Bis(2,2′,2′′-nitrilo­triacetamide-κ3O,N,O′)nickel(II) dinitrate tetra­hydrate

Deng, X.-H.; Nie, Q.-J.; Zhu, F.-J.

doi:10.1107/S160053681205177X

metal-organic compounds

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ISSN: 2056-9890

Volume 69| Part 2| February 2013| Page m89

doi:10.1107/S160053681205177X

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Bis(2,2′,2′′-nitrilotriacetamide-κ³O,N,O′)nickel(II) dinitrate tetrahydrate

Xiao-Hui Deng,^a ^* Qi-Jun Nie ^a and Feng-Juan Zhu ^a

^aInstitute of Economic Crops, Hubei Academy of Agricultural Science, Wuhan 430064, People's Republic of China
^*Correspondence e-mail: xhdengyy@yahoo.com.cn

(Received 17 December 2012; accepted 23 December 2012; online 9 January 2013)

In the title compound, [Ni(C₆H₁₂N₄O₃)₂](NO₃)₂·4H₂O, the Ni^II cation is located on an inversion center and is N,O,O′-chelated by two nitrilotris(acetamide) molecules in a distorted octahedral geometry. The complex cations, nitrate anions and lattice water molecules are connected by O—H⋯O and N—H⋯O hydrogen bonds, forming a three-dimensional supramolecular structure.

Related literature

For related metal complexes, see: Niraj et al. (2012 ); Biswajit et al. (2009 ); Ben Amor et al. (1998 ). For the synthesis of the ligand, see: Donald & George (1974 ).

Experimental

Crystal data

[Ni(C₆H₁₂N₄O₃)₂](NO₃)₂·4H₂O
M_r = 631.17
Triclinic, $[P \overline 1]$
a = 8.557 (7) Å
b = 9.212 (8) Å
c = 9.367 (8) Å
α = 91.180 (14)°
β = 96.215 (14)°
γ = 111.136 (14)°
V = 683.2 (10) Å³
Z = 1
Mo Kα radiation
μ = 0.80 mm⁻¹
T = 296 K
0.42 × 0.38 × 0.33 mm

Data collection

Bruker SMART 1000 CCD area-detector diffractometer
Absorption correction: multi-scan (SADABS; Bruker, 2001 ) T_min = 0.731, T_max = 0.779
3732 measured reflections
2352 independent reflections
2219 reflections with I > 2σ(I)
R_int = 0.014

Refinement

R[F² > 2σ(F²)] = 0.032
wR(F²) = 0.088
S = 1.05
2352 reflections
190 parameters
6 restraints
H atoms treated by a mixture of independent and constrained refinement
Δρ_max = 0.31 e Å⁻³
Δρ_min = −0.24 e Å⁻³

Table 1
Hydrogen-bond geometry (Å, °)

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
N2—H2A⋯O8ⁱ	0.86	2.14	2.988 (3)	169
N2—H2B⋯O6ⁱⁱ	0.86	2.19	3.027 (4)	165
N3—H3A⋯O4ⁱⁱⁱ	0.86	2.28	3.056 (4)	150
N3—H3B⋯O3ⁱⁱ	0.86	1.99	2.848 (3)	173
N4—H4A⋯O7^iv	0.86	2.22	3.002 (3)	152
N4—H4B⋯O7	0.86	2.32	3.068 (4)	145
O7—H7A⋯O4	0.87 (2)	2.08 (2)	2.913 (4)	162 (3)
O7—H7B⋯O8^v	0.87 (2)	1.98 (2)	2.843 (3)	174 (4)
O8—H8A⋯O1ⁱⁱⁱ	0.86 (2)	2.18 (2)	3.018 (3)	165 (3)
O8—H8B⋯O4	0.86 (2)	2.19 (2)	2.999 (4)	157 (3)
O8—H8B⋯O6	0.86 (2)	2.40 (3)	3.107 (4)	141 (3)
Symmetry codes: (i) x+1, y, z+1; (ii) -x+1, -y, -z+2; (iii) -x+1, -y+1, -z+2; (iv) -x+1, -y, -z+1; (v) -x+1, -y+1, -z+1.

Data collection: SMART (Bruker, 2007 ); cell refinement: SAINT (Bruker, 2007); data reduction: SAINT ; program(s) used to solve structure: SHELXTL (Sheldrick, 2008 ); program(s) used to refine structure: SHELXTL; molecular graphics: SHELXTL; software used to prepare material for publication: SHELXTL.

Supporting information

Crystal structure: contains datablocks I, New_Global_Publ_Block. DOI: 10.1107/S160053681205177X/xu5668sup1.cif

Structure factors: contains datablock I. DOI: 10.1107/S160053681205177X/xu5668Isup2.hkl

checkCIF report

Comment top

Coordination chemistry of nitrilotriacetic acid with metal ions is explored extensively owing to their flexible coordinating nature, but nitrilotriacetamide (H₃NTA) is hardly studied (Niraj et al., 2012; Biswajit et al., 2009; Ben Amor et al., 1998). This is the first report of a bis(H₃NTA)–nickel(II) structure in which only H₃NTA acts as a tridentate ligand.

Complex I consists of a Ni(H₃NTA)₂ cation, two nitrate anions and four solvent water molecules (Scheme). Ni(II) has an octahedral coordination environment which is centrosymmetric as Ni(II) occupies an inversion center. The Ni atom is coordinated in a planar geometry by the nitrilotriacetamide N and O atoms. Two trans axial sites of this coordination environment is occupied by O2 and its symmetry related O2' oxygen atoms from ligands(Fig. 1). In the equatorial plane the Ni—N1 distance is 2.131 (2) Å and the Ni—O1 distance is 2.098 (2) Å. The axial Ni—O2 bond is appreciably shortented which is 2.036 (2) Å. A few more selected bond distances and bond angles are presented in Table 1. The molecules are stacked along the a axis and display N—H···O and O—H···O hydrogen-bonds interaction (Fig. 2).

Related literature top

For related metal complexes, see: Niraj et al. (2012); Biswajit et al. (2009); Ben Amor et al. (1998). For the synthesis of the ligand, see: Donald & George (1974).

Experimental top

The synthesis of nitrilotriacetamide was carried out according to US patent 3799981 (Donald & George, 1974). The title compound was synthesized by adding solid Ni(NO₃)₂.6H₂O (291 mg, 1 mmol) to a solution of ligands (376 mg, 2 mmol) in ethanol/water (2:1, 20 ml), then the mixture was stirred for 2 h at room temperature. The solution was filtered and the filtrate was allowed to stand in air for 1 d, and blue crystals were formed at the bottom of the vessel on slow evaporation of the solvent at room temperature.Yield: 73%.

Computing details top

Data collection: SMART (Bruker, 2007); cell refinement: SAINT (Bruker, 2007); data reduction: SAINT (Bruker, 2007); program(s) used to solve structure: SHELXTL (Sheldrick, 2008); program(s) used to refine structure: SHELXTL (Sheldrick, 2008); molecular graphics: SHELXTL (Sheldrick, 2008); software used to prepare material for publication: SHELXTL (Sheldrick, 2008).

Figures top

	Fig. 1. The molecular structure of (I), showing the atom-numbering scheme. Displacement ellipsoids are drawn at the 30% probability level.
	Fig. 2. The packed diagram for the title compound, viewed down the a axis with hydrogen bonds drawn as dashed lines.

Bis(2,2',2''-nitrilotriacetamide-κ³O,N,O')nickel(II) dinitrate tetrahydrate top

Crystal data top

[Ni(C₆H₁₂N₄O₃)₂](NO₃)₂·4H₂O	Z = 1
M_r = 631.17	F(000) = 330
Triclinic, P1	D_x = 1.534 Mg m⁻³
Hall symbol: -P 1	Mo Kα radiation, λ = 0.71073 Å
a = 8.557 (7) Å	Cell parameters from 2322 reflections
b = 9.212 (8) Å	θ = 2.4–28.2°
c = 9.367 (8) Å	µ = 0.80 mm⁻¹
α = 91.180 (14)°	T = 296 K
β = 96.215 (14)°	Block, blue
γ = 111.136 (14)°	0.42 × 0.38 × 0.33 mm
V = 683.2 (10) Å³

Data collection top

Bruker SMART 1000 CCD area-detector diffractometer	2352 independent reflections
Radiation source: fine-focus sealed tube	2219 reflections with I > 2σ(I)
Graphite monochromator	R_int = 0.014
phi and ω scans	θ_max = 25.0°, θ_min = 2.2°
Absorption correction: multi-scan (SADABS; Bruker, 2001)	h = −10→10
T_min = 0.731, T_max = 0.779	k = −10→10
3732 measured reflections	l = −11→9

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) = 0.088	H atoms treated by a mixture of independent and constrained refinement
S = 1.05	w = 1/[σ²(F_o²) + (0.0494P)² + 0.3085P] where P = (F_o² + 2F_c²)/3
2352 reflections	(Δ/σ)_max < 0.001
190 parameters	Δρ_max = 0.31 e Å⁻³
6 restraints	Δρ_min = −0.24 e Å⁻³

Crystal data top

[Ni(C₆H₁₂N₄O₃)₂](NO₃)₂·4H₂O	γ = 111.136 (14)°
M_r = 631.17	V = 683.2 (10) Å³
Triclinic, P1	Z = 1
a = 8.557 (7) Å	Mo Kα radiation
b = 9.212 (8) Å	µ = 0.80 mm⁻¹
c = 9.367 (8) Å	T = 296 K
α = 91.180 (14)°	0.42 × 0.38 × 0.33 mm
β = 96.215 (14)°

Data collection top

Bruker SMART 1000 CCD area-detector diffractometer	2352 independent reflections
Absorption correction: multi-scan (SADABS; Bruker, 2001)	2219 reflections with I > 2σ(I)
T_min = 0.731, T_max = 0.779	R_int = 0.014
3732 measured reflections

Refinement top

R[F² > 2σ(F²)] = 0.032	6 restraints
wR(F²) = 0.088	H atoms treated by a mixture of independent and constrained refinement
S = 1.05	Δρ_max = 0.31 e Å⁻³
2352 reflections	Δρ_min = −0.24 e Å⁻³
190 parameters

Special details top

Experimental. Selected IR data (cm^-1): 3315 (s), 3192 (s), 2935(w), 2783(w), 1666(s), 1596(s), 1276(m), 1134(m), 997(m), 867(m), 729(w), 561(s).

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	U_iso*/U_eq
Ni1	1.0000	0.5000	1.0000	0.02392 (14)
O1	1.0488 (2)	0.43473 (17)	1.20851 (16)	0.0346 (4)
O3	0.7111 (2)	−0.06864 (18)	0.86966 (18)	0.0445 (4)
O2	0.78448 (19)	0.51673 (16)	1.05845 (18)	0.0341 (4)
O4	0.3921 (3)	0.3138 (2)	0.7047 (3)	0.0796 (8)
O5	0.3643 (3)	0.0742 (3)	0.7446 (3)	0.0766 (7)
O6	0.1436 (3)	0.1309 (3)	0.6829 (3)	0.0760 (7)
O8	0.1390 (3)	0.4509 (2)	0.58844 (19)	0.0503 (5)
H8A	0.070 (4)	0.467 (4)	0.640 (3)	0.075*
H8B	0.188 (4)	0.396 (4)	0.635 (3)	0.075*
O7	0.6156 (3)	0.2788 (2)	0.5043 (2)	0.0618 (6)
H7A	0.563 (4)	0.311 (4)	0.564 (4)	0.093*
H7B	0.685 (4)	0.361 (3)	0.470 (4)	0.093*
N4	0.6721 (3)	−0.0015 (2)	0.6398 (2)	0.0488 (6)
H4A	0.6150	−0.0964	0.6083	0.059*
H4B	0.6905	0.0722	0.5816	0.059*
N1	0.8516 (2)	0.25706 (19)	0.97289 (18)	0.0255 (4)
N3	0.5292 (2)	0.3768 (2)	1.1244 (2)	0.0383 (5)
H3A	0.5150	0.4598	1.1533	0.046*
H3B	0.4526	0.2868	1.1308	0.046*
N2	1.0204 (3)	0.2211 (2)	1.3335 (2)	0.0504 (6)
H2A	1.0547	0.2765	1.4138	0.060*
H2B	0.9931	0.1216	1.3325	0.060*
N5	0.3008 (3)	0.1727 (3)	0.7132 (3)	0.0495 (6)
C4	0.6690 (3)	0.3874 (2)	1.0699 (2)	0.0278 (4)
C1	0.9486 (3)	0.1859 (2)	1.0730 (2)	0.0301 (5)
H1A	1.0441	0.1794	1.0299	0.036*
H1B	0.8767	0.0813	1.0920	0.036*
C6	0.7323 (3)	0.0313 (2)	0.7789 (2)	0.0313 (5)
C2	1.0099 (3)	0.2884 (2)	1.2128 (2)	0.0316 (5)
C5	0.8390 (3)	0.2040 (2)	0.8193 (2)	0.0322 (5)
H5A	0.9522	0.2242	0.7956	0.039*
H5B	0.7918	0.2669	0.7599	0.039*
C3	0.6822 (3)	0.2338 (2)	1.0189 (3)	0.0346 (5)
H3C	0.6623	0.1635	1.0963	0.041*
H3D	0.5953	0.1855	0.9388	0.041*

Atomic displacement parameters (Å²) top

	U¹¹	U²²	U³³	U¹²	U¹³	U²³
Ni1	0.0223 (2)	0.0156 (2)	0.0283 (2)	0.00044 (14)	0.00210 (14)	0.00082 (14)
O1	0.0430 (9)	0.0214 (8)	0.0311 (8)	0.0035 (7)	−0.0013 (7)	0.0001 (6)
O3	0.0518 (11)	0.0231 (8)	0.0437 (9)	−0.0027 (7)	0.0006 (8)	0.0012 (7)
O2	0.0284 (8)	0.0193 (7)	0.0515 (9)	0.0033 (6)	0.0110 (7)	0.0018 (6)
O4	0.0941 (18)	0.0344 (11)	0.1007 (18)	0.0035 (11)	0.0446 (15)	−0.0048 (11)
O5	0.0583 (14)	0.0618 (14)	0.109 (2)	0.0227 (12)	0.0036 (13)	0.0220 (13)
O6	0.0538 (13)	0.0572 (13)	0.123 (2)	0.0250 (11)	0.0171 (13)	0.0198 (13)
O8	0.0604 (13)	0.0489 (11)	0.0404 (10)	0.0185 (10)	0.0068 (9)	0.0036 (8)
O7	0.0663 (14)	0.0445 (11)	0.0573 (13)	−0.0015 (10)	0.0122 (10)	−0.0014 (9)
N4	0.0606 (14)	0.0304 (11)	0.0401 (11)	0.0019 (10)	−0.0052 (10)	−0.0068 (9)
N1	0.0240 (9)	0.0187 (8)	0.0296 (9)	0.0033 (7)	0.0013 (7)	−0.0007 (7)
N3	0.0323 (10)	0.0231 (9)	0.0577 (13)	0.0052 (8)	0.0156 (9)	0.0004 (9)
N2	0.0761 (16)	0.0300 (11)	0.0355 (11)	0.0115 (11)	−0.0064 (10)	0.0045 (9)
N5	0.0567 (15)	0.0376 (12)	0.0546 (13)	0.0139 (11)	0.0196 (11)	0.0053 (10)
C4	0.0258 (10)	0.0242 (11)	0.0303 (11)	0.0062 (9)	0.0010 (8)	0.0019 (8)
C1	0.0325 (11)	0.0195 (10)	0.0342 (11)	0.0060 (9)	−0.0007 (9)	0.0019 (8)
C6	0.0305 (11)	0.0234 (11)	0.0358 (11)	0.0050 (9)	0.0040 (9)	−0.0054 (9)
C2	0.0307 (11)	0.0252 (11)	0.0332 (11)	0.0050 (9)	−0.0017 (9)	0.0021 (9)
C5	0.0372 (12)	0.0216 (10)	0.0292 (11)	0.0011 (9)	0.0024 (9)	−0.0001 (8)
C3	0.0247 (11)	0.0211 (10)	0.0529 (14)	0.0017 (9)	0.0079 (10)	−0.0008 (9)

Geometric parameters (Å, º) top

Ni1—O2	2.036 (2)	N1—C5	1.490 (3)
Ni1—O2ⁱ	2.036 (2)	N1—C3	1.499 (3)
Ni1—O1ⁱ	2.098 (2)	N1—C1	1.499 (3)
Ni1—O1	2.098 (2)	N3—C4	1.323 (3)
Ni1—N1	2.131 (2)	N3—H3A	0.8600
Ni1—N1ⁱ	2.131 (2)	N3—H3B	0.8600
O1—C2	1.270 (3)	N2—C2	1.311 (3)
O3—C6	1.244 (3)	N2—H2A	0.8600
O2—C4	1.259 (3)	N2—H2B	0.8600
O4—N5	1.262 (3)	C4—C3	1.530 (3)
O5—N5	1.239 (3)	C1—C2	1.525 (3)
O6—N5	1.256 (3)	C1—H1A	0.9700
O8—H8A	0.856 (17)	C1—H1B	0.9700
O8—H8B	0.859 (17)	C6—C5	1.537 (3)
O7—H7A	0.868 (18)	C5—H5A	0.9700
O7—H7B	0.866 (18)	C5—H5B	0.9700
N4—C6	1.335 (3)	C3—H3C	0.9700
N4—H4A	0.8600	C3—H3D	0.9700
N4—H4B	0.8600

O2—Ni1—O2ⁱ	180.0	C2—N2—H2B	120.0
O2—Ni1—O1ⁱ	92.01 (7)	H2A—N2—H2B	120.0
O2ⁱ—Ni1—O1ⁱ	87.99 (7)	O5—N5—O6	119.8 (2)
O2—Ni1—O1	87.99 (7)	O5—N5—O4	121.1 (3)
O2ⁱ—Ni1—O1	92.01 (7)	O6—N5—O4	119.1 (3)
O1ⁱ—Ni1—O1	180.000 (1)	O2—C4—N3	122.14 (19)
O2—Ni1—N1	83.50 (8)	O2—C4—C3	121.45 (19)
O2ⁱ—Ni1—N1	96.50 (7)	N3—C4—C3	116.40 (18)
O1ⁱ—Ni1—N1	99.63 (7)	N1—C1—C2	108.21 (17)
O1—Ni1—N1	80.37 (7)	N1—C1—H1A	110.1
O2—Ni1—N1ⁱ	96.50 (7)	C2—C1—H1A	110.1
O2ⁱ—Ni1—N1ⁱ	83.50 (8)	N1—C1—H1B	110.1
O1ⁱ—Ni1—N1ⁱ	80.37 (7)	C2—C1—H1B	110.1
O1—Ni1—N1ⁱ	99.63 (7)	H1A—C1—H1B	108.4
N1—Ni1—N1ⁱ	180.0	O3—C6—N4	123.8 (2)
C2—O1—Ni1	112.16 (13)	O3—C6—C5	121.5 (2)
C4—O2—Ni1	114.27 (14)	N4—C6—C5	114.6 (2)
H8A—O8—H8B	109 (2)	O1—C2—N2	122.5 (2)
H7A—O7—H7B	107 (2)	O1—C2—C1	119.24 (18)
C6—N4—H4A	120.0	N2—C2—C1	118.3 (2)
C6—N4—H4B	120.0	N1—C5—C6	115.90 (17)
H4A—N4—H4B	120.0	N1—C5—H5A	108.3
C5—N1—C3	112.27 (17)	C6—C5—H5A	108.3
C5—N1—C1	112.83 (17)	N1—C5—H5B	108.3
C3—N1—C1	111.36 (17)	C6—C5—H5B	108.3
C5—N1—Ni1	108.65 (12)	H5A—C5—H5B	107.4
C3—N1—Ni1	107.87 (12)	N1—C3—C4	112.21 (16)
C1—N1—Ni1	103.32 (13)	N1—C3—H3C	109.2
C4—N3—H3A	120.0	C4—C3—H3C	109.2
C4—N3—H3B	120.0	N1—C3—H3D	109.2
H3A—N3—H3B	120.0	C4—C3—H3D	109.2
C2—N2—H2A	120.0	H3C—C3—H3D	107.9

O2—Ni1—O1—C2	100.65 (16)	O1ⁱ—Ni1—N1—C1	147.65 (13)
O2ⁱ—Ni1—O1—C2	−79.35 (16)	O1—Ni1—N1—C1	−32.35 (13)
O1ⁱ—Ni1—O1—C2	177 (100)	N1ⁱ—Ni1—N1—C1	−136 (100)
N1—Ni1—O1—C2	16.91 (15)	Ni1—O2—C4—N3	171.21 (17)
N1ⁱ—Ni1—O1—C2	−163.09 (15)	Ni1—O2—C4—C3	−9.8 (3)
O2ⁱ—Ni1—O2—C4	178 (100)	C5—N1—C1—C2	159.20 (17)
O1ⁱ—Ni1—O2—C4	106.73 (15)	C3—N1—C1—C2	−73.5 (2)
O1—Ni1—O2—C4	−73.27 (15)	Ni1—N1—C1—C2	42.05 (18)
N1—Ni1—O2—C4	7.27 (15)	Ni1—O1—C2—N2	−175.82 (19)
N1ⁱ—Ni1—O2—C4	−172.73 (15)	Ni1—O1—C2—C1	4.2 (3)
O2—Ni1—N1—C5	118.55 (14)	N1—C1—C2—O1	−33.3 (3)
O2ⁱ—Ni1—N1—C5	−61.45 (14)	N1—C1—C2—N2	146.7 (2)
O1ⁱ—Ni1—N1—C5	27.60 (14)	C3—N1—C5—C6	−59.4 (2)
O1—Ni1—N1—C5	−152.40 (14)	C1—N1—C5—C6	67.4 (2)
N1ⁱ—Ni1—N1—C5	103 (100)	Ni1—N1—C5—C6	−178.62 (15)
O2—Ni1—N1—C3	−3.40 (13)	O3—C6—C5—N1	−25.7 (3)
O2ⁱ—Ni1—N1—C3	176.60 (13)	N4—C6—C5—N1	157.0 (2)
O1ⁱ—Ni1—N1—C3	−94.34 (14)	C5—N1—C3—C4	−119.78 (19)
O1—Ni1—N1—C3	85.66 (14)	C1—N1—C3—C4	112.6 (2)
N1ⁱ—Ni1—N1—C3	−18 (100)	Ni1—N1—C3—C4	−0.1 (2)
O2—Ni1—N1—C1	−121.40 (14)	O2—C4—C3—N1	6.6 (3)
O2ⁱ—Ni1—N1—C1	58.60 (14)	N3—C4—C3—N1	−174.31 (19)

Symmetry code: (i) −x+2, −y+1, −z+2.

Hydrogen-bond geometry (Å, º) top

D—H···A	D—H	H···A	D···A	D—H···A
N2—H2A···O8ⁱⁱ	0.86	2.14	2.988 (3)	169
N2—H2B···O6ⁱⁱⁱ	0.86	2.19	3.027 (4)	165
N3—H3A···O4^iv	0.86	2.28	3.056 (4)	150
N3—H3B···O3ⁱⁱⁱ	0.86	1.99	2.848 (3)	173
N4—H4A···O7^v	0.86	2.22	3.002 (3)	152
N4—H4B···O7	0.86	2.32	3.068 (4)	145
O7—H7A···O4	0.87 (2)	2.08 (2)	2.913 (4)	162 (3)
O7—H7B···O8^vi	0.87 (2)	1.98 (2)	2.843 (3)	174 (4)
O8—H8A···O1^iv	0.86 (2)	2.18 (2)	3.018 (3)	165 (3)
O8—H8B···O4	0.86 (2)	2.19 (2)	2.999 (4)	157 (3)
O8—H8B···O6	0.86 (2)	2.40 (3)	3.107 (4)	141 (3)

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

Experimental details

Crystal data
Chemical formula	[Ni(C₆H₁₂N₄O₃)₂](NO₃)₂·4H₂O
M_r	631.17
Crystal system, space group	Triclinic, P1
Temperature (K)	296
a, b, c (Å)	8.557 (7), 9.212 (8), 9.367 (8)
α, β, γ (°)	91.180 (14), 96.215 (14), 111.136 (14)
V (Å³)	683.2 (10)
Z	1
Radiation type	Mo Kα
µ (mm⁻¹)	0.80
Crystal size (mm)	0.42 × 0.38 × 0.33

Data collection
Diffractometer	Bruker SMART 1000 CCD area-detector diffractometer
Absorption correction	Multi-scan (SADABS; Bruker, 2001)
T_min, T_max	0.731, 0.779
No. of measured, independent and observed [I > 2σ(I)] reflections	3732, 2352, 2219
R_int	0.014
(sin θ/λ)_max (Å⁻¹)	0.595

Refinement
R[F² > 2σ(F²)], wR(F²), S	0.032, 0.088, 1.05
No. of reflections	2352
No. of parameters	190
No. of restraints	6
H-atom treatment	H atoms treated by a mixture of independent and constrained refinement
Δρ_max, Δρ_min (e Å⁻³)	0.31, −0.24

Computer programs: SMART (Bruker, 2007), SAINT (Bruker, 2007), SHELXTL (Sheldrick, 2008).

Hydrogen-bond geometry (Å, º) top

D—H···A	D—H	H···A	D···A	D—H···A
N2—H2A···O8ⁱ	0.86	2.14	2.988 (3)	168.8
N2—H2B···O6ⁱⁱ	0.86	2.19	3.027 (4)	164.9
N3—H3A···O4ⁱⁱⁱ	0.86	2.28	3.056 (4)	149.6
N3—H3B···O3ⁱⁱ	0.86	1.99	2.848 (3)	173.4
N4—H4A···O7^iv	0.86	2.22	3.002 (3)	151.6
N4—H4B···O7	0.86	2.32	3.068 (4)	145.3
O7—H7A···O4	0.868 (18)	2.075 (19)	2.913 (4)	162 (3)
O7—H7B···O8^v	0.866 (18)	1.980 (19)	2.843 (3)	174 (4)
O8—H8A···O1ⁱⁱⁱ	0.856 (17)	2.18 (2)	3.018 (3)	165 (3)
O8—H8B···O4	0.859 (17)	2.188 (19)	2.999 (4)	157 (3)
O8—H8B···O6	0.859 (17)	2.40 (3)	3.107 (4)	141 (3)

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

Acknowledgements

This research was supported by the International Cooperation Special Fund of the Ministry of Science and Technology, China (No. 2011DFB31620). We are grateful to Professor Dr S.-M. Qiu of Hubei Academy of Agricultural Science for his valuable suggestions.

References

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