The title complex, [Ni(pyet)2(H2O)2](sac)2 (sac− is the saccharinate anion, C7H4NO3S−, and pyet is 2-pyridylethanol, C7H9NO), is built of discrete sac− and [Ni(H2O)2(pyet)2]2+ ions. The Co2+ ion sits on a centre of symmetry and exhibits a distorted octahedral geometry, formed by two bidentate pyet and two water molecules. The crystal structure is stabilized by hydrogen-bonding and weak aromatic π–π-stacking interactions between the planar sac− ions, forming a three-dimensional network.
Supporting information
CCDC reference: 202278
Key indicators
- Single-crystal X-ray study
- T = 133 K
- Mean (C-C) = 0.002 Å
- R factor = 0.032
- wR factor = 0.096
- Data-to-parameter ratio = 19.6
checkCIF results
No syntax errors found
ADDSYM reports no extra symmetry
Previously prepared [Ni(sac)2(H2O)4]·2H2O (1.0 mmol, 0.53 g) was dissolved in methanol (30 ml) at 303 K with stirring. Pyet (0.25 g, 2.0 mmol) was then added to the solution dropwise. The resulting solution was allowed to evaporate slowly for crystallization at room temperature. Suitable single crystals obtained within a week were collected by suction filtration, washed with acetone and dried in air.
H atoms of the hydroxyl group and water molecules were refined freely, while H atoms bonded to carbon were included using a riding model, starting from calculated positions.
Data collection: SMART (Bruker, 1998); cell refinement: SAINT (Bruker, 1998); data reduction: SAINT; program(s) used to solve structure: SHELXS97 (Sheldrick, 1990); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: XP (Siemens, 1994); software used to prepare material for publication: SHELXL97.
trans-Diaquabis(2-pyridylethanol-N,
O)nickel(II) disaccharinate
top
Crystal data top
[Ni(C7H9NO)2(H2O)2]·(C7H4NO3S)2 | F(000) = 732 |
Mr = 705.39 | Dx = 1.617 Mg m−3 |
Monoclinic, P21/n | Mo Kα radiation, λ = 0.71073 Å |
a = 8.8009 (6) Å | Cell parameters from 5714 reflections |
b = 8.7664 (6) Å | θ = 2.2–30.5° |
c = 19.0840 (14) Å | µ = 0.88 mm−1 |
β = 100.262 (3)° | T = 133 K |
V = 1448.82 (18) Å3 | Irregular, pale-blue |
Z = 2 | 0.24 × 0.15 × 0.13 mm |
Data collection top
Bruker SMART 1000CCD diffractometer | 4249 independent reflections |
Radiation source: fine-focus sealed tube | 3604 reflections with I > 2σ(I) |
Graphite monochromator | Rint = 0.030 |
Detector resolution: 8.192 pixels mm-1 | θmax = 30.0°, θmin = 2.2° |
ω and ψ scans | h = −12→12 |
Absorption correction: multi-scan (SADABS; Bruker, 1998) | k = −12→12 |
Tmin = 0.826, Tmax = 0.928 | l = −26→26 |
25119 measured reflections | |
Refinement top
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) = 0.096 | H atoms treated by a mixture of independent and constrained refinement |
S = 1.05 | w = 1/[σ2(Fo2) + (0.0635P)2 + 0.2009P] where P = (Fo2 + 2Fc2)/3 |
4249 reflections | (Δ/σ)max = 0.001 |
217 parameters | Δρmax = 1.04 e Å−3 |
0 restraints | Δρmin = −0.28 e Å−3 |
Crystal data top
[Ni(C7H9NO)2(H2O)2]·(C7H4NO3S)2 | V = 1448.82 (18) Å3 |
Mr = 705.39 | Z = 2 |
Monoclinic, P21/n | Mo Kα radiation |
a = 8.8009 (6) Å | µ = 0.88 mm−1 |
b = 8.7664 (6) Å | T = 133 K |
c = 19.0840 (14) Å | 0.24 × 0.15 × 0.13 mm |
β = 100.262 (3)° | |
Data collection top
Bruker SMART 1000CCD diffractometer | 4249 independent reflections |
Absorption correction: multi-scan (SADABS; Bruker, 1998) | 3604 reflections with I > 2σ(I) |
Tmin = 0.826, Tmax = 0.928 | Rint = 0.030 |
25119 measured reflections | |
Refinement top
R[F2 > 2σ(F2)] = 0.032 | 0 restraints |
wR(F2) = 0.096 | H atoms treated by a mixture of independent and constrained refinement |
S = 1.05 | Δρmax = 1.04 e Å−3 |
4249 reflections | Δρmin = −0.28 e Å−3 |
217 parameters | |
Special details top
Geometry. All e.s.d.'s (except the e.s.d. in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell e.s.d.'s are taken into account individually in the estimation of e.s.d.'s in distances, angles and torsion angles; correlations between e.s.d.'s in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell e.s.d.'s is used for estimating e.s.d.'s involving l.s. planes. |
Refinement. Refinement of F2 against ALL reflections. The weighted R-factor wR and goodness of fit S are based on F2, conventional R-factors R are based on F, with F set to zero for negative F2. The threshold expression of F2 > σ(F2) is used only for calculating R-factors(gt) etc. and is not relevant to the choice of reflections for refinement. R-factors based on F2 are statistically about twice as large as those based on F, and R- factors based on ALL data will be even larger. |
Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å2) top | x | y | z | Uiso*/Ueq | |
Ni | 0.0000 | 0.5000 | 0.0000 | 0.01342 (8) | |
S1 | 0.54586 (4) | 0.28708 (4) | 0.132706 (18) | 0.01640 (9) | |
N1 | 0.40479 (16) | 0.29573 (15) | 0.06600 (7) | 0.0197 (3) | |
N2 | 0.02723 (14) | 0.34582 (14) | 0.08366 (6) | 0.0157 (2) | |
O1 | 0.68479 (14) | 0.35220 (13) | 0.11455 (6) | 0.0250 (3) | |
O2 | 0.50389 (15) | 0.34895 (14) | 0.19650 (6) | 0.0254 (3) | |
O3 | −0.03462 (14) | 0.67465 (13) | 0.06800 (6) | 0.0191 (2) | |
H3 | −0.105 (3) | 0.731 (3) | 0.0523 (14) | 0.049 (8)* | |
O4 | 0.23567 (13) | 0.54793 (13) | 0.01537 (6) | 0.0179 (2) | |
H4A | 0.261 (3) | 0.578 (3) | −0.0182 (12) | 0.028 (6)* | |
H4B | 0.290 (3) | 0.473 (3) | 0.0285 (13) | 0.037 (7)* | |
O21 | 0.24888 (14) | 0.13046 (14) | −0.00756 (6) | 0.0252 (3) | |
C11 | 0.41984 (19) | −0.12674 (19) | 0.07775 (9) | 0.0236 (3) | |
H11 | 0.3404 | −0.1667 | 0.0422 | 0.028* | |
C12 | 0.5172 (2) | −0.22303 (19) | 0.12350 (9) | 0.0261 (3) | |
H12 | 0.5043 | −0.3304 | 0.1190 | 0.031* | |
C13 | 0.6332 (2) | −0.16376 (19) | 0.17576 (9) | 0.0246 (3) | |
H13 | 0.6983 | −0.2317 | 0.2062 | 0.030* | |
C14 | 0.65568 (19) | −0.00735 (17) | 0.18432 (9) | 0.0202 (3) | |
H14 | 0.7344 | 0.0333 | 0.2200 | 0.024* | |
C15 | 0.55770 (17) | 0.08643 (17) | 0.13824 (8) | 0.0166 (3) | |
C16 | 0.44254 (18) | 0.02906 (17) | 0.08569 (8) | 0.0176 (3) | |
C21 | 0.35498 (18) | 0.15554 (18) | 0.04337 (8) | 0.0189 (3) | |
C31 | −0.01567 (19) | 0.19835 (18) | 0.06905 (9) | 0.0212 (3) | |
H31 | −0.0581 | 0.1721 | 0.0213 | 0.025* | |
C32 | −0.0007 (2) | 0.08472 (19) | 0.12012 (10) | 0.0266 (3) | |
H32 | −0.0330 | −0.0166 | 0.1076 | 0.032* | |
C33 | 0.0627 (2) | 0.1215 (2) | 0.19034 (10) | 0.0291 (4) | |
H33 | 0.0763 | 0.0460 | 0.2266 | 0.035* | |
C34 | 0.1053 (2) | 0.2722 (2) | 0.20562 (9) | 0.0251 (3) | |
H34 | 0.1492 | 0.3005 | 0.2530 | 0.030* | |
C35 | 0.08411 (18) | 0.38188 (18) | 0.15212 (8) | 0.0193 (3) | |
C36 | 0.1156 (2) | 0.54779 (19) | 0.16934 (8) | 0.0227 (3) | |
H36A | 0.2032 | 0.5822 | 0.1471 | 0.027* | |
H36B | 0.1460 | 0.5597 | 0.2215 | 0.027* | |
C37 | −0.0239 (2) | 0.64808 (19) | 0.14314 (8) | 0.0238 (3) | |
H37A | −0.1189 | 0.5972 | 0.1522 | 0.029* | |
H37B | −0.0131 | 0.7465 | 0.1690 | 0.029* | |
Atomic displacement parameters (Å2) top | U11 | U22 | U33 | U12 | U13 | U23 |
Ni | 0.01362 (13) | 0.01412 (13) | 0.01219 (13) | −0.00042 (9) | 0.00140 (9) | 0.00021 (8) |
S1 | 0.01643 (17) | 0.01530 (17) | 0.01736 (17) | 0.00079 (12) | 0.00272 (13) | 0.00033 (12) |
N1 | 0.0195 (6) | 0.0179 (6) | 0.0204 (6) | 0.0047 (5) | 0.0003 (5) | 0.0011 (5) |
N2 | 0.0140 (5) | 0.0180 (6) | 0.0147 (5) | 0.0003 (4) | 0.0020 (4) | 0.0009 (4) |
O1 | 0.0203 (6) | 0.0249 (6) | 0.0301 (6) | −0.0034 (5) | 0.0049 (5) | 0.0066 (5) |
O2 | 0.0298 (6) | 0.0245 (6) | 0.0222 (5) | 0.0019 (5) | 0.0054 (5) | −0.0062 (4) |
O3 | 0.0220 (5) | 0.0189 (5) | 0.0150 (5) | 0.0046 (4) | −0.0003 (4) | −0.0009 (4) |
O4 | 0.0157 (5) | 0.0178 (5) | 0.0198 (5) | 0.0002 (4) | 0.0023 (4) | 0.0037 (4) |
O21 | 0.0213 (6) | 0.0278 (6) | 0.0236 (5) | 0.0058 (5) | −0.0037 (5) | −0.0046 (5) |
C11 | 0.0218 (8) | 0.0200 (7) | 0.0280 (8) | 0.0007 (6) | 0.0020 (6) | −0.0037 (6) |
C12 | 0.0296 (9) | 0.0159 (7) | 0.0330 (8) | 0.0013 (6) | 0.0064 (7) | 0.0006 (6) |
C13 | 0.0254 (8) | 0.0219 (7) | 0.0267 (8) | 0.0049 (6) | 0.0049 (6) | 0.0061 (6) |
C14 | 0.0196 (7) | 0.0214 (7) | 0.0193 (7) | 0.0020 (6) | 0.0025 (6) | 0.0025 (5) |
C15 | 0.0162 (7) | 0.0165 (6) | 0.0176 (6) | 0.0008 (5) | 0.0043 (5) | 0.0008 (5) |
C16 | 0.0166 (7) | 0.0178 (6) | 0.0187 (6) | 0.0022 (5) | 0.0037 (5) | −0.0002 (5) |
C21 | 0.0177 (7) | 0.0213 (7) | 0.0178 (6) | 0.0049 (6) | 0.0031 (5) | −0.0014 (5) |
C31 | 0.0191 (7) | 0.0209 (7) | 0.0232 (7) | −0.0006 (6) | 0.0030 (6) | 0.0015 (6) |
C32 | 0.0263 (8) | 0.0190 (7) | 0.0340 (9) | −0.0012 (6) | 0.0038 (7) | 0.0058 (6) |
C33 | 0.0266 (9) | 0.0274 (8) | 0.0322 (9) | 0.0000 (7) | 0.0020 (7) | 0.0086 (7) |
C34 | 0.0246 (8) | 0.0295 (8) | 0.0206 (7) | 0.0005 (6) | 0.0024 (6) | 0.0061 (6) |
C35 | 0.0162 (7) | 0.0224 (7) | 0.0191 (7) | 0.0010 (5) | 0.0024 (5) | 0.0017 (6) |
C36 | 0.0256 (8) | 0.0230 (7) | 0.0177 (7) | −0.0012 (6) | −0.0007 (6) | 0.0004 (6) |
C37 | 0.0303 (9) | 0.0214 (7) | 0.0197 (7) | 0.0037 (6) | 0.0044 (6) | −0.0013 (6) |
Geometric parameters (Å, º) top
Ni—O3 | 2.0645 (11) | C13—C14 | 1.391 (2) |
Ni—N2 | 2.0729 (12) | C13—H13 | 0.9500 |
Ni—O4 | 2.0851 (11) | C14—C15 | 1.387 (2) |
S1—O2 | 1.4398 (12) | C14—H14 | 0.9500 |
S1—O1 | 1.4463 (12) | C15—C16 | 1.387 (2) |
S1—N1 | 1.6138 (13) | C16—C21 | 1.501 (2) |
S1—C15 | 1.7641 (15) | C31—C32 | 1.383 (2) |
N1—C21 | 1.350 (2) | C31—H31 | 0.9500 |
N2—C35 | 1.3507 (19) | C32—C33 | 1.395 (3) |
N2—C31 | 1.3616 (19) | C32—H32 | 0.9500 |
O3—C37 | 1.4391 (19) | C33—C34 | 1.390 (3) |
O3—H3 | 0.81 (3) | C33—H33 | 0.9500 |
O4—H4A | 0.76 (2) | C34—C35 | 1.391 (2) |
O4—H4B | 0.82 (3) | C34—H34 | 0.9500 |
O21—C21 | 1.2417 (18) | C35—C36 | 1.506 (2) |
C11—C16 | 1.385 (2) | C36—C37 | 1.520 (2) |
C11—C12 | 1.394 (2) | C36—H36A | 0.9900 |
C11—H11 | 0.9500 | C36—H36B | 0.9900 |
C12—C13 | 1.394 (2) | C37—H37A | 0.9900 |
C12—H12 | 0.9500 | C37—H37B | 0.9900 |
| | | |
O3i—Ni—O3 | 180.00 | C14—C15—C16 | 122.37 (14) |
O3—Ni—N2i | 89.48 (5) | C14—C15—S1 | 130.73 (12) |
O3—Ni—N2 | 90.52 (5) | C16—C15—S1 | 106.89 (11) |
N2i—Ni—N2 | 180.00 | C11—C16—C15 | 120.62 (14) |
O3i—Ni—O4 | 89.05 (5) | C11—C16—C21 | 128.27 (14) |
O3—Ni—O4 | 90.95 (5) | C15—C16—C21 | 111.11 (13) |
N2i—Ni—O4 | 87.28 (5) | O21—C21—N1 | 124.60 (14) |
N2—Ni—O4 | 92.72 (5) | O21—C21—C16 | 122.19 (14) |
O4—Ni—O4i | 180.00 | N1—C21—C16 | 113.20 (13) |
O2—S1—O1 | 114.15 (8) | N2—C31—C32 | 123.45 (15) |
O2—S1—N1 | 111.84 (7) | N2—C31—H31 | 118.3 |
O1—S1—N1 | 110.91 (7) | C32—C31—H31 | 118.3 |
O2—S1—C15 | 110.26 (7) | C31—C32—C33 | 118.82 (16) |
O1—S1—C15 | 111.37 (7) | C31—C32—H32 | 120.6 |
N1—S1—C15 | 97.06 (7) | C33—C32—H32 | 120.6 |
C21—N1—S1 | 111.72 (10) | C34—C33—C32 | 117.92 (16) |
C35—N2—C31 | 117.50 (13) | C34—C33—H33 | 121.0 |
C35—N2—Ni | 124.36 (10) | C32—C33—H33 | 121.0 |
C31—N2—Ni | 118.13 (10) | C33—C34—C35 | 120.48 (15) |
C37—O3—Ni | 121.03 (9) | C33—C34—H34 | 119.8 |
C37—O3—H3 | 112.3 (19) | C35—C34—H34 | 119.8 |
Ni—O3—H3 | 114.3 (19) | N2—C35—C34 | 121.77 (15) |
Ni—O4—H4A | 112.5 (17) | N2—C35—C36 | 117.34 (13) |
Ni—O4—H4B | 113.0 (17) | C34—C35—C36 | 120.81 (14) |
H4A—O4—H4B | 107 (2) | C35—C36—C37 | 112.35 (13) |
C16—C11—C12 | 117.92 (15) | C35—C36—H36A | 109.1 |
C16—C11—H11 | 121.0 | C37—C36—H36A | 109.1 |
C12—C11—H11 | 121.0 | C35—C36—H36B | 109.1 |
C11—C12—C13 | 120.83 (15) | C37—C36—H36B | 109.1 |
C11—C12—H12 | 119.6 | H36A—C36—H36B | 107.9 |
C13—C12—H12 | 119.6 | O3—C37—C36 | 109.10 (13) |
C14—C13—C12 | 121.47 (15) | O3—C37—H37A | 109.9 |
C14—C13—H13 | 119.3 | C36—C37—H37A | 109.9 |
C12—C13—H13 | 119.3 | O3—C37—H37B | 109.9 |
C15—C14—C13 | 116.78 (15) | C36—C37—H37B | 109.9 |
C15—C14—H14 | 121.6 | H37A—C37—H37B | 108.3 |
C13—C14—H14 | 121.6 | | |
| | | |
O2—S1—N1—C21 | −114.55 (12) | C12—C11—C16—C21 | 179.61 (16) |
O1—S1—N1—C21 | 116.77 (12) | C14—C15—C16—C11 | 0.7 (2) |
C15—S1—N1—C21 | 0.64 (13) | S1—C15—C16—C11 | −178.36 (13) |
O3i—Ni—N2—C35 | 150.16 (13) | C14—C15—C16—C21 | −179.56 (15) |
O3—Ni—N2—C35 | −29.84 (13) | S1—C15—C16—C21 | 1.36 (16) |
O4—Ni—N2—C35 | 61.14 (13) | S1—N1—C21—O21 | −179.22 (13) |
O4i—Ni—N2—C35 | −118.86 (13) | S1—N1—C21—C16 | 0.09 (17) |
O3i—Ni—N2—C31 | −30.22 (12) | C11—C16—C21—O21 | −2.0 (3) |
O3—Ni—N2—C31 | 149.78 (12) | C15—C16—C21—O21 | 178.30 (15) |
O4—Ni—N2—C31 | −119.24 (12) | C11—C16—C21—N1 | 178.67 (16) |
O4i—Ni—N2—C31 | 60.76 (12) | C15—C16—C21—N1 | −1.02 (19) |
N2i—Ni—O3—C37 | −177.05 (12) | C35—N2—C31—C32 | −1.5 (2) |
N2—Ni—O3—C37 | 2.95 (12) | Ni—N2—C31—C32 | 178.88 (13) |
O4—Ni—O3—C37 | −89.77 (12) | N2—C31—C32—C33 | −0.5 (3) |
O4i—Ni—O3—C37 | 90.23 (12) | C31—C32—C33—C34 | 1.1 (3) |
C16—C11—C12—C13 | 0.3 (3) | C32—C33—C34—C35 | 0.3 (3) |
C11—C12—C13—C14 | 0.2 (3) | C31—N2—C35—C34 | 2.9 (2) |
C12—C13—C14—C15 | −0.3 (3) | Ni—N2—C35—C34 | −177.47 (12) |
C13—C14—C15—C16 | −0.2 (2) | C31—N2—C35—C36 | −173.69 (15) |
C13—C14—C15—S1 | 178.63 (13) | Ni—N2—C35—C36 | 5.9 (2) |
O2—S1—C15—C14 | −63.73 (17) | C33—C34—C35—N2 | −2.4 (3) |
O1—S1—C15—C14 | 64.06 (17) | C33—C34—C35—C36 | 174.09 (16) |
N1—S1—C15—C14 | 179.83 (16) | N2—C35—C36—C37 | 52.9 (2) |
O2—S1—C15—C16 | 115.24 (11) | C34—C35—C36—C37 | −123.75 (16) |
O1—S1—C15—C16 | −116.97 (11) | Ni—O3—C37—C36 | 43.05 (17) |
N1—S1—C15—C16 | −1.20 (12) | C35—C36—C37—O3 | −79.29 (17) |
C12—C11—C16—C15 | −0.7 (2) | | |
Symmetry code: (i) −x, −y+1, −z. |
Hydrogen-bond geometry (Å, º) top
D—H···A | D—H | H···A | D···A | D—H···A |
O3—H3···O21i | 0.81 (3) | 1.85 (3) | 2.6515 (16) | 172 (3) |
O4—H4A···O1ii | 0.76 (2) | 2.07 (2) | 2.8325 (17) | 175 (2) |
C32—H32···O21iii | 0.95 | 2.64 | 3.357 (2) | 133 |
C33—H33···O2iv | 0.95 | 2.45 | 3.342 (2) | 156 |
Symmetry codes: (i) −x, −y+1, −z; (ii) −x+1, −y+1, −z; (iii) −x, −y, −z; (iv) −x+1/2, y−1/2, −z+1/2. |
Experimental details
Crystal data |
Chemical formula | [Ni(C7H9NO)2(H2O)2]·(C7H4NO3S)2 |
Mr | 705.39 |
Crystal system, space group | Monoclinic, P21/n |
Temperature (K) | 133 |
a, b, c (Å) | 8.8009 (6), 8.7664 (6), 19.0840 (14) |
β (°) | 100.262 (3) |
V (Å3) | 1448.82 (18) |
Z | 2 |
Radiation type | Mo Kα |
µ (mm−1) | 0.88 |
Crystal size (mm) | 0.24 × 0.15 × 0.13 |
|
Data collection |
Diffractometer | Bruker SMART 1000CCD diffractometer |
Absorption correction | Multi-scan (SADABS; Bruker, 1998) |
Tmin, Tmax | 0.826, 0.928 |
No. of measured, independent and observed [I > 2σ(I)] reflections | 25119, 4249, 3604 |
Rint | 0.030 |
(sin θ/λ)max (Å−1) | 0.704 |
|
Refinement |
R[F2 > 2σ(F2)], wR(F2), S | 0.032, 0.096, 1.05 |
No. of reflections | 4249 |
No. of parameters | 217 |
H-atom treatment | H atoms treated by a mixture of independent and constrained refinement |
Δρmax, Δρmin (e Å−3) | 1.04, −0.28 |
Selected geometric parameters (Å, º) topNi—O3 | 2.0645 (11) | Ni—O4 | 2.0851 (11) |
Ni—N2 | 2.0729 (12) | | |
| | | |
O3—Ni—N2i | 89.48 (5) | O3—Ni—O4 | 90.95 (5) |
O3—Ni—N2 | 90.52 (5) | N2i—Ni—O4 | 87.28 (5) |
O3i—Ni—O4 | 89.05 (5) | N2—Ni—O4 | 92.72 (5) |
Symmetry code: (i) −x, −y+1, −z. |
Hydrogen-bond geometry (Å, º) top
D—H···A | D—H | H···A | D···A | D—H···A |
O3—H3···O21i | 0.81 (3) | 1.85 (3) | 2.6515 (16) | 172 (3) |
O4—H4A···O1ii | 0.76 (2) | 2.07 (2) | 2.8325 (17) | 175 (2) |
C32—H32···O21iii | 0.95 | 2.64 | 3.357 (2) | 133 |
C33—H33···O2iv | 0.95 | 2.45 | 3.342 (2) | 156 |
Symmetry codes: (i) −x, −y+1, −z; (ii) −x+1, −y+1, −z; (iii) −x, −y, −z; (iv) −x+1/2, y−1/2, −z+1/2. |
The structure of the title complex, (I), is shown in Fig. 1. The nickel(II) complex is isostructural with the corresponding cobalt(II) complex and consists of a complex cation, [Ni(H2O)2(pyet)2]2+, and two saccharinate (sac) anions. The crystal is centrosymmetric and the NiII ion located at the centre of symmetry is coordinated by a pair of neutral 2-pyridylethanol (pyet) ligands and two water molecules having distorted octahedral geometry. The sac ions are not in the primary coordination sphere, being as a counter-ion. Two pyet ligands are chelated to the NiII ion through the N and hydroxyl O atoms, forming two symmetrically six-membered chelate rings. The two pyet ligands form the equatorial plane of the coordination octahedron, while two water molecules occupy the axial positions with a trans configuration.
The crystal packing is shown in Fig. 2. Packing of molecules in (I) is very similar to its corresponding cobalt(II) complex (Yilmaz et al., 2002). The discrete cations and anions are linked by hydrogen bonds, as well as π–π interactions. The parallel stacking of pairs of the sac ions results in weak π–π interactions (Cg···Cg > 4.0 Å). The H atoms of the water molecules (O4) and hydroxyl group (O3) of pyet form O—H···O hydrogen bonds with the sulfonyl (O1) and carbonyl (O21) O atoms of neighboring sac anions. Additionally, two weak C—H···O interactions between H atoms of the py ring and the carbonyl and sulfonyl O atoms of the adjacent sac ions occur. The ions are held together by hydrogen bonds and weak π–π interactions, creating a three-dimensional network.