Two Fe₃([mu]₃-S)₂(CO)₈ clusters with terminal N-heterocyclic carbenes

The title compounds with terminal N-heterocyclic carbenes, namely octa­carbon­yl(imidazolidinylidene-[kappa]C²)di-[mu]₃-sulfido-tri­iron(II)(2 Fe-Fe), [Fe₃(C₃H₆N₂)([mu]₃-S)₂(CO)₈], (I), and octacarbon­yl(1-methyl­imidazo[1,5-a]pyridin-3-ylidene-[kappa]C³)di-[mu]₃-sulfido-triiron(II)(2 Fe-Fe), [Fe₃(C₈H₈N₂)([mu]₃-S)₂(CO)₈], (II), have been synthesized. Each compound contains two Fe-Fe bonds and two S atoms above and below a triiron triangle. One of the eight carbonyl ligands deviates significantly from linearity. In (I), dimers generated by an N-H...S hydrogen bond are linked into [001] double chains by a second N-H...S hydrogen bond. These chains are packed by a C-H...O hydrogen bond to yield [101] sheets. In (II), dimers generated by an N-H...S hydrogen bond are linked by C-H...O hydrogen bonds to form [111] double chains.

S1. Introduction

Iron–sulfur cluster complexes have attracted considerable attention, not only because of their fascinating chemistry (Song, 2005; Shieh et al., 2012) but also for their ability to act as electron reservoirs, their potential as catalysts and their practical applications as biomimetic models for the active sites of the Fe–Fe hydrogenases (Capon et al., 2009; Taylor et al., 2011; Wang et al., 2010). However, to date, few efficient electrocatalysts have been obtained and the mechanism of the natural production/uptake of hydrogen remains unclear. Therefore, structural and chemical models are necessary to gain a better understanding of the protonation mechanisms implied at the molecular level (Erdem et al., 2011; Tard & Pickett, 2009; Song et al., 2006). For these reasons, we have initiated a project investigating the reactions of hetero­allyl anions G—C(═Y)—Z^- with iron carbonyls in order to develop synthetic methodologies towards iron–sulfur cluster complexes as model compounds (Shi, Cheng, Fu et al., 2013; Shi, Cheng & Cheng, 2013; Shi & Fu, 2013; Shi & Gu, 2013; Shi et al., 2012). As part of this on-going project, we report herein the syntheses and crystal structures of two triiron clusters with N-heterocyclic carbene ligands (Shi et al., 2014; Shi, Cheng et al., 2011; Shi, Lai et al., 2011), namely o­cta­carbonyl­(imidazolidinyl­idene-κC²)di-µ₃-sulfido-triiron(II)(2 Fe—Fe), (I), and o­cta­carbonyl­(1-methyl­imidazo[1,5-a]pyridin-3-yl­idene-κC³)di-µ₃-sulfido-triiron(II)(2 Fe—Fe), (II).

S2. Experimental

S2.1. Synthesis and crystallization

For the preparation of (I), a mixture of Fe₃(CO)₁₂ (1.007 g, 2 mmol) and (CH₂NH)₂CS (0.511 g, 5 mmol) in tetra­hydro­furan (THF; 25 ml) was refluxed for 30 min. After the solvent had been removed under reduced pressure, the resulting residue was chromatographed on a silica-gel column with petroleum ether (333–363 K) and CH₂Cl₂ (1:2 v/v) as eluent to give (I) as a brown–red solid (yield 71%, 0.746 g). Red single crystals of (I) were obtained by slow evaporation of a petroleum ether–CH₂Cl₂ [Solvent ratio?] solution at 277 K. Analysis, calculated for C₁₁H₆Fe₃N₂O₈S₂, (I): C 25.13, H 1.15, N 5.33%; found: C 25.34, H 1.19, N 5.16%. Spectroscopic analysis: IR (KBr disk, cm^-1): ν(NH) 3340 (m); ν(C≡O) 2068 (vs), 2009 (vs, br); ¹H NMR (500 MHz, CDCl₃, TMS, δ, p.p.m.): 3.68–3.81 (m, 4H, C₂H₄), 6.28–6.37 (m, 2H, 2NH).

For the preparation of (II), a mixture of Fe₃(CO)₁₂ (1.5 g, 2.98 mmol) and [HNEt₃][2-C₅H₄NCH(CH₃)NHCS₂] (0.899 g, 3 mmol) in THF (25 ml) was stirred for 3 h at room temperature to form a red–brown solution. To this solution was added PhCOCl (1.04 ml, 9 mmol). After the solution had been stirred for 24 h, the same work-up as for (I) above gave a purple–red solid of (II) (yield 28%, 0.491 g). Red single crystals of (II) were obtained by slow evaporation of a petroleum ether–CH₂Cl₂ [Solvent ratio?] solution at 277 K. Analysis, calculated for C₁₆H₈Fe₃N₂O₈S₂, (II): C 32.69, H 1.37, N 4.76%; found: C 32.83, H 1.19, N 4.79%. Spectroscopic analysis: IR (KBr disk, cm^-1): ν(NH) 3431 (m); ν(C≡O) 2069 (s), 2037 (s), 1998 (vs), 1944 (s); ¹H NMR (500 MHz, CDCl₃, TMS, δ, p.p.m.): 2.53 (s, 3H, CH₃), 6.62, 6.75, 7.27, 8.20 (4s, 4H, C₅H₄N), 9.59 (s, 1H, NH).

S2.2. Refinement

C-bound H atoms were placed at calculated positions and subsequently treated as riding, with C—H = 0.93 (CH, aromatic), 0.97 (CH₂) or 0.96 Å (CH₃), and with U_iso(H) = 1.5U_eq(C) for methyl groups or 1.2U_eq(C) otherwise. N-bound H atoms were located in difference Fourier maps and freely refined isotropically.

S3. Results and discussion

The title compounds, (I) and (II), were synthesized according to the scheme. Thus, reaction of Fe₃(CO)₁₂ with (CH₂NH)₂C═S in refluxing THF afforded cluster (I) in satisfactory yield. Reaction of Fe₃(CO)₁₂ and [HNEt₃][2-C₅H₄NCH(CH₃)NHCS₂] with PhCOCl at room temperature gave cluster (II) containing an unprecedented N-heterocyclic carbene ligand, presumably via initial formation of the thio­urea derivative 1-methyl­imidazo[1,5-a]pyridine-3(2H)-thione, (III).

As shown in Figs. 1 and 2, each of (I) and (II) is a trinuclear iron carbonyl complex, with a distorted square-based pyramidal geometry similar to the previously reported cluster (µ₃-S)₂Fe₃(CO)₉ (Wei & Dahl, 1965). In (µ₃-S)₂Fe₃(CO)₉, each of the two S atoms on the square base triply bridges the two basal Fe(CO)₃ units on the same base and the third Fe(CO)₃ group at the apex of the pyramid, and each of the three Fe atoms obeys the 18-electron rule. Therefore, (I) and (II) may be regarded as involving formal replacement of the axial carbonyl ligand on one of the iron centres on the square base in (µ₃-S)₂Fe₃(CO)₉ by a two-electron carbene group. The carbene ligand leads to small structural effects in (I) and (II): a slight increase in the Fe1—Fe3—Fe2 bond angle [81.885 (12)° for (I) and 81.492 (15)° for (II)] compared with (µ₃-S)₂Fe₃(CO)₉ [81.0 (3)°], and a slight increase in the Fe1—Fe3 bond length compared with the Fe2—Fe3 bond length. In addition, one of the three carbonyl ligands attached to apical atom Fe3 participates in a weak inter­action with the carbene-substituted basal atom Fe1 from a direction trans to the carbene ligand. The C6···Fe1 distances are 2.686 (3) Å for (I) and 2.802 (2) Å for (II), which lie between the sum of the covalent radii and van der Waals radii for Fe and C [r(Fe) + r(C) = 2.13 Å and R(Fe) + R(C) = 3.84 Å; Standard references?]. Associated with this inter­action is a significant deviation of the O6—C6—Fe3 bond angles in (I) and (II) from linearity, with carbonyl atom C6 bent towards atom Fe1 [O6—C6—Fe3 = 171.1 (2)° for (I) and 172.1 (2)° for (II)], whereas the other Fe—C—O bond angles lie in the ranges 176.9 (2)–179.5 (3)° for (I) and 177.2 (2)–179.1 (2)° for (II). Similar inter­actions have been observed in previously reported clusters of the type (µ₃-S)₂Fe₃(CO)₈L (L = carbene), namely L axial, with O—C—Fe = 171.8 (6)° and C···Fe = 2.844 (9) Å [An et al., 1992; Cambridge Structural Database (CSD; Allen, 2002) refcode VOYWAH]; L axial, with O—C—Fe = 171.7 (9)° and C···Fe = 2.750 (10) Å (CSD refcode TAQMAZ; Liu et al., 1996); L equatorial, with O—C—Fe = 173.4 (4)° and C···Fe = 2.805 (6) Å (CSD refcode XEPZAT; Liu et al., 1998); L axial, with O—C—Fe = 172.8 (6)° and C···Fe = 2.751 (7) Å (CCDC deposition number 216503; Hong et al., 2004); and L axial, with O—C—Fe = 172.2 (3)° and C···Fe = 2.757 (4) Å (CSD refcode HY2012 [This is an IUCr paper code. Please give correct CSD code]; Zhang et al., 2008). This type of weak inter­action was also found in [(µ₃-κ¹P:κ²C:κ²S-Ph₂PCS)Fe₃(CO)₈(µ-κ²S-S)]₂ [O—C—Fe = 168.3 (2)° and C···Fe = 2.589 (3) Å; Shi, Cheng & Cheng, 2013].

Each of the above N-heterocyclic carbenes is planar. In agreement with this, the sums of the bond angles around atom C9 are 359.98 (16)° for (I) (Table 2) and 359.02 (15)° for (II) (Table 3), suggesting that this atom is sp²-hybridized (Shi & Fu, 2013). Furthermore, the Fe1—C9, C9—N1 and C9—N2 bond lengths are 1.925 (2), 1.323 (3) and 1.322 (3) Å, respectively, for (I), and 1.944 (2), 1.354 (3) and 1.371 (2) Å, respectively, for (II), comparable with values reported for Fe₃(C₈H₈N₂O)S₂(CO)₈ crystallized in the space group P1 [1.914 (2), 1.348 (3) and 1.355 (3) Å, respectively; Zhang et al., 2008], Fe₃[C(NH₂)NHN═ CH(2—C₄H₃S)]S₂(CO)₈ crystallized in the space group P1 [1.929 (6), 1.345 (7) and 1.311 (8) Å, respectively; Hong et al., 2004], Fe₃[C(NHC(═S)CMe₂NH)]S₂(CO)₈ crystallized in the space group P2₁/n [1.898 (6), 1.310 (9) and 1.382 (9) Å, respectively; Liu et al., 1996] and Fe₃(C₇H₆N₂)S₂(CO)₈ crystallized in the space group P1 [1.916 (5), 1.333 (7) and 1.353 (9) Å, respectively; An et al., 1992], supporting the fact that π-bonding in each case is delocalized over atoms Fe1, C9, N1 and N2. Although the S₂Fe₃ core as in these complexes is well known, triiron clusters with N-heterocyclic carbenes are rare (Shi & Gu, 2013; Liu et al., 1998).

It is worth discussing the packing inter­actions in the title compounds, because there have been no reports on the supra­molecular assemblies of clusters of type (µ₃-S)₂Fe₃(CO)₈L (L = carbene). In (I), two N—H···S and one C—H···O hydrogen bond (Table 4) combine the molecules into sheets that lie in the [101] plane (Fig. 3). For (II), N—H···S and C—H···O inter­actions (Table 5) link the molecules into chains lying along the [111] direction (Fig. 4).

Related literature

For related literature, see: An et al. (1992); Capon et al. (2009); Erdem et al. (2011); Hong et al. (2004); Liu et al. (1996, 1998); Shi & Fu (2013); Shi & Gu (2013); Shi et al. (2012, 2014); Shi, Cheng & Cheng (2013); Shi, Cheng, Fu, Gu & Wu (2013); Shi, Cheng, Yuan & Li (2011); Shi, Lai, Shen & Yuan (2011); Shieh et al. (2012); Song (2005); Song et al. (2006); Tard & Pickett (2009); Taylor et al. (2011); Wang et al. (2010); Wei & Dahl (1965); Zhang et al. (2008).

Structure description

Iron–sulfur cluster complexes have attracted considerable attention, not only because of their fascinating chemistry (Song, 2005; Shieh et al., 2012) but also for their ability to act as electron reservoirs, their potential as catalysts and their practical applications as biomimetic models for the active sites of the Fe–Fe hydrogenases (Capon et al., 2009; Taylor et al., 2011; Wang et al., 2010). However, to date, few efficient electrocatalysts have been obtained and the mechanism of the natural production/uptake of hydrogen remains unclear. Therefore, structural and chemical models are necessary to gain a better understanding of the protonation mechanisms implied at the molecular level (Erdem et al., 2011; Tard & Pickett, 2009; Song et al., 2006). For these reasons, we have initiated a project investigating the reactions of hetero­allyl anions G—C(═Y)—Z^- with iron carbonyls in order to develop synthetic methodologies towards iron–sulfur cluster complexes as model compounds (Shi, Cheng, Fu et al., 2013; Shi, Cheng & Cheng, 2013; Shi & Fu, 2013; Shi & Gu, 2013; Shi et al., 2012). As part of this on-going project, we report herein the syntheses and crystal structures of two triiron clusters with N-heterocyclic carbene ligands (Shi et al., 2014; Shi, Cheng et al., 2011; Shi, Lai et al., 2011), namely o­cta­carbonyl­(imidazolidinyl­idene-κC²)di-µ₃-sulfido-triiron(II)(2 Fe—Fe), (I), and o­cta­carbonyl­(1-methyl­imidazo[1,5-a]pyridin-3-yl­idene-κC³)di-µ₃-sulfido-triiron(II)(2 Fe—Fe), (II).

The title compounds, (I) and (II), were synthesized according to the scheme. Thus, reaction of Fe₃(CO)₁₂ with (CH₂NH)₂C═S in refluxing THF afforded cluster (I) in satisfactory yield. Reaction of Fe₃(CO)₁₂ and [HNEt₃][2-C₅H₄NCH(CH₃)NHCS₂] with PhCOCl at room temperature gave cluster (II) containing an unprecedented N-heterocyclic carbene ligand, presumably via initial formation of the thio­urea derivative 1-methyl­imidazo[1,5-a]pyridine-3(2H)-thione, (III).

As shown in Figs. 1 and 2, each of (I) and (II) is a trinuclear iron carbonyl complex, with a distorted square-based pyramidal geometry similar to the previously reported cluster (µ₃-S)₂Fe₃(CO)₉ (Wei & Dahl, 1965). In (µ₃-S)₂Fe₃(CO)₉, each of the two S atoms on the square base triply bridges the two basal Fe(CO)₃ units on the same base and the third Fe(CO)₃ group at the apex of the pyramid, and each of the three Fe atoms obeys the 18-electron rule. Therefore, (I) and (II) may be regarded as involving formal replacement of the axial carbonyl ligand on one of the iron centres on the square base in (µ₃-S)₂Fe₃(CO)₉ by a two-electron carbene group. The carbene ligand leads to small structural effects in (I) and (II): a slight increase in the Fe1—Fe3—Fe2 bond angle [81.885 (12)° for (I) and 81.492 (15)° for (II)] compared with (µ₃-S)₂Fe₃(CO)₉ [81.0 (3)°], and a slight increase in the Fe1—Fe3 bond length compared with the Fe2—Fe3 bond length. In addition, one of the three carbonyl ligands attached to apical atom Fe3 participates in a weak inter­action with the carbene-substituted basal atom Fe1 from a direction trans to the carbene ligand. The C6···Fe1 distances are 2.686 (3) Å for (I) and 2.802 (2) Å for (II), which lie between the sum of the covalent radii and van der Waals radii for Fe and C [r(Fe) + r(C) = 2.13 Å and R(Fe) + R(C) = 3.84 Å; Standard references?]. Associated with this inter­action is a significant deviation of the O6—C6—Fe3 bond angles in (I) and (II) from linearity, with carbonyl atom C6 bent towards atom Fe1 [O6—C6—Fe3 = 171.1 (2)° for (I) and 172.1 (2)° for (II)], whereas the other Fe—C—O bond angles lie in the ranges 176.9 (2)–179.5 (3)° for (I) and 177.2 (2)–179.1 (2)° for (II). Similar inter­actions have been observed in previously reported clusters of the type (µ₃-S)₂Fe₃(CO)₈L (L = carbene), namely L axial, with O—C—Fe = 171.8 (6)° and C···Fe = 2.844 (9) Å [An et al., 1992; Cambridge Structural Database (CSD; Allen, 2002) refcode VOYWAH]; L axial, with O—C—Fe = 171.7 (9)° and C···Fe = 2.750 (10) Å (CSD refcode TAQMAZ; Liu et al., 1996); L equatorial, with O—C—Fe = 173.4 (4)° and C···Fe = 2.805 (6) Å (CSD refcode XEPZAT; Liu et al., 1998); L axial, with O—C—Fe = 172.8 (6)° and C···Fe = 2.751 (7) Å (CCDC deposition number 216503; Hong et al., 2004); and L axial, with O—C—Fe = 172.2 (3)° and C···Fe = 2.757 (4) Å (CSD refcode HY2012 [This is an IUCr paper code. Please give correct CSD code]; Zhang et al., 2008). This type of weak inter­action was also found in [(µ₃-κ¹P:κ²C:κ²S-Ph₂PCS)Fe₃(CO)₈(µ-κ²S-S)]₂ [O—C—Fe = 168.3 (2)° and C···Fe = 2.589 (3) Å; Shi, Cheng & Cheng, 2013].

Each of the above N-heterocyclic carbenes is planar. In agreement with this, the sums of the bond angles around atom C9 are 359.98 (16)° for (I) (Table 2) and 359.02 (15)° for (II) (Table 3), suggesting that this atom is sp²-hybridized (Shi & Fu, 2013). Furthermore, the Fe1—C9, C9—N1 and C9—N2 bond lengths are 1.925 (2), 1.323 (3) and 1.322 (3) Å, respectively, for (I), and 1.944 (2), 1.354 (3) and 1.371 (2) Å, respectively, for (II), comparable with values reported for Fe₃(C₈H₈N₂O)S₂(CO)₈ crystallized in the space group P1 [1.914 (2), 1.348 (3) and 1.355 (3) Å, respectively; Zhang et al., 2008], Fe₃[C(NH₂)NHN═ CH(2—C₄H₃S)]S₂(CO)₈ crystallized in the space group P1 [1.929 (6), 1.345 (7) and 1.311 (8) Å, respectively; Hong et al., 2004], Fe₃[C(NHC(═S)CMe₂NH)]S₂(CO)₈ crystallized in the space group P2₁/n [1.898 (6), 1.310 (9) and 1.382 (9) Å, respectively; Liu et al., 1996] and Fe₃(C₇H₆N₂)S₂(CO)₈ crystallized in the space group P1 [1.916 (5), 1.333 (7) and 1.353 (9) Å, respectively; An et al., 1992], supporting the fact that π-bonding in each case is delocalized over atoms Fe1, C9, N1 and N2. Although the S₂Fe₃ core as in these complexes is well known, triiron clusters with N-heterocyclic carbenes are rare (Shi & Gu, 2013; Liu et al., 1998).

It is worth discussing the packing inter­actions in the title compounds, because there have been no reports on the supra­molecular assemblies of clusters of type (µ₃-S)₂Fe₃(CO)₈L (L = carbene). In (I), two N—H···S and one C—H···O hydrogen bond (Table 4) combine the molecules into sheets that lie in the [101] plane (Fig. 3). For (II), N—H···S and C—H···O inter­actions (Table 5) link the molecules into chains lying along the [111] direction (Fig. 4).

For related literature, see: An et al. (1992); Capon et al. (2009); Erdem et al. (2011); Hong et al. (2004); Liu et al. (1996, 1998); Shi & Fu (2013); Shi & Gu (2013); Shi et al. (2012, 2014); Shi, Cheng & Cheng (2013); Shi, Cheng, Fu, Gu & Wu (2013); Shi, Cheng, Yuan & Li (2011); Shi, Lai, Shen & Yuan (2011); Shieh et al. (2012); Song (2005); Song et al. (2006); Tard & Pickett (2009); Taylor et al. (2011); Wang et al. (2010); Wei & Dahl (1965); Zhang et al. (2008).

Synthesis and crystallization

For the preparation of (I), a mixture of Fe₃(CO)₁₂ (1.007 g, 2 mmol) and (CH₂NH)₂CS (0.511 g, 5 mmol) in tetra­hydro­furan (THF; 25 ml) was refluxed for 30 min. After the solvent had been removed under reduced pressure, the resulting residue was chromatographed on a silica-gel column with petroleum ether (333–363 K) and CH₂Cl₂ (1:2 v/v) as eluent to give (I) as a brown–red solid (yield 71%, 0.746 g). Red single crystals of (I) were obtained by slow evaporation of a petroleum ether–CH₂Cl₂ [Solvent ratio?] solution at 277 K. Analysis, calculated for C₁₁H₆Fe₃N₂O₈S₂, (I): C 25.13, H 1.15, N 5.33%; found: C 25.34, H 1.19, N 5.16%. Spectroscopic analysis: IR (KBr disk, cm^-1): ν(NH) 3340 (m); ν(C≡O) 2068 (vs), 2009 (vs, br); ¹H NMR (500 MHz, CDCl₃, TMS, δ, p.p.m.): 3.68–3.81 (m, 4H, C₂H₄), 6.28–6.37 (m, 2H, 2NH).

For the preparation of (II), a mixture of Fe₃(CO)₁₂ (1.5 g, 2.98 mmol) and [HNEt₃][2-C₅H₄NCH(CH₃)NHCS₂] (0.899 g, 3 mmol) in THF (25 ml) was stirred for 3 h at room temperature to form a red–brown solution. To this solution was added PhCOCl (1.04 ml, 9 mmol). After the solution had been stirred for 24 h, the same work-up as for (I) above gave a purple–red solid of (II) (yield 28%, 0.491 g). Red single crystals of (II) were obtained by slow evaporation of a petroleum ether–CH₂Cl₂ [Solvent ratio?] solution at 277 K. Analysis, calculated for C₁₆H₈Fe₃N₂O₈S₂, (II): C 32.69, H 1.37, N 4.76%; found: C 32.83, H 1.19, N 4.79%. Spectroscopic analysis: IR (KBr disk, cm^-1): ν(NH) 3431 (m); ν(C≡O) 2069 (s), 2037 (s), 1998 (vs), 1944 (s); ¹H NMR (500 MHz, CDCl₃, TMS, δ, p.p.m.): 2.53 (s, 3H, CH₃), 6.62, 6.75, 7.27, 8.20 (4s, 4H, C₅H₄N), 9.59 (s, 1H, NH).

Refinement details

C-bound H atoms were placed at calculated positions and subsequently treated as riding, with C—H = 0.93 (CH, aromatic), 0.97 (CH₂) or 0.96 Å (CH₃), and with U_iso(H) = 1.5U_eq(C) for methyl groups or 1.2U_eq(C) otherwise. N-bound H atoms were located in difference Fourier maps and freely refined isotropically.

Computing details

For both compounds, data collection: SMART (Bruker, 2002); cell refinement: SAINT-Plus (Bruker, 2003); data reduction: SAINT-Plus (Bruker, 2003); program(s) used to solve structure: SIR2004 (Burla et al., 2005); program(s) used to refine structure: SHELXTL (Sheldrick, 2008b); molecular graphics: PLATON (Spek, 2009) and WinGX (Farrugia, 2012); software used to prepare material for publication: publCIF (Westrip, 2010).

Figures

Fig. 1. The asymmetric unit of complex (I), showing the atom-labelling scheme. Displacement ellipsoids are drawn at the 20% probability level. H atoms attached to C atoms have been omitted for clarity. The dashed line indicates the weak intramolecular interaction.

Fig. 2. The asymmetric unit of complex (II), showing the atom-labelling scheme. Displacement ellipsoids are drawn at the 20% probability level. H atoms attached to C atoms have been omitted for clarity. The dashed line indicates the weak intramolecular interaction.

Fig. 3. A partial packing diagram for (I), showing the formation of a [101] sheet. Dashed lines indicate hydrogen bonds. For clarity, H atoms not involved in the motif shown have been omitted. Atoms marked with a hash (#), an asterisk (*) or a dollar sign ($) are at the symmetry positions (x + 1, y, z), (-x + 1, -y + 1, -z + 1) or (x, y, z + 1), respectively.

Fig. 4. A partial packing diagram for (II), showing the formation of a [111] chain. Dashed lines indicate hydrogen bonds. For clarity, H atoms not involved in the motif shown have been omitted. Atoms marked with a hash (#) or an asterisk (*) are at the symmetry positions (-x , -y, -z) or (-x + 1, -y + 1, -z + 1), respectively.

(1) Octacarbonyl(imidazolidinyl-κC²)di-µ₃-sulfido-triiron(II)(2 Fe—Fe)

Crystal data

[Fe3(C3H6N2)S2(CO)8]	Z = 2
Mr = 525.87	F(000) = 520
Triclinic, P1	Dx = 1.900 Mg m^−3
a = 8.7679 (3) Å	Mo Kα radiation, λ = 0.71073 Å
b = 10.0811 (3) Å	Cell parameters from 4141 reflections
c = 11.8549 (15) Å	θ = 1.8–27.5°
α = 78.4565 (14)°	µ = 2.60 mm^−1
β = 72.7596 (13)°	T = 296 K
γ = 67.3315 (14)°	Block, red
V = 919.07 (12) Å^3	0.18 × 0.13 × 0.13 mm

Data collection

Bruker APEXII CCD area-detector diffractometer	4141 independent reflections
Radiation source: fine-focus sealed tube	3710 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.032
φ and ω scans	θmax = 27.5°, θmin = 1.8°
Absorption correction: multi-scan (SADABS; Sheldrick, 2008a)	h = −10→11
Tmin = 0.651, Tmax = 0.708	k = −13→13
7989 measured reflections	l = −15→15

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)] = 0.027	H atoms treated by a mixture of independent and constrained refinement
wR(F^2) = 0.080	w = 1/[σ^2(Fo^2) + (0.0423P)^2 + 0.130P] where P = (Fo^2 + 2Fc^2)/3
S = 1.07	(Δ/σ)max = 0.001
4141 reflections	Δρmax = 0.47 e Å^−3
244 parameters	Δρmin = −0.30 e Å^−3
0 restraints	Extinction correction: SHELXTL (Sheldrick, 2008b), Fc^*=kFc[1+0.001xFc^2λ^3/sin(2θ)]^-1/4
Primary atom site location: structure-invariant direct methods	Extinction coefficient: 0.042 (2)

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
C1	0.6460 (3)	0.6802 (2)	0.7929 (2)	0.0456 (5)
C2	0.6362 (3)	0.6785 (2)	0.5752 (2)	0.0431 (5)
C3	0.3538 (3)	0.2950 (3)	0.8391 (2)	0.0524 (5)
C4	0.6398 (3)	0.0960 (3)	0.9071 (2)	0.0505 (5)
C5	0.6007 (4)	0.0964 (3)	0.6964 (2)	0.0578 (6)
C6	0.9491 (3)	0.4399 (2)	0.6604 (2)	0.0457 (5)
C7	0.9582 (3)	0.2074 (3)	0.5769 (2)	0.0497 (5)
C8	0.9745 (3)	0.1859 (3)	0.7959 (2)	0.0501 (5)
C9	0.3648 (3)	0.6593 (2)	0.75631 (17)	0.0360 (4)
C10	0.0884 (3)	0.7427 (3)	0.8751 (2)	0.0628 (7)
H10A	0.0333	0.8313	0.9138	0.075*
H10B	0.0363	0.6723	0.9185	0.075*
C11	0.0801 (3)	0.7700 (3)	0.7454 (2)	0.0597 (6)
H11A	0.0094	0.7241	0.7313	0.072*
H11B	0.0374	0.8726	0.7204	0.072*
Fe1	0.60847 (3)	0.56686 (3)	0.71292 (2)	0.03342 (10)
Fe2	0.58059 (4)	0.23067 (3)	0.78620 (3)	0.03822 (10)
Fe3	0.84395 (3)	0.30967 (3)	0.70201 (2)	0.03373 (10)
H1N	0.289 (4)	0.694 (3)	0.611 (3)	0.059 (8)*
H2N	0.316 (4)	0.655 (3)	0.922 (3)	0.065 (9)*
N1	0.2597 (2)	0.7028 (3)	0.68538 (18)	0.0577 (6)
N2	0.2706 (3)	0.6871 (3)	0.86465 (17)	0.0559 (5)
O1	0.6707 (3)	0.7485 (2)	0.8464 (2)	0.0759 (6)
O2	0.6545 (3)	0.7497 (2)	0.48830 (17)	0.0669 (5)
O3	0.2091 (3)	0.3422 (3)	0.8727 (2)	0.0841 (7)
O4	0.6810 (3)	0.0131 (2)	0.9822 (2)	0.0787 (6)
O5	0.6102 (4)	0.0136 (2)	0.6405 (3)	0.0954 (8)
O6	1.0352 (2)	0.5076 (2)	0.63203 (19)	0.0673 (5)
O7	1.0296 (3)	0.1421 (3)	0.4979 (2)	0.0853 (7)
O8	1.0564 (3)	0.1054 (2)	0.8551 (2)	0.0825 (6)
S1	0.63208 (6)	0.39129 (5)	0.86325 (4)	0.03702 (13)
S2	0.61240 (6)	0.38781 (5)	0.62498 (4)	0.03564 (12)

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
C1	0.0472 (12)	0.0420 (11)	0.0508 (12)	−0.0178 (9)	−0.0108 (9)	−0.0079 (10)
C2	0.0412 (10)	0.0395 (11)	0.0466 (11)	−0.0145 (9)	−0.0097 (9)	−0.0004 (9)
C3	0.0493 (13)	0.0506 (13)	0.0599 (14)	−0.0245 (11)	−0.0146 (11)	0.0057 (11)
C4	0.0471 (12)	0.0461 (12)	0.0594 (14)	−0.0214 (10)	−0.0169 (10)	0.0090 (11)
C5	0.0678 (16)	0.0417 (12)	0.0671 (16)	−0.0177 (11)	−0.0245 (13)	−0.0025 (11)
C6	0.0449 (11)	0.0449 (12)	0.0462 (12)	−0.0169 (9)	−0.0059 (9)	−0.0076 (9)
C7	0.0484 (12)	0.0488 (13)	0.0496 (12)	−0.0112 (10)	−0.0119 (10)	−0.0116 (10)
C8	0.0480 (12)	0.0466 (12)	0.0555 (13)	−0.0113 (10)	−0.0190 (10)	−0.0055 (10)
C9	0.0412 (10)	0.0346 (9)	0.0330 (9)	−0.0140 (8)	−0.0091 (7)	−0.0034 (7)
C10	0.0430 (12)	0.0763 (18)	0.0519 (14)	−0.0075 (12)	−0.0011 (10)	−0.0114 (13)
C11	0.0410 (12)	0.0719 (17)	0.0625 (15)	−0.0090 (11)	−0.0133 (11)	−0.0192 (13)
Fe1	0.03642 (16)	0.03113 (16)	0.03280 (16)	−0.01207 (11)	−0.00879 (11)	−0.00204 (11)
Fe2	0.04031 (17)	0.03477 (17)	0.04056 (18)	−0.01631 (12)	−0.01102 (12)	0.00266 (12)
Fe3	0.03439 (16)	0.03344 (16)	0.03300 (16)	−0.01115 (11)	−0.00861 (11)	−0.00315 (11)
N1	0.0394 (10)	0.0898 (16)	0.0380 (10)	−0.0116 (10)	−0.0110 (8)	−0.0136 (10)
N2	0.0452 (10)	0.0753 (14)	0.0333 (9)	−0.0032 (10)	−0.0096 (8)	−0.0110 (9)
O1	0.0850 (14)	0.0771 (13)	0.0859 (14)	−0.0387 (11)	−0.0220 (11)	−0.0291 (11)
O2	0.0746 (12)	0.0620 (11)	0.0564 (11)	−0.0284 (10)	−0.0148 (9)	0.0187 (9)
O3	0.0441 (10)	0.0925 (16)	0.1062 (17)	−0.0254 (10)	−0.0095 (10)	0.0012 (13)
O4	0.0773 (13)	0.0734 (13)	0.0841 (14)	−0.0334 (11)	−0.0390 (11)	0.0391 (12)
O5	0.127 (2)	0.0595 (13)	0.1128 (19)	−0.0250 (13)	−0.0442 (16)	−0.0289 (13)
O6	0.0575 (11)	0.0610 (11)	0.0887 (14)	−0.0355 (9)	−0.0045 (10)	−0.0086 (10)
O7	0.0868 (15)	0.0880 (15)	0.0683 (13)	−0.0063 (12)	−0.0097 (11)	−0.0426 (12)
O8	0.0891 (15)	0.0691 (13)	0.0896 (16)	−0.0077 (11)	−0.0591 (13)	0.0076 (11)
S1	0.0424 (3)	0.0394 (3)	0.0278 (2)	−0.0127 (2)	−0.00969 (18)	−0.00136 (19)
S2	0.0422 (3)	0.0358 (2)	0.0311 (2)	−0.01377 (19)	−0.01277 (19)	−0.00166 (18)

Geometric parameters (Å, º)

C1—O1	1.137 (3)	C9—Fe1	1.925 (2)
C1—Fe1	1.795 (2)	C10—N2	1.450 (3)
C2—O2	1.138 (3)	C10—C11	1.525 (4)
C2—Fe1	1.798 (2)	C10—H10A	0.9700
C3—O3	1.143 (3)	C10—H10B	0.9700
C3—Fe2	1.788 (2)	C11—N1	1.467 (3)
C4—O4	1.133 (3)	C11—H11A	0.9700
C4—Fe2	1.812 (2)	C11—H11B	0.9700
C5—O5	1.131 (3)	Fe1—S1	2.2418 (6)
C5—Fe2	1.811 (3)	Fe1—S2	2.2428 (5)
C6—O6	1.142 (3)	Fe1—Fe2	3.4111 (6)
C6—Fe1	2.686 (3)	Fe1—Fe3	2.6176 (4)
C6—Fe3	1.795 (2)	Fe2—S2	2.2479 (6)
C7—O7	1.133 (3)	Fe2—S1	2.2494 (6)
C7—Fe3	1.789 (2)	Fe2—Fe3	2.5876 (4)
C8—O8	1.135 (3)	Fe3—S1	2.2645 (5)
C8—Fe3	1.790 (2)	Fe3—S2	2.2704 (6)
C9—N2	1.322 (3)	N1—H1N	0.85 (3)
C9—N1	1.323 (3)	N2—H2N	0.84 (3)
O1—C1—Fe1	177.8 (2)	C4—Fe2—S2	157.92 (8)
O2—C2—Fe1	179.4 (2)	C3—Fe2—S1	97.66 (8)
O3—C3—Fe2	176.9 (2)	C5—Fe2—S1	163.11 (9)
O4—C4—Fe2	177.9 (2)	C4—Fe2—S1	90.25 (8)
O5—C5—Fe2	178.8 (3)	S2—Fe2—S1	79.92 (2)
O6—C6—Fe3	171.1 (2)	C3—Fe2—Fe3	144.06 (8)
O7—C7—Fe3	179.5 (3)	C5—Fe2—Fe3	107.88 (9)
O8—C8—Fe3	178.7 (2)	C4—Fe2—Fe3	102.73 (7)
N2—C9—N1	107.11 (19)	S2—Fe2—Fe3	55.470 (15)
N2—C9—Fe1	125.81 (16)	S1—Fe2—Fe3	55.298 (15)
N1—C9—Fe1	127.06 (15)	C7—Fe3—C8	93.34 (11)
N2—C10—C11	101.87 (19)	C7—Fe3—C6	97.10 (11)
N2—C10—H10A	111.4	C8—Fe3—C6	97.96 (11)
C11—C10—H10A	111.4	C7—Fe3—S1	157.49 (8)
N2—C10—H10B	111.4	C8—Fe3—S1	90.38 (8)
C11—C10—H10B	111.4	C6—Fe3—S1	104.36 (7)
H10A—C10—H10B	109.3	C7—Fe3—S2	87.25 (8)
N1—C11—C10	101.51 (19)	C8—Fe3—S2	151.60 (8)
N1—C11—H11A	111.5	C6—Fe3—S2	110.16 (8)
C10—C11—H11A	111.5	S1—Fe3—S2	79.13 (2)
N1—C11—H11B	111.5	C7—Fe3—Fe2	102.74 (8)
C10—C11—H11B	111.5	C8—Fe3—Fe2	97.80 (8)
H11A—C11—H11B	109.3	C6—Fe3—Fe2	153.80 (7)
C1—Fe1—C2	93.25 (11)	S1—Fe3—Fe2	54.748 (16)
C1—Fe1—C9	93.83 (9)	S2—Fe3—Fe2	54.655 (16)
C2—Fe1—C9	94.43 (9)	C7—Fe3—Fe1	129.23 (8)
C1—Fe1—S1	91.35 (8)	C8—Fe3—Fe1	136.70 (8)
C2—Fe1—S1	166.56 (7)	C6—Fe3—Fe1	72.29 (7)
C9—Fe1—S1	97.85 (6)	S1—Fe3—Fe1	54.085 (15)
C1—Fe1—S2	167.25 (8)	S2—Fe3—Fe1	54.060 (15)
C2—Fe1—S2	93.01 (7)	Fe2—Fe3—Fe1	81.885 (12)
C9—Fe1—S2	96.75 (6)	C9—N1—C11	114.0 (2)
S1—Fe1—S2	80.19 (2)	C9—N1—H1N	125 (2)
C1—Fe1—Fe3	112.25 (7)	C11—N1—H1N	120.6 (19)
C2—Fe1—Fe3	111.75 (7)	C9—N2—C10	114.58 (19)
C9—Fe1—Fe3	140.93 (6)	C9—N2—H2N	119 (2)
S1—Fe1—Fe3	54.894 (15)	C10—N2—H2N	125 (2)
S2—Fe1—Fe3	55.044 (15)	Fe1—S1—Fe2	98.84 (2)
C3—Fe2—C5	98.20 (12)	Fe1—S1—Fe3	71.021 (18)
C3—Fe2—C4	100.26 (11)	Fe2—S1—Fe3	69.954 (17)
C5—Fe2—C4	92.60 (12)	Fe1—S2—Fe2	98.85 (2)
C3—Fe2—S2	100.61 (8)	Fe1—S2—Fe3	70.896 (17)
C5—Fe2—S2	91.48 (9)	Fe2—S2—Fe3	69.875 (18)

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
C11—H11A···O6^i	0.97	2.59	3.391 (3)	141
N1—H1N···S2^ii	0.85 (3)	2.87 (3)	3.707 (2)	170 (2)
N2—H2N···S1^iii	0.84 (3)	2.64 (3)	3.442 (2)	162 (3)

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

(2) Octacarbonyl(1-methylimidazo[1,5-a]pyridin-3-yl-κC³)di-µ₃-sulfido-triiron(II)(2 Fe—Fe)

Crystal data

[Fe3(C8H8N2)S2(CO)8]	Z = 2
Mr = 587.93	F(000) = 584
Triclinic, P1	Dx = 1.844 Mg m^−3
a = 8.9723 (12) Å	Mo Kα radiation, λ = 0.71073 Å
b = 11.1249 (11) Å	Cell parameters from 4073 reflections
c = 12.0611 (16) Å	θ = 1.9–27.5°
α = 108.477 (5)°	µ = 2.27 mm^−1
β = 107.608 (2)°	T = 296 K
γ = 96.455 (8)°	Block, red-purple
V = 1059.1 (2) Å^3	0.17 × 0.13 × 0.13 mm

Data collection

Bruker APEXII CCD area-detector diffractometer	4784 independent reflections
Radiation source: fine-focus sealed tube	4073 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.032
φ and ω scans	θmax = 27.5°, θmin = 1.9°
Absorption correction: multi-scan (SADABS; Sheldrick, 2008a)	h = −11→11
Tmin = 0.697, Tmax = 0.741	k = −14→14
9290 measured reflections	l = −14→15

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)] = 0.028	Hydrogen site location: inferred from neighbouring sites
wR(F^2) = 0.081	H atoms treated by a mixture of independent and constrained refinement
S = 1.06	w = 1/[σ^2(Fo^2) + (0.0392P)^2 + 0.0391P] where P = (Fo^2 + 2Fc^2)/3
4784 reflections	(Δ/σ)max = 0.001
285 parameters	Δρmax = 0.32 e Å^−3
0 restraints	Δρmin = −0.29 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
C1	0.3574 (3)	0.6550 (2)	0.6344 (2)	0.0530 (5)
C2	0.4721 (3)	0.8911 (2)	0.7945 (2)	0.0529 (5)
C3	0.9653 (3)	0.7421 (2)	0.6719 (3)	0.0577 (6)
C4	0.9925 (3)	0.5436 (2)	0.7588 (2)	0.0501 (5)
C5	1.1142 (3)	0.7818 (2)	0.9197 (2)	0.0537 (6)
C6	0.5227 (3)	0.6540 (2)	0.9021 (2)	0.0558 (6)
C7	0.8131 (3)	0.7938 (3)	1.0615 (2)	0.0631 (6)
C8	0.7822 (3)	0.5441 (2)	0.9280 (2)	0.0562 (6)
C9	0.5835 (2)	0.80764 (19)	0.5909 (2)	0.0428 (4)
C10	0.6107 (4)	0.7103 (3)	0.2754 (3)	0.0819 (9)
H10A	0.6841	0.6539	0.2783	0.123*
H10B	0.6404	0.7712	0.2401	0.123*
H10C	0.5036	0.6594	0.2245	0.123*
C11	0.6171 (3)	0.7820 (2)	0.4038 (2)	0.0510 (5)
C12	0.6796 (3)	0.9107 (2)	0.4800 (2)	0.0471 (5)
C13	0.7593 (3)	1.0211 (2)	0.4681 (2)	0.0596 (6)
H13	0.7797	1.0131	0.3952	0.072*
C14	0.8049 (3)	1.1370 (2)	0.5628 (3)	0.0656 (7)
H14	0.8564	1.2098	0.5553	0.079*
C15	0.7747 (3)	1.1491 (2)	0.6750 (3)	0.0636 (7)
H15	0.8046	1.2305	0.7390	0.076*
C16	0.7043 (3)	1.0460 (2)	0.6904 (2)	0.0530 (5)
H16	0.6881	1.0554	0.7651	0.064*
Fe1	0.55420 (3)	0.75865 (3)	0.72526 (3)	0.04104 (9)
Fe2	0.92683 (3)	0.69495 (3)	0.79106 (3)	0.03959 (9)
Fe3	0.72209 (4)	0.68388 (3)	0.90112 (3)	0.04242 (9)
H1N	0.512 (3)	0.644 (3)	0.443 (2)	0.063 (7)*
N1	0.5624 (2)	0.72524 (17)	0.47447 (18)	0.0475 (4)
N2	0.6555 (2)	0.92438 (16)	0.59346 (16)	0.0435 (4)
O1	0.2344 (2)	0.5881 (2)	0.5776 (2)	0.0844 (6)
O2	0.4161 (3)	0.9707 (2)	0.83834 (19)	0.0780 (6)
O3	0.9860 (3)	0.7744 (3)	0.5966 (2)	0.0995 (8)
O4	1.0315 (2)	0.44821 (17)	0.7375 (2)	0.0792 (6)
O5	1.2307 (2)	0.8352 (2)	1.0017 (2)	0.0851 (6)
O6	0.4007 (2)	0.6263 (2)	0.9108 (2)	0.0825 (6)
O7	0.8690 (3)	0.8659 (3)	1.16251 (19)	0.0966 (7)
O8	0.8154 (3)	0.4526 (2)	0.9421 (2)	0.0831 (6)
S1	0.66779 (6)	0.58725 (5)	0.69227 (5)	0.04116 (12)
S2	0.80693 (6)	0.85570 (5)	0.85743 (5)	0.04302 (13)

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
C1	0.0439 (13)	0.0651 (14)	0.0575 (14)	0.0143 (11)	0.0251 (11)	0.0254 (12)
C2	0.0481 (13)	0.0652 (14)	0.0545 (14)	0.0210 (11)	0.0234 (11)	0.0263 (11)
C3	0.0543 (14)	0.0683 (14)	0.0746 (17)	0.0245 (11)	0.0409 (13)	0.0371 (13)
C4	0.0436 (12)	0.0458 (11)	0.0604 (14)	0.0096 (9)	0.0219 (11)	0.0161 (10)
C5	0.0474 (13)	0.0471 (11)	0.0642 (15)	0.0168 (10)	0.0247 (12)	0.0112 (11)
C6	0.0510 (14)	0.0683 (14)	0.0610 (15)	0.0207 (11)	0.0311 (12)	0.0279 (12)
C7	0.0540 (15)	0.0873 (18)	0.0514 (15)	0.0159 (13)	0.0237 (12)	0.0260 (13)
C8	0.0546 (14)	0.0707 (15)	0.0619 (15)	0.0217 (12)	0.0298 (12)	0.0376 (13)
C9	0.0419 (11)	0.0435 (10)	0.0490 (12)	0.0133 (8)	0.0193 (9)	0.0208 (9)
C10	0.113 (3)	0.0728 (17)	0.0566 (16)	−0.0012 (16)	0.0441 (17)	0.0141 (13)
C11	0.0573 (14)	0.0519 (12)	0.0468 (12)	0.0086 (10)	0.0217 (11)	0.0206 (10)
C12	0.0469 (12)	0.0502 (11)	0.0499 (12)	0.0114 (9)	0.0188 (10)	0.0243 (10)
C13	0.0632 (15)	0.0601 (14)	0.0643 (16)	0.0082 (11)	0.0243 (12)	0.0349 (13)
C14	0.0743 (17)	0.0523 (13)	0.0728 (17)	0.0034 (12)	0.0250 (14)	0.0315 (13)
C15	0.0726 (17)	0.0421 (11)	0.0706 (17)	0.0085 (11)	0.0231 (14)	0.0178 (11)
C16	0.0587 (14)	0.0457 (11)	0.0523 (13)	0.0137 (10)	0.0196 (11)	0.0152 (10)
Fe1	0.03886 (17)	0.04684 (16)	0.04599 (18)	0.01386 (12)	0.02065 (14)	0.02175 (13)
Fe2	0.03811 (17)	0.03823 (15)	0.04785 (18)	0.01034 (12)	0.02211 (13)	0.01607 (13)
Fe3	0.04096 (18)	0.05190 (17)	0.04507 (18)	0.01455 (13)	0.02267 (14)	0.02356 (14)
N1	0.0553 (11)	0.0398 (9)	0.0481 (10)	0.0056 (8)	0.0216 (9)	0.0162 (8)
N2	0.0449 (10)	0.0437 (9)	0.0463 (10)	0.0118 (7)	0.0182 (8)	0.0201 (8)
O1	0.0480 (11)	0.0979 (15)	0.0896 (15)	0.0003 (10)	0.0192 (11)	0.0228 (12)
O2	0.0806 (13)	0.0825 (13)	0.0837 (14)	0.0466 (11)	0.0442 (12)	0.0239 (11)
O3	0.1075 (18)	0.140 (2)	0.1192 (19)	0.0520 (16)	0.0793 (16)	0.0906 (18)
O4	0.0713 (13)	0.0482 (10)	0.1129 (17)	0.0243 (9)	0.0344 (12)	0.0185 (10)
O5	0.0562 (12)	0.0757 (12)	0.0828 (14)	0.0138 (10)	0.0085 (11)	−0.0070 (11)
O6	0.0568 (11)	0.1098 (16)	0.1024 (16)	0.0223 (10)	0.0504 (11)	0.0453 (13)
O7	0.0882 (16)	0.1288 (19)	0.0493 (12)	0.0114 (14)	0.0202 (11)	0.0117 (12)
O8	0.0934 (15)	0.0851 (13)	0.1061 (17)	0.0414 (11)	0.0459 (13)	0.0644 (13)
S1	0.0416 (3)	0.0386 (2)	0.0458 (3)	0.0071 (2)	0.0193 (2)	0.0163 (2)
S2	0.0436 (3)	0.0380 (2)	0.0498 (3)	0.0124 (2)	0.0202 (2)	0.0149 (2)

Geometric parameters (Å, º)

C1—O1	1.129 (3)	C10—H10C	0.9600
C1—Fe1	1.795 (2)	C11—C12	1.372 (3)
C2—O2	1.132 (3)	C11—N1	1.376 (3)
C2—Fe1	1.802 (2)	C12—N2	1.414 (3)
C3—O3	1.133 (3)	C12—C13	1.420 (3)
C3—Fe2	1.788 (2)	C13—C14	1.342 (4)
C4—O4	1.132 (3)	C13—H13	0.9300
C4—Fe2	1.811 (2)	C14—C15	1.428 (4)
C5—O5	1.134 (3)	C14—H14	0.9300
C5—Fe2	1.809 (3)	C15—C16	1.339 (3)
C6—O6	1.149 (3)	C15—H15	0.9300
C6—Fe1	2.802 (2)	C16—N2	1.394 (3)
C6—Fe3	1.787 (2)	C16—H16	0.9300
C7—O7	1.140 (3)	Fe1—S2	2.2406 (7)
C7—Fe3	1.796 (3)	Fe1—S1	2.2437 (6)
C8—O8	1.141 (3)	Fe1—Fe2	3.4050 (6)
C8—Fe3	1.793 (2)	Fe1—Fe3	2.6319 (5)
C9—N1	1.354 (3)	Fe2—S2	2.2456 (6)
C9—N2	1.371 (2)	Fe2—S1	2.2473 (7)
C9—Fe1	1.944 (2)	Fe2—Fe3	2.5846 (5)
C10—C11	1.480 (3)	Fe3—S2	2.2505 (6)
C10—H10A	0.9600	Fe3—S1	2.2719 (7)
C10—H10B	0.9600	N1—H1N	0.86 (3)
O1—C1—Fe1	178.9 (2)	S1—Fe1—Fe3	54.850 (17)
O2—C2—Fe1	177.2 (2)	C3—Fe2—C5	99.42 (12)
O3—C3—Fe2	177.7 (2)	C3—Fe2—C4	98.80 (11)
O4—C4—Fe2	179.1 (2)	C5—Fe2—C4	92.05 (10)
O5—C5—Fe2	178.8 (3)	C3—Fe2—S2	96.58 (8)
O6—C6—Fe3	172.1 (2)	C5—Fe2—S2	91.21 (7)
O7—C7—Fe3	178.3 (3)	C4—Fe2—S2	163.53 (7)
O8—C8—Fe3	177.6 (2)	C3—Fe2—S1	101.03 (9)
N1—C9—N2	102.41 (17)	C5—Fe2—S1	158.50 (8)
N1—C9—Fe1	126.24 (14)	C4—Fe2—S1	91.32 (7)
N2—C9—Fe1	130.37 (16)	S2—Fe2—S1	79.95 (2)
C11—C10—H10A	109.5	C3—Fe2—Fe3	143.35 (8)
C11—C10—H10B	109.5	C5—Fe2—Fe3	103.38 (8)
H10A—C10—H10B	109.5	C4—Fe2—Fe3	108.57 (7)
C11—C10—H10C	109.5	S2—Fe2—Fe3	55.001 (17)
H10A—C10—H10C	109.5	S1—Fe2—Fe3	55.565 (18)
H10B—C10—H10C	109.5	C6—Fe3—C8	99.40 (11)
C12—C11—N1	105.01 (19)	C6—Fe3—C7	95.81 (12)
C12—C11—C10	130.7 (2)	C8—Fe3—C7	95.94 (12)
N1—C11—C10	124.2 (2)	C6—Fe3—S2	118.87 (8)
C11—C12—N2	106.24 (17)	C8—Fe3—S2	141.52 (8)
C11—C12—C13	134.6 (2)	C7—Fe3—S2	84.66 (9)
N2—C12—C13	119.2 (2)	C6—Fe3—S1	99.32 (8)
C14—C13—C12	119.4 (2)	C8—Fe3—S1	91.40 (8)
C14—C13—H13	120.3	C7—Fe3—S1	161.87 (9)
C12—C13—H13	120.3	S2—Fe3—S1	79.33 (2)
C13—C14—C15	120.3 (2)	C6—Fe3—Fe2	153.00 (8)
C13—C14—H14	119.9	C8—Fe3—Fe2	89.34 (7)
C15—C14—H14	119.9	C7—Fe3—Fe2	108.72 (8)
C16—C15—C14	121.6 (2)	S2—Fe3—Fe2	54.822 (16)
C16—C15—H15	119.2	S1—Fe3—Fe2	54.672 (17)
C14—C15—H15	119.2	C6—Fe3—Fe1	76.04 (8)
C15—C16—N2	119.3 (2)	C8—Fe3—Fe1	142.49 (9)
C15—C16—H16	120.3	C7—Fe3—Fe1	121.48 (9)
N2—C16—H16	120.3	S2—Fe3—Fe1	53.950 (18)
C1—Fe1—C2	91.72 (11)	S1—Fe3—Fe1	53.854 (17)
C1—Fe1—C9	95.87 (10)	Fe2—Fe3—Fe1	81.492 (15)
C2—Fe1—C9	99.14 (10)	C9—N1—C11	114.84 (18)
C1—Fe1—S2	167.63 (8)	C9—N1—H1N	123.7 (17)
C2—Fe1—S2	94.02 (8)	C11—N1—H1N	121.3 (17)
C9—Fe1—S2	94.02 (7)	C9—N2—C16	128.35 (19)
C1—Fe1—S1	91.33 (8)	C9—N2—C12	111.49 (17)
C2—Fe1—S1	163.43 (8)	C16—N2—C12	120.16 (18)
C9—Fe1—S1	96.75 (6)	Fe1—S1—Fe2	98.60 (2)
S2—Fe1—S1	80.14 (2)	Fe1—S1—Fe3	71.297 (19)
C1—Fe1—Fe3	113.41 (8)	Fe2—S1—Fe3	69.763 (19)
C2—Fe1—Fe3	109.23 (8)	Fe1—S2—Fe2	98.75 (2)
C9—Fe1—Fe3	137.75 (6)	Fe1—S2—Fe3	71.75 (2)
S2—Fe1—Fe3	54.301 (16)	Fe2—S2—Fe3	70.177 (19)

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
N1—H1N···S1^i	0.86 (3)	2.59 (3)	3.4404 (19)	168 (2)
C16—H16···O5^ii	0.93	2.51	3.359 (3)	151

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