Di­aqua­bis­[N-(2-fluoro­benz­yl)-N-nitroso­hydroxy­laminato-κ2O,O′]nickel(II)

Kovalchukova, O.; Bostanabad, A.S.; Stash, A.; Strashnova, S.; Zyuzin, I.

doi:10.1107/S1600536814002876

metal-organic compounds

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ISSN: 2056-9890

Volume 70| Part 3| March 2014| Pages m98-m99

doi:10.1107/S1600536814002876

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Diaquabis[N-(2-fluorobenzyl)-N-nitrosohydroxylaminato-κ²O,O′]nickel(II)

Olga Kovalchukova,^a ^* Ali Sheikh Bostanabad,^a Adam Stash,^b Svetlana Strashnova ^a and Igor Zyuzin ^c

^aPeoples' Friendship University of Russia, 6 Miklukho-Mallaya, 117198 Moscow, Russia, ^bKarpov Institute of Physical Chemistry, 10 Vorontsovo Pole, 105064 Moscow, Russia, and ^cThe Institute of Problems of Chemical Physics of the Russian Academy of Sciences (IPCP RAS), Academician Semenov Avenue 1, Chernogolovka, Moscow Region, 142432 , Russian Federation
^*Correspondence e-mail: okovalchukova@mail.ru

(Received 6 January 2014; accepted 8 February 2014; online 15 February 2014)

In the centrosymmetric title compound, [Ni(C₇H₆FN₂O₂)₂(H₂O)₂], the Ni^II cation is in a slightly distorted octahedral environment and is surrounded by four O atoms from the N—O groups of the organic ligands [Ni—O = 2.0179 (13) and 2.0283 (12) Å], and two water molecules [Ni—O = 2.0967 (14) Å]. The N-(2-fluorobenzyl)-N-nitrosohydroxylaminate monoanions act as bidentate chelating ligands. In the crystal, the Ni cations in the columns are shifted in such a way that the coordinated water molecules are involved in the formation of hydrogen bonds with the O atoms of the organic species of neighbouring molecules. Thus, a two-dimensional network parallel to (100) is built up by hydrogen-bonded molecules.

CCDC reference: 985943

Related literature

For the synthesis of the potassium N-(2-fluorobenzyl)-N-nitrosohydroxylaminate salt, see: Zyuzin et al. (1997 ) and of the Ni complex of N-(2-fluorobenzyl)-N-nitrosohydroxylaminate, see: Kovalchukova et al. (2013 ). For the structures of some 3d-metal complexes with N-nitrosohydroxylamine derivatives, see: Deák et al. (1998 ); Okabe & Tamaki (1995 ); Tamaki & Okabe (1996 , 1998 ). For the synthesis, properties and applications of other metal nitrosohydroxylaminates, see: Okabe et al. (1995 ); Abraham et al. (1987 ); Venter et al. (2009 ); Popov & Wendlandt (1954 ); Lundell & Knowles (1920 ); Buscarons & Canela (1974 ); Oztekin & Erim (2000 ); Yi et al. (1995 ); McGill et al. (2000 ); Shiino et al. (2001 ).

Experimental

Crystal data

[Ni(C₇H₆FN₂O₂)₂(H₂O)₂]
M_r = 433.02
Monoclinic, P 2₁ /c
a = 15.411 (3) Å
b = 7.235 (1) Å
c = 7.604 (1) Å
β = 91.65 (3)°
V = 847.5 (3) Å³
Z = 2
Mo Kα radiation
μ = 1.21 mm⁻¹
T = 293 K
0.75 × 0.20 × 0.05 mm

Data collection

Enraf–Nonius CAD-4 diffractometer
Absorption correction: part of the refinement model (ΔF) (Walker & Stuart, 1983 ) T_min = 0.427, T_max = 0.809
1703 measured reflections
1571 independent reflections
1181 reflections with I > 2σ(I)
R_int = 0.022
3 standard reflections every 60 min intensity decay: 0.0%

Refinement

R[F² > 2σ(F²)] = 0.022
wR(F²) = 0.066
S = 1.01
1571 reflections
132 parameters
2 restraints
H atoms treated by a mixture of independent and constrained refinement
Δρ_max = 0.31 e Å⁻³
Δρ_min = −0.32 e Å⁻³

Table 1
Hydrogen-bond geometry (Å, °)

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
O3—H31⋯O1ⁱ	0.84 (1)	1.97 (1)	2.7987 (18)	169 (3)
O3—H32⋯O2ⁱⁱ	0.84 (1)	1.98 (1)	2.8078 (18)	170 (2)
Symmetry codes: (i) $[x, -y+{\script{3\over 2}}, z+{\script{1\over 2}}]$ ; (ii) $[x, -y+{\script{1\over 2}}, z+{\script{1\over 2}}]$ .

Data collection: CAD-4-PC (Enraf–Nonius, 1993 $[Enraf-Nonius (1993). CAD-4 Diffractometer Control Software. Enraf-Nonius, Delft, The Netherlands.]$ ); cell refinement: CAD-4-PC; data reduction: CAD-4-PC; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008 ); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: SHELXTL (Sheldrick, 2008); software used to prepare material for publication: CIFTAB97 (Sheldrick, 2008) and SHELX97.

Supporting information

CCDC reference: 985943

Crystal structure: contains datablocks I, global. DOI: 10.1107/S1600536814002876/bv2230sup1.cif

Structure factors: contains datablock I. DOI: 10.1107/S1600536814002876/bv2230Isup2.hkl

checkCIF report

Comment top

N-nitrosohydroxylamine derivatives are good chelating agents which form stable complexes with a wide range of metal ions (Okabe et al., 1995; Abraham et al., 1987; Venter et al., 2009; Popov & Wendlandt, 1954). The phenyl and naphthyl derivatives, known as cupferron and neocupferron, are reported as good analytical reagents for the determination of zirconium in its ores and metallurgical products, as well as for the separation of iron and titanium from manganese and aluminum in limestone analysis, separation and direct UV detection of lanthanides and other analyses (Lundell & Knowles, 1920; Buscarons & Canela, 1974; Oztekin & Erim, 2000). R₂N[N₂0₂] anions are smooth nonenzymatic releasers of nitric oxide in physiological media (Yi et al., 1995; McGill et al., 2000) and possess the property of inhibition of mushroom tyrosinase (Shiino et al., 2001).

In the title compound, C₁₄H₁₆F₂N₄NiO₆, the Ni cation of the centrosymmetrical structure is in a slightly distorted octahedral coordination and is surrounded by four oxo O atoms of the N—O groups of the organic ligands [Ni—O = 2.0179 (13) and 2.0283 (12) Å], and two water molecules in the axial positions [Ni—O = 2.0967 (14) Å]. The described coordination type of the central atom correlates with those described previously for the dimethanolo-bis(N– nitroso-N-phenyl-hydroxylaminato-o,o) cobalt(II) (Deak et al., 1998) and the dimethanolo-bis (N-nitroso-N-phenylhydroxylaminato-O,O')nickel(II) (Okabe & Tamaki, 1995). On the other hand, in the reported structure of the diaquabis[N-(1-naphthyl)-N-nitrosohydroxylaminato- O, O'] cobalt(II) (Tamaki & Okabe, 1998), the two coordinated water molecules are in the cis arrangement. In addition in the bis(N-nitroso-N-phenylhydroxylaminato)manganese, or manganese cupferronate (Tamaki & Okabe, 1996), the saturation of the coordination sphere of the Mn(II) cation occurs with the two O atoms of the nitroso groups of two adjacent cupferron ligands. The N-(2-fluorobenzyl)-N-nitrosohydroxylaminate monoanions act as bidentate chelating ligands. The Ni cations in the columns are shifted in such a way that the coordinated H₂O molecules are involved in the formation of hydrogen bonds with the O atoms of the organic species of the neighbouring molecules in the columns. Thus, the crystal lattice of the reported structure is a supramolecular architecture built up by infinite one dimensional chains of hydrogen bonded molecules.

Related literature top

For the synthesis of the potassium N-(2-fluorobenzyl)-N-nitrosohydroxylaminate salt, see: Zyuzin et al. (1997) and of the Ni complex of N-(2-fluorobenzyl)-N-nitrosohydroxylaminate, see: Kovalchukova et al. (2013). For the structures of some 3d-metal complexes with N-nitrosohydroxylamine derivatives, see: Deak et al. (1998); Okabe & Tamaki (1995); Tamaki & Okabe (1996, 1998). For the synthesis, properties and applications of other metal nitrosohydroxylaminates, see: Okabe et al. (1995); Abraham et al. (1987); Venter et al. (2009); Popov & Wendlandt (1954); Lundell & Knowles (1920); Buscarons & Canela (1974); Oztekin & Erim (2000); Yi et al. (1995); McGill et al. (2000); Shiino et al. (2001).

Experimental top

The potassium N-(2-fluorobenzyl)-N-nitrosohydroxylaminate salt and its Ni complex was prepared (see Fig. 3) according to procedures described previously (Zyuzin et al., 1997; Kovalchukova et al., 2013). Single crystals of C₁₄H₁₆F₂N₄O₆ were grown by the slow evaporation of the ethanol solution of the diaquabis[N-(2-fluorobenzyl)-N-nitrosohydroxylaminato-O,O']nickel(II) powdered sample.

Computing details top

Data collection: CAD-4-PC (Enraf–Nonius, 1993); cell refinement: CAD-4-PC (Enraf–Nonius, 1993); data reduction: CAD-4-PC (Enraf–Nonius, 1993); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: SHELXTL (Sheldrick, 2008); software used to prepare material for publication: CIFTAB97 and SHELX97 (Sheldrick, 2008).

Figures top

	Fig. 1. ORTEP view of C₁₄H₁₆F₂N₄O₆ with atom labeling scheme (displacement ellipsoids are drawn at the 50% probability level for non-hydrogen atoms).
	Fig. 2. Molecular packing in the crystal of the complex along the crystallographic axis b.
	Fig. 3. The synthesis of the potassium N-(2-fluorobenzyl)-Nnitrosohydroxylaminate salt

Diaquabis[N-(2-fluorobenzyl)-N-nitrosohydroxylaminato-κ²O,O']nickel(II) top

Crystal data top

[Ni(C₇H₆FN₂O₂)₂(H₂O)₂]	F(000) = 444
M_r = 433.02	D_x = 1.697 Mg m⁻³
Monoclinic, P2₁/c	Mo Kα radiation, λ = 0.71073 Å
a = 15.411 (3) Å	Cell parameters from 24 reflections
b = 7.235 (1) Å	θ = 10.9–12.5°
c = 7.604 (1) Å	µ = 1.21 mm⁻¹
β = 91.65 (3)°	T = 293 K
V = 847.5 (3) Å³	Plate, green
Z = 2	0.75 × 0.20 × 0.05 mm

Data collection top

Enraf–Nonius CAD-4 diffractometer	1181 reflections with I > 2σ(I)
Radiation source: fine-focus tube	R_int = 0.022
β-filter monochromator	θ_max = 25.5°, θ_min = 2.6°
ω/2θ scans	h = −18→18
Absorption correction: part of the refinement model (ΔF) (Walker & Stuart, 1983)	k = 0→8
T_min = 0.427, T_max = 0.809	l = 0→9
1703 measured reflections	3 standard reflections every 60 min
1571 independent reflections	intensity decay: 0.0%

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)] = 0.022	Hydrogen site location: difference Fourier map
wR(F²) = 0.066	H atoms treated by a mixture of independent and constrained refinement
S = 1.01	w = 1/[σ²(F_o²) + (0.0471P)²] where P = (F_o² + 2F_c²)/3
1571 reflections	(Δ/σ)_max < 0.001
132 parameters	Δρ_max = 0.31 e Å⁻³
2 restraints	Δρ_min = −0.32 e Å⁻³

Crystal data top

[Ni(C₇H₆FN₂O₂)₂(H₂O)₂]	V = 847.5 (3) Å³
M_r = 433.02	Z = 2
Monoclinic, P2₁/c	Mo Kα radiation
a = 15.411 (3) Å	µ = 1.21 mm⁻¹
b = 7.235 (1) Å	T = 293 K
c = 7.604 (1) Å	0.75 × 0.20 × 0.05 mm
β = 91.65 (3)°

Data collection top

Enraf–Nonius CAD-4 diffractometer	1181 reflections with I > 2σ(I)
Absorption correction: part of the refinement model (ΔF) (Walker & Stuart, 1983)	R_int = 0.022
T_min = 0.427, T_max = 0.809	3 standard reflections every 60 min
1703 measured reflections	intensity decay: 0.0%
1571 independent reflections

Refinement top

R[F² > 2σ(F²)] = 0.022	2 restraints
wR(F²) = 0.066	H atoms treated by a mixture of independent and constrained refinement
S = 1.01	Δρ_max = 0.31 e Å⁻³
1571 reflections	Δρ_min = −0.32 e Å⁻³
132 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	U_iso*/U_eq
Ni1	0.5000	0.5000	0.5000	0.02414 (12)
F1	0.12983 (10)	0.46369 (18)	0.3199 (2)	0.0610 (4)
O1	0.39701 (8)	0.63578 (16)	0.39297 (15)	0.0292 (3)
O2	0.41642 (8)	0.28946 (16)	0.44659 (16)	0.0312 (3)
N1	0.34766 (9)	0.51068 (19)	0.31185 (19)	0.0278 (3)
N2	0.35419 (10)	0.3370 (2)	0.3362 (2)	0.0317 (3)
C1	0.14337 (13)	0.6479 (3)	0.3049 (3)	0.0386 (4)
C2	0.22021 (12)	0.7072 (3)	0.2360 (2)	0.0329 (4)
C3	0.23158 (14)	0.8967 (3)	0.2205 (3)	0.0406 (5)
H3	0.2824	0.9423	0.1738	0.049*
C4	0.16858 (17)	1.0184 (3)	0.2733 (3)	0.0519 (6)
H4	0.1773	1.1451	0.2629	0.062*
C5	0.09283 (16)	0.9527 (3)	0.3412 (3)	0.0531 (6)
H5	0.0504	1.0354	0.3760	0.064*
C6	0.07923 (13)	0.7649 (3)	0.3581 (3)	0.0477 (5)
H6	0.0282	0.7193	0.4041	0.057*
C7	0.28684 (13)	0.5742 (3)	0.1721 (2)	0.0369 (4)
H71	0.2575	0.4679	0.1206	0.044*
H72	0.3194	0.6333	0.0805	0.044*
O3	0.45896 (10)	0.53062 (17)	0.75889 (18)	0.0371 (3)
H31	0.4344 (17)	0.628 (3)	0.790 (4)	0.075 (9)*
H32	0.4418 (15)	0.443 (2)	0.821 (3)	0.052 (7)*

Atomic displacement parameters (Å²) top

	U¹¹	U²²	U³³	U¹²	U¹³	U²³
Ni1	0.02426 (18)	0.02405 (17)	0.02409 (17)	0.00166 (12)	0.00050 (11)	0.00039 (11)
F1	0.0577 (8)	0.0447 (7)	0.0812 (10)	−0.0079 (6)	0.0135 (7)	−0.0001 (6)
O1	0.0292 (6)	0.0261 (5)	0.0321 (6)	0.0014 (5)	−0.0027 (5)	−0.0010 (5)
O2	0.0330 (7)	0.0271 (6)	0.0335 (6)	−0.0003 (5)	−0.0004 (5)	0.0022 (5)
N1	0.0243 (7)	0.0317 (7)	0.0274 (7)	0.0030 (6)	−0.0003 (6)	−0.0027 (6)
N2	0.0304 (8)	0.0317 (8)	0.0331 (7)	0.0006 (6)	0.0021 (6)	−0.0030 (6)
C1	0.0366 (11)	0.0405 (10)	0.0382 (10)	0.0008 (8)	−0.0049 (8)	−0.0023 (8)
C2	0.0286 (9)	0.0419 (10)	0.0279 (9)	0.0051 (7)	−0.0059 (7)	−0.0005 (7)
C3	0.0381 (11)	0.0441 (11)	0.0394 (10)	0.0001 (8)	−0.0046 (9)	0.0047 (8)
C4	0.0595 (14)	0.0403 (11)	0.0553 (13)	0.0083 (10)	−0.0067 (11)	0.0006 (9)
C5	0.0494 (13)	0.0590 (14)	0.0504 (13)	0.0228 (11)	−0.0050 (10)	−0.0083 (10)
C6	0.0317 (11)	0.0679 (15)	0.0434 (11)	0.0052 (10)	0.0013 (9)	−0.0062 (10)
C7	0.0351 (10)	0.0484 (10)	0.0269 (9)	0.0077 (9)	−0.0029 (8)	−0.0001 (8)
O3	0.0518 (8)	0.0300 (7)	0.0303 (6)	0.0022 (6)	0.0127 (6)	0.0008 (5)

Geometric parameters (Å, º) top

Ni1—O1ⁱ	2.0179 (13)	C2—C3	1.388 (3)
Ni1—O1	2.0179 (13)	C2—C7	1.498 (3)
Ni1—O2	2.0283 (12)	C3—C4	1.379 (3)
Ni1—O2ⁱ	2.0283 (12)	C3—H3	0.9300
Ni1—O3	2.0967 (14)	C4—C5	1.375 (4)
Ni1—O3ⁱ	2.0967 (14)	C4—H4	0.9300
F1—C1	1.354 (2)	C5—C6	1.381 (3)
O1—N1	1.3233 (19)	C5—H5	0.9300
O2—N2	1.302 (2)	C6—H6	0.9300
N1—N2	1.274 (2)	C7—H71	0.9700
N1—C7	1.470 (2)	C7—H72	0.9700
C1—C6	1.371 (3)	O3—H31	0.838 (10)
C1—C2	1.377 (3)	O3—H32	0.837 (10)

O1ⁱ—Ni1—O1	180.0	C1—C2—C3	116.90 (18)
O1ⁱ—Ni1—O2	101.70 (5)	C1—C2—C7	121.86 (17)
O1—Ni1—O2	78.30 (5)	C3—C2—C7	121.17 (18)
O1ⁱ—Ni1—O2ⁱ	78.30 (5)	C4—C3—C2	121.0 (2)
O1—Ni1—O2ⁱ	101.70 (5)	C4—C3—H3	119.5
O2—Ni1—O2ⁱ	180.0	C2—C3—H3	119.5
O1ⁱ—Ni1—O3	85.86 (6)	C5—C4—C3	120.1 (2)
O1—Ni1—O3	94.14 (6)	C5—C4—H4	120.0
O2—Ni1—O3	93.46 (6)	C3—C4—H4	120.0
O2ⁱ—Ni1—O3	86.54 (6)	C4—C5—C6	120.5 (2)
O1ⁱ—Ni1—O3ⁱ	94.14 (6)	C4—C5—H5	119.7
O1—Ni1—O3ⁱ	85.86 (6)	C6—C5—H5	119.7
O2—Ni1—O3ⁱ	86.54 (6)	C1—C6—C5	117.8 (2)
O2ⁱ—Ni1—O3ⁱ	93.46 (6)	C1—C6—H6	121.1
O3—Ni1—O3ⁱ	180.0	C5—C6—H6	121.1
N1—O1—Ni1	106.85 (9)	N1—C7—C2	113.27 (14)
N2—O2—Ni1	112.47 (10)	N1—C7—H71	108.9
N2—N1—O1	124.40 (14)	C2—C7—H71	108.9
N2—N1—C7	117.37 (14)	N1—C7—H72	108.9
O1—N1—C7	117.96 (14)	C2—C7—H72	108.9
N1—N2—O2	114.08 (14)	H71—C7—H72	107.7
F1—C1—C6	117.94 (19)	Ni1—O3—H31	120 (2)
F1—C1—C2	118.37 (17)	Ni1—O3—H32	124.0 (18)
C6—C1—C2	123.69 (19)	H31—O3—H32	109 (3)

Symmetry code: (i) −x+1, −y+1, −z+1.

Hydrogen-bond geometry (Å, º) top

D—H···A	D—H	H···A	D···A	D—H···A
O3—H31···O1ⁱⁱ	0.84 (1)	1.97 (1)	2.7987 (18)	169 (3)
O3—H32···O2ⁱⁱⁱ	0.84 (1)	1.98 (1)	2.8078 (18)	170 (2)

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

Hydrogen-bond geometry (Å, º) top

D—H···A	D—H	H···A	D···A	D—H···A
O3—H31···O1ⁱ	0.838 (10)	1.972 (12)	2.7987 (18)	169 (3)
O3—H32···O2ⁱⁱ	0.837 (10)	1.979 (11)	2.8078 (18)	170 (2)

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

Acknowledgements

This research was supported by the Russian Foundation for Basic Research (grant 13–03–00079).

References

Abraham, M. H., Bullock, J. I., Garland, J. H. N., Golder, A. J., Harden, G. J., Larkworti-Iy, L. F., Povey, D. C., Riedl, M. J. & Smith, G. W. (1987). Polyhedron, 6, 1375–1381. CSD CrossRef CAS Web of Science Google Scholar
Buscarons, F. & Canela, J. (1974). Anal. Chim. Acta, 70, 113–120. CrossRef CAS Web of Science Google Scholar
Deák, A., Párkányi, L., Kálmán, A., Venter, M. & Haiduc, I. (1998). Acta Cryst. C54, IUC9800036. CrossRef IUCr Journals Google Scholar
Enraf–Nonius (1993). CAD-4 Diffractometer Control Software. Enraf–Nonius, Delft, The Netherlands. Google Scholar
Kovalchukova, O., Bostanabad, A. S., Sergienko, V., Polyakova, I., Zyuzin, I. & Strashnova, S. (2013). Open J. Inorg. Chem., 3, 1–6. CSD CrossRef CAS Google Scholar
Lundell, G. E. F. & Knowles, H. B. (1920). J. Ind. Eng. Chem. 12, 344–350. CrossRef CAS Google Scholar
McGill, A. D., Zhang, W., Wittbrodt, J., Wang, J., Schlegel, H. B. & Wang, P. G. (2000). Bioorg. Med. Chem. 8, 405–412. Web of Science CrossRef PubMed CAS Google Scholar
Okabe, N. & Tamaki, K. (1995). Acta Cryst. C51, 2004–2005. CSD CrossRef CAS Web of Science IUCr Journals Google Scholar
Okabe, N., Tamaki, K., Suga, T. & Kohyama, Y. (1995). Acta Cryst. C51, 1295–1297. CSD CrossRef CAS Web of Science IUCr Journals Google Scholar
Oztekin, N. & Erim, F. B. (2000). J. Chromatogr. A, 895, 263–268. Web of Science PubMed CAS Google Scholar
Popov, A. I. & Wendlandt, W. W. (1954). Anal. Chem. 26, 883–886. CrossRef CAS Web of Science Google Scholar
Sheldrick, G. M. (2008). Acta Cryst. A64, 112–122. Web of Science CrossRef CAS IUCr Journals Google Scholar
Shiino, M., Watanabe, Y. & Umezawa, K. (2001). Bioorg. Med. Chem. 9, 1233–1240. Web of Science CrossRef PubMed CAS Google Scholar
Tamaki, K. & Okabe, N. (1996). Acta Cryst. C52, 1612–1614. CSD CrossRef CAS Web of Science IUCr Journals Google Scholar
Tamaki, K. & Okabe, N. (1998). Acta Cryst. C54, 195–197. Web of Science CSD CrossRef CAS IUCr Journals Google Scholar
Venter, J. A., Purcell, W., Visser, H. G. & Muller, T. J. (2009). Acta Cryst. E65, m1578. Web of Science CSD CrossRef IUCr Journals Google Scholar
Walker, N. & Stuart, D. (1983). Acta Cryst. A39, 158–166. CrossRef CAS Web of Science IUCr Journals Google Scholar
Yi, G.-B., Khan, M. A. & Richter-Addo, G. B. (1995). Inorg. Chem. 34, 5703–5704. CrossRef CAS Web of Science Google Scholar
Zyuzin, I. N., Nechiporenko, G. N., Golovina, N. I., Trofimova, R. F. & Loginova, M. V. (1997). Russ. Chem. Bull. 46, 1421–1429. Google Scholar

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