(IUCr) Iron(II) hydrazinium sulfate

Volume 63
Part 2
Pages i41-i42
February 2007

Received 22 December 2006
Accepted 29 December 2006
Online 12 January 2007

Key indicators
Single-crystal X-ray study
T = 120 K
Mean (N-N) = 0.004 Å
R = 0.032
wR = 0.076
Data-to-parameter ratio = 11.2
Details

Iron(II) hydrazinium sulfate

Krishnan Srinivasan,^a Subbaiah Govindarajan ^a and William T. A. Harrison ^b ^*

^aDepartment of Chemistry, Bharathiar University, Coimbatore 641 046, India, and ^bDepartment of Chemistry, University of Aberdeen, Meston Walk, Aberdeen AB24 3UE, Scotland
Correspondence e-mail: w.harrison@abdn.ac.uk

The title compound, poly[[dihydraziniumiron(II)]-di- [mu] -sulfato- [kappa] ⁴O:O'], [Fe(SO₄)₂(N₂H₅)₂]_n, contains fairly regular trans-FeN₂O₄ octahedra. The Fe atoms (site symmetry $[\overline{1}]$ ) are bridged by pairs of sulfate groups into infinite [100] chains, which are cross-linked by a network of N-HO hydrogen bonds. Fe(N₂H₅)₂(SO₄)₂ is isostructural with its zinc, chromium(II) and cadmium-containing analogues.

Comment

The divalent-metal-hydrazinium sulfates of general formula M(N₂H₅)₂(SO₄)₂, where M = Cr, Mn, Fe, Co, Ni, Cu, Zn and Cd can be readily prepared by reacting a salt of the respective metal with hydrazinium sulfate in dilute sulfuric acid (Hand & Prout, 1966), although this method usually results in a microcrystalline product. Recently, we described the single-crystal structure of Cd(N₂H₅)₂(SO₄)₂ (Srinivasan et al., 2006) and we now report the isostructural title compound, (I), Fe(N₂H₅)₂(SO₄)₂. The compounds Zn(N₂H₅)₂(SO₄)₂ (Prout & Powell, 1961) and Cr(N₂H₅)₂(SO₄)₂ (Parkins et al., 2001) also share the same stucture.

Compound (I) contains trans-FeN₂O₄ octahedra (Fig. 1), in which the N atom is part of a hydrazinium (N₂H₅⁺) cation. The Fe atoms (site symmetry $[\overline{1}]$ ) are connected by pairs of sulfate groups into infinite chains that propagate in [100]. The intra-chain FeFe separation in (I) is equal to the a unit-cell dimension, i.e. 5.3306 (3) Å. The two distinct Fe-O bond lengths in (I) are similar (Table 1) and do not show the gross differences seen in the chromium and zinc analogues.

The iron-sulfate chains in (I) are cross-linked by N-HO hydrogen bonds (Table 2), resulting in the same hydrogen-bonding network seen in the other analogues noted above. A well defined trifurcated N2-H3C(O,O,O) interaction occurs (mean bond angle about H3C = 107.3°).

Figure 1
The asymmetric unit of (I) expanded to show the iron coordination (50% displacement ellipsoids; arbitrary spheres for the H atoms). Symmetry codes: (i) -x, -y, -z; (ii) x - 1, y, z; (iii) 1 - x, -y, -z.

Figure 2
Polyhedral view of a fragment of the chain structure of (I). Colour key: Fe octahedra green, S tetrahedra yellow, O pink, N blue, H grey. The H

O portions of the hydrogen bonds are coloured light blue.

Experimental

The reaction of hydrazine monohydrate (N₂H₄·H₂O; 0.50 g, 10 mmol) and ethyl bromoacetate (1.671 g, 10 mmol) in 5 ml of dry ethanol resulted in the formation of a white solid containing hydrazinium bromide and ethyl hydrazinoacetate, as reported earlier (Srinivasan et al., 2006). This white solid (0.236 g) was dissolved in water (30 ml) and mixed with an aqueous solution (30 ml) of FeSO₄·7H₂O (0.278 g, 1 mmol) and a few drops of conc. H₂SO₄. The resulting clear solution, with a pH of 2, was concentrated over a water bath to 20 ml and kept for crystallization at room temperature. After three days, many block-shaped light-green crystals of (I) had formed. These were recovered by filtration, washed with cold water and dried in air.

Crystal data

[Fe(SO₄)₂(N₂H₅)₂]
M_r = 314.08
Triclinic, $[P \overline 1]$
a = 5.3306 (3) Å
b = 5.8205 (3) Å
c = 7.3835 (4) Å
= 92.034 (3)°
= 103.313 (3)°
= 99.237 (3)°
V = 219.41 (2) Å³
Z = 1
D_x = 2.377 Mg m^-3
Mo K radiation
= 2.23 mm^-1
T = 120 (2) K
Lath, pale green
0.05 × 0.02 × 0.01 mm

Data collection

Nonius KappaCCD diffractometer
and scans
Absorption correction: multi-scan (SADABS; Bruker, 2003) T_min = 0.897, T_max = 0.978
3957 measured reflections
1004 independent reflections
911 reflections with I > 2(I)
R_int = 0.043
_max = 28.0°

Refinement

Refinement on F²
R[F² > 2(F²)] = 0.032
wR(F²) = 0.076
S = 1.12
1004 reflections
90 parameters
All H-atom parameters refined
w = 1/[²(F_o²) + (0.0127P)² + 0.6538P] where P = (F_o² + 2F_c²)/3
(/)_max < 0.001
_max = 0.37 e Å^-3
_min = -0.58 e Å^-3

Table 1
Selected geometric parameters (Å, °)

Fe1-O1	2.109 (2)
Fe1-O2ⁱ	2.147 (2)
Fe1-N1	2.184 (2)

S1-O1-Fe1	142.94 (13)
S1-O2-Fe1ⁱⁱ	128.85 (12)
Symmetry codes: (i) x-1, y, z; (ii) x+1, y, z.

Table 2
Hydrogen-bond geometry (Å, °)

D-HA	D-H	HA	DA	D-HA
N1-H1AO3ⁱⁱⁱ	0.82 (4)	2.37 (4)	3.070 (3)	143 (3)
N1-H1BO4^iv	0.82 (4)	2.12 (4)	2.867 (3)	151 (4)
N2-H2AO4ⁱⁱⁱ	0.88 (4)	1.96 (4)	2.799 (3)	160 (4)
N2-H2BO3	0.80 (4)	2.02 (4)	2.769 (4)	156 (4)
N2-H2CO2^v	0.82 (4)	2.51 (4)	2.849 (3)	106 (3)
N2-H2CO2^iv	0.82 (4)	2.32 (4)	3.011 (4)	141 (4)
N2-H2CO1^vi	0.82 (4)	2.45 (4)	3.073 (3)	133 (4)
Symmetry codes: (iii) -x+1, -y, -z+1; (iv) x-1, y-1, z; (v) -x+1, -y, -z; (vi) x, y-1, z.

The H atoms were located in difference maps and their positions and U_iso values were freely refined.

Data collection: Collect (Nonius, 1998); cell refinement: HKL SCALEPACK (Otwinowski & Minor 1997); data reduction: HKL DENZO and SCALEPACK (Otwinowski & Minor 1997) & SORTAV (Blessing 1995); program(s) used to solve structure: SHELXS97 (Sheldrick, 1997); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: ORTEP-3 (Farrugia, 1997); software used to prepare material for publication: SHELXL97.

Acknowledgements

We thank the EPSRC National Crystallography Service (University of Southampton) for the data collection.

References

Blessing, R. H. (1995). Acta Cryst. A51, 33-38.
Bruker (2003). SADABS, Bruker AXS Inc., Madison, Wisconsin, USA.
Farrugia, L. J. (1997). J. Appl. Cryst. 30, 565.
Hand, D. W. & Prout, C. K. (1966). J. Chem. Soc. A, pp. 168-171.
Nonius (1998). COLLECT. Nonius BV, Delft, The Netherlands.
Otwinowski, Z. & Minor, W. (1997). Methods in Enzymology, Vol. 276, Macromolecular Crystallography, Part A, edited by C. W. Carter, Jr & R. M. Sweet, pp. 307-326. New York: Academic Press.
Parkins, A. W., Prince, P. D., Smith, R. A. L. & Steed, J. W. (2001). Acta Cryst. C57, 670-671.
Prout, C. K. & Powell, H. M. (1961). J. Chem. Soc. pp. 4177-4182.
Sheldrick, G. M. (1997). SHELXS97 and SHELXL97. University of Göttingen, Germany.
Srinivasan, K., Govindarajan, S. & Harrison, W. T. A. (2006). Acta Cryst. E62, i219-i221.

inorganic compounds