Hexakis­(aceto­nitrile)­iron(II) hexa­fluoro­antimonate

The title compound, [Fe(C₂H₃N)₆][SbF₆]₂, (I), synthesized by reaction of AgSbF₆ with FeCl₂ in CH₃CN, is isostructural with the analogous nickel complex [see Leban et al. (1987), Acta Cryst. C43, 1888-1890]. The Fe^II centre in the cation occupies a crystallographic site and is octahedrally coordinated by six aceto­nitrile ligands, with an Fe-N distance of 2.153 (2) Å and an N-Fe-N angle of 88.05 (10)°. The SbF₆^- anion lies on a crystallographic threefold rotation axis.

Key indicators

• Single-crystal X-ray study
• T = 173 K
• Mean [sigma](C-C) = 0.004 Å
• R factor = 0.024
• wR factor = 0.069
• Data-to-parameter ratio = 18.8

checkCIF results

No syntax errors found

ADDSYM reports no extra symmetry


 Alert Level C:



PLAT_731  Alert C Bond    Calc    1.839(5), Rep    1.839(2) ....       2.50 s.u-Ratio
                     SB1  -F1      1.555   3.665

General Notes



ABSTM_02  When printed, the submitted absorption T values will be replaced
          by the scaled T values. Since the ratio of scaled T's is
          identical to the ratio of reported T values, the scaling does
          not imply a change to the absorption corrections used in the
          study.
          Ratio of Tmax expected/reported      0.490
          Tmax scaled      0.441 Tmin scaled      0.295


 0 Alert Level A = Potentially serious problem

 0 Alert Level B = Potential problem

 1 Alert Level C = Please check

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S1. Comment

NO COMMENT

S2. Experimental

Caution: exothermic reaction! AgSbF₆ (25.00 g, 72 mmol) was slowly added to FeCl₂ (9.23 g, 72 mmol) in CH₃CN and allowed to stir overnight. The precipitate was removed by filtration and washed several times with CH₃CN. Removal of the solvent from the filtrate yielded a white powder. Dissolving this solid in a minimal amount of CH₃CN and layering with Et₂O led to a clear colourless microcrystalline solid which becomes a white powder upon drying under vacuum. Yield: 11.95 g (21.2%). Analysis calculated for C₁₂H₁₈F₁₂FeN₆Sb₂ (%): C 18.63, H 2.35, N 10.86, F 29.47%; found (%): C 18.42, H 2.21, N 10.57, F 29.20. Crystallographic quality single crystals were obtained by vapour diffusion of Et₂O into a CH₃CN solution of this compound (Fig. 1).

S3. Refinement

The positions of the Fe and Sb atoms were found using Patterson methods (Sheldrick, 1990). H atoms were placed geometrically on the MeCN ligands optimizing the fit with diffraction data and then refined as a rigid rotor.

Computing details

Data collection: SMART (Bruker, 2000); cell refinement: SAINT (Bruker, 2000); data reduction: SAINT; program(s) used to solve structure: SHELXS97 (Sheldrick, 1990); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: SHELXTL/PC (Sheldrick, 1998); software used to prepare material for publication: SHELXTL/PC and PLATON (Spek, 2001).

Figures

Fig. 1. A view of the title compound showing the atom-numbering scheme. Displacement ellipsoids are drawn at the 50% probability level.

hexakis(acetonitrile) iron(II) hexafluoroantimonate

Crystal data

[Fe(C2H3N)6][SbF6]2	Dx = 1.994 Mg m^−3
Mr = 773.67	Mo Kα radiation, λ = 0.71073 Å
Hexagonal, R3	Cell parameters from 4001 reflections
a = 11.3398 (6) Å	θ = 2.4–27.5°
c = 17.3584 (11) Å	µ = 2.73 mm^−1
V = 1933.1 (2) Å^3	T = 173 K
Z = 3	Block cut from hexagonal prism, colourless
F(000) = 1104	0.40 × 0.30 × 0.30 mm

Data collection

Bruker CCD area-detector diffractometer	996 independent reflections
Radiation source: fine-focus sealed tube	933 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.028
ϕ and ω scans	θmax = 27.5°, θmin = 2.4°
Absorption correction: multi-scan (SADABS; Blessing, 1995; Sheldrick, 2000)	h = −14→14
Tmin = 0.602, Tmax = 0.900	k = −14→14
5690 measured reflections	l = −22→22

Refinement

Refinement on F^2	Secondary atom site location: difference Fourier map
Least-squares matrix: full	Hydrogen site location: inferred from neighbouring sites
R[F^2 > 2σ(F^2)] = 0.024	H-atom parameters constrained
wR(F^2) = 0.069	w = 1/[σ^2(Fo^2) + (0.0368P)^2 + 4.867P] where P = (Fo^2 + 2Fc^2)/3
S = 1.12	(Δ/σ)max = 0.001
996 reflections	Δρmax = 0.55 e Å^−3
53 parameters	Δρmin = −0.47 e Å^−3
0 restraints	Extinction correction: SHELXL97, Fc^*=kFc[1+0.001xFc^2λ^3/sin(2θ)]^-1/4
Primary atom site location: heavy-atom method	Extinction coefficient: 0.0107 (5)

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
Fe1	0.6667	0.3333	0.3333	0.02141 (19)
N1	0.6659 (2)	0.4906 (2)	0.40253 (12)	0.0321 (5)
C1	0.6658 (2)	0.5774 (2)	0.43437 (14)	0.0288 (5)
C2	0.6651 (3)	0.6881 (3)	0.4763 (2)	0.0424 (7)
H2A	0.6723	0.6760	0.5316	0.064*
H2B	0.5800	0.6878	0.4657	0.064*
H2C	0.7425	0.7751	0.4597	0.064*
Sb1	0.6667	0.3333	0.661838 (14)	0.02892 (17)
F1	0.6682 (3)	0.1981 (3)	0.7195 (2)	0.1068 (11)
F2	0.5350 (3)	0.1968 (3)	0.60083 (19)	0.0921 (9)

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
Fe1	0.0214 (2)	0.0214 (2)	0.0215 (4)	0.01069 (12)	0.000	0.000
N1	0.0328 (10)	0.0315 (10)	0.0331 (10)	0.0171 (8)	−0.0006 (8)	−0.0040 (8)
C1	0.0252 (10)	0.0299 (11)	0.0313 (11)	0.0137 (9)	−0.0021 (8)	−0.0033 (9)
C2	0.0416 (16)	0.0364 (13)	0.054 (2)	0.0230 (13)	−0.0058 (11)	−0.0167 (13)
Sb1	0.03148 (19)	0.03148 (19)	0.0238 (2)	0.01574 (9)	0.000	0.000
F1	0.111 (2)	0.094 (2)	0.118 (2)	0.0533 (18)	−0.0103 (19)	0.0595 (19)
F2	0.0745 (16)	0.0736 (16)	0.120 (2)	0.0309 (13)	−0.0527 (16)	−0.0450 (16)

Geometric parameters (Å, º)

Fe1—N1^i	2.153 (2)	C2—H2B	0.9800
Fe1—N1^ii	2.153 (2)	C2—H2C	0.9800
Fe1—N1^iii	2.153 (2)	Sb1—F1	1.839 (2)
Fe1—N1	2.153 (2)	Sb1—F1^iii	1.839 (2)
Fe1—N1^iv	2.153 (2)	Sb1—F1^ii	1.839 (2)
Fe1—N1^v	2.153 (2)	Sb1—F2^iii	1.854 (2)
N1—C1	1.129 (3)	Sb1—F2	1.854 (2)
C1—C2	1.455 (4)	Sb1—F2^ii	1.854 (2)
C2—H2A	0.9800
N1^i—Fe1—N1^ii	180.0	H2A—C2—H2B	109.5
N1^i—Fe1—N1^iii	88.10 (8)	C1—C2—H2C	109.5
N1^ii—Fe1—N1^iii	91.91 (8)	H2A—C2—H2C	109.5
N1^i—Fe1—N1	88.10 (8)	H2B—C2—H2C	109.5
N1^ii—Fe1—N1	91.91 (8)	F1—Sb1—F1^iii	93.15 (17)
N1^iii—Fe1—N1	91.91 (8)	F1—Sb1—F1^ii	93.15 (17)
N1^i—Fe1—N1^iv	91.91 (8)	F1^iii—Sb1—F1^ii	93.15 (17)
N1^ii—Fe1—N1^iv	88.09 (8)	F1—Sb1—F2^iii	88.85 (16)
N1^iii—Fe1—N1^iv	180.0	F1^iii—Sb1—F2^iii	87.37 (16)
N1—Fe1—N1^iv	88.10 (8)	F1^ii—Sb1—F2^iii	177.90 (13)
N1^i—Fe1—N1^v	91.90 (8)	F1—Sb1—F2	87.37 (16)
N1^ii—Fe1—N1^v	88.09 (8)	F1^iii—Sb1—F2	177.90 (13)
N1^iii—Fe1—N1^v	88.10 (8)	F1^ii—Sb1—F2	88.85 (16)
N1—Fe1—N1^v	180.0	F2^iii—Sb1—F2	90.60 (16)
N1^iv—Fe1—N1^v	91.90 (8)	F1—Sb1—F2^ii	177.90 (13)
C1—N1—Fe1	175.4 (2)	F1^iii—Sb1—F2^ii	88.85 (16)
N1—C1—C2	179.3 (3)	F1^ii—Sb1—F2^ii	87.37 (15)
C1—C2—H2A	109.5	F2^iii—Sb1—F2^ii	90.60 (16)
C1—C2—H2B	109.5	F2—Sb1—F2^ii	90.60 (16)

Symmetry codes: (i) x−y+1/3, x−1/3, −z+2/3; (ii) −x+y+1, −x+1, z; (iii) −y+1, x−y, z; (iv) y+1/3, −x+y+2/3, −z+2/3; (v) −x+4/3, −y+2/3, −z+2/3.