Bis­[2-hydroxy-3-(1H-imidazol-4-yl)­propionato]­nickel(II)

In the title compound, [Ni(C₆H₇N₂O₃)₂], the Ni^II ion has a slightly distorted octahedral coordination geometry and lies on a twofold rotation axis. 2-Hydro­xy-3-(1H-imidazol-4-yl)­propionic acid ligates in a tridentate manner. Two carboxyl­ate-O atoms and two hydroxyl-O atoms are coordinated in cis positions with respect to each other and form the equatorial plane, and two imidazole-N atoms are coordinated in axial positions. The mol­ecules are held together by an intermolecular hydrogen-bonding network involving the carboxyl­ate, imino and hydroxyl groups.

Key indicators

• Single-crystal X-ray study
• T = 296 K
• Mean [sigma](C-C) = 0.003 Å
• R factor = 0.019
• wR factor = 0.057
• Data-to-parameter ratio = 9.6

checkCIF results

No syntax errors found

ADDSYM reports no extra symmetry

General Notes



REFLT_03
         From the CIF: _diffrn_reflns_theta_max           27.50
         From the CIF: _reflns_number_total               1018
         Count of symmetry unique reflns         1018
         Completeness (_total/calc)            100.00%
         TEST3: Check Friedels for noncentro structure
         Estimate of Friedel pairs measured         0
         Fraction of Friedel pairs measured     0.000
         Are heavy atom types Z>Si present          yes
          WARNING: Large fraction of Friedel related reflns may
                   be needed to determine absolute structure

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S1. Comment

2-Hydroxy-3-(1H-imidazol-4yl)propionic acid [L-β-imidazolelactic acid, (I)] is one of the final catabolites of L-histidine. Patients with liver cirrhosis or histidinemia have high urinary concentrations of (I) (Dubovsky & Dubovska, 1965; Murray et al., 1993). It also has an inhibitory action on cholinesterase and monoamine oxidase (Kurocochi et al., 1956). Understanding the coordination ability and diversity of biologically important metal ions is helpful in clarifying their functions in biological systems. Up to now, crystal structure of Co^II complex have been determined (Okabe & Adachi, 1999). In this study, we have crystallized another metal complex, Ni^II complex, (II), and the structure analysis of it was carried out.

The Ni^II ion is in a distorted octahedral environment, with Ni^II on a twofold axis, similar to Co^II complex. Compound (I) acts as a tridentate ligand and forms a distorted five-membered ring, which includes the Ni^II and the 2-hydroxyl and carboxylate O atoms. These O atoms bind to the Ni^II in cis positions with respect to each other in the equatorial plane. The imidazole N atoms bind to nickel in the axial positions. No significant distortion is observed among the six coordination bonds of the complex: Ni1—O2 2.076 (2) Å, Ni1—O3 2.066 (2) Å and Ni1—N3 2.066 (2) Å. This coordination mode is similar to Co^II complex [Co1—O2 2.114 (2) Å, Co1—O3 2.100 (2) Å and Co1—N3 2.103 (2) Å]. The ionized propionic acid side chain adopts a gauche conformation: C4—C6—C7—C8 - 52.2 (2)°, this is also similar to Co^II complex. Therefore, it is suggested that the coordinate mode of (I) with transition metals is identical.

The molecules of (II) are linked by intermolecular hydrogen bonds between carboxylate, imino and hydroxyl groups. No stacking interactions between imidazole rings are observed in (II).

S2. Experimental

Light-blue pillar-shaped crystals of the title compound were obtained by the slow evaporation at room temperature of a mixture of water solution of 2-hydroxy-3-(1H-imidazol-4yl)propionic acid and ammonium nickel(II) sulfate hexahydrate (molar ratio 2:1) adjusted to pH 10 with dilute ammonia water.

S3. Refinement

H atoms are placed in a difference Fourier map and were not refined.

Computing details

Data collection: MSC/AFC Diffractometer Control Software (Molecular Structure Corporation, 1992); cell refinement: MSC/AFC Diffractometer Control Software; data reduction: TEXSAN (Molecular Structure Corporation & Rigaku, 1999); program(s) used to solve structure: SIR97 (Altomare et al., 1999); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: ORTEP (Johnson, 1976); software used to prepare material for publication: TEXSAN.

Figures

Fig. 1. ORTEPII (Johnson, 1976) drawing of the title compound, with the atomic numbering scheme. Ellipsoids for non-H atoms correspond to 50% probability.

(I)

Crystal data

[Ni(C6H7N2O3)2]	Dx = 1.664 Mg m^−3
Mr = 368.96	Mo Kα radiation, λ = 0.7107 Å
Orthorhombic, P21212	Cell parameters from 25 reflections
a = 10.631 (3) Å	θ = 24.7–25.0°
b = 13.283 (3) Å	µ = 1.36 mm^−1
c = 5.214 (3) Å	T = 296 K
V = 736.3 (4) Å^3	Pillar, light_blue
Z = 2	0.50 × 0.30 × 0.30 mm
F(000) = 380.0

Data collection

Rigaku AFC-5R diffractometer	Rint = 0.000
ω–2θ scans	θmax = 27.5°
Absorption correction: ψ scan (North et al., 1968)	h = 0→13
Tmin = 0.621, Tmax = 0.666	k = 0→17
1018 measured reflections	l = 0→6
1018 independent reflections	3 standard reflections every 150 reflections
991 reflections with I > 2σ(I)	intensity decay: 0.5%

Refinement

Refinement on F^2	(Δ/σ)max < 0.001
R[F^2 > 2σ(F^2)] = 0.019	Δρmax = 0.32 e Å^−3
wR(F^2) = 0.057	Δρmin = −0.31 e Å^−3
S = 1.10	Extinction correction: SHELXL, Fc^*=kFc[1+0.001xFc^2λ^3/sin(2θ)]^-1/4
1018 reflections	Extinction coefficient: 0.0230
106 parameters	Absolute structure: Flack (1983), 1016 Friedel pairs
H-atom parameters not refined	Absolute structure parameter: −0.03 (3)
w = 1/[σ^2(Fo^2) + (0.037P)^2 + 0.1736P] where P = (Fo^2 + 2Fc^2)/3

Special details

Refinement. Refinement using reflections with F² > -10.0 σ(F²). The weighted R-factor (wR) and goodness of fit (S) are based on F². R-factor (gt) are based on F. The threshold expression of F² > 2.0 σ(F²) is used only for calculating R-factor (gt).

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Ų)

	x	y	z	Uiso*/Ueq
Ni1	0.5000	0.5000	0.24618 (6)	0.0172 (1)
O1	0.1467 (1)	0.5299 (1)	−0.0244 (3)	0.0304 (4)
O2	0.3480 (1)	0.4851 (2)	−0.0009 (3)	0.0230 (5)
O3	0.3492 (2)	0.4831 (2)	0.4923 (3)	0.0224 (5)
N1	0.4786 (2)	0.8126 (1)	0.1327 (4)	0.0352 (5)
N3	0.4655 (2)	0.6531 (1)	0.2406 (4)	0.0241 (3)
C2	0.5369 (2)	0.7229 (2)	0.1337 (5)	0.0302 (5)
C4	0.3546 (2)	0.7010 (1)	0.3110 (4)	0.0242 (4)
C5	0.3630 (2)	0.7998 (1)	0.2441 (6)	0.0324 (4)
C6	0.2495 (2)	0.6477 (2)	0.4439 (4)	0.0271 (4)
C7	0.2436 (2)	0.5347 (2)	0.3873 (4)	0.0214 (4)
C8	0.2440 (2)	0.5153 (1)	0.0974 (4)	0.0199 (4)
H1	0.5056	0.8719	0.0817	0.0332*
H2	0.6190	0.7132	0.0621	0.0332*
H3	0.2991	0.8565	0.2722	0.0332*
H4	0.2550	0.6521	0.6163	0.0332*
H5	0.1724	0.6830	0.3980	0.0332*
H6	0.1621	0.5118	0.4525	0.0332*
H7	0.3586	0.4886	0.6334	0.0332*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
Ni1	0.0180 (2)	0.0183 (2)	0.0154 (2)	0.0025 (1)	0.0000	0.0000
O1	0.0234 (7)	0.0363 (8)	0.0317 (8)	0.0064 (6)	−0.0050 (7)	0.0005 (7)
O2	0.0204 (6)	0.033 (1)	0.0160 (6)	0.0053 (8)	−0.0010 (6)	−0.0007 (7)
O3	0.0244 (6)	0.027 (1)	0.0155 (6)	0.0033 (8)	0.0013 (6)	0.0038 (6)
N1	0.037 (1)	0.0201 (8)	0.048 (1)	−0.0048 (7)	−0.0001 (10)	0.0051 (8)
N3	0.0244 (7)	0.0193 (7)	0.0287 (8)	0.0016 (6)	0.0015 (8)	0.0010 (8)
C2	0.0270 (9)	0.0249 (10)	0.039 (1)	−0.0014 (8)	0.0010 (10)	0.0036 (10)
C4	0.0273 (9)	0.0203 (9)	0.025 (1)	0.0022 (8)	0.0003 (8)	−0.0021 (8)
C5	0.035 (1)	0.0203 (8)	0.042 (1)	0.0032 (7)	0.001 (1)	−0.001 (1)
C6	0.0295 (9)	0.0263 (9)	0.026 (1)	0.0071 (9)	0.0083 (9)	−0.0033 (8)
C7	0.0196 (8)	0.0241 (9)	0.0204 (9)	0.0009 (8)	0.0041 (8)	0.0026 (7)
C8	0.0238 (9)	0.0169 (10)	0.0191 (8)	0.0004 (8)	0.0004 (8)	0.0028 (7)

Geometric parameters (Å, º)

NI1—O2	2.076 (2)	N3—C4	1.388 (3)
NI1—O3	2.066 (2)	C2—H2	0.957
NI1—N3	2.067 (2)	C4—C5	1.361 (3)
O1—C8	1.229 (3)	C4—C6	1.493 (3)
O2—C8	1.283 (3)	C5—H3	1.025
O3—C7	1.425 (3)	C6—C7	1.531 (3)
O3—H7	0.746	C6—H4	0.903
N1—C2	1.343 (3)	C6—H5	0.974
N1—C5	1.369 (3)	C7—C8	1.533 (3)
N1—H1	0.880	C7—H6	0.980
N3—C2	1.322 (3)
O1···N1^i	2.810 (2)	O2···O3^iv	2.643 (2)
O1···O1^ii	3.219 (3)	O2···C7^iv	3.442 (3)
O1···N1^iii	3.228 (2)	O2···C5^iii	3.564 (3)
O1···C7^iv	3.237 (3)	O3···C8^v	3.375 (2)
O1···C5^iii	3.266 (3)	O3···C5^vi	3.594 (3)
O1···C6^iv	3.367 (3)	C2···C6^vii	3.593 (3)
O1···O3^iv	3.372 (2)	C5···C8^viii	3.558 (3)
O1···C2^i	3.531 (3)
O2—NI1—O2^ix	103.28 (8)	N1—C5—C4	106.7 (2)
O2—NI1—O3	76.78 (6)	N1—C5—H3	124.3
O2—NI1—O3^ix	179.22 (10)	C4—C5—H3	128.9
O2—NI1—N3	86.96 (8)	C4—C6—C7	113.9 (2)
O2—NI1—N3^ix	92.04 (9)	C4—C6—H4	112.6
O2—NI1^ix—O3	76.77 (6)	C4—C6—H5	106.7
O2—NI1^ix—O3^ix	179.22 (10)	C7—C6—H4	104.9
O2—NI1^ix—N3	86.96 (9)	C7—C6—H5	113.0
O2—NI1^ix—N3^ix	92.04 (9)	H4—C6—H5	105.6
O3—NI1—O3^ix	103.17 (9)	O3—C7—C6	111.4 (2)
O3—NI1—N3	88.71 (7)	O3—C7—C8	107.2 (2)
O3—NI1—N3^ix	92.29 (7)	O3—C7—H6	114.4
O3—NI1^ix—N3	88.74 (9)	C6—C7—C8	110.8 (2)
O3—NI1^ix—N3^ix	92.27 (9)	C6—C7—H6	106.0
N3—NI1—N3^ix	178.4 (1)	C8—C7—H6	107.0
NI1—O2—C8	113.2 (1)	O1—C8—O2	124.6 (2)
NI1—O3—C7	108.7 (1)	O1—C8—C7	118.7 (2)
NI1—O3—H7	119.9	O2—C8—C7	116.6 (2)
C7—O3—H7	115.9	N1—H1—N1^x	152.5
C2—N1—C5	107.6 (2)	N1—H1—O3^xi	82.8
C2—N1—H1	130.2	N1—H1—O3^vii	118.6
C5—N1—H1	122.2	N1—H1^x—O3^xi	61.92
NI1—N3—C2	126.4 (1)	N1—H1^x—O3^vii	71.54
NI1—N3—C4	126.7 (1)	N1—H2—O3^ix	116.5
C2—N3—C4	106.1 (2)	N1—H2—O3^xii	128.8
N1—C2—N3	111.0 (2)	N1—H2—N1^xiii	144.3
N1—C2—H2	122.6	N1—H2—O3	83.6
N3—C2—H2	126.4	O3—H2^ix—O3^xii	89.0
N3—C4—C5	108.6 (2)	O3—H2^ix—N1^xiii	70.89
N3—C4—C6	122.8 (2)	O3—H2^xii—N1^xiii	54.14
C5—C4—C6	128.7 (2)	O3—H2^xii—O3	89.0
NI1—O2—C8—O1	167.0 (2)	O2—C8—C7—C6	103.1 (2)
NI1—O2—C8—C7	−12.6 (2)	O3—NI1—O2—C8	27.6 (2)
NI1—O2^ix—C8^ix—O1^ix	167.0 (2)	O3—NI1—O3^ix—C7^ix	141.8 (2)
NI1—O2^ix—C8^ix—C7^ix	−12.6 (2)	O3—NI1—N3—C2	172.5 (2)
NI1—O3—C7—C6	−81.2 (2)	O3—NI1—N3—C4	−18.6 (2)
NI1—O3—C7—C8	40.2 (2)	O3—NI1—N3^ix—C2^ix	69.3 (2)
NI1—O3^ix—C7^ix—C6^ix	−81.2 (2)	O3—NI1—N3^ix—C4^ix	−121.7 (2)
NI1—O3^ix—C7^ix—C8^ix	40.2 (2)	O3—C7—C6—C4	67.1 (2)
NI1—N3—C2—N1	171.1 (2)	N1—C2—N3—C4	0.3 (3)
NI1—N3—C4—C5	−171.0 (2)	N1—C5—C4—N3	0.1 (3)
NI1—N3—C4—C6	10.5 (3)	N1—C5—C4—C6	178.5 (2)
NI1—N3^ix—C2^ix—N1^ix	171.1 (2)	N3—NI1—O2—C8	−61.8 (2)
NI1—N3^ix—C4^ix—C5^ix	−171.0 (2)	N3—NI1—O2^ix—C8^ix	119.5 (2)
NI1—N3^ix—C4^ix—C6^ix	10.5 (3)	N3—NI1—O3—C7	49.8 (1)
O1—C8—C7—O3	161.7 (2)	N3—NI1—O3^ix—C7^ix	−129.0 (1)
O1—C8—C7—C6	−76.5 (2)	N3—C2—N1—C5	−0.3 (3)
O2—NI1—O2^ix—C8^ix	−153.1 (2)	N3—C4—C6—C7	−27.1 (3)
O2—NI1—O3—C7	−37.4 (1)	C2—N1—C5—C4	0.1 (3)
O2—NI1—N3—C2	−110.7 (2)	C2—N3—C4—C5	−0.2 (3)
O2—NI1—N3—C4	58.3 (2)	C2—N3—C4—C6	−178.8 (2)
O2—NI1—N3^ix—C2^ix	−7.5 (2)	C4—C6—C7—C8	−52.2 (2)
O2—NI1—N3^ix—C4^ix	161.5 (2)	C5—C4—C6—C7	154.7 (2)
O2—C8—C7—O3	−18.7 (3)

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

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
N1—H1···O1^xiii	0.88	2.01	2.808 (3)	150
O3—H7···O2^v	0.75	1.91	2.642 (2)	167

Symmetry codes: (v) x, y, z+1; (xiii) x+1/2, −y+3/2, −z.