Triaqua­(4-hydroxy­pyridine-2,6-dicarboxyl­ato)nickel(II) sesquihydrate

The reaction of nickel(II) nitrate hexa­hydrate with the proton-transfer compound piperazinediium 4-hydroxy­pyridine-2,6-dicarboxyl­ate, (pipzH₂)(hypydc), where pipz is piperazine and hypydcH₂ is 4-hydroxy­pyridine-2,6-dicarboxylic acid, in aqueous solution leads to the formation of the title complex, [Ni(C₇H₃NO₅)(H₂O)₃]·1.5H₂O. Nickel(II) is coordinated by three donor atoms of the tridentate dianionic ligand, and three water molecules, in a slightly distorted octahedral geometry. The range of H...A and D...A distances, and D—H...A angles indicates the presence of strong hydrogen bonding in this complex, which involves the coordinated and uncoordinated water molecules (one of which lies on a twofold rotation axis), giving a three-dimensional network.

Key indicators

• Single-crystal X-ray study
• T = 150 K
• Mean [sigma](C-C) = 0.006 Å
• R factor = 0.057
• wR factor = 0.161
• Data-to-parameter ratio = 11.9

checkCIF/PLATON results

No syntax errors found



Alert level B
PLAT417_ALERT_2_B Short Inter D-H..H-D       H6B    ..  H10A    ..       1.46 Ang.
PLAT417_ALERT_2_B Short Inter D-H..H-D       H8B    ..  H10B    ..       2.03 Ang.

Alert level C
RINTA01_ALERT_3_C  The value of Rint is greater than 0.10
            Rint given   0.121
PLAT020_ALERT_3_C The value of Rint is greater than 0.10 .........       0.12
PLAT041_ALERT_1_C Calc. and Rep. SumFormula Strings    Differ ....          ?
PLAT042_ALERT_1_C Calc. and Rep. MoietyFormula Strings Differ ....          ?
PLAT045_ALERT_1_C Calculated and Reported Z Differ by ............       0.50 Ratio
PLAT094_ALERT_2_C Ratio of Maximum / Minimum Residual Density ....       2.05
PLAT369_ALERT_2_C Long   C(sp2)-C(sp2) Bond  C1     -   C2     ...       1.53 Ang.
PLAT790_ALERT_4_C Centre of Gravity not Within Unit Cell: Resd.  #          2
              H2 O

Alert level G
PLAT794_ALERT_5_G Check Predicted Bond Valency for Ni1         (2)       1.94

   0 ALERT level A = In general: serious problem
   2 ALERT level B = Potentially serious problem
   8 ALERT level C = Check and explain
   1 ALERT level G = General alerts; check

   3 ALERT type 1 CIF construction/syntax error, inconsistent or missing data
   4 ALERT type 2 Indicator that the structure model may be wrong or deficient
   2 ALERT type 3 Indicator that the structure quality may be low
   1 ALERT type 4 Improvement, methodology, query or suggestion
   1 ALERT type 5 Informative message, check

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S1. Comment

The chemical formula and the ORTEP diagram indicate that the cationic fragment (pipzH₂)²⁺ has been missed during complexation and only the anionic species of the starting proton transfer compound has contributed to the complex. This is similar to some other complexes containing only the anionic fragments of their starting proton transfer compounds. The N(1)–Ni(1)–O(7) angle revealed an octahedral axis with 3.73° deviation from ideal linearity, therefore, O(1), O(4), O(6) and O(8) are equatorial positions of the distorted octahedral. Both weak and strong hydrogen bonds with D···A distances ranging from 2.649 (5)to 3.142 (6) Å, are observed in the crystal. The presence of OH group of 4-hydroxypyridine-2,6-dicarboxylate, carboxylate and water molecules in the crystal structure causes the hydrogen bonding network of the system to be more extended, as its hydrogen bonds has an important linking role among the crystal lattice fragments. Also, two halves of the units [Ni(hypydc)(H₂O)₃], are kept together through hydrogen bonding between water molecules and oxygen atom of carboxylate group. Figures 1 and 2 are shown the molecular structure and packing diagram of this complex, respectively.

Related literature

In recent years, we have been interested in the synthesis of proton-transfer compounds and have studied their behaviour with metal ions. We have focused on proton delivery from dicarboxylic acids, which are considered to be very good donors. Several proton acceptors were selected and employed. The result was the preparation of several proton-transfer compounds possessing anionic forms of diacid as donors. The application of these compounds in the preparation of metal–organic structures has also been investigated. Some of these metal complexes show the contribution of both cationic and anionic fragments of the starting proton-transfer compound, while others contain only one of these species as ligands (Aghabozorg et al., 2006; Aghabozorg et al., 2006a,b; Moghimi et al., 2005; Sheshmani et al., 2006).

S2. Experimental

To 20 ml of an aqueous solution of (pipzH₂)(hypydc) (584 mg, 2 mmol) was added 10 ml of an aqueous solution of nickel(II) nitrate hexahydrate (290 mg, 1 mmol). Upon standing, crystals were precipitated after 20 days. The pure crystalline complex [Ni(hypydc)(H₂O)₃]. 2H₂O,were decomposed at >400 °C.

S3. Refinement

Hydrogen atoms were positioned geometrically and refined with a riding model (including torsional freedom for methyl groups), with C—H = 0.95–0.98 Å, and with U(H) constrained to be 1.2 (1.5 for methyl groups) times U_eq of the carrier atom.

Computing details

Data collection: SMART (Bruker, 1998); cell refinement: SMART; 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.

Figures

	Fig. 1. The molecular structure of (I), with atom labels and 50% probability displacement ellipsoids.
	Fig. 2. The packing of (I), showing molecules connected by O–H···O hydrogen bonds (dashed lines).

Triaqua(4-hydroxypyridine-2,6-dicarboxylato)nickel(II) sesquihydrate

Crystal data

[Ni(C7H3NO5)(H2O)3]·1.5H2O	F(000) = 1320
Mr = 320.89	Dx = 1.859 Mg m^−3
Monoclinic, C2/c	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -C2yc	Cell parameters from 4075 reflections
a = 14.881 (12) Å	θ = 2.7–27.3°
b = 6.878 (6) Å	µ = 1.74 mm^−1
c = 22.409 (19) Å	T = 150 K
β = 90.049 (15)°	Block, blue
V = 2294 (3) Å^3	0.43 × 0.34 × 0.07 mm
Z = 8

Data collection

Bruker SMART 1000 diffractometer	2019 independent reflections
Radiation source: fine-focus sealed tube	1567 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.121
Detector resolution: 100 pixels mm^-1	θmax = 25.0°, θmin = 1.8°
ω scans	h = −17→17
Absorption correction: multi-scan (SADABS; Bruker, 1998)	k = −8→8
Tmin = 0.522, Tmax = 0.888	l = −26→26
10569 measured reflections

Refinement

Refinement on F^2	Primary atom site location: structure-invariant direct methods
Least-squares matrix: full	Secondary atom site location: difference Fourier map
R[F^2 > 2σ(F^2)] = 0.057	Hydrogen site location: inferred from neighbouring sites
wR(F^2) = 0.161	H-atom parameters constrained
S = 1.06	w = 1/[σ^2(Fo^2) + (0.1044P)^2 + 2.0879P] where P = (Fo^2 + 2Fc^2)/3
2019 reflections	(Δ/σ)max = 0.001
169 parameters	Δρmax = 2.09 e Å^−3
0 restraints	Δρmin = −1.02 e Å^−3

Special details

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 (Ų)

	x	y	z	Uiso*/Ueq
Ni1	0.52210 (4)	0.24829 (8)	0.63815 (2)	0.0155 (3)
N1	0.6177 (2)	0.1265 (5)	0.58918 (16)	0.0139 (8)
O1	0.4739 (2)	0.2898 (4)	0.54619 (14)	0.0164 (7)
O2	0.5152 (2)	0.2401 (4)	0.45093 (14)	0.0186 (8)
O3	0.7282 (2)	−0.0631 (5)	0.71543 (14)	0.0266 (8)
O4	0.6134 (2)	0.1517 (5)	0.70553 (13)	0.0201 (7)
O5	0.83039 (19)	−0.0744 (5)	0.48988 (13)	0.0177 (7)
H5	0.8737	−0.1062	0.5119	0.021*
O6	0.4476 (2)	−0.0092 (5)	0.64449 (15)	0.0242 (8)
H6A	0.4428	−0.0682	0.6063	0.029*
H6B	0.3863	0.0217	0.6373	0.029*
O7	0.4278 (2)	0.3656 (5)	0.69271 (14)	0.0238 (8)
H7A	0.4393	0.4831	0.7137	0.029*
H7B	0.3992	0.2843	0.7213	0.029*
O8	0.5778 (2)	0.5276 (5)	0.63456 (14)	0.0214 (7)
H8A	0.5601	0.5938	0.5992	0.026*
H8B	0.6406	0.5324	0.6418	0.026*
O9	0.5000	−0.2882 (9)	0.7500	0.073 (3)
H9A	0.5060	−0.2133	0.7146	0.088*
O10	0.7368 (2)	0.0525 (5)	0.83145 (15)	0.0283 (8)
H10A	0.6805	0.0147	0.8152	0.034*
H10B	0.7587	0.1679	0.8133	0.034*
C1	0.5283 (3)	0.2279 (6)	0.5061 (2)	0.0183 (11)
C2	0.6146 (3)	0.1338 (6)	0.52935 (19)	0.0137 (9)
C3	0.6850 (3)	0.0626 (6)	0.49478 (19)	0.0137 (9)
H3	0.6818	0.0663	0.4524	0.016*
C4	0.7612 (3)	−0.0153 (6)	0.5238 (2)	0.0146 (9)
C5	0.7629 (3)	−0.0255 (6)	0.5870 (2)	0.0172 (10)
H5A	0.8129	−0.0786	0.6077	0.021*
C6	0.6881 (3)	0.0456 (6)	0.6176 (2)	0.0159 (9)
C7	0.6769 (3)	0.0447 (7)	0.6852 (2)	0.0173 (10)

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
Ni1	0.0124 (4)	0.0218 (4)	0.0122 (4)	0.0028 (2)	0.0006 (3)	−0.0001 (2)
N1	0.0115 (17)	0.0175 (19)	0.0128 (19)	0.0013 (14)	−0.0006 (14)	−0.0005 (15)
O1	0.0119 (16)	0.0214 (17)	0.0158 (17)	0.0039 (12)	0.0018 (13)	0.0003 (13)
O2	0.0207 (19)	0.0224 (18)	0.0125 (19)	0.0041 (12)	−0.0068 (14)	−0.0010 (12)
O3	0.0264 (18)	0.040 (2)	0.0137 (17)	0.0100 (15)	−0.0024 (14)	0.0013 (15)
O4	0.0208 (16)	0.0279 (19)	0.0118 (16)	0.0080 (14)	0.0007 (12)	0.0003 (14)
O5	0.0127 (15)	0.0247 (18)	0.0156 (16)	0.0069 (12)	0.0026 (12)	0.0001 (14)
O6	0.0220 (17)	0.0281 (18)	0.0226 (18)	−0.0020 (13)	0.0033 (14)	−0.0038 (15)
O7	0.0232 (17)	0.032 (2)	0.0161 (17)	0.0059 (14)	0.0043 (13)	0.0009 (15)
O8	0.0210 (16)	0.0252 (18)	0.0180 (17)	0.0002 (13)	−0.0010 (13)	0.0020 (14)
O9	0.145 (8)	0.038 (4)	0.036 (4)	0.000	0.035 (5)	0.000
O10	0.0250 (18)	0.037 (2)	0.0226 (19)	−0.0041 (15)	−0.0039 (14)	0.0024 (16)
C1	0.022 (3)	0.013 (2)	0.021 (3)	−0.0016 (17)	0.004 (2)	0.0016 (18)
C2	0.012 (2)	0.016 (2)	0.013 (2)	−0.0011 (17)	−0.0020 (16)	−0.0009 (18)
C3	0.016 (2)	0.015 (2)	0.010 (2)	−0.0022 (16)	−0.0007 (17)	−0.0002 (17)
C4	0.014 (2)	0.015 (2)	0.015 (2)	−0.0005 (16)	0.0013 (17)	0.0010 (18)
C5	0.015 (2)	0.020 (2)	0.016 (2)	0.0035 (17)	0.0000 (18)	−0.0002 (19)
C6	0.013 (2)	0.019 (2)	0.015 (2)	−0.0005 (17)	−0.0027 (17)	0.0020 (18)
C7	0.013 (2)	0.025 (2)	0.014 (2)	0.0018 (18)	0.0008 (18)	0.0001 (19)

Geometric parameters (Å, º)

Ni1—N1	1.983 (4)	O7—H7A	0.9501
Ni1—O7	2.029 (3)	O7—H7B	0.9501
Ni1—O8	2.094 (4)	O8—H8A	0.9500
Ni1—O6	2.094 (4)	O8—H8B	0.9501
Ni1—O4	2.136 (3)	O9—H9A	0.9500
Ni1—O1	2.200 (4)	O10—H10A	0.9500
N1—C2	1.342 (6)	O10—H10B	0.9499
N1—C6	1.346 (6)	C1—C2	1.529 (6)
O1—C1	1.283 (6)	C2—C3	1.393 (6)
O2—C1	1.254 (6)	C3—C4	1.412 (6)
O3—C7	1.261 (5)	C3—H3	0.9500
O4—C7	1.282 (5)	C4—C5	1.418 (7)
O5—C4	1.344 (5)	C5—C6	1.395 (6)
O5—H5	0.8400	C5—H5A	0.9500
O6—H6A	0.9499	C6—C7	1.525 (6)
O6—H6B	0.9500
N1—Ni1—O7	176.51 (13)	H7A—O7—H7B	104.3
N1—Ni1—O8	94.73 (14)	Ni1—O8—H8A	111.2
O7—Ni1—O8	86.10 (14)	Ni1—O8—H8B	114.5
N1—Ni1—O6	93.45 (14)	H8A—O8—H8B	113.5
O7—Ni1—O6	85.93 (14)	H10A—O10—H10B	111.5
O8—Ni1—O6	171.13 (13)	O2—C1—O1	124.8 (4)
N1—Ni1—O4	78.67 (14)	O2—C1—C2	119.6 (4)
O7—Ni1—O4	97.90 (14)	O1—C1—C2	115.6 (4)
O8—Ni1—O4	93.50 (13)	N1—C2—C3	121.1 (4)
O6—Ni1—O4	91.46 (14)	N1—C2—C1	112.6 (4)
N1—Ni1—O1	76.72 (14)	C3—C2—C1	126.2 (4)
O7—Ni1—O1	106.71 (13)	C2—C3—C4	118.8 (4)
O8—Ni1—O1	88.48 (12)	C2—C3—H3	120.6
O6—Ni1—O1	90.07 (13)	C4—C3—H3	120.6
O4—Ni1—O1	155.39 (12)	O5—C4—C3	118.0 (4)
C2—N1—C6	120.9 (4)	O5—C4—C5	122.5 (4)
C2—N1—Ni1	120.8 (3)	C3—C4—C5	119.5 (4)
C6—N1—Ni1	118.2 (3)	C6—C5—C4	117.3 (4)
C1—O1—Ni1	114.0 (3)	C6—C5—H5A	121.3
C7—O4—Ni1	113.3 (3)	C4—C5—H5A	121.3
C4—O5—H5	109.5	N1—C6—C5	122.3 (4)
Ni1—O6—H6A	109.8	N1—C6—C7	112.7 (4)
Ni1—O6—H6B	107.9	C5—C6—C7	125.1 (4)
H6A—O6—H6B	82.7	O3—C7—O4	126.3 (4)
Ni1—O7—H7A	120.8	O3—C7—C6	118.0 (4)
Ni1—O7—H7B	118.8	O4—C7—C6	115.6 (4)
O8—Ni1—N1—C2	−83.2 (3)	Ni1—N1—C2—C1	−4.7 (5)
O6—Ni1—N1—C2	93.4 (3)	O2—C1—C2—N1	−178.2 (4)
O4—Ni1—N1—C2	−175.8 (3)	O1—C1—C2—N1	1.9 (5)
O1—Ni1—N1—C2	4.1 (3)	O2—C1—C2—C3	2.4 (7)
O8—Ni1—N1—C6	93.3 (3)	O1—C1—C2—C3	−177.5 (4)
O6—Ni1—N1—C6	−90.1 (3)	N1—C2—C3—C4	−1.1 (6)
O4—Ni1—N1—C6	0.7 (3)	C1—C2—C3—C4	178.3 (4)
O1—Ni1—N1—C6	−179.4 (3)	C2—C3—C4—O5	−176.7 (4)
N1—Ni1—O1—C1	−2.8 (3)	C2—C3—C4—C5	2.2 (6)
O7—Ni1—O1—C1	177.9 (3)	O5—C4—C5—C6	178.1 (4)
O8—Ni1—O1—C1	92.4 (3)	C3—C4—C5—C6	−0.8 (6)
O6—Ni1—O1—C1	−96.3 (3)	C2—N1—C6—C5	3.2 (6)
O4—Ni1—O1—C1	−2.7 (5)	Ni1—N1—C6—C5	−173.3 (3)
N1—Ni1—O4—C7	−8.3 (3)	C2—N1—C6—C7	−177.7 (4)
O7—Ni1—O4—C7	171.0 (3)	Ni1—N1—C6—C7	5.8 (5)
O8—Ni1—O4—C7	−102.4 (3)	C4—C5—C6—N1	−1.9 (7)
O6—Ni1—O4—C7	84.9 (3)	C4—C5—C6—C7	179.1 (4)
O1—Ni1—O4—C7	−8.4 (5)	Ni1—O4—C7—O3	−164.3 (4)
Ni1—O1—C1—O2	−178.6 (3)	Ni1—O4—C7—C6	13.6 (5)
Ni1—O1—C1—C2	1.3 (4)	N1—C6—C7—O3	164.9 (4)
C6—N1—C2—C3	−1.6 (6)	C5—C6—C7—O3	−16.0 (7)
Ni1—N1—C2—C3	174.7 (3)	N1—C6—C7—O4	−13.2 (6)
C6—N1—C2—C1	179.0 (4)	C5—C6—C7—O4	165.8 (4)

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
O5—H5···O1^i	0.84	1.82	2.649 (5)	167
O6—H6A···O2^ii	0.95	1.85	2.720 (5)	151
O6—H6B···O10^iii	0.95	1.97	2.829 (5)	149
O7—H7A···O9^iv	0.95	1.99	2.911 (7)	163
O7—H7B···O4^iii	0.95	1.89	2.782 (5)	156
O8—H8A···O2^v	0.95	1.96	2.852 (5)	157
O8—H8A···O5^vi	0.95	2.58	3.123 (5)	116
O8—H8B···O10^vii	0.95	1.92	2.867 (5)	172
O9—H9A···O6	0.95	2.28	3.142 (6)	151
O10—H10A···O6^iii	0.95	2.12	2.829 (5)	131
O10—H10B···O3^vii	0.95	1.97	2.893 (5)	164

Symmetry codes: (i) x+1/2, y−1/2, z; (ii) −x+1, −y, −z+1; (iii) −x+1, y, −z+3/2; (iv) x, y+1, z; (v) −x+1, −y+1, −z+1; (vi) −x+3/2, −y+1/2, −z+1; (vii) −x+3/2, y+1/2, −z+3/2.