Download citation
Download citation
link to html
In the title compound, [Ni(C6H5O5)2(H2O)2], the NiII atom, located on an inversion centre, is coordinated by four O atoms from two malate ligands and two water mol­ecules in an octa­hedral geometry showing a very large axial distortion. The packing is governed by inter­molecular O—H...O hydrogen bonds.

Supporting information

cif

Crystallographic Information File (CIF) https://doi.org/10.1107/S1600536807042730/hb2529sup1.cif
Contains datablocks I, global

hkl

Structure factor file (CIF format) https://doi.org/10.1107/S1600536807042730/hb2529Isup2.hkl
Contains datablock I

CCDC reference: 664185

Key indicators

  • Single-crystal X-ray study
  • T = 298 K
  • Mean [sigma](C-C) = 0.002 Å
  • R factor = 0.021
  • wR factor = 0.061
  • Data-to-parameter ratio = 12.1

checkCIF/PLATON results

No syntax errors found



Alert level B PLAT232_ALERT_2_B Hirshfeld Test Diff (M-X) Ni1 - O3 .. 10.60 su
Alert level C PLAT062_ALERT_4_C Rescale T(min) & T(max) by ..................... 0.99 PLAT232_ALERT_2_C Hirshfeld Test Diff (M-X) Ni1 - O1 .. 9.51 su
Alert level G PLAT793_ALERT_1_G Check the Absolute Configuration of C2 = ... S PLAT860_ALERT_3_G Note: Number of Least-Squares Restraints ....... 3
0 ALERT level A = In general: serious problem 1 ALERT level B = Potentially serious problem 2 ALERT level C = Check and explain 2 ALERT level G = General alerts; check 1 ALERT type 1 CIF construction/syntax error, inconsistent or missing data 2 ALERT type 2 Indicator that the structure model may be wrong or deficient 1 ALERT type 3 Indicator that the structure quality may be low 1 ALERT type 4 Improvement, methodology, query or suggestion 0 ALERT type 5 Informative message, check

Comment top

Some hydroxypolycarboxylic acids are present in fruits and living cells and they also play an important role in biological processes (Kotsakis et al., 2003). Hydroxypolycarboxylic acids can act not only as hydrogen-bond acceptors but also as hydrogen-bond donors, depending on the number of deprotonated carboxyl group.

In this paper, we report the synthesis and crystal structure of the title compound, (I). The NiII atom, located on an inversion center, is coordinated by four O atoms from two malate ligands and two water molecules in an axially distorted octahedral geometry (Fig. 1, Table 1).

Intermolecular O—H···O hydrogen bonds (Table 2) help to consolidate the crystal packing.

Related literature top

For background, see: Kotsakis et al. (2003).

Experimental top

Malic acid (0.15 g, 1.01 mmol) and NiCl2.6H2O (0.028 g, 0.12 mmol), were added to a mixed solvent system of methanol and acetonitrile. The mixture was heated for six hours under reflux at 389 K with stirring. The resultant solution was filtered and placed in a closed container, into which diethyl ether was allowed to infuse. After a week, green blocks of (I) were recovered.

Refinement top

The water H atoms were located in a difference Fourier map and were refined as riding in their as-found relative positions with Uiso(H) = 1.2Ueq(O). The other H atoms were placed in calculated positions (C—H = 0.93–0.97 Å, O—H = 0.82–0.86 Å) and refined using a riding model, with Uiso(H) = 1.2Ueq(carrier). The maximum difference peak is 1.12Å from C3.

Structure description top

Some hydroxypolycarboxylic acids are present in fruits and living cells and they also play an important role in biological processes (Kotsakis et al., 2003). Hydroxypolycarboxylic acids can act not only as hydrogen-bond acceptors but also as hydrogen-bond donors, depending on the number of deprotonated carboxyl group.

In this paper, we report the synthesis and crystal structure of the title compound, (I). The NiII atom, located on an inversion center, is coordinated by four O atoms from two malate ligands and two water molecules in an axially distorted octahedral geometry (Fig. 1, Table 1).

Intermolecular O—H···O hydrogen bonds (Table 2) help to consolidate the crystal packing.

For background, see: Kotsakis et al. (2003).

Computing details top

Data collection: APEX2 (Bruker, ????); cell refinement: SAINT (Bruker, 1998); data reduction: SAINT (Bruker, 1998); program(s) used to solve structure: SHELXS97 (Sheldrick, 1997); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: SHELXTL (Bruker, 1998); software used to prepare material for publication: SHELXTL (Bruker, 1998).

Figures top
[Figure 1] Fig. 1. The molecular structure of (I). Non-H atoms are shown as 50% probability displacement ellipsoids. Atoms marked with a ' are generated by the symmetry operation (-x, -y, -z).
Diaquabis(malato-κ2O,O')nickel(II) top
Crystal data top
[Ni(C6H5O5)2(H2O)2]F(000) = 372
Mr = 360.90Dx = 1.890 Mg m3
Monoclinic, P21/cMo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2ybcCell parameters from 1171 reflections
a = 8.4762 (5) Åθ = 2.5–25.5°
b = 7.4377 (4) ŵ = 1.60 mm1
c = 10.3117 (6) ÅT = 298 K
β = 102.680 (1)°Block, green
V = 634.23 (6) Å30.28 × 0.25 × 0.18 mm
Z = 2
Data collection top
Bruker APEXII CCD
diffractometer
1171 independent reflections
Radiation source: fine-focus sealed tube1018 reflections with I > 2σ(I)
Graphite monochromatorRint = 0.016
φ and ω scansθmax = 25.5°, θmin = 2.5°
Absorption correction: multi-scan
(SADABS; Sheldrick, 1996)
h = 105
Tmin = 0.664, Tmax = 0.762k = 89
3133 measured reflectionsl = 1112
Refinement top
Refinement on F2Primary atom site location: structure-invariant direct methods
Least-squares matrix: fullSecondary atom site location: difference Fourier map
R[F2 > 2σ(F2)] = 0.021Hydrogen site location: difmap and geom
wR(F2) = 0.061H-atom parameters constrained
S = 1.02 w = 1/[σ2(Fo2) + (0.0426P)2 + 0.0527P]
where P = (Fo2 + 2Fc2)/3
1171 reflections(Δ/σ)max < 0.001
97 parametersΔρmax = 0.24 e Å3
3 restraintsΔρmin = 0.20 e Å3
Crystal data top
[Ni(C6H5O5)2(H2O)2]V = 634.23 (6) Å3
Mr = 360.90Z = 2
Monoclinic, P21/cMo Kα radiation
a = 8.4762 (5) ŵ = 1.60 mm1
b = 7.4377 (4) ÅT = 298 K
c = 10.3117 (6) Å0.28 × 0.25 × 0.18 mm
β = 102.680 (1)°
Data collection top
Bruker APEXII CCD
diffractometer
1171 independent reflections
Absorption correction: multi-scan
(SADABS; Sheldrick, 1996)
1018 reflections with I > 2σ(I)
Tmin = 0.664, Tmax = 0.762Rint = 0.016
3133 measured reflections
Refinement top
R[F2 > 2σ(F2)] = 0.0213 restraints
wR(F2) = 0.061H-atom parameters constrained
S = 1.02Δρmax = 0.24 e Å3
1171 reflectionsΔρmin = 0.20 e Å3
97 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
xyzUiso*/Ueq
Ni10.00000.00000.00000.02590 (14)
O10.16156 (16)0.12408 (17)0.13402 (12)0.0315 (3)
H10.15910.10890.21620.047*
O1W0.22841 (16)0.18371 (18)0.05033 (13)0.0382 (3)
H1W0.21380.28260.08430.057*
H2W0.27350.12420.09740.057*
O20.1701 (2)0.44803 (18)0.11539 (13)0.0406 (4)
O30.03754 (16)0.19406 (17)0.11125 (12)0.0329 (3)
O40.39452 (18)0.4001 (2)0.35137 (14)0.0438 (4)
O50.61196 (18)0.2846 (2)0.29611 (14)0.0490 (4)
H50.65150.29980.37530.074*
C10.1317 (2)0.3162 (2)0.05532 (17)0.0281 (4)
C20.2029 (2)0.3002 (2)0.09437 (17)0.0292 (4)
H20.15500.39190.14220.035*
C30.3842 (2)0.3234 (3)0.12309 (19)0.0351 (5)
H3A0.43140.22110.08720.042*
H3B0.40960.43010.07760.042*
C40.4609 (2)0.3402 (2)0.26915 (18)0.0311 (4)
Atomic displacement parameters (Å2) top
U11U22U33U12U13U23
Ni10.0297 (2)0.0300 (2)0.01576 (19)0.00928 (13)0.00016 (13)0.00256 (12)
O10.0419 (7)0.0330 (7)0.0178 (6)0.0093 (6)0.0025 (5)0.0026 (5)
O1W0.0401 (8)0.0379 (8)0.0383 (8)0.0043 (6)0.0123 (7)0.0047 (6)
O20.0631 (10)0.0318 (7)0.0247 (7)0.0091 (7)0.0052 (7)0.0041 (6)
O30.0375 (7)0.0379 (7)0.0206 (7)0.0083 (6)0.0001 (6)0.0029 (5)
O40.0424 (8)0.0591 (10)0.0299 (8)0.0064 (7)0.0083 (6)0.0017 (7)
O50.0381 (8)0.0670 (11)0.0379 (9)0.0049 (8)0.0003 (7)0.0145 (7)
C10.0321 (10)0.0296 (10)0.0229 (9)0.0010 (8)0.0064 (8)0.0012 (7)
C20.0352 (10)0.0286 (10)0.0233 (9)0.0024 (8)0.0055 (8)0.0001 (7)
C30.0363 (11)0.0426 (11)0.0263 (10)0.0050 (9)0.0066 (8)0.0012 (8)
C40.0353 (10)0.0294 (10)0.0283 (10)0.0061 (8)0.0066 (8)0.0004 (7)
Geometric parameters (Å, º) top
Ni1—O31.9134 (12)O3—C11.262 (2)
Ni1—O3i1.9134 (12)O4—C41.202 (2)
Ni1—O1i1.9509 (12)O5—C41.316 (2)
Ni1—O11.9509 (12)O5—H50.8200
Ni1—O1W2.5151 (13)C1—C21.534 (2)
Ni1—O1Wi2.5151 (13)C2—C31.510 (3)
O1—C21.438 (2)C2—H20.9800
O1—H10.8600C3—C41.509 (3)
O1W—H1W0.8126C3—H3A0.9700
O1W—H2W0.8117C3—H3B0.9700
O2—C11.241 (2)
O3—Ni1—O3i180.0C1—O3—Ni1116.15 (11)
O3—Ni1—O1i96.63 (5)C4—O5—H5109.4
O3i—Ni1—O1i83.37 (5)O2—C1—O3123.34 (17)
O3—Ni1—O183.37 (5)O2—C1—C2118.40 (16)
O3i—Ni1—O196.63 (5)O3—C1—C2118.26 (15)
O1i—Ni1—O1180.0O1—C2—C3110.43 (16)
O3—Ni1—O1W87.18 (5)O1—C2—C1106.89 (14)
O3i—Ni1—O1W92.82 (5)C3—C2—C1110.30 (15)
O1i—Ni1—O1W87.17 (5)O1—C2—H2109.7
O1—Ni1—O1W92.83 (5)C3—C2—H2109.7
O1—Ni1—O1Wi87.18 (5)C1—C2—H2109.7
O1i—Ni1—O1Wi92.82 (5)C4—C3—C2113.71 (16)
O3i—Ni1—O1Wi87.17 (5)C4—C3—H3A108.8
O3—Ni1—O1Wi92.83 (5)C2—C3—H3A108.8
O1W—Ni1—O1Wi180.0C4—C3—H3B108.8
C2—O1—Ni1113.97 (10)C2—C3—H3B108.8
C2—O1—H1117.4H3A—C3—H3B107.7
Ni1—O1—H1118.1O4—C4—O5123.53 (19)
Ni1—O1W—H1W122.0O4—C4—C3124.69 (18)
Ni1—O1W—H2W108.1O5—C4—C3111.76 (16)
H1W—O1W—H2W106.4
Symmetry code: (i) x, y, z.
Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
O1—H1···O2ii0.861.772.6245 (17)172
O1W—H1W···O2iii0.812.052.8374 (19)163
O1W—H2W···O4iv0.812.082.843 (2)156
O5—H5···O1Wv0.821.872.6835 (19)171
Symmetry codes: (ii) x, y+1/2, z+1/2; (iii) x, y+1, z; (iv) x, y1/2, z+1/2; (v) x+1, y+1/2, z+1/2.

Experimental details

Crystal data
Chemical formula[Ni(C6H5O5)2(H2O)2]
Mr360.90
Crystal system, space groupMonoclinic, P21/c
Temperature (K)298
a, b, c (Å)8.4762 (5), 7.4377 (4), 10.3117 (6)
β (°) 102.680 (1)
V3)634.23 (6)
Z2
Radiation typeMo Kα
µ (mm1)1.60
Crystal size (mm)0.28 × 0.25 × 0.18
Data collection
DiffractometerBruker APEXII CCD
Absorption correctionMulti-scan
(SADABS; Sheldrick, 1996)
Tmin, Tmax0.664, 0.762
No. of measured, independent and
observed [I > 2σ(I)] reflections
3133, 1171, 1018
Rint0.016
(sin θ/λ)max1)0.606
Refinement
R[F2 > 2σ(F2)], wR(F2), S 0.021, 0.061, 1.02
No. of reflections1171
No. of parameters97
No. of restraints3
H-atom treatmentH-atom parameters constrained
Δρmax, Δρmin (e Å3)0.24, 0.20

Computer programs: APEX2 (Bruker, ????), SAINT (Bruker, 1998), SHELXS97 (Sheldrick, 1997), SHELXL97 (Sheldrick, 1997), SHELXTL (Bruker, 1998).

Selected bond lengths (Å) top
Ni1—O31.9134 (12)Ni1—O1W2.5151 (13)
Ni1—O11.9509 (12)
Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
O1—H1···O2i0.861.772.6245 (17)172
O1W—H1W···O2ii0.812.052.8374 (19)163
O1W—H2W···O4iii0.812.082.843 (2)156
O5—H5···O1Wiv0.821.872.6835 (19)171
Symmetry codes: (i) x, y+1/2, z+1/2; (ii) x, y+1, z; (iii) x, y1/2, z+1/2; (iv) x+1, y+1/2, z+1/2.
 

Follow Acta Cryst. E
Sign up for e-alerts
Follow Acta Cryst. on Twitter
Follow us on facebook
Sign up for RSS feeds