Supporting information
Crystallographic Information File (CIF) https://doi.org/10.1107/S1600536807038196/ci2403sup1.cif | |
Structure factor file (CIF format) https://doi.org/10.1107/S1600536807038196/ci2403Isup2.hkl |
CCDC reference: 660096
To an ethanol/water (30 ml, 1:1) containing NiCl24H2O (1 mmol) and disodium dipicolinate (1 mmol), dien (1 mmol) was added slowly with continuous stirring. The resulting solution was refluxed for 1 h and then filtered. The green filtrate was allowed to stand for about two weeks at room temperature, after which time light-green crystals of the title compound suitable for X-ray diffraction analysis were collected.
Atoms Ni1, N1, N2, N3, C4 and C5 lie on the crystallographic mirror plane. Atom C6 is disordered across the mirror plane and as a result the occupancy factor for the disordered components were fixed at 0.50 each. The independent ethyl group is disordered over two orientations with equal occupancy. The corresponding N—C and C—C distances involving the disorder components were restrained to be equal. In the ethyl group, the components of the displacement parameters in the direction of the bond were restrained to be equal. The displacement parameters of atoms C22A, C23A, C22B, C23B and O4 were restrained to approximate isotropic behaviour. The N1—C6 distance was restrained to 1.45 (1) Å. H atoms of the coordinated water molecule were located in a difference map and refined with O—H and H···H distances restrained to 0.84 (1) and 1.37 (2) Å, respectively. H atoms on O5 and N2 were located in a difference map and refined freely. H atoms on O5 are disordered over two positions. H atoms on one of the free water molecules (O4) could not be located from the difference map. H atoms attached to C atoms were placed at calculated positions (C—H = 0.93–0.97 Å) and were allowed to ride on the parent atom [Uiso(H) = 1.2–1.5Ueq(C)].
Pyridine-2,6-dicarboxylic acid, known as dipicolinic acid (H2dpc), is a versatile ligand and it can function as a neutral, mono basic or dibasic tridentate chelating ligand (Nathan & Mai, 2000; Perry et al., 2004). Having potential donor oxygen and nitrogen atoms, dipicolinic acid has attracted the scientist from the coordination chemistry and number of studies have been carried out with dipicolinate (dpc) ligand by both inorganic and bioinorganic chemists during the past few years (Krillova et al., 2007). Dipicolinates commonly coordinate to transition metals by either carboxylate bridges between metal centres, to form polymeric (Ma et al., 2003) or dimeric complexes (Ramezaniopour et al., 2005), or tridentate (O, N, O') chelation to one metal ion (Okabe & Oya, 2000). The dipicolinate ligand with NiII ions commonly has one or two coordination modes. In one coordination mode, a single planar dpc ligand binds in the equatorial plane of a NiII cation and other ligands such as H2O or pyridine based heterocycles occupy the remaining sites, thereby forming square pyramidal or octahedral coordination geometry (Liu et al., 2006; Zhang et al., 2003), or two planar dpc molecules coordinate perpendicularly generating a distorted octahedral coordination geometry (Park et al., 2007). In our ongoing research on determination of further coordination modes of chelates of dipicolinic acid with biologically important transition metal ions, we have recently synthesized mixed-ligand metal(II) complexes of dipicolinic acid and their structures have been reported (Uçar et al., 2005; Uçar et al., 2007). As a continuation of these studies, we have now prepared and characterized a new NiII complex containing dipicolinate anion together with diethylethylenediamine (dien)ligand, namely [Ni(dien)(dpc)(H2O)].2.5H2O.
The asymmetric unit of the title compound consists of one-half of a discrete neutral [Ni(dien)(dpc)(H2O)] unit and 1.25 lattice water molecules. The [Ni(dien)(dpc)(H2O)] unit lies across a mirror plane with atoms Ni1, N1, N2, N3, C4 and C5 on the mirror plane. Atom C6 is disordered over two positions across the mirror plane (Fig. 1). The H2dpc is deprotoned during the reaction and acts as a tridentate ligand. The NiII ion is six-coordinated in a distorted octahedral geometry, with one N (N3) two O atoms of the tridentate dpc dianion and one N atom from the dien (N1) ligand composing the basal plane, and the aqua O atom and the other N atom (N2) of the dien ligand occuping the axial sites.
The fact that the Ni1—Ndpc [1.986 (3) Å] length is significantly shorter than Ni1—Ndien [2.070 (3) and 2.122 (3)] bond lengths indicates that atom N3 is the strongest site, because the two carboxylate groups in ortho positions enhance the basicity of this atom. The Ni1—Ndpc, Ni1—Odpc [2.145 (2) Å] and Ni1—Oaqua [2.070 (2) Å] bond lengths in the title complex are slightly different from those observed in previously reported mixed-ligand nickel(II) dipicolinate complexes (Ramadevi et al., 2005; Liu et al., 2006; Park et al., 2007). The dpc chelate angle is 77.79 (10)°, which is comparable to that found in other dipicolinate-metal complexes (Chaigneau et al., 2004; Altin et al., 2004).
The crystal packing is stabilized by intermolecular O—H···O and N—H···O hydrogen bonds, involving the oxygen atoms of coordinated and free water molecules (see Table 2 and Fig. 2).
For related literature, see: Altin et al. (2004); Chaigneau et al. (2004); Krillova et al. (2007); Liu et al. (2006); Ma et al. (2003); Nathan & Mai (2000); Okabe & Oya (2000); Park et al. (2007); Perry et al. (2004); Ramadevi et al. (2005); Ramezaniopour et al. (2005); Uçar et al. (2005, 2007); Zhang et al. (2003).
Data collection: X-AREA (Stoe & Cie, 2002); cell refinement: X-AREA; data reduction: X-RED32 (Stoe & Cie, 2002); program(s) used to solve structure: SHELXS97 (Sheldrick, 1997); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: ORTEP-3 (Farrugia, 1997); software used to prepare material for publication: WinGX (Farrugia, 1999).
[Ni(C7H3NO4)(C6H16N2)(H2O)]·2.5H2O | F(000) = 1672.0 |
Mr = 403.08 | Dx = 1.457 Mg m−3 |
Orthorhombic, Imcb | Mo Kα radiation, λ = 0.71069 Å |
Hall symbol: -I 2a 2 | Cell parameters from 1657 reflections |
a = 11.268 (4) Å | θ = 1.7–27.2° |
b = 14.141 (5) Å | µ = 1.11 mm−1 |
c = 22.831 (12) Å | T = 297 K |
V = 3638 (3) Å3 | Prism, light green |
Z = 8 | 0.42 × 0.30 × 0.25 mm |
Stoe IPDS2 diffractometer | 2120 independent reflections |
Radiation source: fine-focus sealed tube | 1926 reflections with I > 2σ(I) |
Graphite monochromator | Rint = 0.047 |
Detector resolution: 6.67 pixels mm-1 | θmax = 27.2°, θmin = 1.7° |
ω scans | h = −14→14 |
Absorption correction: integration (X-RED32; Stoe & Cie, 2002) | k = −18→18 |
Tmin = 0.925, Tmax = 0.974 | l = −29→29 |
28305 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)] = 0.046 | Hydrogen site location: inferred from neighbouring sites |
wR(F2) = 0.123 | H atoms treated by a mixture of independent and constrained refinement |
S = 1.18 | w = 1/[σ2(Fo2) + (0.0761P)2 + 2.2047P] where P = (Fo2 + 2Fc2)/3 |
2120 reflections | (Δ/σ)max = 0.001 |
157 parameters | Δρmax = 0.41 e Å−3 |
38 restraints | Δρmin = −1.12 e Å−3 |
[Ni(C7H3NO4)(C6H16N2)(H2O)]·2.5H2O | V = 3638 (3) Å3 |
Mr = 403.08 | Z = 8 |
Orthorhombic, Imcb | Mo Kα radiation |
a = 11.268 (4) Å | µ = 1.11 mm−1 |
b = 14.141 (5) Å | T = 297 K |
c = 22.831 (12) Å | 0.42 × 0.30 × 0.25 mm |
Stoe IPDS2 diffractometer | 2120 independent reflections |
Absorption correction: integration (X-RED32; Stoe & Cie, 2002) | 1926 reflections with I > 2σ(I) |
Tmin = 0.925, Tmax = 0.974 | Rint = 0.047 |
28305 measured reflections |
R[F2 > 2σ(F2)] = 0.046 | 38 restraints |
wR(F2) = 0.123 | H atoms treated by a mixture of independent and constrained refinement |
S = 1.18 | Δρmax = 0.41 e Å−3 |
2120 reflections | Δρmin = −1.12 e Å−3 |
157 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. |
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 | Occ. (<1) | |
C1 | 0.2093 (2) | 0.13012 (16) | 0.29423 (11) | 0.0402 (5) | |
C2 | 0.10328 (19) | 0.14295 (16) | 0.33506 (10) | 0.0392 (5) | |
C3 | 0.1064 (2) | 0.1627 (2) | 0.39387 (11) | 0.0523 (6) | |
H3 | 0.1783 | 0.1694 | 0.4134 | 0.063* | |
C4 | 0.0000 | 0.1726 (3) | 0.42341 (17) | 0.0602 (10) | |
H4 | 0.0000 | 0.1859 | 0.4633 | 0.072* | |
C5 | 0.0000 | −0.0869 (3) | 0.17882 (19) | 0.0589 (10) | |
H5A | 0.0386 | −0.1471 | 0.1830 | 0.071* | 0.50 |
H5B | −0.0800 | −0.0976 | 0.1659 | 0.071* | 0.50 |
C6 | 0.0666 (6) | −0.0233 (4) | 0.1345 (2) | 0.0596 (14) | 0.50 |
H6A | 0.0663 | −0.0538 | 0.0969 | 0.072* | 0.50 |
H6B | 0.1476 | −0.0153 | 0.1466 | 0.072* | 0.50 |
C22A | −0.1050 (6) | 0.0632 (5) | 0.1032 (3) | 0.0673 (16) | 0.50 |
H22A | −0.0730 | 0.0670 | 0.0638 | 0.081* | 0.50 |
H22B | −0.1522 | 0.0059 | 0.1045 | 0.081* | 0.50 |
C23A | −0.1689 (8) | 0.1566 (5) | 0.0959 (3) | 0.0741 (18) | 0.50 |
H23A | −0.1947 | 0.1790 | 0.1335 | 0.111* | 0.50 |
H23B | −0.2366 | 0.1481 | 0.0709 | 0.111* | 0.50 |
H23C | −0.1160 | 0.2020 | 0.0787 | 0.111* | 0.50 |
C22B | −0.0951 (7) | 0.1371 (5) | 0.1028 (3) | 0.0656 (16) | 0.50 |
H22C | −0.1670 | 0.1319 | 0.1259 | 0.079* | 0.50 |
H22D | −0.0677 | 0.2019 | 0.1060 | 0.079* | 0.50 |
C23B | −0.1277 (10) | 0.1164 (6) | 0.0386 (3) | 0.098 (3) | 0.50 |
H23D | −0.0638 | 0.1362 | 0.0135 | 0.147* | 0.50 |
H23E | −0.1985 | 0.1505 | 0.0284 | 0.147* | 0.50 |
H23F | −0.1410 | 0.0499 | 0.0337 | 0.147* | 0.50 |
N1 | 0.0000 | 0.0711 (2) | 0.13202 (13) | 0.0537 (8) | |
N2 | 0.0000 | −0.0374 (2) | 0.23465 (14) | 0.0428 (6) | |
H2 | 0.061 (2) | −0.051 (2) | 0.2546 (12) | 0.043 (7)* | |
N3 | 0.0000 | 0.13362 (19) | 0.30763 (12) | 0.0354 (5) | |
O1 | 0.0000 | 0.25168 (16) | 0.20606 (13) | 0.0472 (6) | |
H1A | 0.0615 (9) | 0.2816 (15) | 0.1993 (13) | 0.058 (8)* | |
O2 | 0.18606 (15) | 0.11705 (12) | 0.24116 (8) | 0.0433 (4) | |
O3 | 0.31037 (14) | 0.13235 (15) | 0.31665 (8) | 0.0520 (5) | |
O4 | 0.3847 (3) | 0.1075 (3) | 0.43248 (15) | 0.1158 (13) | |
O5 | 0.2500 | 0.0000 | 0.5000 | 0.1026 (19) | |
H5 | 0.294 (4) | 0.030 (4) | 0.4753 (19) | 0.042 (14)* | 0.50 |
Ni1 | 0.0000 | 0.10766 (2) | 0.222149 (16) | 0.03365 (18) |
U11 | U22 | U33 | U12 | U13 | U23 | |
C1 | 0.0317 (11) | 0.0375 (10) | 0.0516 (12) | −0.0017 (9) | 0.0012 (9) | 0.0059 (10) |
C2 | 0.0324 (11) | 0.0397 (11) | 0.0455 (11) | −0.0001 (8) | −0.0018 (9) | 0.0030 (9) |
C3 | 0.0415 (14) | 0.0685 (17) | 0.0470 (12) | −0.0032 (12) | −0.0069 (10) | −0.0014 (11) |
C4 | 0.053 (2) | 0.086 (3) | 0.0423 (18) | 0.000 | 0.000 | −0.0039 (18) |
C5 | 0.081 (3) | 0.0297 (15) | 0.066 (2) | 0.000 | 0.000 | −0.0072 (15) |
C6 | 0.081 (4) | 0.046 (3) | 0.052 (3) | 0.015 (3) | 0.009 (3) | −0.010 (2) |
C22A | 0.081 (4) | 0.058 (3) | 0.063 (3) | 0.002 (3) | −0.023 (3) | −0.014 (3) |
C23A | 0.087 (5) | 0.065 (4) | 0.070 (4) | 0.013 (4) | −0.020 (4) | −0.003 (3) |
C22B | 0.085 (5) | 0.060 (4) | 0.051 (3) | 0.010 (3) | −0.016 (3) | 0.001 (3) |
C23B | 0.132 (7) | 0.097 (5) | 0.066 (4) | 0.003 (5) | −0.035 (5) | 0.005 (4) |
N1 | 0.081 (2) | 0.0355 (15) | 0.0451 (15) | 0.000 | 0.000 | −0.0027 (12) |
N2 | 0.0412 (15) | 0.0309 (13) | 0.0562 (17) | 0.000 | 0.000 | 0.0047 (12) |
N3 | 0.0299 (12) | 0.0356 (12) | 0.0408 (13) | 0.000 | 0.000 | 0.0010 (10) |
O1 | 0.0350 (12) | 0.0284 (10) | 0.0783 (16) | 0.000 | 0.000 | 0.0055 (11) |
O2 | 0.0358 (9) | 0.0462 (9) | 0.0480 (9) | 0.0015 (7) | 0.0037 (7) | −0.0003 (7) |
O3 | 0.0303 (8) | 0.0657 (11) | 0.0601 (11) | −0.0043 (8) | −0.0018 (7) | 0.0083 (9) |
O4 | 0.086 (2) | 0.175 (4) | 0.0863 (19) | 0.006 (2) | −0.0049 (17) | 0.0427 (19) |
O5 | 0.129 (6) | 0.111 (5) | 0.068 (4) | 0.000 | 0.000 | 0.000 |
Ni1 | 0.0328 (3) | 0.0287 (3) | 0.0394 (3) | 0.000 | 0.000 | −0.00016 (13) |
C1—O3 | 1.249 (3) | C23A—H23A | 0.96 |
C1—O2 | 1.253 (3) | C23A—H23B | 0.96 |
C1—C2 | 1.526 (3) | C23A—H23C | 0.96 |
C2—N3 | 1.328 (3) | C22B—C23B | 1.540 (8) |
C2—C3 | 1.372 (3) | C22B—N1 | 1.570 (7) |
C3—C4 | 1.382 (3) | C22B—H22C | 0.97 |
C3—H3 | 0.93 | C22B—H22D | 0.97 |
C4—C3i | 1.382 (3) | C23B—H23D | 0.96 |
C4—H4 | 0.93 | C23B—H23E | 0.96 |
C5—N2 | 1.455 (5) | C23B—H23F | 0.96 |
C5—C6i | 1.548 (7) | N1—C22Ai | 1.358 (6) |
C5—C6 | 1.548 (7) | N1—C6i | 1.533 (5) |
C5—H5A | 0.96 | N1—C22Bi | 1.570 (7) |
C5—H5B | 0.96 | N1—Ni1 | 2.122 (3) |
C6—C22Ai | 1.481 (9) | N2—Ni1 | 2.070 (3) |
C6—C6i | 1.501 (13) | N2—H2 | 0.85 (3) |
C6—N1 | 1.533 (5) | N3—C2i | 1.328 (3) |
C6—H6A | 0.96 | N3—Ni1 | 1.986 (3) |
C6—H6B | 0.96 | O1—Ni1 | 2.070 (2) |
C22A—N1 | 1.358 (6) | O1—H1A | 0.827 (10) |
C22A—C6i | 1.481 (9) | O2—Ni1 | 2.145 (2) |
C22A—C23A | 1.514 (9) | O5—H5 | 0.862 (11) |
C22A—H22A | 0.97 | Ni1—O2i | 2.145 (2) |
C22A—H22B | 0.97 | ||
O3—C1—O2 | 126.2 (2) | N1—C22B—H22D | 108.2 |
O3—C1—C2 | 117.4 (2) | H22A—C22B—H22D | 133.1 |
O2—C1—C2 | 116.4 (2) | H22C—C22B—H22D | 107.3 |
N3—C2—C3 | 120.2 (2) | C22B—C23B—H23D | 109.5 |
N3—C2—C1 | 112.7 (2) | C22B—C23B—H23E | 109.5 |
C3—C2—C1 | 127.0 (2) | H23D—C23B—H23E | 109.5 |
C2—C3—C4 | 118.4 (2) | C22B—C23B—H23F | 109.5 |
C2—C3—H3 | 120.8 | H23D—C23B—H23F | 109.5 |
C4—C3—H3 | 120.8 | H23E—C23B—H23F | 109.5 |
C3i—C4—C3 | 120.2 (3) | C22A—N1—C6 | 111.9 (4) |
C3i—C4—H4 | 119.9 | C22A—N1—C22Bi | 116.0 (5) |
C3—C4—H4 | 119.9 | C6—N1—C22Bi | 101.5 (4) |
N2—C5—C6i | 107.0 (3) | C22Ai—N1—C22B | 116.0 (5) |
N2—C5—C6 | 107.0 (3) | C6i—N1—C22B | 101.5 (4) |
N2—C5—H5A | 109.9 | C22A—N1—Ni1 | 119.3 (3) |
C6—C5—H5A | 111.1 | C22Ai—N1—Ni1 | 119.3 (3) |
N2—C5—H5B | 110.1 | C6—N1—Ni1 | 100.2 (2) |
C6—C5—H5B | 110.2 | C6i—N1—Ni1 | 100.2 (2) |
H5A—C5—H5B | 108.4 | C22Bi—N1—Ni1 | 105.5 (3) |
N1—C6—C5 | 107.0 (4) | C22B—N1—Ni1 | 105.5 (3) |
N1—C6—H6A | 110.9 | C5—N2—Ni1 | 110.9 (2) |
C5—C6—H6A | 108.8 | C5—N2—H2 | 111.0 (19) |
N1—C6—H6B | 111.9 | Ni1—N2—H2 | 108 (2) |
C5—C6—H6B | 109.9 | C2—N3—C2i | 122.4 (3) |
H6A—C6—H6B | 108.3 | C2—N3—Ni1 | 118.79 (14) |
N1—C22A—C23A | 113.3 (6) | C2i—N3—Ni1 | 118.79 (14) |
N1—C22A—H22A | 96.9 | Ni1—O1—H1A | 122.5 (15) |
C23A—C22A—H22A | 91.5 | C1—O2—Ni1 | 114.12 (15) |
N1—C22A—H22B | 122.2 | N3—Ni1—O1 | 89.57 (11) |
C23A—C22A—H22B | 118.1 | N3—Ni1—N2 | 92.73 (12) |
H22A—C22A—H22B | 106.1 | O1—Ni1—N2 | 177.70 (12) |
C22A—C23A—H23A | 109.5 | N3—Ni1—N1 | 176.55 (11) |
C22A—C23A—H23B | 109.5 | O1—Ni1—N1 | 93.88 (12) |
H23A—C23A—H23B | 109.5 | N2—Ni1—N1 | 83.83 (12) |
C23A—C23A—H23C | 109.5 | N3—Ni1—O2i | 77.86 (5) |
H23B—C23A—H23C | 109.5 | O1—Ni1—O2i | 88.57 (5) |
H23B—C23A—H22C | 119.6 | N2—Ni1—O2i | 91.92 (5) |
H23C—C23A—H22C | 130.6 | N1—Ni1—O2i | 102.20 (5) |
C23B—C22B—N1 | 117.1 (6) | N3—Ni1—O2 | 77.86 (5) |
C23B—C22B—H22C | 107.7 | O1—Ni1—O2 | 88.57 (5) |
N1—C22B—H22C | 107.0 | N2—Ni1—O2 | 91.92 (5) |
H22A—C22B—H22C | 117.0 | N1—Ni1—O2 | 102.20 (5) |
C23B—C22B—H22D | 109.2 | O2i—Ni1—O2 | 155.57 (10) |
O3—C1—C2—N3 | −176.1 (2) | C3—C2—N3—C2i | 0.1 (5) |
O2—C1—C2—N3 | 3.0 (3) | C1—C2—N3—C2i | −179.40 (19) |
O3—C1—C2—C3 | 4.4 (4) | C3—C2—N3—Ni1 | 178.7 (2) |
O2—C1—C2—C3 | −176.5 (2) | C1—C2—N3—Ni1 | −0.8 (3) |
N3—C2—C3—C4 | 0.0 (5) | O3—C1—O2—Ni1 | 175.5 (2) |
C1—C2—C3—C4 | 179.4 (3) | C2—C1—O2—Ni1 | −3.5 (2) |
C2—C3—C4—C3i | −0.1 (6) | C2—N3—Ni1—O1 | −89.3 (2) |
N2—C5—C6—C22Ai | −41.7 (17) | C2i—N3—Ni1—O1 | 89.3 (2) |
C6i—C5—C6—C22Ai | 58.1 (17) | C2—N3—Ni1—N2 | 90.7 (2) |
N2—C5—C6—C6i | −99.78 (19) | C2i—N3—Ni1—N2 | −90.7 (2) |
N2—C5—C6—N1 | −58.8 (4) | C2—N3—Ni1—O2i | −177.9 (2) |
C6i—C5—C6—N1 | 41.0 (4) | C2i—N3—Ni1—O2i | 0.7 (2) |
C6i—C22A—N1—C22Ai | 99.5 (7) | C2—N3—Ni1—O2 | −0.7 (2) |
C23A—C22A—N1—C22Ai | −106.9 (6) | C2i—N3—Ni1—O2 | 177.9 (2) |
C6i—C22A—N1—C6 | 30.7 (4) | C5—N2—Ni1—N3 | 180.0 |
C23A—C22A—N1—C6 | −175.6 (5) | C5—N2—Ni1—N1 | 0.0 |
C23A—C22A—N1—C6i | 153.6 (7) | C5—N2—Ni1—O2i | 102.07 (5) |
C6i—C22A—N1—C22Bi | 146.5 (5) | C5—N2—Ni1—O2 | −102.07 (5) |
C23A—C22A—N1—C22Bi | −59.9 (7) | C22A—N1—Ni1—O1 | −87.5 (4) |
C6i—C22A—N1—C22B | −165.6 (7) | C22Ai—N1—Ni1—O1 | 87.5 (4) |
C23A—C22A—N1—C22B | −11.9 (6) | C6—N1—Ni1—O1 | 150.2 (3) |
C6i—C22A—N1—Ni1 | −85.6 (4) | C6i—N1—Ni1—O1 | −150.2 (3) |
C23A—C22A—N1—Ni1 | 68.0 (7) | C22Bi—N1—Ni1—O1 | 45.1 (3) |
C22Ai—C6—N1—C22A | 114.6 (7) | C22B—N1—Ni1—O1 | −45.1 (3) |
C6i—C6—N1—C22A | −31.7 (4) | C22A—N1—Ni1—N2 | 92.5 (4) |
C5—C6—N1—C22A | −72.8 (5) | C22Ai—N1—Ni1—N2 | −92.5 (4) |
C6i—C6—N1—C22Ai | −146.3 (4) | C6—N1—Ni1—N2 | −29.8 (3) |
C5—C6—N1—C22Ai | 172.6 (5) | C6i—N1—Ni1—N2 | 29.8 (3) |
C22Ai—C6—N1—C6i | 146.3 (4) | C22Bi—N1—Ni1—N2 | −134.9 (3) |
C5—C6—N1—C6i | −41.1 (4) | C22B—N1—Ni1—N2 | 134.9 (3) |
C22Ai—C6—N1—C22Bi | −9.7 (4) | C22A—N1—Ni1—O2i | 1.9 (4) |
C6i—C6—N1—C22Bi | −155.9 (4) | C22Ai—N1—Ni1—O2i | 176.9 (4) |
C5—C6—N1—C22Bi | 163.0 (4) | C6—N1—Ni1—O2i | −120.5 (3) |
C22Ai—C6—N1—C22B | 92.7 (9) | C6i—N1—Ni1—O2i | −60.8 (3) |
C6i—C6—N1—C22B | −53.5 (7) | C22Bi—N1—Ni1—O2i | 134.5 (3) |
C5—C6—N1—C22B | −94.6 (8) | C22B—N1—Ni1—O2i | 44.3 (3) |
C22Ai—C6—N1—Ni1 | −118.0 (3) | C22A—N1—Ni1—O2 | −176.9 (4) |
C6i—C6—N1—Ni1 | 95.78 (15) | C22Ai—N1—Ni1—O2 | −1.9 (4) |
C5—C6—N1—Ni1 | 54.7 (4) | C6—N1—Ni1—O2 | 60.8 (3) |
C23B—C22B—N1—C22A | −54.3 (7) | C6i—N1—Ni1—O2 | 120.5 (3) |
C23B—C22B—N1—C22Ai | 54.2 (8) | C22Bi—N1—Ni1—O2 | −44.3 (3) |
C23B—C22B—N1—C6 | −22.8 (12) | C22B—N1—Ni1—O2 | −134.5 (3) |
C23B—C22B—N1—C6i | −67.2 (7) | C1—O2—Ni1—N3 | 2.43 (16) |
C23B—C22B—N1—C22Bi | 83.7 (7) | C1—O2—Ni1—O1 | 92.30 (17) |
C23B—C22B—N1—Ni1 | −171.3 (6) | C1—O2—Ni1—N2 | −89.94 (17) |
C6i—C5—N2—Ni1 | −30.5 (3) | C1—O2—Ni1—N1 | −174.04 (17) |
C6—C5—N2—Ni1 | 30.5 (3) | C1—O2—Ni1—O2i | 8.9 (3) |
Symmetry code: (i) −x, y, z. |
D—H···A | D—H | H···A | D···A | D—H···A |
O5—H5···O4 | 0.86 (1) | 1.79 (1) | 2.644 (3) | 171 (6) |
N2—H2···O3ii | 0.85 (3) | 2.33 (3) | 3.142 (3) | 161 (3) |
O1—H1A···O3iii | 0.83 (1) | 1.92 (1) | 2.743 (2) | 171 (2) |
Symmetry codes: (ii) −x+1/2, −y, z; (iii) −x+1/2, −y+1/2, −z+1/2. |
Experimental details
Crystal data | |
Chemical formula | [Ni(C7H3NO4)(C6H16N2)(H2O)]·2.5H2O |
Mr | 403.08 |
Crystal system, space group | Orthorhombic, Imcb |
Temperature (K) | 297 |
a, b, c (Å) | 11.268 (4), 14.141 (5), 22.831 (12) |
V (Å3) | 3638 (3) |
Z | 8 |
Radiation type | Mo Kα |
µ (mm−1) | 1.11 |
Crystal size (mm) | 0.42 × 0.30 × 0.25 |
Data collection | |
Diffractometer | Stoe IPDS2 |
Absorption correction | Integration (X-RED32; Stoe & Cie, 2002) |
Tmin, Tmax | 0.925, 0.974 |
No. of measured, independent and observed [I > 2σ(I)] reflections | 28305, 2120, 1926 |
Rint | 0.047 |
(sin θ/λ)max (Å−1) | 0.642 |
Refinement | |
R[F2 > 2σ(F2)], wR(F2), S | 0.046, 0.123, 1.18 |
No. of reflections | 2120 |
No. of parameters | 157 |
No. of restraints | 38 |
H-atom treatment | H atoms treated by a mixture of independent and constrained refinement |
Δρmax, Δρmin (e Å−3) | 0.41, −1.12 |
Computer programs: X-AREA (Stoe & Cie, 2002), X-AREA, X-RED32 (Stoe & Cie, 2002), SHELXS97 (Sheldrick, 1997), SHELXL97 (Sheldrick, 1997), ORTEP-3 (Farrugia, 1997), WinGX (Farrugia, 1999).
N1—Ni1 | 2.122 (3) | O1—Ni1 | 2.070 (2) |
N2—Ni1 | 2.070 (3) | O2—Ni1 | 2.145 (2) |
N3—Ni1 | 1.986 (3) | Ni1—O2i | 2.145 (2) |
N3—Ni1—O1 | 89.57 (11) | N3—Ni1—O2 | 77.86 (5) |
N3—Ni1—N2 | 92.73 (12) | O1—Ni1—O2 | 88.57 (5) |
O1—Ni1—N2 | 177.70 (12) | N2—Ni1—O2 | 91.92 (5) |
N3—Ni1—N1 | 176.55 (11) | N1—Ni1—O2 | 102.20 (5) |
O1—Ni1—N1 | 93.88 (12) | O2i—Ni1—O2 | 155.57 (10) |
N2—Ni1—N1 | 83.83 (12) |
Symmetry code: (i) −x, y, z. |
D—H···A | D—H | H···A | D···A | D—H···A |
O5—H5···O4 | 0.862 (11) | 1.789 (14) | 2.644 (3) | 171 (6) |
N2—H2···O3ii | 0.85 (3) | 2.33 (3) | 3.142 (3) | 161 (3) |
O1—H1A···O3iii | 0.827 (10) | 1.922 (12) | 2.743 (2) | 171 (2) |
Symmetry codes: (ii) −x+1/2, −y, z; (iii) −x+1/2, −y+1/2, −z+1/2. |
Pyridine-2,6-dicarboxylic acid, known as dipicolinic acid (H2dpc), is a versatile ligand and it can function as a neutral, mono basic or dibasic tridentate chelating ligand (Nathan & Mai, 2000; Perry et al., 2004). Having potential donor oxygen and nitrogen atoms, dipicolinic acid has attracted the scientist from the coordination chemistry and number of studies have been carried out with dipicolinate (dpc) ligand by both inorganic and bioinorganic chemists during the past few years (Krillova et al., 2007). Dipicolinates commonly coordinate to transition metals by either carboxylate bridges between metal centres, to form polymeric (Ma et al., 2003) or dimeric complexes (Ramezaniopour et al., 2005), or tridentate (O, N, O') chelation to one metal ion (Okabe & Oya, 2000). The dipicolinate ligand with NiII ions commonly has one or two coordination modes. In one coordination mode, a single planar dpc ligand binds in the equatorial plane of a NiII cation and other ligands such as H2O or pyridine based heterocycles occupy the remaining sites, thereby forming square pyramidal or octahedral coordination geometry (Liu et al., 2006; Zhang et al., 2003), or two planar dpc molecules coordinate perpendicularly generating a distorted octahedral coordination geometry (Park et al., 2007). In our ongoing research on determination of further coordination modes of chelates of dipicolinic acid with biologically important transition metal ions, we have recently synthesized mixed-ligand metal(II) complexes of dipicolinic acid and their structures have been reported (Uçar et al., 2005; Uçar et al., 2007). As a continuation of these studies, we have now prepared and characterized a new NiII complex containing dipicolinate anion together with diethylethylenediamine (dien)ligand, namely [Ni(dien)(dpc)(H2O)].2.5H2O.
The asymmetric unit of the title compound consists of one-half of a discrete neutral [Ni(dien)(dpc)(H2O)] unit and 1.25 lattice water molecules. The [Ni(dien)(dpc)(H2O)] unit lies across a mirror plane with atoms Ni1, N1, N2, N3, C4 and C5 on the mirror plane. Atom C6 is disordered over two positions across the mirror plane (Fig. 1). The H2dpc is deprotoned during the reaction and acts as a tridentate ligand. The NiII ion is six-coordinated in a distorted octahedral geometry, with one N (N3) two O atoms of the tridentate dpc dianion and one N atom from the dien (N1) ligand composing the basal plane, and the aqua O atom and the other N atom (N2) of the dien ligand occuping the axial sites.
The fact that the Ni1—Ndpc [1.986 (3) Å] length is significantly shorter than Ni1—Ndien [2.070 (3) and 2.122 (3)] bond lengths indicates that atom N3 is the strongest site, because the two carboxylate groups in ortho positions enhance the basicity of this atom. The Ni1—Ndpc, Ni1—Odpc [2.145 (2) Å] and Ni1—Oaqua [2.070 (2) Å] bond lengths in the title complex are slightly different from those observed in previously reported mixed-ligand nickel(II) dipicolinate complexes (Ramadevi et al., 2005; Liu et al., 2006; Park et al., 2007). The dpc chelate angle is 77.79 (10)°, which is comparable to that found in other dipicolinate-metal complexes (Chaigneau et al., 2004; Altin et al., 2004).
The crystal packing is stabilized by intermolecular O—H···O and N—H···O hydrogen bonds, involving the oxygen atoms of coordinated and free water molecules (see Table 2 and Fig. 2).