the a axis and display N—H···O and O—H···O hydrogen-bonds interaction (Fig. 2).