Triclinic and monoclinic polymorphs of meso-(E,E)-1,1′-[1,2-bis­(4-chloro­phen­yl)ethane-1,2-di­yl]bis­(phenyl­diazene): the high-yield synthesis of an unexpected product, concomitant polymorphism and configurational disorder

Pyrazolidine-3,5-diones and their derivatives exhibit a wide range of biological activities. Seeking to explore the effect of combining a hydro­carbyl ring substituent, as present in sulfinpyrazone (used to treat gout), with a chlorinated aryl ring, as present in muzolimine (a diuretic), we explored the reaction between 1-phenyl­pyrazolidine-3,5-dione and 4-chloro­benzaldehyde under mildly basic conditions in the expectation of producing the simple condensation product 4-(4-chloro­benzyl­idene)-1-phenyl­pyrazolidine-3,5-dione. However, the reaction product proved to be meso-(E,E)-1,1′-[1,2-bis(4-chloro­phen­yl)ethane-1,2-di­yl]bis­(phenyl­diazene), C₂₆H₂₀Cl₂N₄, and a tentative mechanism is proposed. Crystallization from ethanol produces two concomitant polymorphs, i.e. a triclinic form, (I), in the space group P, and a monoclinic form, (II), in the space group C2/c. In both polymorphs, the mol­ecules lie across centres of inversion, but in (II), the mol­ecules are subject to whole-mol­ecule disorder equivalent to configurational disorder with occupancies of 0.6021 (19) and 0.3979 (19). There are no hydrogen bonds in the crystal structure of polymorph (I), but the mol­ecules of polymorph (II) are linked by C—H...π(arene) hydrogen bonds into complex chains, which are further linked into sheets by C—H...N inter­actions.

S1. Introduction

Pyrazolidine-3,5-diones and their derivatives exhibit a very wide range of biological activities (Baccolini & Gianelli, 1995; Barnes et al., 2001; Chioua et al., 2009; Ragavan et al., 2010; Shen et al., 2011; Li et al., 2011). Amongst the specific bioactive compounds are 1,2-di­phenyl-4-[2-(phenyl­sulfinyl)­ethyl]­pyrazolidine-3,5-dione (sulfinpyrazone), which is used to treat gout by stimulating the urinary excretion of uric acid (Underwood, 2006), and the amino derivative 5-amino-2-[1-(3,4-di­chloro­phenyl)­ethyl]-4H-pyrazol-3-one (muzolimine), which is a diuretic used in the treatment of hypertension (Wangemann et al., 1987). Seeking to explore the effect of combining a hydro­carbyl ring substituent, as present in sulfinpyrazone, with a chlorinated aryl ring, as present in muzolimine, we have now explored the reaction between 1-phenyl­pyrazolidine-3,5-dione and 4-chloro­benzaldehyde under mildly basic conditions, in the expe­cta­tion of producing the simple condensation product 4-(4-chloro­benzyl­idene)-1-phenyl­pyrazolidine-3,5-dione (A) (see Scheme 1). However, the IR spectrum of the product from this reaction indicated the presence of neither carbonyl groups nor an N—H unit, effectively ruling out the formation of product (A). On the other hand, the ¹³C NMR spectrum showed the presence of eight resonances, three of them quaternary, in the aromatic region, consistent with the presence of both a 4-chloro­phenyl ring and an unsubstituted phenyl ring. The structure determination reported here shows that, instead of the expected product (A), the reaction has produced in high yield the unexpected product meso-(E,E)-1,1'-[1,2-bis­(4-chloro­phenyl)­ethane-1,2-diyl]bis­(phenyl­diazene), which we have obtained in two polymorphic forms, a triclinic form, (I), in the space group P1 and a monoclinic form, (II), in the space group C2/c. The formation of the title compound in this reaction, as opposed to the simple condensation product (A), has evidently involved the complete disruption of the heterocyclic ring in the pyrazolidinedione rea­ctant, with only the two N atoms and the phenyl ring being retained in the final product. Thus, the formation of the title compound can be tentatively envisaged as indicated in Scheme 2, i.e. an initial ring opening of the heterocyclic rea­ctant by ethano­lamine yields the acyclic amino inter­mediate (B), condensation of which with the aldehyde component provides the Schiff base inter­mediate (C). Solvolysis of (C) leads to the asymmetrically disubstituted diazene (D), oxidation of which provides the final product, although it is entirely possible that the oxidation step precedes the solvolysis step. Crystallization from ethanol produces a mixture of the two polymorphs (I) and (II) which were separated mechanically, although no attempt was made to estimate their relative qu­anti­ties. Polymorphs (I) and (II) are thus concomitant polymorphs (Bernstein et al., 1999; Bernstein, 2002), whose formation required not only that the thermodynamic stabilities of the two forms are similar at ambient temperature, but also that their rates of crystallization from the solvent in question, here ethanol, are also similar.

S2. Experimental

S2.1. Synthesis and crystallization

For the synthesis of the title compound, a mixture of 1-phenyl­pyrazolidine-3,5-dione (1.0 mmol), 4-chloro­rbenzaldehyde (0.5 mmol) and ethano­lamine (0.5 mmol) in ethanol (10 ml) was heated under reflux in the presence of air for 4 h. The solution was then allowed to cool to ambient temperature and the resulting solid product was collected by filtration, dried and recrystallized from ethanol (yield 87%, m. p. 395 K). ¹³C NMR (di­methyl sulfoxide-d₆) δ 57.31, 111.91, 112.16 (q), 118.81, 126.98, 128.52, 131.89 (q), 134.80, 144.92 (q). Colourless crystals suitable for single-crystal X-ray diffraction anlysis were obtained by slow evaporation, at ambient temperature and in the presence of air, of a solution in ethanol, which provided a mixture of the two polymorphs (I) and (II), which were separated mechanically prior to data collection.

S2.2. Refinement

Crystal data, data collection and structure refinement details are summarized in Table 1. All H atoms were located in difference maps and were then treated as riding atoms, with C—H = 0.95 or 1.00 Å and with U_iso(H) = 1.2U_eq(C). It was apparent from an early stage in the refinement of monoclinic polymorph (II) than the molecule was disordered over two sets of atomic sites having unequal occupancies. For the minor-disorder component, the bond lengths and the one-angle nonbonded distances were restrained to be the same as the corresponding distances in the major-disorder form subject to standard uncertainties of 0.005 and 0.01 Å, respectively. In addition, the anisotropic displacement parameters for atoms C224 and C225 in the minor-disorder component were constrained to be identical. Under these conditions, independent refinement of the occupancies of the two disorder forms gave values of 0.60 (2) and 0.398 (14); thereafter these occupancies were constrained to sum to unity, giving values of 0.0.6021 (19) and 0.3979 (19) for the two disorder components. Prompted by the unequal occupancies of the two disorder components and their opposite configurations, a number of other refinement models were investigated in each of the possible alternative space groups Cc and P2/c, including ordered and disordered forms of the meso and racemic diastereoisomers. Most of the models proved to be wholly unsatisfactory, the only exceptions being the disordered form of the meso isomer in each of Cc and P2/c. Although both refinements were somewhat impaired by low data-to-parameter ratios, both gave essentially the same outcome as the disordered structure in C2/c reported here. A trial solution in P2/c, using a data set which had been had prepared assuming a primitive monoclinic cell, gave the same disordered meso form with unequal occupancies, although scrutiny of this data set showed that the structure is genuinely C-centred rather than pseudo-C-centred. Although the final difference map for (I) contained a number of peaks representing electron densities greater that 0.3 e Å^-3, no chemically plausible disorder model could be developed from them. For (II), the final difference map contained only one peak, 0.24 e Å^-3, greater than 0.15 e Å^-3. For (I), there was a high value of K in the analysis of variance (i.e. 3.651) for the group of very weak reflections having F_c/F_c(max) in the range 0.000 < F_c/F_c(max) < 0.009; for (II), a high value (i.e. 7.609) was associated with the group of very weak reflections having F_c/F_c(max) in the range 0.000 < F_c/F_c(max) < 0.007.

S3. Results and discussion

In the triclinic polymorph, (I), the molecules lie across centres of inversion and the reference molecule was selected as that lying across (1/2, 1/2, 1/2) (Fig. 1). The molecule contains a stereogenic centre at atom C1 and the reference molecule was selected to have the R configuration at this site. Hence, the inversion-related site, denoted C1a in Fig. 1, has the S configuration, so that the compound is a meso form with configuration (1R,2S), although the (1S,2R) form would be identical.

The molecules in the monoclinic polymorph, (II), also lie across centres of inversion and here the reference molecule was selected as that lying across (1/4, 1/4, 1/2). However, this polymorph exhibits whole-molecule disorder over two sets of atomic sites having occupancies of 0.6021 (19) and 0.3979 (19). The relationship between the major (Fig. 2a) and minor (Fig. 2b) disorder components can best be regarded as a reflection across a plane which is close to, but not coincident with, the central H—C—C—H plane of the molecule, so accounting for the opposite configurations of the selected asymmetric units for two disorder components; thus the net effect of the disorder is the exchange in the positions of the 4-choloro­phenyl and the phenyl­diazene units in the minor component relative to their locations in the major component (Fig. 2c). Alternatively, the minor component can be regarded as resulting from a rotation of the major form by ca 180° about an axis approximately, but not exactly, normal to the central H—C—C—H plane. For the major-disorder component, the reference molecule was selected to have the R configuration at the stereogenic atom C11 (Fig. 2a), but in the minor-disorder component the corresponding atom C21 (Fig 2b) has the S configuration consequent upon the exchanged locations of the 4-chloro­phenyl and phenyl­diazene units (Fig. 2c). Hence, the whole-molecule disorder exhibited by this polymorph is, in fact, configurational disorder.

The density of triclinic polymorph (I) (1.331 Mg m^-3), as deduced from the unit-cell dimensions, is slightly higher than that of the monoclinic polymorph (1.317 Mg m^-3). It has long been thought (Kitaigorodskii, 1961; Bernstein, 2002) that in any series of polymorphs, the form with the highest density has the highest thermodynamic stability. However, the generality of this correlation has recently been questioned, particularly for systems in which extensive hydrogen bonding occurs (Nelyubina et al., 2010; Ng et al., 2014). As discussed below, there is no strong hydrogen bonding present in the structure of either of polymorphs (I) and (II), so that it is reasonable to deduce in this case that the more dense triclinic polymorph is thermodynamically the more stable of the two forms.

The overall conformation of the molecules in polymorph (I) is fairly similar to that of the major form in polymorph (II), as indicated by the key torsion angles (Table 2), while the corresponding pairs of torsion angles in the major and minor form of (II) generally have fairly similar magnitudes but opposite signs, consistent with their opposite configurations.

Although the molecule of the title compound contains two independent N atoms both carrying lone pairs and two independent aryl rings, the crystal structure of triclinic polymorph (I) contains no C—H···N or C—H···π(arene) hydrogen bonds, nor any aromatic π–π stacking inter­actions. By contrast there are several C—H···π(arene) inter­actions in the disordered structure of monoclinic polymorph (II) (Table 3) and the combined effect of these inter­actions, allied to the molecular inversion symmetry, is to link the molecules into complex chains running parallel to the [001] direction (Fig. 3); two chains of this type pass through each unit cell. The C—H···N hydrogen bond in the structure of polymorph (II) (Table 3) links inversion-related pairs of the minor component forming an R₂²(12) (Bernstein et al., 1995) motif. If this component had unit occupancy, propagation of the R₂²(12) motif by inversion would lead to the formation of a chain of rings running parallel to the [010] direction (Fig. 4). However, the actual occupancy for this component means that only ca 16% of the molecular sites are involved in such a motif, so that at best only short fragments of such a chain of rings are likely to occur. Nonetheless, even isolated occurrences of this motif are sufficient to link the [001] chains (Fig. 3) into a sheet lying parallel to (100).

The only other direction-specific inter­molecular inter­actions in the crystal structures of polymorphs (I) and (II) are C—Cl···π(arene) contacts (Table 4). It has been deduced (Imai et al., 2008) using database analysis that the most favourable geometry for such contacts was the face-on arrangement with the Cl···(ring centroid) distance less than any of the Cl···(ring C atom) distances and with an average Cl···centroid distance of ca 3.6 Å, so that the contact in polymorph (I) lies comfortably within these criteria, while those in the monoclinic polymorph also fall into this category. In addition, it was deduced that in the region of the average inter­molecular geometry, the attractive inter­action energy was ca 8.5 kJ mol^-1, arising largely from dispersion forces (Imai et al., 2008). In polymorph (II), the major C—Cl···π(arene) inter­action lies within the hydrogen-bonded chain, but for polymorph (I) it involves molecules related by translation along the [110] direction (Fig. 5).

Structure description

Pyrazolidine-3,5-diones and their derivatives exhibit a very wide range of biological activities (Baccolini & Gianelli, 1995; Barnes et al., 2001; Chioua et al., 2009; Ragavan et al., 2010; Shen et al., 2011; Li et al., 2011). Amongst the specific bioactive compounds are 1,2-di­phenyl-4-[2-(phenyl­sulfinyl)­ethyl]­pyrazolidine-3,5-dione (sulfinpyrazone), which is used to treat gout by stimulating the urinary excretion of uric acid (Underwood, 2006), and the amino derivative 5-amino-2-[1-(3,4-di­chloro­phenyl)­ethyl]-4H-pyrazol-3-one (muzolimine), which is a diuretic used in the treatment of hypertension (Wangemann et al., 1987). Seeking to explore the effect of combining a hydro­carbyl ring substituent, as present in sulfinpyrazone, with a chlorinated aryl ring, as present in muzolimine, we have now explored the reaction between 1-phenyl­pyrazolidine-3,5-dione and 4-chloro­benzaldehyde under mildly basic conditions, in the expe­cta­tion of producing the simple condensation product 4-(4-chloro­benzyl­idene)-1-phenyl­pyrazolidine-3,5-dione (A) (see Scheme 1). However, the IR spectrum of the product from this reaction indicated the presence of neither carbonyl groups nor an N—H unit, effectively ruling out the formation of product (A). On the other hand, the ¹³C NMR spectrum showed the presence of eight resonances, three of them quaternary, in the aromatic region, consistent with the presence of both a 4-chloro­phenyl ring and an unsubstituted phenyl ring. The structure determination reported here shows that, instead of the expected product (A), the reaction has produced in high yield the unexpected product meso-(E,E)-1,1'-[1,2-bis­(4-chloro­phenyl)­ethane-1,2-diyl]bis­(phenyl­diazene), which we have obtained in two polymorphic forms, a triclinic form, (I), in the space group P1 and a monoclinic form, (II), in the space group C2/c. The formation of the title compound in this reaction, as opposed to the simple condensation product (A), has evidently involved the complete disruption of the heterocyclic ring in the pyrazolidinedione rea­ctant, with only the two N atoms and the phenyl ring being retained in the final product. Thus, the formation of the title compound can be tentatively envisaged as indicated in Scheme 2, i.e. an initial ring opening of the heterocyclic rea­ctant by ethano­lamine yields the acyclic amino inter­mediate (B), condensation of which with the aldehyde component provides the Schiff base inter­mediate (C). Solvolysis of (C) leads to the asymmetrically disubstituted diazene (D), oxidation of which provides the final product, although it is entirely possible that the oxidation step precedes the solvolysis step. Crystallization from ethanol produces a mixture of the two polymorphs (I) and (II) which were separated mechanically, although no attempt was made to estimate their relative qu­anti­ties. Polymorphs (I) and (II) are thus concomitant polymorphs (Bernstein et al., 1999; Bernstein, 2002), whose formation required not only that the thermodynamic stabilities of the two forms are similar at ambient temperature, but also that their rates of crystallization from the solvent in question, here ethanol, are also similar.

In the triclinic polymorph, (I), the molecules lie across centres of inversion and the reference molecule was selected as that lying across (1/2, 1/2, 1/2) (Fig. 1). The molecule contains a stereogenic centre at atom C1 and the reference molecule was selected to have the R configuration at this site. Hence, the inversion-related site, denoted C1a in Fig. 1, has the S configuration, so that the compound is a meso form with configuration (1R,2S), although the (1S,2R) form would be identical.

The molecules in the monoclinic polymorph, (II), also lie across centres of inversion and here the reference molecule was selected as that lying across (1/4, 1/4, 1/2). However, this polymorph exhibits whole-molecule disorder over two sets of atomic sites having occupancies of 0.6021 (19) and 0.3979 (19). The relationship between the major (Fig. 2a) and minor (Fig. 2b) disorder components can best be regarded as a reflection across a plane which is close to, but not coincident with, the central H—C—C—H plane of the molecule, so accounting for the opposite configurations of the selected asymmetric units for two disorder components; thus the net effect of the disorder is the exchange in the positions of the 4-choloro­phenyl and the phenyl­diazene units in the minor component relative to their locations in the major component (Fig. 2c). Alternatively, the minor component can be regarded as resulting from a rotation of the major form by ca 180° about an axis approximately, but not exactly, normal to the central H—C—C—H plane. For the major-disorder component, the reference molecule was selected to have the R configuration at the stereogenic atom C11 (Fig. 2a), but in the minor-disorder component the corresponding atom C21 (Fig 2b) has the S configuration consequent upon the exchanged locations of the 4-chloro­phenyl and phenyl­diazene units (Fig. 2c). Hence, the whole-molecule disorder exhibited by this polymorph is, in fact, configurational disorder.

The density of triclinic polymorph (I) (1.331 Mg m^-3), as deduced from the unit-cell dimensions, is slightly higher than that of the monoclinic polymorph (1.317 Mg m^-3). It has long been thought (Kitaigorodskii, 1961; Bernstein, 2002) that in any series of polymorphs, the form with the highest density has the highest thermodynamic stability. However, the generality of this correlation has recently been questioned, particularly for systems in which extensive hydrogen bonding occurs (Nelyubina et al., 2010; Ng et al., 2014). As discussed below, there is no strong hydrogen bonding present in the structure of either of polymorphs (I) and (II), so that it is reasonable to deduce in this case that the more dense triclinic polymorph is thermodynamically the more stable of the two forms.

The overall conformation of the molecules in polymorph (I) is fairly similar to that of the major form in polymorph (II), as indicated by the key torsion angles (Table 2), while the corresponding pairs of torsion angles in the major and minor form of (II) generally have fairly similar magnitudes but opposite signs, consistent with their opposite configurations.

Although the molecule of the title compound contains two independent N atoms both carrying lone pairs and two independent aryl rings, the crystal structure of triclinic polymorph (I) contains no C—H···N or C—H···π(arene) hydrogen bonds, nor any aromatic π–π stacking inter­actions. By contrast there are several C—H···π(arene) inter­actions in the disordered structure of monoclinic polymorph (II) (Table 3) and the combined effect of these inter­actions, allied to the molecular inversion symmetry, is to link the molecules into complex chains running parallel to the [001] direction (Fig. 3); two chains of this type pass through each unit cell. The C—H···N hydrogen bond in the structure of polymorph (II) (Table 3) links inversion-related pairs of the minor component forming an R₂²(12) (Bernstein et al., 1995) motif. If this component had unit occupancy, propagation of the R₂²(12) motif by inversion would lead to the formation of a chain of rings running parallel to the [010] direction (Fig. 4). However, the actual occupancy for this component means that only ca 16% of the molecular sites are involved in such a motif, so that at best only short fragments of such a chain of rings are likely to occur. Nonetheless, even isolated occurrences of this motif are sufficient to link the [001] chains (Fig. 3) into a sheet lying parallel to (100).

The only other direction-specific inter­molecular inter­actions in the crystal structures of polymorphs (I) and (II) are C—Cl···π(arene) contacts (Table 4). It has been deduced (Imai et al., 2008) using database analysis that the most favourable geometry for such contacts was the face-on arrangement with the Cl···(ring centroid) distance less than any of the Cl···(ring C atom) distances and with an average Cl···centroid distance of ca 3.6 Å, so that the contact in polymorph (I) lies comfortably within these criteria, while those in the monoclinic polymorph also fall into this category. In addition, it was deduced that in the region of the average inter­molecular geometry, the attractive inter­action energy was ca 8.5 kJ mol^-1, arising largely from dispersion forces (Imai et al., 2008). In polymorph (II), the major C—Cl···π(arene) inter­action lies within the hydrogen-bonded chain, but for polymorph (I) it involves molecules related by translation along the [110] direction (Fig. 5).

Synthesis and crystallization

For the synthesis of the title compound, a mixture of 1-phenyl­pyrazolidine-3,5-dione (1.0 mmol), 4-chloro­rbenzaldehyde (0.5 mmol) and ethano­lamine (0.5 mmol) in ethanol (10 ml) was heated under reflux in the presence of air for 4 h. The solution was then allowed to cool to ambient temperature and the resulting solid product was collected by filtration, dried and recrystallized from ethanol (yield 87%, m. p. 395 K). ¹³C NMR (di­methyl sulfoxide-d₆) δ 57.31, 111.91, 112.16 (q), 118.81, 126.98, 128.52, 131.89 (q), 134.80, 144.92 (q). Colourless crystals suitable for single-crystal X-ray diffraction anlysis were obtained by slow evaporation, at ambient temperature and in the presence of air, of a solution in ethanol, which provided a mixture of the two polymorphs (I) and (II), which were separated mechanically prior to data collection.

Refinement details

Crystal data, data collection and structure refinement details are summarized in Table 1. All H atoms were located in difference maps and were then treated as riding atoms, with C—H = 0.95 or 1.00 Å and with U_iso(H) = 1.2U_eq(C). It was apparent from an early stage in the refinement of monoclinic polymorph (II) than the molecule was disordered over two sets of atomic sites having unequal occupancies. For the minor-disorder component, the bond lengths and the one-angle nonbonded distances were restrained to be the same as the corresponding distances in the major-disorder form subject to standard uncertainties of 0.005 and 0.01 Å, respectively. In addition, the anisotropic displacement parameters for atoms C224 and C225 in the minor-disorder component were constrained to be identical. Under these conditions, independent refinement of the occupancies of the two disorder forms gave values of 0.60 (2) and 0.398 (14); thereafter these occupancies were constrained to sum to unity, giving values of 0.0.6021 (19) and 0.3979 (19) for the two disorder components. Prompted by the unequal occupancies of the two disorder components and their opposite configurations, a number of other refinement models were investigated in each of the possible alternative space groups Cc and P2/c, including ordered and disordered forms of the meso and racemic diastereoisomers. Most of the models proved to be wholly unsatisfactory, the only exceptions being the disordered form of the meso isomer in each of Cc and P2/c. Although both refinements were somewhat impaired by low data-to-parameter ratios, both gave essentially the same outcome as the disordered structure in C2/c reported here. A trial solution in P2/c, using a data set which had been had prepared assuming a primitive monoclinic cell, gave the same disordered meso form with unequal occupancies, although scrutiny of this data set showed that the structure is genuinely C-centred rather than pseudo-C-centred. Although the final difference map for (I) contained a number of peaks representing electron densities greater that 0.3 e Å^-3, no chemically plausible disorder model could be developed from them. For (II), the final difference map contained only one peak, 0.24 e Å^-3, greater than 0.15 e Å^-3. For (I), there was a high value of K in the analysis of variance (i.e. 3.651) for the group of very weak reflections having F_c/F_c(max) in the range 0.000 < F_c/F_c(max) < 0.009; for (II), a high value (i.e. 7.609) was associated with the group of very weak reflections having F_c/F_c(max) in the range 0.000 < F_c/F_c(max) < 0.007.

Computing details

For both compounds, data collection: Rigaku CrystalClear-SM Expert 3.1 b18 (Rigaku, 2012); cell refinement: Rigaku CrystalClear-SM Expert 3.1 b18; data reduction: Rigaku CrystalClear-SM Expert 3.1 b18; program(s) used to solve structure: SUPERFLIP (Palatinus & Chapuis, 2007); program(s) used to refine structure: SHELXL2014 (Sheldrick, 2015); molecular graphics: PLATON (Spek, 2009); software used to prepare material for publication: SHELXL2014 and PLATON.

Figures

	Fig. 1. The molecular structure of the title compound in triclinic polymorph (I), showing the atom-labelling scheme. Displacement ellipsoids are drawn at the 30% probability level and atoms marked with the suffix 'a' are at the symmetry position (-x+1, -y+1, -z+1).
	Fig. 2. The molecular structures of the disordered components of the title compound in monoclinic polymorph (II), showing the atom-labelling scheme: (a) the major component, (b) the minor component and (c) the two components together. In parts (a) and (b), the displacement ellipsoids are drawn at the 30% probability level, and in part (c), most of the atom labels have been omitted for the sake of clarity. In each part, atoms marked with the suffix 'a' are at the symmetry position (-x+1/2, -y+1/2, -z+1).
	Fig. 3. A stereoview of part of the crystal structure of monoclinic polymorph (II), showing the formation of a chain built from C—H···π(arene) hydrogen bonds. The bonds in the major components are shown as full lines and those in the minor components as dashed lines within the molecules: hydrogen bonds are shown as dashed lines between the molecules and, for the sake of clarity, H atoms not involved in the motif shown have been omitted.
	Fig. 4. A stereoview of part of the crystal structure of compound (II), showing the chain of hydrogen-bonded R2^2(12) rings which would result if the minor disorder component had unit occupancy. For the sake of clarity, H atoms not involved in the motif shown have been omitted and hydrogen bonds are shown as dashed lines.
	Fig. 5. Part of the crystal structure of polymorph (I), showing a chain of rings along the [110] direction built from short C—Cl···π(arene) contacts, shown as dashed lines. Atoms marked with an asterisk (*), a hash (#) or a dollar sign ($) are at the symmetry positions (-x+1, -y+1, -z+1), (-x+2, -y+2, -z+1) and (x-1, y-1, z), respectively.

(I) meso-(E,E)-1,1'-[1,2-Bis(4-chlorophenyl)ethane-1,2-diyl]bis(phenyldiazene)

Crystal data

C26H20Cl2N4	Z = 1
Mr = 459.36	F(000) = 238
Triclinic, P1	Dx = 1.331 Mg m^−3
a = 6.1037 (4) Å	Mo Kα radiation, λ = 0.71075 Å
b = 9.3345 (7) Å	Cell parameters from 3602 reflections
c = 10.4146 (7) Å	θ = 2.2–27.5°
α = 83.039 (1)°	µ = 0.31 mm^−1
β = 77.139 (9)°	T = 100 K
γ = 85.055 (1)°	Plate, yellow
V = 573.15 (7) Å^3	0.19 × 0.08 × 0.01 mm

Data collection

Rigaku AFC12 (Right) diffractometer	2397 independent reflections
Radiation source: Rotating anode	1919 reflections with I > 2σ(I)
Detector resolution: 28.5714 pixels mm^-1	Rint = 0.037
profile data from ω–scans	θmax = 26.5°, θmin = 2.2°
Absorption correction: multi-scan CrystalClear-SM Expert 3.1 b18 (Rigaku, 2012)	h = −5→7
Tmin = 0.710, Tmax = 0.997	k = −11→11
6269 measured reflections	l = −11→13

Refinement

Refinement on F^2	0 restraints
Least-squares matrix: full	Hydrogen site location: inferred from neighbouring sites
R[F^2 > 2σ(F^2)] = 0.062	H-atom parameters constrained
wR(F^2) = 0.177	w = 1/[σ^2(Fo^2) + (0.0856P)^2 + 0.5249P] where P = (Fo^2 + 2Fc^2)/3
S = 1.08	(Δ/σ)max < 0.001
2397 reflections	Δρmax = 0.64 e Å^−3
145 parameters	Δρmin = −0.28 e Å^−3

Special details

Geometry. All esds (except the esd in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell esds are taken into account individually in the estimation of esds in distances, angles and torsion angles; correlations between esds in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell esds is used for estimating esds involving l.s. planes.

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Ų)

	x	y	z	Uiso*/Ueq
C1	0.4771 (4)	0.5466 (3)	0.4371 (2)	0.0294 (5)
H1	0.3158	0.5838	0.4521	0.035*
C11	0.6299 (4)	0.6722 (3)	0.3977 (2)	0.0310 (6)
C12	0.5393 (5)	0.8137 (3)	0.4014 (3)	0.0350 (6)
H12	0.3816	0.8314	0.4318	0.042*
C13	0.6755 (5)	0.9302 (3)	0.3614 (3)	0.0385 (6)
H13	0.6127	1.0267	0.3648	0.046*
C14	0.9040 (5)	0.9024 (3)	0.3167 (3)	0.0382 (6)
Cl14	1.07726 (13)	1.04685 (8)	0.26681 (9)	0.0541 (3)
C15	0.9980 (5)	0.7624 (3)	0.3107 (3)	0.0358 (6)
H15	1.1553	0.7452	0.2785	0.043*
C16	0.8604 (4)	0.6476 (3)	0.3522 (3)	0.0332 (6)
H16	0.9242	0.5512	0.3495	0.040*
N1	0.5266 (4)	0.4526 (2)	0.3290 (2)	0.0308 (5)
N2	0.3702 (4)	0.4581 (2)	0.2701 (2)	0.0337 (5)
C21	0.4133 (5)	0.3687 (3)	0.1627 (3)	0.0358 (6)
C22	0.6063 (5)	0.2756 (3)	0.1324 (3)	0.0382 (6)
H22	0.7208	0.2692	0.1818	0.046*
C23	0.6245 (6)	0.1930 (3)	0.0279 (3)	0.0495 (8)
H23	0.7519	0.1275	0.0061	0.059*
C24	0.4581 (5)	0.2054 (3)	−0.0448 (3)	0.0394 (7)
H24	0.4744	0.1491	−0.1168	0.047*
C25	0.2730 (6)	0.2958 (4)	−0.0155 (3)	0.0516 (9)
H25	0.1605	0.3025	−0.0663	0.062*
C26	0.2482 (5)	0.3797 (3)	0.0906 (3)	0.0429 (7)
H26	0.1186	0.4433	0.1124	0.051*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
C1	0.0244 (12)	0.0304 (12)	0.0320 (13)	−0.0020 (9)	−0.0051 (10)	0.0005 (10)
C11	0.0311 (13)	0.0397 (14)	0.0225 (12)	−0.0089 (10)	−0.0065 (9)	0.0021 (10)
C12	0.0322 (13)	0.0389 (14)	0.0329 (14)	−0.0061 (11)	−0.0034 (10)	−0.0035 (11)
C13	0.0388 (15)	0.0340 (14)	0.0420 (15)	−0.0029 (11)	−0.0074 (12)	−0.0035 (12)
C14	0.0395 (15)	0.0352 (14)	0.0386 (15)	−0.0103 (11)	−0.0077 (12)	0.0061 (12)
Cl14	0.0430 (5)	0.0365 (4)	0.0778 (6)	−0.0132 (3)	−0.0078 (4)	0.0117 (4)
C15	0.0307 (13)	0.0377 (14)	0.0372 (14)	−0.0044 (11)	−0.0064 (11)	0.0027 (11)
C16	0.0339 (13)	0.0311 (13)	0.0338 (13)	−0.0025 (10)	−0.0083 (10)	0.0017 (10)
N1	0.0311 (11)	0.0314 (11)	0.0292 (11)	−0.0060 (8)	−0.0059 (9)	0.0011 (9)
N2	0.0351 (12)	0.0303 (11)	0.0344 (12)	−0.0079 (9)	−0.0052 (9)	0.0019 (9)
C21	0.0440 (15)	0.0309 (13)	0.0323 (13)	−0.0158 (11)	−0.0061 (11)	0.0027 (11)
C22	0.0443 (16)	0.0340 (14)	0.0353 (14)	−0.0097 (11)	−0.0051 (12)	−0.0010 (11)
C23	0.058 (2)	0.0375 (16)	0.0492 (18)	−0.0120 (14)	−0.0007 (15)	−0.0045 (13)
C24	0.0623 (19)	0.0349 (14)	0.0219 (12)	−0.0246 (13)	−0.0017 (12)	−0.0051 (10)
C25	0.071 (2)	0.0544 (19)	0.0376 (16)	−0.0319 (17)	−0.0249 (15)	0.0088 (14)
C26	0.0440 (16)	0.0402 (16)	0.0441 (16)	−0.0114 (12)	−0.0110 (13)	0.0066 (13)

Geometric parameters (Å, º)

C1—N1	1.473 (3)	C16—H16	0.9500
C1—C11	1.522 (3)	N1—N2	1.239 (3)
C1—C1^i	1.549 (5)	N2—C21	1.440 (4)
C1—H1	1.0000	C21—C26	1.375 (4)
C11—C16	1.389 (4)	C21—C22	1.403 (4)
C11—C12	1.389 (4)	C22—C23	1.388 (4)
C12—C13	1.392 (4)	C22—H22	0.9500
C12—H12	0.9500	C23—C24	1.385 (5)
C13—C14	1.381 (4)	C23—H23	0.9500
C13—H13	0.9500	C24—C25	1.351 (5)
C14—C15	1.384 (4)	C24—H24	0.9500
C14—Cl14	1.743 (3)	C25—C26	1.404 (5)
C15—C16	1.387 (4)	C25—H25	0.9500
C15—H15	0.9500	C26—H26	0.9500
N1—C1—C11	108.29 (19)	C15—C16—H16	119.7
N1—C1—C1^i	107.2 (2)	C11—C16—H16	119.7
C11—C1—C1^i	111.4 (3)	N2—N1—C1	112.1 (2)
N1—C1—H1	110.0	N1—N2—C21	113.8 (2)
C11—C1—H1	110.0	C26—C21—C22	121.3 (3)
C1^i—C1—H1	110.0	C26—C21—N2	114.9 (3)
C16—C11—C12	119.0 (2)	C22—C21—N2	123.8 (3)
C16—C11—C1	120.7 (2)	C23—C22—C21	117.9 (3)
C12—C11—C1	120.3 (2)	C23—C22—H22	121.1
C11—C12—C13	121.1 (2)	C21—C22—H22	121.1
C11—C12—H12	119.4	C24—C23—C22	120.4 (3)
C13—C12—H12	119.4	C24—C23—H23	119.8
C14—C13—C12	118.6 (3)	C22—C23—H23	119.8
C14—C13—H13	120.7	C25—C24—C23	121.5 (3)
C12—C13—H13	120.7	C25—C24—H24	119.2
C13—C14—C15	121.4 (3)	C23—C24—H24	119.2
C13—C14—Cl14	119.2 (2)	C24—C25—C26	119.5 (3)
C15—C14—Cl14	119.4 (2)	C24—C25—H25	120.2
C14—C15—C16	119.3 (3)	C26—C25—H25	120.2
C14—C15—H15	120.3	C21—C26—C25	119.4 (3)
C16—C15—H15	120.3	C21—C26—H26	120.3
C15—C16—C11	120.6 (3)	C25—C26—H26	120.3
N1—C1—C11—C16	−50.1 (3)	C11—C1—N1—N2	−110.4 (2)
C1^i—C1—C11—C16	67.6 (4)	C1^i—C1—N1—N2	129.3 (3)
N1—C1—C11—C12	127.1 (2)	C1—N1—N2—C21	179.38 (19)
C1^i—C1—C11—C12	−115.2 (3)	N1—N2—C21—C26	−176.2 (2)
C16—C11—C12—C13	−0.5 (4)	N1—N2—C21—C22	4.4 (3)
C1—C11—C12—C13	−177.7 (2)	C26—C21—C22—C23	−0.8 (4)
C11—C12—C13—C14	0.5 (4)	N2—C21—C22—C23	178.6 (2)
C12—C13—C14—C15	0.3 (4)	C21—C22—C23—C24	1.2 (4)
C12—C13—C14—Cl14	−179.8 (2)	C22—C23—C24—C25	−1.0 (4)
C13—C14—C15—C16	−0.9 (4)	C23—C24—C25—C26	0.2 (4)
Cl14—C14—C15—C16	179.1 (2)	C22—C21—C26—C25	0.0 (4)
C14—C15—C16—C11	0.9 (4)	N2—C21—C26—C25	−179.4 (2)
C12—C11—C16—C15	−0.2 (4)	C24—C25—C26—C21	0.2 (4)
C1—C11—C16—C15	177.1 (2)

Symmetry code: (i) −x+1, −y+1, −z+1.

(II) meso-(E,E)-1,1'-[1,2-bis(4-chlorophenyl)ethane- 1,2-diyl]bis(phenyldiazene), monoclinic polymorph

Crystal data

C26H20Cl2N4	F(000) = 952
Mr = 459.36	Dx = 1.317 Mg m^−3
Monoclinic, C2/c	Mo Kα radiation, λ = 0.71073 Å
a = 22.657 (10) Å	Cell parameters from 3065 reflections
b = 5.4399 (18) Å	θ = 2.2–30.3°
c = 19.086 (6) Å	µ = 0.30 mm^−1
β = 99.967 (7)°	T = 100 K
V = 2316.9 (15) Å^3	Needle, yellow
Z = 4	0.50 × 0.06 × 0.05 mm

Data collection

Rigaku AFC12 (Right) diffractometer	2407 independent reflections
Radiation source: Rotating anode	1978 reflections with I > 2σ(I)
Detector resolution: 28.5714 pixels mm^-1	Rint = 0.029
profile data from ω–scans	θmax = 26.5°, θmin = 2.6°
Absorption correction: multi-scan CrystalClear-SM Expert 3.1 b18 (Rigaku, 2012)	h = −28→22
Tmin = 0.797, Tmax = 0.985	k = −6→6
7570 measured reflections	l = −23→23

Refinement

Refinement on F^2	38 restraints
Least-squares matrix: full	Hydrogen site location: mixed
R[F^2 > 2σ(F^2)] = 0.052	H-atom parameters constrained
wR(F^2) = 0.124	w = 1/[σ^2(Fo^2) + (0.0498P)^2 + 0.8661P] where P = (Fo^2 + 2Fc^2)/3
S = 1.13	(Δ/σ)max < 0.001
2407 reflections	Δρmax = 0.24 e Å^−3
284 parameters	Δρmin = −0.21 e Å^−3

Special details

Geometry. All esds (except the esd in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell esds are taken into account individually in the estimation of esds in distances, angles and torsion angles; correlations between esds in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell esds is used for estimating esds involving l.s. planes.

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Ų)

	x	y	z	Uiso*/Ueq	Occ. (<1)
C11	0.24840 (15)	0.3593 (7)	0.53128 (18)	0.0420 (9)	0.6021 (19)
H11	0.2379	0.5211	0.5072	0.050*	0.6021 (19)
C111	0.2190 (3)	0.3352 (9)	0.5955 (3)	0.0395 (13)	0.6021 (19)
C112	0.17967 (16)	0.5197 (6)	0.61067 (2)	0.0450 (8)	0.6021 (19)
H112	0.1724	0.6605	0.5810	0.054*	0.6021 (19)
C113	0.1517 (5)	0.4952 (16)	0.6690 (5)	0.0503 (17)	0.6021 (19)
H113	0.1242	0.6180	0.6782	0.060*	0.6021 (19)
C114	0.16244 (14)	0.3007 (6)	0.7133 (2)	0.0456 (8)	0.6021 (19)
Cl14	0.12544 (10)	0.2738 (4)	0.7859 (2)	0.0645 (4)	0.6021 (19)
C115	0.2027 (5)	0.1139 (19)	0.7015 (6)	0.0370 (14)	0.6021 (19)
H115	0.2111	−0.0218	0.7330	0.044*	0.6021 (19)
C116	0.22948 (12)	0.1378 (5)	0.6416 (2)	0.0437 (7)	0.6021 (19)
H116	0.2562	0.0128	0.6319	0.052*	0.6021 (19)
N11	0.31377 (15)	0.3454 (5)	0.55591 (15)	0.0406 (7)	0.6021 (19)
N12	0.34223 (16)	0.5271 (6)	0.53973 (18)	0.0420 (8)	0.6021 (19)
C121	0.40540 (13)	0.5162 (6)	0.5657 (2)	0.0402 (7)	0.6021 (19)
C122	0.4328 (4)	0.3391 (16)	0.6076 (5)	0.064 (3)	0.6021 (19)
H122	0.4093	0.2072	0.6205	0.077*	0.6021 (19)
C123	0.49348 (15)	0.3392 (7)	0.6329 (2)	0.0793 (13)	0.6021 (19)
H123	0.5126	0.2052	0.6597	0.095*	0.6021 (19)
C124	0.5240 (4)	0.534 (2)	0.6183 (6)	0.109 (5)	0.6021 (19)
H124	0.5647	0.5480	0.6410	0.131*	0.6021 (19)
C125	0.50095 (17)	0.7168 (7)	0.5728 (2)	0.0631 (10)	0.6021 (19)
H125	0.5256	0.8419	0.5584	0.076*	0.6021 (19)
C126	0.4386 (3)	0.7102 (14)	0.5480 (5)	0.0576 (17)	0.6021 (19)
H126	0.4196	0.8398	0.5192	0.069*	0.6021 (19)
C21	0.27233 (17)	0.3520 (11)	0.5198 (2)	0.0315 (13)	0.3979 (19)
H21	0.2542	0.5141	0.5034	0.038*	0.3979 (19)
C211	0.3381 (2)	0.3983 (10)	0.5416 (3)	0.0295 (13)	0.3979 (19)
C212	0.36359 (18)	0.6150 (8)	0.5206 (2)	0.0372 (11)	0.3979 (19)
H212	0.3394	0.7311	0.4915	0.045*	0.3979 (19)
C213	0.4242 (3)	0.6588 (16)	0.5424 (6)	0.044 (2)	0.3979 (19)
H213	0.4416	0.8018	0.5260	0.053*	0.3979 (19)
C214	0.45892 (15)	0.5036 (8)	0.5864 (2)	0.0447 (12)	0.3979 (19)
Cl24	0.53473 (13)	0.5666 (6)	0.6153 (2)	0.0517 (5)	0.3979 (19)
C215	0.4353 (5)	0.283 (2)	0.6086 (6)	0.038 (2)	0.3979 (19)
H215	0.4598	0.1694	0.6383	0.045*	0.3979 (19)
C216	0.37480 (16)	0.2373 (7)	0.5853 (2)	0.0403 (10)	0.3979 (19)
H216	0.3580	0.0899	0.5999	0.048*	0.3979 (19)
N21	0.24736 (18)	0.2883 (8)	0.5841 (2)	0.0339 (10)	0.3979 (19)
N22	0.2064 (3)	0.4236 (11)	0.5963 (3)	0.0333 (15)	0.3979 (19)
C221	0.18165 (17)	0.3655 (8)	0.6581 (2)	0.0374 (11)	0.3979 (19)
C222	0.1944 (7)	0.167 (2)	0.6993 (8)	0.034 (3)	0.3979 (19)
H222	0.2224	0.0524	0.6870	0.041*	0.3979 (19)
C223	0.16903 (19)	0.1197 (8)	0.7588 (2)	0.0466 (12)	0.3979 (19)
H223	0.1776	−0.0257	0.7862	0.056*	0.3979 (19)
C224	0.1321 (6)	0.290 (2)	0.7748 (6)	0.0615 (14)	0.3979 (19)
H224	0.1166	0.2695	0.8176	0.074*	0.3979 (19)
C225	0.1144 (2)	0.4931 (8)	0.7350 (3)	0.0615 (14)	0.3979 (19)
H225	0.0848	0.6011	0.7470	0.074*	0.3979 (19)
C226	0.1419 (7)	0.537 (2)	0.6751 (7)	0.035 (2)	0.3979 (19)
H226	0.1331	0.6815	0.6473	0.042*	0.3979 (19)

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
C11	0.049 (3)	0.0291 (16)	0.042 (3)	−0.0008 (18)	−0.0094 (18)	0.0057 (16)
C111	0.035 (3)	0.041 (4)	0.037 (2)	−0.006 (3)	−0.009 (2)	−0.003 (2)
C112	0.053 (2)	0.0276 (17)	0.047 (2)	−0.0012 (14)	−0.0141 (16)	0.0053 (16)
C113	0.059 (4)	0.034 (3)	0.053 (4)	0.006 (2)	−0.004 (3)	−0.009 (3)
C114	0.0475 (17)	0.0452 (19)	0.0393 (17)	−0.0111 (15)	−0.0060 (14)	−0.0060 (16)
Cl14	0.0725 (8)	0.0692 (8)	0.0530 (7)	−0.0151 (6)	0.0142 (5)	−0.0046 (5)
C115	0.041 (3)	0.023 (3)	0.040 (3)	0.002 (2)	−0.0150 (19)	0.006 (2)
C116	0.0444 (16)	0.0316 (15)	0.0475 (17)	0.0018 (12)	−0.0130 (13)	0.0026 (13)
N11	0.0470 (19)	0.0315 (14)	0.0400 (16)	−0.0052 (14)	−0.0018 (15)	0.0030 (12)
N12	0.054 (2)	0.036 (2)	0.0332 (16)	−0.0093 (18)	0.0009 (13)	0.0038 (17)
C121	0.0484 (18)	0.0374 (17)	0.0350 (15)	−0.0022 (14)	0.0077 (14)	−0.0002 (14)
C122	0.053 (3)	0.049 (4)	0.097 (5)	0.012 (2)	0.033 (3)	0.025 (3)
C123	0.047 (2)	0.069 (3)	0.125 (4)	0.0149 (18)	0.022 (2)	0.037 (2)
C124	0.051 (5)	0.123 (8)	0.157 (9)	0.004 (4)	0.024 (4)	−0.008 (6)
C125	0.075 (2)	0.055 (2)	0.057 (2)	−0.0225 (19)	0.0052 (19)	0.0042 (18)
C126	0.071 (4)	0.045 (3)	0.049 (3)	−0.019 (2)	−0.012 (2)	0.012 (2)
C21	0.027 (3)	0.032 (2)	0.037 (3)	0.001 (2)	0.008 (3)	0.0022 (19)
C211	0.022 (2)	0.039 (4)	0.028 (2)	−0.006 (3)	0.0062 (18)	−0.001 (3)
C212	0.041 (3)	0.033 (3)	0.037 (3)	0.001 (2)	0.008 (2)	−0.003 (2)
C213	0.041 (4)	0.040 (5)	0.052 (4)	−0.009 (3)	0.008 (3)	−0.011 (3)
C214	0.035 (2)	0.052 (3)	0.046 (3)	−0.004 (2)	0.005 (2)	−0.019 (2)
Cl24	0.0324 (8)	0.0646 (11)	0.0557 (10)	−0.0053 (7)	0.0007 (7)	−0.0135 (8)
C215	0.037 (3)	0.026 (4)	0.043 (4)	0.007 (3)	−0.009 (3)	0.004 (3)
C216	0.043 (2)	0.028 (2)	0.045 (3)	−0.0029 (17)	−0.0052 (19)	0.0057 (19)
N21	0.032 (2)	0.039 (2)	0.031 (2)	−0.0036 (19)	0.0062 (18)	0.0020 (18)
N22	0.032 (3)	0.037 (4)	0.031 (2)	0.000 (3)	0.006 (2)	−0.003 (3)
C221	0.032 (2)	0.047 (3)	0.032 (2)	−0.014 (2)	0.0025 (17)	−0.007 (2)
C222	0.037 (5)	0.028 (6)	0.036 (4)	0.000 (4)	0.000 (4)	0.003 (3)
C223	0.058 (3)	0.046 (3)	0.031 (2)	−0.021 (2)	−0.004 (2)	0.009 (2)
C224	0.080 (3)	0.045 (3)	0.063 (3)	−0.014 (2)	0.023 (2)	−0.017 (2)
C225	0.080 (3)	0.045 (3)	0.063 (3)	−0.014 (2)	0.023 (2)	−0.017 (2)
C226	0.049 (4)	0.016 (3)	0.042 (4)	0.000 (3)	0.015 (3)	−0.003 (3)

Geometric parameters (Å, º)

C11—N11	1.476 (3)	C21—N21	1.479 (4)
C11—C111	1.498 (5)	C21—C211	1.498 (5)
C11—H11	1.0021	C21—H21	0.9995
C111—C116	1.383 (5)	C211—C216	1.383 (5)
C111—C112	1.405 (5)	C211—C212	1.401 (5)
C112—C113	1.379 (7)	C212—C213	1.384 (8)
C112—H112	0.9500	C212—H212	0.9500
C113—C114	1.350 (8)	C213—C214	1.345 (9)
C113—H113	0.9500	C213—H213	0.9500
C114—C115	1.409 (8)	C214—C215	1.410 (9)
C114—Cl14	1.745 (3)	C214—Cl24	1.745 (4)
C115—C116	1.390 (8)	C215—C216	1.387 (9)
C115—H115	0.9500	C215—H215	0.9500
C116—H116	0.9500	C216—H216	0.9500
N11—N12	1.248 (4)	N21—N22	1.237 (5)
N12—C121	1.432 (4)	N22—C221	1.428 (5)
C121—C122	1.334 (8)	C221—C222	1.336 (9)
C121—C126	1.371 (6)	C221—C226	1.374 (7)
C122—C123	1.377 (9)	C222—C223	1.382 (10)
C122—H122	0.9500	C222—H222	0.9500
C123—C124	1.323 (10)	C223—C224	1.319 (10)
C123—H123	0.9500	C223—H223	0.9500
C124—C125	1.363 (11)	C224—C225	1.361 (11)
C124—H124	0.9500	C224—H224	0.9500
C125—C126	1.411 (8)	C225—C226	1.412 (8)
C125—H125	0.9500	C225—H225	0.9500
C126—H126	0.9500	C226—H226	0.9500
N11—C11—C111	107.4 (3)	N21—C21—C211	108.3 (4)
N11—C11—H11	109.7	N21—C21—H21	105.7
C111—C11—H11	110.3	C211—C21—H21	105.9
C116—C111—C112	117.9 (4)	C216—C211—C212	118.1 (4)
C116—C111—C11	122.5 (4)	C216—C211—C21	121.7 (5)
C112—C111—C11	119.6 (4)	C212—C211—C21	120.0 (4)
C113—C112—C111	119.6 (4)	C213—C212—C211	119.6 (5)
C113—C112—H112	120.2	C213—C212—H212	120.2
C111—C112—H112	120.2	C211—C212—H212	120.2
C114—C113—C112	121.5 (5)	C214—C213—C212	121.5 (6)
C114—C113—H113	119.2	C214—C213—H213	119.2
C112—C113—H113	119.2	C212—C213—H213	119.2
C113—C114—C115	121.1 (5)	C213—C214—C215	120.7 (6)
C113—C114—Cl14	120.2 (4)	C213—C214—Cl24	120.8 (4)
C115—C114—Cl14	118.6 (4)	C215—C214—Cl24	118.5 (5)
C116—C115—C114	116.8 (6)	C216—C215—C214	117.5 (7)
C116—C115—H115	121.6	C216—C215—H215	121.3
C114—C115—H115	121.6	C214—C215—H215	121.3
C111—C116—C115	123.0 (5)	C211—C216—C215	122.5 (5)
C111—C116—H116	118.5	C211—C216—H216	118.8
C115—C116—H116	118.5	C215—C216—H216	118.8
N12—N11—C11	114.4 (3)	N22—N21—C21	115.0 (4)
N11—N12—C121	114.2 (3)	N21—N22—C221	115.9 (5)
C122—C121—C126	119.1 (5)	C222—C221—C226	119.5 (6)
C122—C121—N12	124.8 (4)	C222—C221—N22	126.1 (5)
C126—C121—N12	116.1 (4)	C226—C221—N22	114.4 (5)
C121—C122—C123	122.8 (6)	C221—C222—C223	123.8 (8)
C121—C122—H122	118.6	C221—C222—H222	118.1
C123—C122—H122	118.6	C223—C222—H222	118.1
C124—C123—C122	117.0 (6)	C224—C223—C222	115.4 (6)
C124—C123—H123	121.5	C224—C223—H223	122.3
C122—C123—H123	121.5	C222—C223—H223	122.3
C123—C124—C125	124.2 (7)	C223—C224—C225	125.2 (7)
C123—C124—H124	117.9	C223—C224—H224	117.4
C125—C124—H124	117.9	C225—C224—H224	117.4
C124—C125—C126	116.5 (5)	C224—C225—C226	117.5 (6)
C124—C125—H125	121.8	C224—C225—H225	121.3
C126—C125—H125	121.8	C226—C225—H225	121.3
C121—C126—C125	119.8 (6)	C221—C226—C225	118.3 (7)
C121—C126—H126	120.1	C221—C226—H226	120.8
C125—C126—H126	120.1	C225—C226—H226	120.8
N11—C11—C111—C116	−55.6 (6)	N21—C21—C211—C216	48.3 (7)
N11—C11—C111—C112	123.7 (5)	N21—C21—C211—C212	−128.7 (5)
C116—C111—C112—C113	−2.0 (10)	C216—C211—C212—C213	1.4 (8)
C11—C111—C112—C113	178.7 (7)	C21—C211—C212—C213	178.5 (6)
C111—C112—C113—C114	1.9 (14)	C211—C212—C213—C214	−3.3 (12)
C112—C113—C114—C115	−0.2 (15)	C212—C213—C214—C215	3.7 (14)
C112—C113—C114—Cl14	−179.2 (7)	C212—C213—C214—Cl24	−178.2 (6)
C113—C114—C115—C116	−1.3 (15)	C213—C214—C215—C216	−2.2 (15)
Cl14—C114—C115—C116	177.6 (6)	Cl24—C214—C215—C216	179.6 (7)
C112—C111—C116—C115	0.5 (10)	C212—C211—C216—C215	0.0 (9)
C11—C111—C116—C115	179.7 (8)	C21—C211—C216—C215	−177.1 (8)
C114—C115—C116—C111	1.2 (14)	C214—C215—C216—C211	0.4 (14)
C111—C11—N11—N12	−122.7 (4)	C211—C21—N21—N22	122.1 (7)
C11—N11—N12—C121	178.1 (3)	C21—N21—N22—C221	−180.0 (5)
N11—N12—C121—C122	−4.3 (7)	N21—N22—C221—C222	−7.1 (15)
N11—N12—C121—C126	178.8 (5)	N21—N22—C221—C226	172.0 (11)
C126—C121—C122—C123	−1.4 (13)	C226—C221—C222—C223	1 (2)
N12—C121—C122—C123	−178.3 (6)	N22—C221—C222—C223	−180.0 (11)
C121—C122—C123—C124	4.9 (13)	C221—C222—C223—C224	−2 (2)
C122—C123—C124—C125	−8.9 (13)	C222—C223—C224—C225	5.2 (19)
C123—C124—C125—C126	9.0 (13)	C223—C224—C225—C226	−6.1 (19)
C122—C121—C126—C125	1.5 (11)	C222—C221—C226—C225	−2 (2)
N12—C121—C126—C125	178.6 (5)	N22—C221—C226—C225	179.1 (10)
C124—C125—C126—C121	−5.0 (11)	C224—C225—C226—C221	4.1 (19)

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
C115—H115···Cg1^i	0.95	2.93	3.690 (12)	137
C212—H212···N22^ii	0.95	2.61	3.545 (7)	168
C223—H223···Cg1^i	0.95	3.12	3.699 (11)	121
C224—H224···Cg2^i	0.95	2.92	3.760 (12)	148

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