Hexakis(μ2-2-aminoethanethiolato)triiron(III) tris(perchlorate)

In the title salt, [Fe3(C2H6NS)6](ClO4)3, the trinuclear cation lies on a special position of site symmetry; the central Fe atom is coordinated by six thiolate groups from the two flanking fac-(S)-[Fe(C2H6NS)3] units. In the flanking units, the three C2H6NS groups each chelate to the metal atom. The cations interact with the perchlorate anions through weak N—H⋯O hydrogen bonds resulting in a three-dimensional network. In the asymmetric unit two cations are present, one of which is disordered over two positions with occupancies of 0.75 and 0.25.

In the title salt, [Fe 3 (C 2 H 6 NS) 6 ](ClO 4 ) 3 , the trinuclear cation lies on a special position of 3 site symmetry; the central Fe atom is coordinated by six thiolate groups from the two flanking fac-(S)-[Fe(C 2 H 6 NS) 3 ] units. In the flanking units, the three C 2 H 6 NS groups each chelate to the metal atom. The cations interact with the perchlorate anions through weak N-HÁ Á ÁO hydrogen bonds resulting in a three-dimensional network. In the asymmetric unit two cations are present, one of which is disordered over two positions with occupancies of 0.75 and 0.25.    Hydrogen-bond geometry (Å , ). Symmetry codes: (ii) Àx þ y; Àx þ 1; z; (iii) x À y þ 1 3 ; x þ 2 3 ; Àz þ 2 3 .

S1. Comment
Due to the high Lewis basicity of thiolate groups, a great number of thiolate-bridged complexes have been synthesized up to now. 2-Aminoethanethiolate (aet) is the simplest N,S-chelating ligand that has been used for the formation of Sbridged polynuclear structures. For example, it has been shown that the aet ligand reacts with the octahedral metal ions to give linear-type S-bridged trinuclear structures, such as Co III 3 (Busch and Jicha, 1962;Heeg et al., 1985;Marsh et al., 1986), Rh III 3 (Mahboob et al., 2004, and Ru III 3 (Matsuura et al., 2006). In this paper, we report on the crystal structure of the title compound (I), which was obtained by the reaction of aet and Fe(ClO 4 ) 3 . The asymmetric unit of the compound (I) contains two complex cations having a threefold rotation-inversion axis and one perchlorate anion. One of the complex cations is disordered over two positions with occupancies of 0.75 and 0.25. In the complex cation of (I), two

fac(S)-[Fe(aet) 3 ] units coordinate to a central Fe atom through thiolato bridges to form a linear-type trinuclear structure.
Each terminal Fe atom is in an N 3 S 3 octahedral environment, whereas the central Fe atom is in an S 6 octahedral environment. Considering the charge balance, it is assumed that all Fe atoms have a +III oxidation state.

S2. Experimental
To a solution containing 2-aminoethanethiol hydrochloride (0.11 g, 1 mmol) in 20 ml of methanol/CH 2 Cl 2 (1:1) was added a solution of Et 3 N (0.10 g, 1 mmol) in 10 ml of methanol and a solution of Fe(ClO 4 ) 3 .6H 2 O (0.09 g, 0.2 mmol) in 2 ml of methanol. The resulting dark brown solution was stood at room temperature overnight to give black crystals, which was filtered and washed with methanol. Yield: 31 mg (50% based on Fe). Anal. Calcd for [Fe 3 (aet) 6 ](ClO 4 ) 3 = C 12 H 36 Cl 3 Fe 3 N 6 O 12 S 6 : C, 15.62; H, 3.93; N, 9.11%. Found: C, 15.82; H, 3.88; N, 9.00%.  The asymmetric unit of (I), with atom labels and 50% probability displacement ellipsoids for non-H atoms. Hydrogen atoms are omitted for clarity.  The cation units of (I). The molecule with open bonds is the minor component of the disordered unit. Symmetry codes:

Hexakis(µ 2 -2-aminoethanethiolato)triiron(III) tris(perchlorate)
Crystal data Refinement. Refinement of F 2 against ALL reflections. The weighted R-factor wR and goodness of fit S are based on F 2 , conventional R-factors R are based on F, with F set to zero for negative F 2 . The threshold expression of F 2 > σ(F 2 ) is used only for calculating R-factors(gt) etc. and is not relevant to the choice of reflections for refinement. R-factors based on F 2 are statistically about twice as large as those based on F, and R-factors based on ALL data will be even larger. The 2aminoethanethiolate ligand of one unit containing Fe3 and Fe4 atoms is disordered over two positions with the occupancies of 0.75 and 0.25. The C3B atom in the minor component is restrained based on ISOR.