Co-crystallized cis and trans isomers of dichloro­bis(2-picolylamine)iron(II)

The octa­hedral cis and trans isomers of dichloro­bis(2-picolyl­amine)iron(II), [FeCl₂(C₆H₈N₂)₂], co-crystallize in a 1:1 ratio. The cis isomer lies on a twofold axis, whereas the trans isomer lies on an inversion centre. The structure is fully ordered, with both Fe atoms in a pure high-spin state. The Fe, Cl and N(H₂) atoms of both isomers lie in the same plane, allowing all Cl and amine H atoms to be engaged in extensive two-dimensional hydrogen bonding. The hydrogen-bonded layers are inter­connected through π–π inter­actions between the pyridine rings. Searches in the Cambridge Structural Database uncover very few examples of such isomer co-existence.

S1. Comment

Preparation of the methanol, ethanol, 1-propanol, 2-propanol, tert-butanol and allyl-alcohol solvates of [tris(2-picolylamine)iron(II)]dichloride from the corresponding alcohol solutions is straightforward (Hostettler et al., 2004). An attempt to synthesize the 1-butanol solvate, however, resulted in co-crystals of the cis and trans isomers of the title compound, (I), dichloro-bis(2-picolylamine)iron(II) (Fig. 1).

The cis-configured molecule has a twofold symmetry axis, while the trans isomer is located on an inversion centre. The Fe—N bond distances indicate that both Fe atoms are in a high-spin state. Nonetheless, chemically comparable Fe–ligand bond lengths differ slightly between the two isomers (Table 1). The Fe—NH₂ bonds lengthen by 0.030 (2) Å on going from the trans to the cis isomer. This change is almost compensated for by a corresponding decrease of the Fe—Cl bond length by 0.033 (1) Å. A larger difference of 0.045 (2) Å is found for the Fe—N(py) bonds, with the distances in the cis isomer being longer.

The only other FeN₄L₂ compounds for which at least an approximate comparison can be made are bis{trans-isothiocyanato[4-methylphenyl-3,5 -bis(pyridin-2-yl)-1,2,4-triazole]}iron(II) and bis{cis-isothiocyanato[3-methylphenyl-3,5-bis(pyridin-2-yl)-1,2,4- triazole]}iron(II) [Cambridge Structural Database (CSD; Allen, 2002) refcodes FADVUC and FADWAJ; Zhu et al., 2002). In this case, the trans and cis isomers actually differ in the substitution of the peripheral phenyl rings, but the variation in the coordination geometry shows an effect similar to that observed in (I), the Fe—NCS distances in the trans isomer being longer by 0.063 (3) Å than those in the cis isomer. This difference is compensated for by a decrease in the Fe—N(triazole) bond length of 0.056 (3) Å. In contrast with (I), the Fe—N(py) distances are almost the same in these two isomers. The structural cis/trans influence has been studied in detail elsewhere (Pidcock et al., 1966; Coe & Glenwright, 2000; Gupta et al., 2000).

In the trans isomer of (I), symmetry dictates an N(py)—Fe—N(py) angle of 180°, but in the cis form the corresponding angle is smaller by about 17°. The dihedral angles between the two pyridine rings are 0 and 72.9 (1)° in the trans and cis isomers, respectively, and 50° on average in the tris(picolylamine)iron(II) series of solvates (Hostettler et al., 2004). The trend in conformational angles correlates with the observed lengthening of the Fe—N(py) distances from the trans to the cis isomer of (I) (Table 1), while the average Fe—N(py) trans distance in the high-spin tris(picolylamine)iron(II) complexes is intermediate, at 2.21 Å (Chernyshov et al., 2003; Hostettler et al., 2004).

The crystal structure of (I) may be considered as being built from layers of cis isomers alternating with layers of trans isomers along the (100) direction. Alternatively, the structure may be viewed in terms of layers parallel to the (101) planes. In these layers, cis and trans isomers are connected through N—H···Cl hydrogen bonds, which form a two-dimensional network of `tiles' in the shape of eight-membered rings, four around each Fe atom (Fig. 2). The hydrogen-bonded layers are stacked through π–π interactions, with typical centroid-to-centroid distances of 3.619 (1) Å (Fig. 3, Table 2).

As discussed in the Experimental section, searches in the CSD (version 5.25, November 2003 update with 298097 entries) for other co-crystals of cis- and trans-MN₄L₂ complexes have revealed only one other example with an ordered crystal structure, namely dichlorobis(2-methyl-1,3-propanediamine)cobalt(III) chloride methanol solvate. The trans isomer is located on an inversion centre, whereas the cis isomer lies in a general position (CSD refcode CAWPOF; Mather et al., 1983; M is any transition metal ion, N is any type of nitrogen ligand, and L is a halogen, O, S, N or P atom).

The rare occurrence of the cis/trans co-crystallization phenomenon may be understood intuitively. Firstly, the two isomers are expected to have different energies and also, most probably, different synthesis conditions, and are therefore not necessarily present simultaneously during synthesis and subsequent crystallization. Secondly, co-crystallization must be more favourable in thermodynamic and/or kinetic terms than crystallization of the individual isomers.

S2. Experimental

Compound (I) was synthesized as follows. A mixture of 2-picolylamine (1-pyridine-2-ylmethanamine; 2.4 mmol) and FeCl₂·4H₂O (0.7 mmol) in 1-butanol (120 ml) was left standing with partial reflux under an N₂ atmosphere at ~355 K for 5 d. A minute quantity of yellow crystals was found in the round flask just below the surface of the reaction liquid, and these were shown to contain a 1:1 cis and trans mixture of (I). Exposed to the air, the crystals deteriorate within hours.

The searches of the CSD were carried out as follows. The search for MN₄L₂ fragments with any transition metal (M) coordinated to four N atoms and to any two other atoms (L), with M–ligand bond type `ANY', resulted in 11769 hits, while a search for crystal structures with Z' ≥ 2 with reported coordinates resulted in 21665 hits. Combining the two sets led to 605 hits. Only two of these show both the cis and trans isomers in the unit cell, namely refcodes CAWPOF (Mather et al., 1983), discussed above, and UCAHUB (Kozmin et al., 2001), (propylene-1,2-diamine-N,N')dichlorodinitroplatinum(IV). The latter is disordered, and both sites in the asymmetric part of the unit cell have been modelled with a superposition of cis and trans isomers. Therefore, this crystal structure cannot be considered an unambiguous case of cis/trans co-crystallization.

The CSD was also searched for Fe^II–N₄L₂ complexes for which the cis and trans isomers are found in different crystals (L is any non-cyclic ligand atom). Among these 338 crystal structures, there are three pairs of cis and transisomers. RUHLUB and RUHMAI (Guilard et al., 1997) refer to the trans and cis isomers of the complex dichloro(1,4,8,11-tetraazacyclotetradecane)iron(III), respectively. These were obtained in the same synthesis, but the trans isomer crystallizes with a tetrachloroiron(III) anion, while the cis isomer has a chloride counterion. FEVKAS and FEVMIC (Meyer et al., 1999) refer to the trans and cis isomers of the complex diazido(1,4,8,11-tetra-azacyclotetradecane)iron(III), respectively. The trans isomer crystallizes with a hexafluorophosphate and the cis isomer with a perchlorate anion. Both compounds were obtained from the same reaction mixture but at different temperatures, 323 and 291 K, respectively. FADVUC and FADWAJ (Zhu et al., 2002), discussed above, refer to compounds with the same chemical sum formulae, with trans and cis coordination geometry, but with ligands differing in the position of the methyl group on the phenyl rings. Finally, we are aware of the analogous example of dithiocyanatobis[4 − p(or m)-methylphenyl-3,5-bis(pyridin-2-yl)-1,2,4- triazole]iron(II), which displays a Cd^II–O₄L₂ coordination geometry (Soldatov et al., 2001).

S3. Refinement

H atoms were located geometrically and treated as riding, with C—H distances in the range 0.95–0.99 Å and N—H distances of 0.92 Å, and with U_iso(H) = 1.2U_eq(C,N). [Please check added text and correct as necessary.]

Computing details

Data collection: SMART (Bruker, 1999); cell refinement: SAINT (Bruker, 2001); data reduction: SAINT; program(s) used to solve structure: SHELXS97 (Sheldrick, 1997); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: SHELXTL (Sheldrick, 2000); software used to prepare material for publication: PLATON (Spek, 2003).

Figures

	Fig. 1. The cis and trans isomers of (I). Atom Fe1 sits on an inversion centre and atom Fe2 on a twofold axis. Anisotropic displacement parameters are drawn at the 50% probability level. [Symmetry codes: (i) 1/2 − x, 3/2 − y, −z, (ii) 1 − x, y, 1/2 − z.]
	Fig. 2. The chessboard layer of hydrogen-bonded complexes, viewed along the (101) direction.
	Fig. 3. The structure of (I), viewed along the b axis.

cis/trans-dichlorobis(2-picolylamine)iron(II)

Crystal data

[FeCl2(C6H8N2)2]	F(000) = 1408
Mr = 343.04	Dx = 1.591 Mg m^−3
Monoclinic, C2/c	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -C 2yc	Cell parameters from 2031 reflections
a = 26.626 (2) Å	θ = 2.6–27.9°
b = 6.6818 (5) Å	µ = 1.42 mm^−1
c = 16.8821 (13) Å	T = 150 K
β = 107.565 (1)°	Irregular prism, yellow
V = 2863.5 (4) Å^3	0.35 × 0.25 × 0.18 mm
Z = 8

Data collection

Siemens SMART 1K CCD area-detector diffractometer	3276 independent reflections
Radiation source: normal-focus sealed tube	2676 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.025
ω scans	θmax = 28.1°, θmin = 2.5°
Absorption correction: multi-scan (SADABS; Sheldrick, 2003)	h = −33→34
Tmin = 0.671, Tmax = 0.775	k = −8→8
14985 measured reflections	l = −22→21

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)] = 0.027	Hydrogen site location: inferred from neighbouring sites
wR(F^2) = 0.063	H-atom parameters constrained
S = 1.04	w = 1/[σ^2(Fo^2) + (0.0302P)^2 + 2.1803P] where P = (Fo^2 + 2Fc^2)/3
3276 reflections	(Δ/σ)max = 0.001
174 parameters	Δρmax = 0.39 e Å^−3
0 restraints	Δρmin = −0.23 e Å^−3

Special details

Experimental. Comment on transmission values: The program SADABS (v2.06) outputs the ratio of minimum to maximum apparent transmission (0.86590). We have set T(max) to the expected value, i.e. exp(-r_min*mu) and we calculate T(min) from the minimum to maximum apparent transmission given by SADABS.

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	0.2500	0.7500	0.0000	0.01732 (9)
Cl1	0.312318 (16)	1.01509 (6)	0.07476 (2)	0.02246 (10)
N1	0.31203 (5)	0.5213 (2)	0.03628 (8)	0.0204 (3)
H1A	0.3406	0.5726	0.0766	0.024*
H1B	0.2997	0.4129	0.0584	0.024*
C1	0.18185 (7)	0.8894 (3)	0.10330 (10)	0.0199 (3)
N2	0.21563 (5)	0.7419 (2)	0.10159 (8)	0.0194 (3)
C2	0.15885 (7)	0.9035 (3)	0.16724 (11)	0.0243 (4)
H2	0.1347	1.0082	0.1671	0.029*
C3	0.17136 (7)	0.7647 (3)	0.23059 (11)	0.0264 (4)
H3	0.1561	0.7731	0.2746	0.032*
C4	0.20654 (7)	0.6129 (3)	0.22916 (11)	0.0282 (4)
H4	0.2162	0.5161	0.2723	0.034*
C5	0.22709 (7)	0.6062 (3)	0.16351 (11)	0.0255 (4)
H5	0.2506	0.5004	0.1618	0.031*
C6	0.32876 (7)	0.4556 (3)	−0.03536 (11)	0.0240 (4)
H6A	0.3099	0.3307	−0.0582	0.029*
H6B	0.3669	0.4254	−0.0162	0.029*
Fe2	0.5000	0.19638 (5)	0.2500	0.01782 (9)
Cl2	0.436406 (17)	0.44402 (6)	0.16968 (3)	0.02504 (11)
N3	0.44029 (6)	−0.0442 (2)	0.20511 (9)	0.0216 (3)
H3A	0.4108	0.0094	0.1675	0.026*
H3B	0.4537	−0.1399	0.1780	0.026*
N4	0.53275 (6)	0.1473 (2)	0.14522 (9)	0.0204 (3)
C7	0.59057 (7)	−0.0476 (3)	0.09209 (11)	0.0269 (4)
H7	0.6141	−0.1575	0.0991	0.032*
C8	0.58075 (7)	0.0711 (3)	0.02259 (11)	0.0287 (4)
H8	0.5973	0.0451	−0.0189	0.034*
C9	0.54614 (8)	0.2294 (3)	0.01458 (11)	0.0303 (4)
H9	0.5383	0.3139	−0.0328	0.036*
C10	0.52328 (8)	0.2623 (3)	0.07659 (11)	0.0275 (4)
H10	0.4996	0.3717	0.0707	0.033*
C11	0.56592 (7)	−0.0067 (3)	0.15230 (10)	0.0216 (4)
C12	0.57514 (8)	−0.1402 (3)	0.22693 (11)	0.0293 (4)
H12A	0.5547	−0.2652	0.2104	0.035*
H12B	0.6129	−0.1763	0.2473	0.035*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
Fe1	0.01793 (18)	0.01892 (18)	0.01616 (17)	0.00234 (13)	0.00671 (13)	0.00080 (13)
Cl1	0.0219 (2)	0.0240 (2)	0.0218 (2)	−0.00264 (16)	0.00713 (17)	−0.00366 (16)
N1	0.0209 (7)	0.0225 (8)	0.0191 (7)	0.0016 (6)	0.0080 (6)	0.0011 (6)
C1	0.0196 (8)	0.0209 (9)	0.0190 (8)	−0.0029 (7)	0.0056 (7)	−0.0032 (7)
N2	0.0186 (7)	0.0227 (7)	0.0167 (7)	0.0004 (6)	0.0049 (6)	0.0005 (6)
C2	0.0251 (9)	0.0253 (10)	0.0247 (9)	−0.0022 (8)	0.0111 (7)	−0.0053 (7)
C3	0.0269 (10)	0.0352 (11)	0.0187 (8)	−0.0071 (8)	0.0095 (7)	−0.0044 (7)
C4	0.0270 (10)	0.0370 (11)	0.0200 (9)	0.0005 (8)	0.0063 (7)	0.0074 (8)
C5	0.0221 (9)	0.0318 (10)	0.0223 (8)	0.0041 (8)	0.0059 (7)	0.0044 (8)
C6	0.0296 (10)	0.0201 (9)	0.0257 (9)	0.0046 (7)	0.0138 (8)	0.0001 (7)
Fe2	0.02003 (19)	0.01700 (18)	0.01772 (17)	0.000	0.00764 (14)	0.000
Cl2	0.0243 (2)	0.0237 (2)	0.0262 (2)	0.00658 (17)	0.00630 (17)	0.00133 (17)
N3	0.0233 (8)	0.0232 (8)	0.0190 (7)	−0.0010 (6)	0.0074 (6)	−0.0034 (6)
N4	0.0213 (7)	0.0206 (7)	0.0202 (7)	0.0023 (6)	0.0078 (6)	0.0014 (6)
C7	0.0288 (10)	0.0271 (10)	0.0266 (9)	0.0063 (8)	0.0111 (8)	−0.0033 (8)
C8	0.0301 (10)	0.0371 (11)	0.0225 (9)	−0.0008 (8)	0.0133 (8)	−0.0032 (8)
C9	0.0347 (11)	0.0354 (11)	0.0230 (9)	0.0032 (8)	0.0120 (8)	0.0085 (8)
C10	0.0306 (10)	0.0289 (10)	0.0252 (9)	0.0089 (8)	0.0119 (8)	0.0078 (8)
C11	0.0238 (9)	0.0211 (9)	0.0203 (8)	−0.0002 (7)	0.0073 (7)	−0.0013 (7)
C12	0.0403 (11)	0.0247 (10)	0.0264 (9)	0.0115 (8)	0.0154 (8)	0.0048 (8)

Geometric parameters (Å, º)

Fe1—N1	2.1969 (14)	C6—C1^i	1.508 (2)
Fe1—N2	2.1746 (13)	C6—H6A	0.9900
Fe2—N3	2.2267 (14)	C6—H6B	0.9900
Fe2—N4	2.2198 (14)	Fe2—N4^ii	2.2198 (14)
Fe1—N2^i	2.1746 (13)	Fe2—N3^ii	2.2267 (14)
Fe1—N1^i	2.1969 (14)	Fe2—Cl2^ii	2.4613 (5)
Fe1—Cl1	2.4939 (4)	N3—C12^ii	1.477 (2)
Fe1—Cl1^i	2.4939 (4)	N3—H3A	0.9200
Fe2—Cl2	2.4613 (5)	N3—H3B	0.9200
N1—C6	1.476 (2)	N4—C11	1.338 (2)
N1—H1A	0.9200	N4—C10	1.350 (2)
N1—H1B	0.9200	C7—C8	1.375 (3)
C1—N2	1.340 (2)	C7—C11	1.393 (2)
C1—C2	1.396 (2)	C7—H7	0.9500
C1—C6^i	1.508 (2)	C8—C9	1.382 (3)
N2—C5	1.347 (2)	C8—H8	0.9500
C2—C3	1.378 (3)	C9—C10	1.378 (3)
C2—H2	0.9500	C9—H9	0.9500
C3—C4	1.386 (3)	C10—H10	0.9500
C3—H3	0.9500	C11—C12	1.502 (2)
C4—C5	1.377 (2)	C12—N3^ii	1.477 (2)
C4—H4	0.9500	C12—H12A	0.9900
C5—H5	0.9500	C12—H12B	0.9900
N1—Fe1—N1^i	180.00 (7)	N3—Fe2—N3^ii	87.58 (8)
N1—Fe1—Cl1	91.35 (4)	N3—Fe2—Cl2^ii	167.06 (4)
N1^i—Fe1—Cl1	88.65 (4)	N3—Fe2—Cl2	89.77 (4)
N2—Fe1—N1	102.87 (5)	N4^ii—Fe2—N3	75.68 (5)
N2^i—Fe1—N1	77.13 (5)	N4—Fe2—N3	91.94 (5)
N2—Fe1—N1^i	77.13 (5)	N4^ii—Fe2—N3^ii	91.94 (5)
N2^i—Fe1—N1^i	102.87 (5)	N4—Fe2—N3^ii	75.68 (5)
N2—Fe1—Cl1	89.57 (4)	N4^ii—Fe2—N4	162.99 (8)
N2^i—Fe1—Cl1	90.43 (4)	N4^ii—Fe2—Cl2^ii	91.76 (4)
N2—Fe1—Cl1^i	90.43 (4)	N4—Fe2—Cl2^ii	99.68 (4)
N2^i—Fe1—Cl1^i	89.57 (4)	N3^ii—Fe2—Cl2^ii	89.77 (4)
N2—Fe1—N2^i	180.00 (6)	N4^ii—Fe2—Cl2	99.68 (4)
N1—Fe1—Cl1^i	88.65 (4)	N4—Fe2—Cl2	91.76 (4)
N1^i—Fe1—Cl1^i	91.35 (4)	N3^ii—Fe2—Cl2	167.06 (4)
Cl1—Fe1—Cl1^i	180.000 (17)	Cl2^ii—Fe2—Cl2	95.51 (2)
C6—N1—Fe1	111.47 (10)	C12^ii—N3—Fe2	112.74 (10)
C6—N1—H1A	109.3	C12^ii—N3—H3A	109.0
Fe1—N1—H1A	109.3	Fe2—N3—H3A	109.0
C6—N1—H1B	109.3	C12^ii—N3—H3B	109.0
Fe1—N1—H1B	109.3	Fe2—N3—H3B	109.0
H1A—N1—H1B	108.0	H3A—N3—H3B	107.8
N2—C1—C2	121.36 (16)	C11—N4—C10	117.53 (14)
N2—C1—C6^i	117.50 (14)	C11—N4—Fe2	116.76 (11)
C2—C1—C6^i	121.10 (15)	C10—N4—Fe2	125.69 (12)
C1—N2—C5	118.32 (14)	C8—C7—C11	119.96 (17)
C1—N2—Fe1	116.34 (11)	C8—C7—H7	120.0
C5—N2—Fe1	125.30 (12)	C11—C7—H7	120.0
C3—C2—C1	119.66 (17)	C7—C8—C9	118.33 (16)
C3—C2—H2	120.2	C7—C8—H8	120.8
C1—C2—H2	120.2	C9—C8—H8	120.8
C2—C3—C4	119.03 (16)	C10—C9—C8	118.84 (17)
C2—C3—H3	120.5	C10—C9—H9	120.6
C4—C3—H3	120.5	C8—C9—H9	120.6
C5—C4—C3	118.22 (17)	N4—C10—C9	123.37 (17)
C5—C4—H4	120.9	N4—C10—H10	118.3
C3—C4—H4	120.9	C9—C10—H10	118.3
N2—C5—C4	123.40 (17)	N4—C11—C7	121.97 (16)
N2—C5—H5	118.3	N4—C11—C12	117.89 (14)
C4—C5—H5	118.3	C7—C11—C12	120.12 (16)
N1—C6—C1^i	112.64 (14)	N3^ii—C12—C11	112.36 (14)
N1—C6—H6A	109.1	N3^ii—C12—H12A	109.1
C1^i—C6—H6A	109.1	C11—C12—H12A	109.1
N1—C6—H6B	109.1	N3^ii—C12—H12B	109.1
C1^i—C6—H6B	109.1	C11—C12—H12B	109.1
H6A—C6—H6B	107.8	H12A—C12—H12B	107.9
N2—Fe1—N1—C6	161.43 (11)	N4—Fe2—N3—C12^ii	151.49 (12)
N2^i—Fe1—N1—C6	−18.57 (11)	Cl2^ii—Fe2—N3—C12^ii	−2.4 (3)
Cl1—Fe1—N1—C6	−108.69 (11)	Cl2—Fe2—N3—C12^ii	−116.75 (12)
Cl1^i—Fe1—N1—C6	71.31 (11)	N3—Fe2—N4—C11	−79.96 (13)
C2—C1—N2—C5	0.0 (2)	N3^ii—Fe2—N4—C11	7.05 (12)
C6^i—C1—N2—C5	177.58 (15)	Cl2^ii—Fe2—N4—C11	94.31 (12)
C2—C1—N2—Fe1	−177.67 (13)	Cl2—Fe2—N4—C11	−169.79 (12)
C6^i—C1—N2—Fe1	0.0 (2)	N3—Fe2—N4—C10	102.10 (15)
N1—Fe1—N2—C1	169.60 (12)	N3^ii—Fe2—N4—C10	−170.89 (16)
N1^i—Fe1—N2—C1	−10.40 (12)	Cl2^ii—Fe2—N4—C10	−83.62 (15)
Cl1—Fe1—N2—C1	78.32 (12)	Cl2—Fe2—N4—C10	12.27 (15)
Cl1^i—Fe1—N2—C1	−101.68 (12)	C11—C7—C8—C9	−0.1 (3)
N1—Fe1—N2—C5	−7.83 (15)	C7—C8—C9—C10	0.5 (3)
N1^i—Fe1—N2—C5	172.17 (15)	C11—N4—C10—C9	−0.3 (3)
Cl1—Fe1—N2—C5	−99.12 (14)	Fe2—N4—C10—C9	177.59 (15)
Cl1^i—Fe1—N2—C5	80.88 (14)	C8—C9—C10—N4	−0.2 (3)
N2—C1—C2—C3	0.7 (3)	C10—N4—C11—C7	0.7 (3)
C6^i—C1—C2—C3	−176.84 (17)	Fe2—N4—C11—C7	−177.43 (13)
C1—C2—C3—C4	−0.3 (3)	C10—N4—C11—C12	−177.76 (16)
C2—C3—C4—C5	−0.7 (3)	Fe2—N4—C11—C12	4.1 (2)
C1—N2—C5—C4	−1.1 (3)	C8—C7—C11—N4	−0.5 (3)
Fe1—N2—C5—C4	176.33 (14)	C8—C7—C11—C12	177.95 (18)
C3—C4—C5—N2	1.5 (3)	N4—C11—C12—N3^ii	−18.8 (2)
Fe1—N1—C6—C1^i	24.19 (18)	C7—C11—C12—N3^ii	162.71 (16)
N4^ii—Fe2—N3—C12^ii	−16.70 (12)

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

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
N1—H1A···Cl2	0.92	2.70	3.4358 (15)	137
N1—H1B···Cl1^iii	0.92	2.68	3.4440 (15)	141
N3—H3A···Cl1^iii	0.92	2.62	3.4762 (15)	156
N3—H3B···Cl2^iii	0.92	2.81	3.4678 (15)	129

Symmetry code: (iii) x, y−1, z.