fac-Tris­(di­methyl­form­amide)­tris­(iso­thio­cyanato)­iron(III)

The reaction of FeCl₃, NaSCN and Gd(NO₃)₃·6H₂O in 1:10 DMF/H₂O led to the formation of the title compound, [Fe(NCS)₃(C₄H₇N)₃], in which the six-coordinated Fe atom is in an octahedral fac environment.

Key indicators

• Single-crystal X-ray study
• T = 293 K
• Mean [sigma](N-C) = 0.003 Å
• R factor = 0.062
• wR factor = 0.146
• Data-to-parameter ratio = 16.7

checkCIF results

No syntax errors found

ADDSYM reports no extra symmetry

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S1. Comment

The SCN⁻ ligand has been extensively investigated in the recent years (Vinogradova et al., 2001; Ren et al., 2001; Kuang et al., 2001; Sudbrake & Vahrenkamp, 2001). In most of the reported iron(III) complexes, the SCN⁻ ligand acts in a monodentate manner (Marchivie et al., 2002; Zhu et al., 2002; Marlin et al., 2002). During our research on the 3 d-4f metal complexes, we obtained the title compound, (I), a mononuclear iron(III) complex containing the SCN⁻ ligand. Herein, we report the structure of (I).

In the title complex (Fig. 1), the six-coordinated Fe^III atom is surrounded by three SCN⁻ anions and three DMF molecules with mean Fe—N and Fe—O distances of 2.009 (6) and 2.037 (8) Å, respectively. Atoms N41, N51, O61 and O21 are coplanar, and the deviation of atom Fe1 from the above plane is 0.0554 (3) Å. The structure of (I) is similar to the structure of fac-tris(isothiocyanato)tris(triphenylphosphine oxide)iron(III) (Olejnik et al., 1995). All six fac-positioned ligands are monodentate. Three near linear SCN⁻ ligands in (I) have an average S—C—N bond angle of 179.2 (2)°. The S—C and C—N bond distances in the SCN ligand are comparable to reported values (Olejnik et al., 1995). The packing of (I) in the unit cell is shown in Fig. 2. The crystal structure is stabilized by van der Waals interactions.

S2. Experimental

FeCl₃ (1 mmol, 162 mg) was added to a 10 ml aqueous solution of NaSCN (6 mmol, 486 mg). After a clear red solution was formed, Gd(NO₃)₃·6H₂O (1 mmol, 451 mg) and DMF (1 ml) were added successively. The final solution was filtrated and allowed to stand in ambient environment. Black–red prismatic crystals formed after several days.

S3. Refinement

H atoms were fixed geometrically and allowed to ride on their parent atoms. A rotating group model was used for the methyl groups. The low ratio (0.49) of observed to unique reflections and the relatively large U_eq values for the non-H atoms may be as a result of the poor diffraction quality of the crystal.

Computing details

Data collection: SMART (Siemens, 1996); cell refinement: SAINT (Siemens, 1994); data reduction: SAINT; program(s) used to solve structure: SHELXTL (Siemens, 1994); program(s) used to refine structure: SHELXTL; molecular graphics: SHELXTL; software used to prepare material for publication: SHELXTL.

Figures

	Fig. 1. The molecular structure of (I). Displacement ellipsoids are drawn at the 30% probability level and H atoms have been omitted for clarity.
	Fig. 2. The molecular packing, viewed down the a axis. H atoms have been omitted for clarity.

fac-tris(isothiocyanato)-tris(dimethylformamide)-iron(III)

Crystal data

[Fe(NCS)3(C4H7N)3]	F(000) = 932
Mr = 449.38	Dx = 1.330 Mg m^−3
Monoclinic, P21/c	Melting point: not measured K
Hall symbol: -P 2ybc	Mo Kα radiation, λ = 0.71073 Å
a = 8.7570 (4) Å	Cell parameters from 1832 reflections
b = 16.8849 (8) Å	θ = 1.8–25.1°
c = 15.3070 (6) Å	µ = 0.97 mm^−1
β = 97.591 (2)°	T = 293 K
V = 2243.47 (17) Å^3	Prism, black–red
Z = 4	0.26 × 0.22 × 0.18 mm

Data collection

SMART CCD area-detector diffractometer	3864 independent reflections
Radiation source: fine-focus sealed tube	1904 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.055
ω scans	θmax = 25.1°, θmin = 1.8°
Absorption correction: multi-scan (SADABS; Sheldrick, 1996)	h = −9→7
Tmin = 0.772, Tmax = 0.839	k = −20→14
7394 measured reflections	l = −16→18

Refinement

Refinement on F^2	Primary atom site location: structure-invariant direct methods
Least-squares matrix: full	Secondary atom site location: difference Fourier map
R[F^2 > 2σ(F^2)] = 0.062	Hydrogen site location: inferred from neighbouring sites
wR(F^2) = 0.146	H-atom parameters constrained
S = 1.00	w = 1/[σ^2(Fo^2) + (0.0426P)^2 + 1.9621P] where P = (Fo^2 + 2Fc^2)/3
3864 reflections	(Δ/σ)max = 0.003
232 parameters	Δρmax = 0.47 e Å^−3
6 restraints	Δρmin = −0.32 e Å^−3

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	0.05440 (4)	0.24572 (2)	0.17738 (2)	0.05477 (11)
S31	0.31647 (11)	0.12447 (6)	−0.03905 (6)	0.1106 (4)
S41	0.53051 (10)	0.38121 (6)	0.21952 (7)	0.1064 (4)
S51	−0.19306 (15)	0.39240 (7)	−0.06202 (7)	0.1384 (5)
C11	−0.0513 (3)	0.36637 (17)	0.29694 (18)	0.0690 (10)
H11A	−0.0055	0.4025	0.2626	0.083*
C12	−0.1280 (4)	0.47919 (19)	0.3792 (2)	0.1217 (15)
H12A	−0.0733	0.5077	0.3389	0.183*
H12B	−0.0820	0.4896	0.4386	0.183*
H12C	−0.2337	0.4960	0.3720	0.183*
C13	−0.1926 (4)	0.3424 (2)	0.41791 (19)	0.1082 (13)
H13A	−0.1715	0.2884	0.4041	0.162*
H13B	−0.3019	0.3512	0.4093	0.162*
H13C	−0.1526	0.3531	0.4782	0.162*
C21	−0.2499 (3)	0.17665 (17)	0.19350 (18)	0.0722 (10)
H21A	−0.2696	0.2248	0.2193	0.087*
C22	−0.3286 (4)	0.0470 (2)	0.1595 (3)	0.1764 (19)
H22A	−0.2603	0.0514	0.1155	0.265*
H22B	−0.4260	0.0264	0.1330	0.265*
H22C	−0.2846	0.0120	0.2054	0.265*
C23	−0.4908 (3)	0.13222 (19)	0.2354 (2)	0.0947 (12)
H23A	−0.4928	0.1842	0.2605	0.142*
H23B	−0.4938	0.0933	0.2808	0.142*
H23C	−0.5786	0.1256	0.1913	0.142*
C31	0.2199 (3)	0.16016 (16)	0.03298 (16)	0.0608 (9)
C41	0.3612 (3)	0.34309 (16)	0.21265 (16)	0.0600 (9)
C51	−0.1138 (3)	0.35166 (17)	0.02675 (19)	0.0764 (11)
C61	0.2035 (3)	0.17300 (17)	0.34395 (18)	0.0692 (10)
H61A	0.2212	0.2248	0.3634	0.083*
C62	0.2163 (5)	0.0345 (2)	0.3728 (2)	0.149 (2)
H62A	0.1857	0.0322	0.3102	0.224*
H62B	0.1353	0.0136	0.4026	0.224*
H62C	0.3081	0.0036	0.3879	0.224*
C63	0.3217 (5)	0.1297 (2)	0.4877 (2)	0.1311 (17)
H63A	0.3493	0.1845	0.4947	0.197*
H63B	0.4129	0.0976	0.4979	0.197*
H63C	0.2530	0.1157	0.5291	0.197*
N11	−0.1206 (2)	0.39417 (14)	0.36128 (14)	0.0695 (8)
N21	−0.3506 (2)	0.12251 (12)	0.19542 (14)	0.0636 (7)
N31	0.1495 (2)	0.18575 (13)	0.08436 (14)	0.0635 (7)
N41	0.2413 (2)	0.31474 (14)	0.20753 (14)	0.0689 (8)
N51	−0.0548 (3)	0.32274 (15)	0.09161 (15)	0.0772 (9)
N61	0.2464 (3)	0.11634 (14)	0.39935 (14)	0.0769 (8)
O11	−0.04294 (19)	0.29536 (11)	0.27892 (11)	0.0643 (6)
O21	−0.1290 (2)	0.17151 (11)	0.16086 (12)	0.0737 (6)
O61	0.1412 (2)	0.16339 (10)	0.26765 (11)	0.0651 (6)

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
Fe1	0.0562 (2)	0.0547 (2)	0.0556 (2)	−0.0029 (2)	0.01535 (16)	−0.0032 (2)
S31	0.1456 (7)	0.1014 (7)	0.0966 (6)	0.0297 (6)	0.0600 (5)	−0.0095 (5)
S41	0.0690 (5)	0.1091 (7)	0.1382 (8)	−0.0301 (5)	0.0026 (5)	−0.0018 (6)
S51	0.1988 (11)	0.1272 (9)	0.0772 (6)	0.0486 (8)	−0.0266 (7)	−0.0008 (6)
C11	0.0593 (17)	0.072 (2)	0.0752 (19)	0.0041 (16)	0.0077 (15)	−0.0037 (16)
C12	0.137 (3)	0.091 (2)	0.132 (3)	0.035 (2)	−0.004 (2)	−0.058 (2)
C13	0.110 (2)	0.145 (3)	0.074 (2)	0.053 (2)	0.0243 (18)	0.007 (2)
C21	0.0708 (18)	0.0565 (19)	0.091 (2)	−0.0054 (16)	0.0152 (16)	−0.0151 (16)
C22	0.145 (3)	0.101 (3)	0.308 (4)	−0.042 (2)	0.121 (3)	−0.068 (3)
C23	0.0578 (17)	0.109 (3)	0.124 (2)	−0.0104 (18)	0.0372 (17)	−0.020 (2)
C31	0.0805 (18)	0.0506 (17)	0.0520 (15)	0.0005 (15)	0.0108 (14)	−0.0062 (14)
C41	0.0734 (17)	0.0549 (17)	0.0521 (15)	−0.0032 (15)	0.0096 (14)	−0.0019 (14)
C51	0.089 (2)	0.066 (2)	0.0731 (19)	0.0135 (17)	0.0086 (17)	−0.0164 (16)
C61	0.0810 (18)	0.0531 (18)	0.0765 (18)	0.0149 (16)	0.0219 (15)	−0.0046 (15)
C62	0.265 (5)	0.070 (3)	0.113 (3)	0.013 (3)	0.028 (3)	0.013 (2)
C63	0.190 (4)	0.122 (3)	0.076 (2)	0.067 (3)	−0.002 (2)	0.000 (2)
N11	0.0685 (14)	0.0803 (17)	0.0573 (13)	0.0171 (14)	−0.0010 (12)	−0.0171 (13)
N21	0.0657 (13)	0.0510 (14)	0.0764 (14)	−0.0136 (12)	0.0178 (12)	−0.0168 (12)
N31	0.0686 (13)	0.0611 (15)	0.0637 (13)	−0.0024 (13)	0.0190 (11)	−0.0040 (12)
N41	0.0658 (14)	0.0765 (17)	0.0652 (14)	−0.0154 (13)	0.0112 (12)	0.0004 (13)
N51	0.0792 (16)	0.0778 (18)	0.0724 (16)	0.0071 (15)	0.0018 (14)	0.0021 (14)
N61	0.1114 (18)	0.0638 (16)	0.0573 (14)	0.0267 (15)	0.0177 (13)	−0.0001 (12)
O11	0.0670 (11)	0.0577 (11)	0.0710 (11)	0.0055 (10)	0.0196 (9)	−0.0081 (10)
O21	0.0672 (11)	0.0771 (13)	0.0823 (12)	−0.0222 (11)	0.0298 (9)	−0.0210 (11)
O61	0.0827 (12)	0.0602 (12)	0.0530 (10)	0.0024 (10)	0.0109 (9)	0.0018 (10)

Geometric parameters (Å, º)

Fe1—N51	2.000 (2)	C22—N21	1.412 (4)
Fe1—N41	2.012 (2)	C22—H22A	0.96
Fe1—N31	2.015 (2)	C22—H22B	0.96
Fe1—O21	2.0261 (18)	C22—H22C	0.96
Fe1—O61	2.0353 (17)	C23—N21	1.452 (3)
Fe1—O11	2.0481 (18)	C23—H23A	0.96
S31—C31	1.594 (3)	C23—H23B	0.96
S41—C41	1.607 (3)	C23—H23C	0.96
S51—C51	1.598 (3)	C31—N31	1.146 (3)
C11—O11	1.235 (3)	C41—N41	1.147 (3)
C11—N11	1.310 (3)	C51—N51	1.164 (4)
C11—H11A	0.93	C61—O61	1.233 (3)
C12—N11	1.465 (4)	C61—N61	1.301 (3)
C12—H12A	0.96	C61—H61A	0.93
C12—H12B	0.96	C62—N61	1.455 (4)
C12—H12C	0.96	C62—H62A	0.96
C13—N11	1.434 (4)	C62—H62B	0.96
C13—H13A	0.96	C62—H62C	0.96
C13—H13B	0.96	C63—N61	1.441 (4)
C13—H13C	0.96	C63—H63A	0.96
C21—O21	1.233 (3)	C63—H63B	0.96
C21—N21	1.273 (3)	C63—H63C	0.96
C21—H21A	0.93
N51—Fe1—N41	94.47 (9)	N21—C23—H23A	109.5
N51—Fe1—N31	93.98 (9)	N21—C23—H23B	109.5
N41—Fe1—N31	93.07 (9)	H23A—C23—H23B	109.5
N51—Fe1—O21	91.02 (9)	N21—C23—H23C	109.5
N41—Fe1—O21	173.63 (8)	H23A—C23—H23C	109.5
N31—Fe1—O21	89.75 (8)	H23B—C23—H23C	109.5
N51—Fe1—O61	173.41 (9)	N31—C31—S31	179.5 (3)
N41—Fe1—O61	91.17 (8)	N41—C41—S41	178.9 (3)
N31—Fe1—O61	89.11 (8)	N51—C51—S51	179.2 (3)
O21—Fe1—O61	83.17 (7)	O61—C61—N61	125.1 (3)
N51—Fe1—O11	91.21 (8)	O61—C61—H61A	117.5
N41—Fe1—O11	89.79 (8)	N61—C61—H61A	117.5
N31—Fe1—O11	173.86 (8)	N61—C62—H62A	109.5
O21—Fe1—O11	86.87 (7)	N61—C62—H62B	109.5
O61—Fe1—O11	85.40 (7)	H62A—C62—H62B	109.5
O11—C11—N11	124.3 (3)	N61—C62—H62C	109.5
O11—C11—H11A	117.9	H62A—C62—H62C	109.5
N11—C11—H11A	117.9	H62B—C62—H62C	109.5
N11—C12—H12A	109.5	N61—C63—H63A	109.5
N11—C12—H12B	109.5	N61—C63—H63B	109.5
H12A—C12—H12B	109.5	H63A—C63—H63B	109.5
N11—C12—H12C	109.5	N61—C63—H63C	109.5
H12A—C12—H12C	109.5	H63A—C63—H63C	109.5
H12B—C12—H12C	109.5	H63B—C63—H63C	109.5
N11—C13—H13A	109.5	C11—N11—C13	121.4 (3)
N11—C13—H13B	109.5	C11—N11—C12	121.9 (3)
H13A—C13—H13B	109.5	C13—N11—C12	116.7 (3)
N11—C13—H13C	109.5	C21—N21—C22	120.6 (3)
H13A—C13—H13C	109.5	C21—N21—C23	123.7 (2)
H13B—C13—H13C	109.5	C22—N21—C23	115.6 (2)
O21—C21—N21	126.4 (3)	C31—N31—Fe1	169.9 (2)
O21—C21—H21A	116.8	C41—N41—Fe1	165.1 (2)
N21—C21—H21A	116.8	C51—N51—Fe1	162.3 (2)
N21—C22—H22A	109.5	C61—N61—C63	123.6 (3)
N21—C22—H22B	109.5	C61—N61—C62	119.4 (3)
H22A—C22—H22B	109.5	C63—N61—C62	117.0 (3)
N21—C22—H22C	109.5	C11—O11—Fe1	127.58 (18)
H22A—C22—H22C	109.5	C21—O21—Fe1	127.97 (18)
H22B—C22—H22C	109.5	C61—O61—Fe1	129.21 (18)