Hydrogen-bonding patterns in bis­[2,4,6-triazan­iumylcyclohexane-1,3,5-tris(olate)-κ³O,O′,O′′]germanium(IV) tetra­chloride hexa­hydrate

A first preliminary report on the crystal structure of a hydrated salt formulated as [Ge(taci)₂]Cl₄·13H₂O (taci is 1,3,5-tri­amino-1,3,5-tride­oxy-cis-inositol) appeared more than 20 years ago [Ghisletta (1994). PhD thesis, ETH Zürich. Switzerland]. At that time it was not possible to discriminate unambiguously between the positions of some of the chloride ions and water O atoms, and disorder was thus postulated. In a new determination, a conclusive scheme of hydrogen bonding proves to be a particularly appealing aspect of the structure. Single crystals of the title compound, C₁₂H₃₀GeN₆O₆⁴⁺·4Cl⁻·6H₂O or [Ge(taci)₂]₂Cl₈·12H₂O, were grown from an aqueous solution by slow evaporation of the solvent. The two [Ge(taci)₂]⁴⁺ cations exhibit a double-adamantane-type structure with exclusive O-atom coordination and approximate D_3d symmetry. The taci ligands adopt a zwitterionic form with deprotonated hy­droxy groups and protonated amino groups. Both cations are hydrogen bonded to six water mol­ecules. The structure of the hydration shell of the two cations is, however, slightly different. The {[Ge(taci)₂]·6H₂O}⁴⁺ aggregates are inter­linked in all three dimensions by further hydrogen bonds of the types N—H...Cl...H—N, N—H...O(H)₂...H—N, (Ge)O...H—O(H)...H—N, N—H...O(H)—H...Cl...H—N, (Ge)O...H—O—H...Cl...H—N, N—H...O(H)—H...Cl...H—(H)O...H—N, (Ge)O...H—O—H...Cl...H—(H)O...H—N and Ge(O)...H—O—H...Cl...H—O—H...O(Ge).

S1. Introduction

A first preliminary report on the crystal structure of a hydrated salt formulated as [Ge(taci)₂]Cl₄.13H₂O (taci = 1,3,5-tri­amino-1,3,5-tri­deoxy-cis-inositol) appeared more than 20 years ago (Ghisletta, 1994). However, at that time, structure elucidation remained unsatisfactory. It was not possible to discriminate unambiguously between the positions of some of the chloride ions and water O atoms. As a consequence, a disorder was postulated, with an occupation of these positions by the two atom types at random. This artifact is particularly regrettable, because a conclusive scheme of hydrogen bonding, which is – as we shall show in this contribution – a particularly appealing aspect of the structure, could not be elucidated. We therefore regrew single crystals of this complex, following Ghisletta's protocol, and repeated the structure elucidation at low temperature. In agreement with Ghisletta's description, the structure could again be solved and refined in the triclinic centrosymmetric space group P1. However, in contrast to the previous investigation, where only one position for the [Ge(taci)₂]⁴⁺ cation has been considered, we encountered two crystallographically independent Ge-atom positions, both located on a centre of inversion. In addition, the amount of hydration appeared to be smaller and we formulate the new structure as [Ge(taci)₂]₂Cl₈.12H₂O. The new attempt now allowed an unambiguous discrimination between O atom and chloride anion positions. Consequently, a complete resolution of the structure without any disorder proved possible.

S2. Experimental

S2.1. Synthesis and crystallization

1,3,5-Tri­amino-1,3,5-tri­deoxy-cis-inositol (taci) was prepared as described by Hegetschweiler et al. (1990). The title compound, i.e. [Ge(taci)₂]₂Cl₈.12H₂O, was prepared by combining solutions of GeCl₄ (0.50 g, 2.33 mmol in 5 ml of MeOH) and taci (0.82 g, 4.63 mmol in 25 ml of MeOH) following the protocol given by Ghisletta (1994). Colourless single crystals suitable for X-ray analysis were grown from an aqueous solution by slow evaporation at ambient temperature. ¹H NMR (D₂O): δ 4.53, 3.53; ¹³C NMR (D₂O): δ 75.3, 54.7.

The crystals effloresce under ambient conditions when exposed to the air and lose two of the six equivalents of water, forming the terahydrate [Ge(taci)₂]Cl₄.4H₂O. Elemental analysis calculated (%) for C₁₂H₃₈Cl₄GeN₆O₁₀: C 22.49, H 5.98, Cl 22.13, Ge 11.33, N, 13.11; found: C 22.52, H 5.69, Cl 22.62, Ge 11.25, N, 12.80. Ge was determined by ICP–MS (inductively coupled plasma mass spectrometry) and Cl was determined by argentometric titrations.

S2.2. Refinement

Crystal data, data collection and structure refinement details are summarized in Table 1. All H atoms were located in a difference Fourier map and were treated as recommended by Müller et al. (2006). A riding model was used for the C-bonded H atoms. The positional parameters of the O- and N-bonded H atoms were refined using isotropic displacement parameters which were set at 1.5×U_eq of the pivot atom. In addition, restraints of 0.84 and 0.88 Å were used for the O—H and N—H bond lengths, respectively.

S3. Results and discussion

In general, no significant difference in geometry has been noted for the two crystallographically independent [Ge(taci)₂]⁴⁺ units of the title compound, (I). In agreement with Ghisletta's findings, the two ligand moieties coordinate exclusively via O-atom donors, forming a double-adamantane-type skeleton with approximate D_3d symmetry. The hy­droxy H atoms were all transferred to the amino groups, which act as inter­nal bases. It has frequently been proposed that the adoption of such a zwitterionic form contributes in particular to a high stability: It allows binding of the Ge^IV centre to six highly nucleophilic alkoxo groups without any necessity for a deprotonation of the complex as a whole by an external base (Hegetschweiler, 1999).

Only two examples of complexes with a tetra­valent centre, exhibiting such a zwitterionic bis-taci-type skeleton have structurally been characterized: [V(taci)₂]⁴⁺ and [V(tdci)₂]⁴⁺ (Morgenstern et al., 2004; tdci = 1,3,5-tri­deoxy-1,3,5-tris­(di­methyl­amino)-cis-inositol). The molecular structure of these complexes resembles the [Ge(taci)₂]⁴⁺ cations of the title compound quite closely. A similar double-adamantane skeleton with exclusive O-atom coordination has also been observed for [Al(taci)₂]³⁺, [Cr(taci)₂]³⁺ and a series of corresponding tdci complexes with Al³⁺, Fe³⁺, Ga³⁺ and In³⁺ (Hegetschweiler, 1999). The two GeO₆ polyhedra of (I) revealed, however, some structural peculiarities, which have not been mentioned in any of the previous reports. In the Ge complex, the mean intra­ligand O···O separation [2.707(?) Å for Ge1 and 2.686(?) Å for Ge2] is slightly larger than the mean inter­ligand separation [2.638(?) Å for Ge1 and 2.643(?) Å for Ge2]. In addition, close inspection of the individual O···O distances exhibits the presence of a pseudo-mirror plane within error limits (Fig. 1). Together with the crystallographically imposed centre of inversion, the molecular symmetry of the two complexes adds up to C_2h. Although small, the deviation from the expected D_3d symmetry is significant. It is observed for both cations, although they are embedded in different environments. Therefore, it is not conclusive to explain this distortion simply by a specific packing. It is noteworthy that the O···O distances are all substanti­ally shorter than the sum of the van der Waals radii of two O atoms (3.14 Å). Moreover, the intra­molecular distances are also significantly shorter than in the free ligand or in its protonation products H_ntaciⁿ⁺ (Neis & Hegetschweiler, 2014), where the O···O separations range from 2.9 to 3.1 Å, or from 2.7 to 2.8 Å if an intra­molecular hydrogen bond is formed. In terms of simple VSEPR (valence shell electron pair repulsion) considerations, one would expect strict O_h symmetry for an unstrained GeO₆ moiety. Regarding some negative charges on the alkoxo donors, enhanced ligand–ligand repulsion should result in an increase of inter­ligand O···O distances (Hegetschweiler et al., 1995). As a matter of fact, in all our previous investigations, inter­ligand O···O separations have been found to be larger than corresponding intra­ligand distances throughout. It appears thus that the Ge^IV centre might be too small to fit unconstrainedly in the cavity, formed by the six O atoms of two taci molecules. Such an assumption is further supported by a strong puckering of the cyclo­hexane rings. Puckering parameters were calculated according to Cremer & Pople, 1975): Q = 0.627 Å, θ = 1.62 ° and φ = 274.74 ° (for Ge1), and Q = 0.641 Å, θ = 1.20 ° and φ = 306.73 ° (for Ge2). These values confirm a pure chair conformation for both cations, however, the value of the total puckering amplitude Q is significantly larger in comparison to the free taci, its protonation products or metal complexes (Neis & Hegetschweiler, 2014; Neis et al., 2014). Inter­estingly, the Ge—O bonds appear, however, not to be widened. The Cambridge Structural Database (CSD, Version ???; Groom & Allen 2014) contains only one entry for Ge^IV bonded to six alkoxo donors for comparison. It is a complex of a deprotonated β-cyclo­dextrine reported by Benner et al. (2006), with a mean Ge—O bond length of 1.914 Å.

In recent times, we spent particular attention to the hydrogen-bonding properties of taci, its protonation products and its metal complexes (Neis & Hegetschweiler, 2014). These studies have shown that R—O—H···NH₂—R' inter­actions are observed quite frequently and, the pairing of two OH—CH—CH—NH₂-groups appears to be a particularly favoured motif. In terms of graph-set analysis (Bernstein et al., 1995), such a pattern receives the descriptor R₂²(10). In (I), the chloride anions and the alkoxo groups are potential acceptors and the ammonium groups potential donors, whereas the water molecules may undergo both donating and accepting inter­actions. Among them, the ammonium group represents the strongest donor and the coordinated alkoxo group the strongest acceptor. However, no N—H···O_alkoxo inter­actions have been observed in the structure of (I). Instead, inter­connection of [Ge(taci)₂]⁴⁺ cations is mediated via water molecules and chloride counter-ions. With respect to the approximate D_3d symmetry of the [Ge(taci)₂]⁴⁺ cation, the ammonium groups all adopt an orientation with one N—H bond in an axial orientation and the other two in equatorial orientations. The two equatorial N—H bonds point to the outside of the molecule (Fig. 2). The axial N—H protons point, however, towards an alkoxo O atom. Despite an N···O distance of 2.8–2.9 Å between such a vicinal ammonium–alkoxo group, the small N—H···O angle (<110 °) precludes an inter­pretation as intra­molecular hydrogen bonding.

Both cations are surrounded by six water molecules. In cations of Ge2, all these water molecules accept an axial N—H hydrogen and donate an H atom to a coordinated alkoxo group of the opposite ligand. This inter­action (denoted type-A) results in the formation of a nine-membered N—H···O(H)—H···O—Ge—O—C—C ring. The cations of Ge1, however, exhibit only four such type-A inter­actions. The remaining two water molecules (O5W) also accept an axial N2—H hydrogen but donate an H atom to a coordinated alkoxo group (O1) of the same ligand moiety. This inter­action (denoted type-B) results in the formation of a seven-membered N—H···O(H)—H···O—C—C ring. Moreover, the axial N—H hydrogen of the type-B inter­action is bifurcated, forming an additional hydrogen bond to O4W, which in turn represents again a type-A inter­action (Fig. 2a). As a consequence, the remaining axial N—H hydrogen at atom N4 is not involved in this particular hydration scheme. Type-A inter­actions have been observed previously in other taci complexes with such a zwitterionic form (Hegetschweiler et al., 1995), whereas type-B inter­actions have not been reported yet. The specific structure of the taci ligand together with the characteristic hydration shell of the cations resulted in a strongly dipolar shape of the entire aggregate with two hydro­phobic poles (the C₆H₆ frames) and a hydro­philic belt. Inter­connection of these hydrated cations emerges mainly via inter­molecular hydrogen bonding (Table 2) between the hydro­philic belts of neighbouring complex molecules either with or without participation of the chloride counter-ions. The following inter­actions are observed:

(i): N—H···Cl···H—N;

(ii): N—H···O(H)₂···H—N, together with O_alkoxo···H(OH)···H—N;

(iii): N—H···O(H)—H···Cl···H—N, together with O_alkoxo···H—O—H···Cl···H—N;

(iv): N—H···O(H)—H···Cl···H—(H)O···H—N, together with O_alkoxo···H—O—H···Cl···H—(H)O···H—N and O_alkoxo···H—O—H···Cl···H—O—H···O_alkoxo.

Cations of Ge1 are inter­connected via inter­action types (i), (ii) and (iii), forming chains along the crystallographic a axis. Additional type (i) inter­linking along the b axis generates layers, which are oriented parallel to the ab plane (Fig. 3a). Similarly, the cations of Ge2 form chains along the a axis via inter­action types (i), (ii) and (iv). Further inter­linking by type (i) hydrogen bonds along b results again in the formation of layers parallel to the ab plane (Fig. 3b). Finally, inter­linking of the two different cationic species (Ge1 and Ge2) by all four inter­action types constitutes layers oriented parallel to the bc plane (Fig. 3c). The four inter­action types give rise to the formation of a variety of different cyclic patterns. Some of them are displayed in Fig. 4. The first example (Fig. 4a) shows the direct inter­linking of [Ge1(taci)₂](H₂O)₆⁴⁺ aggregates via type-B-bonded H₂O molecules. In terms of a graph-set description, the type-B binding comprises two individual finite hydrogen bonds and the corresponding first-level (N₁) descriptor is DD. The cyclic nature of this arrangement becomes evident from the second level (N₂) analysis with the descriptor R₂²(7). This pattern is further extended to chains of the type C₁²(9) along the a axis considering the additional hydrogen bond from O3W to O7, and the combination of two symmetry-related C₁²(9) patterns finally constitute large rings of the type R₄²(24). The inter­linking of type-A-bonded water molecules, as observed for Ge2, takes place by a somewhat different mechanism (Fig. 4b). Again, the type-A binding comprises two finite hydrogen bonds (N₁: DD). The emerging ring pattern (N₂) is, however, R₂²(9). The formation of C₁²(9) chains follows again from the additional hydrogen bonding (O3W···O7) to a neighbouring cation, and the combination of symmetry-related C₁²(9) chains generates R₄²(8) and (more complex) R₄⁴(24) rings. It has been pointed out by Bernstein et al. that the R₄²(8) pattern is quite common for hydrogen bonding and is observed in a variety of different structures. The archetypal nature of the R₄²(8) pattern is also evident in the title compound. It is not only found for the abovementioned Ge2-cation···water inter­linking along [100] (Fig. 4b), but also for the cation–chloride inter­actions of Ge1 along [110] (Fig. 4c). Further cyclic patterns containing ammonium groups and chloride anions with larger rings are obtained as some parts of the ligand skeleton is included within the loop. Fig. 4(d) shows the alignment of Ge1 along the b axis, forming R₄²(16)-rings, whereas connection of the Ge1 cations along the a axis is not only mediated via water molecules (Fig. 4a), but also via chloride anions (Fig. 4e), forming R₄²(12) and large R₄³(24) patterns. The latter are again obtained by combining two symmetry-related R₄²(12) motifs within the Ge1···Ge1 chain. Finally, even more complex structures evolve, if both H₂O and Cl^- are included within the cycle. Such an example, comprising two chloride anions and four water molecules, adding up to R₈⁶(22) (for a loop via N—H···OH₂) or R₈⁶(20) (for a loop via H—O—H···O_alkoxo) is shown for the Ge2···Ge2 inter­action along the b axis in Fig. 4(f).

With regard to the counter-ions (Fig. 5), Cl1 accepts one N—H and four H—O (water) hydrogens, thus having a coordination number of five. It is engaged by the inter­connection from three cations (two Ge2 and one Ge1). Cl2 accepts three N—H hydrogens from three cations (two Ge1 and one Ge2), Cl3 accepts four N—H hydrogens from four cations (three Ge2 and one Ge1) and Cl4 accepts three N—H hydrogens and one water H atom, inter­linking three cations of Ge1. As can be seen in Fig. 5, the geometry of the corresponding Cl1H₅, Cl2H₃, Cl3H₄ and Cl4H₄ polyhedra is strongly irregular throughout.

S4. Conclusions

The title compound exhibits a remarkably complex three-dimensional network of hydrogen bonds. Although a waste variety of different types of inter­actions are formed, direct taci–taci contacts, such as N—H···O_alkoxo, are not observed. It is obvious that bis-taci complexes with a zwitterionic form of the ligand display a completely different behaviour than the free ligand, its protonation products and metal complexes with the ligand in a nonzwitterionic form (Neis et al., 2014). In addition, no direct inter­actions between the hydro­phobic poles of the [Ge(taci)₂]⁴⁺ cations in the form of C—H···H—C van der Waals contacts are observed. As can be seen in Figs. 3(b) and 3(c), the nearest neighbours of the hydro­phobic poles are either water molecules or chloride ions, with H···O distances around 2.5 Å and H···Cl distances in the range from 2.6–2.8 Å. It remains questionable whether these inter­actions could be regarded as additional weak C—H···X hydrogen bonds. Inspection of this structure also supports the conclusion that simple electrostatic inter­actions contribute extensively to its stability. The non-observance of direct N—H···O_alkoxo inter­actions could be explained by the considerable Coulombic repulsion between the fourfold cations. On the other hand, cation–anion attraction, which of course results in a general Madelung-type stabilization, is directly visible (Fig. 5d), displaying a `salt bridge' with an ammonium group (N8) where all three H atoms (N8) are directed towards Cl4 [N8···Cl4 separation = 3.2(?) Å]. It is also noteworthy that in contrast to the well balanced pairing of vicinal HO—CH—CH—NH₂ groups mentioned above, the hydrogen-bonding scheme in the title compound remains unbalanced. One of the water H atoms (H3W—O2W), as an example, remains without an acceptor (Fig. 3c).

Structure description

A first preliminary report on the crystal structure of a hydrated salt formulated as [Ge(taci)₂]Cl₄.13H₂O (taci = 1,3,5-tri­amino-1,3,5-tri­deoxy-cis-inositol) appeared more than 20 years ago (Ghisletta, 1994). However, at that time, structure elucidation remained unsatisfactory. It was not possible to discriminate unambiguously between the positions of some of the chloride ions and water O atoms. As a consequence, a disorder was postulated, with an occupation of these positions by the two atom types at random. This artifact is particularly regrettable, because a conclusive scheme of hydrogen bonding, which is – as we shall show in this contribution – a particularly appealing aspect of the structure, could not be elucidated. We therefore regrew single crystals of this complex, following Ghisletta's protocol, and repeated the structure elucidation at low temperature. In agreement with Ghisletta's description, the structure could again be solved and refined in the triclinic centrosymmetric space group P1. However, in contrast to the previous investigation, where only one position for the [Ge(taci)₂]⁴⁺ cation has been considered, we encountered two crystallographically independent Ge-atom positions, both located on a centre of inversion. In addition, the amount of hydration appeared to be smaller and we formulate the new structure as [Ge(taci)₂]₂Cl₈.12H₂O. The new attempt now allowed an unambiguous discrimination between O atom and chloride anion positions. Consequently, a complete resolution of the structure without any disorder proved possible.

In general, no significant difference in geometry has been noted for the two crystallographically independent [Ge(taci)₂]⁴⁺ units of the title compound, (I). In agreement with Ghisletta's findings, the two ligand moieties coordinate exclusively via O-atom donors, forming a double-adamantane-type skeleton with approximate D_3d symmetry. The hy­droxy H atoms were all transferred to the amino groups, which act as inter­nal bases. It has frequently been proposed that the adoption of such a zwitterionic form contributes in particular to a high stability: It allows binding of the Ge^IV centre to six highly nucleophilic alkoxo groups without any necessity for a deprotonation of the complex as a whole by an external base (Hegetschweiler, 1999).

Only two examples of complexes with a tetra­valent centre, exhibiting such a zwitterionic bis-taci-type skeleton have structurally been characterized: [V(taci)₂]⁴⁺ and [V(tdci)₂]⁴⁺ (Morgenstern et al., 2004; tdci = 1,3,5-tri­deoxy-1,3,5-tris­(di­methyl­amino)-cis-inositol). The molecular structure of these complexes resembles the [Ge(taci)₂]⁴⁺ cations of the title compound quite closely. A similar double-adamantane skeleton with exclusive O-atom coordination has also been observed for [Al(taci)₂]³⁺, [Cr(taci)₂]³⁺ and a series of corresponding tdci complexes with Al³⁺, Fe³⁺, Ga³⁺ and In³⁺ (Hegetschweiler, 1999). The two GeO₆ polyhedra of (I) revealed, however, some structural peculiarities, which have not been mentioned in any of the previous reports. In the Ge complex, the mean intra­ligand O···O separation [2.707(?) Å for Ge1 and 2.686(?) Å for Ge2] is slightly larger than the mean inter­ligand separation [2.638(?) Å for Ge1 and 2.643(?) Å for Ge2]. In addition, close inspection of the individual O···O distances exhibits the presence of a pseudo-mirror plane within error limits (Fig. 1). Together with the crystallographically imposed centre of inversion, the molecular symmetry of the two complexes adds up to C_2h. Although small, the deviation from the expected D_3d symmetry is significant. It is observed for both cations, although they are embedded in different environments. Therefore, it is not conclusive to explain this distortion simply by a specific packing. It is noteworthy that the O···O distances are all substanti­ally shorter than the sum of the van der Waals radii of two O atoms (3.14 Å). Moreover, the intra­molecular distances are also significantly shorter than in the free ligand or in its protonation products H_ntaciⁿ⁺ (Neis & Hegetschweiler, 2014), where the O···O separations range from 2.9 to 3.1 Å, or from 2.7 to 2.8 Å if an intra­molecular hydrogen bond is formed. In terms of simple VSEPR (valence shell electron pair repulsion) considerations, one would expect strict O_h symmetry for an unstrained GeO₆ moiety. Regarding some negative charges on the alkoxo donors, enhanced ligand–ligand repulsion should result in an increase of inter­ligand O···O distances (Hegetschweiler et al., 1995). As a matter of fact, in all our previous investigations, inter­ligand O···O separations have been found to be larger than corresponding intra­ligand distances throughout. It appears thus that the Ge^IV centre might be too small to fit unconstrainedly in the cavity, formed by the six O atoms of two taci molecules. Such an assumption is further supported by a strong puckering of the cyclo­hexane rings. Puckering parameters were calculated according to Cremer & Pople, 1975): Q = 0.627 Å, θ = 1.62 ° and φ = 274.74 ° (for Ge1), and Q = 0.641 Å, θ = 1.20 ° and φ = 306.73 ° (for Ge2). These values confirm a pure chair conformation for both cations, however, the value of the total puckering amplitude Q is significantly larger in comparison to the free taci, its protonation products or metal complexes (Neis & Hegetschweiler, 2014; Neis et al., 2014). Inter­estingly, the Ge—O bonds appear, however, not to be widened. The Cambridge Structural Database (CSD, Version ???; Groom & Allen 2014) contains only one entry for Ge^IV bonded to six alkoxo donors for comparison. It is a complex of a deprotonated β-cyclo­dextrine reported by Benner et al. (2006), with a mean Ge—O bond length of 1.914 Å.

In recent times, we spent particular attention to the hydrogen-bonding properties of taci, its protonation products and its metal complexes (Neis & Hegetschweiler, 2014). These studies have shown that R—O—H···NH₂—R' inter­actions are observed quite frequently and, the pairing of two OH—CH—CH—NH₂-groups appears to be a particularly favoured motif. In terms of graph-set analysis (Bernstein et al., 1995), such a pattern receives the descriptor R₂²(10). In (I), the chloride anions and the alkoxo groups are potential acceptors and the ammonium groups potential donors, whereas the water molecules may undergo both donating and accepting inter­actions. Among them, the ammonium group represents the strongest donor and the coordinated alkoxo group the strongest acceptor. However, no N—H···O_alkoxo inter­actions have been observed in the structure of (I). Instead, inter­connection of [Ge(taci)₂]⁴⁺ cations is mediated via water molecules and chloride counter-ions. With respect to the approximate D_3d symmetry of the [Ge(taci)₂]⁴⁺ cation, the ammonium groups all adopt an orientation with one N—H bond in an axial orientation and the other two in equatorial orientations. The two equatorial N—H bonds point to the outside of the molecule (Fig. 2). The axial N—H protons point, however, towards an alkoxo O atom. Despite an N···O distance of 2.8–2.9 Å between such a vicinal ammonium–alkoxo group, the small N—H···O angle (<110 °) precludes an inter­pretation as intra­molecular hydrogen bonding.

Both cations are surrounded by six water molecules. In cations of Ge2, all these water molecules accept an axial N—H hydrogen and donate an H atom to a coordinated alkoxo group of the opposite ligand. This inter­action (denoted type-A) results in the formation of a nine-membered N—H···O(H)—H···O—Ge—O—C—C ring. The cations of Ge1, however, exhibit only four such type-A inter­actions. The remaining two water molecules (O5W) also accept an axial N2—H hydrogen but donate an H atom to a coordinated alkoxo group (O1) of the same ligand moiety. This inter­action (denoted type-B) results in the formation of a seven-membered N—H···O(H)—H···O—C—C ring. Moreover, the axial N—H hydrogen of the type-B inter­action is bifurcated, forming an additional hydrogen bond to O4W, which in turn represents again a type-A inter­action (Fig. 2a). As a consequence, the remaining axial N—H hydrogen at atom N4 is not involved in this particular hydration scheme. Type-A inter­actions have been observed previously in other taci complexes with such a zwitterionic form (Hegetschweiler et al., 1995), whereas type-B inter­actions have not been reported yet. The specific structure of the taci ligand together with the characteristic hydration shell of the cations resulted in a strongly dipolar shape of the entire aggregate with two hydro­phobic poles (the C₆H₆ frames) and a hydro­philic belt. Inter­connection of these hydrated cations emerges mainly via inter­molecular hydrogen bonding (Table 2) between the hydro­philic belts of neighbouring complex molecules either with or without participation of the chloride counter-ions. The following inter­actions are observed:

(i): N—H···Cl···H—N;

(ii): N—H···O(H)₂···H—N, together with O_alkoxo···H(OH)···H—N;

(iii): N—H···O(H)—H···Cl···H—N, together with O_alkoxo···H—O—H···Cl···H—N;

(iv): N—H···O(H)—H···Cl···H—(H)O···H—N, together with O_alkoxo···H—O—H···Cl···H—(H)O···H—N and O_alkoxo···H—O—H···Cl···H—O—H···O_alkoxo.

Cations of Ge1 are inter­connected via inter­action types (i), (ii) and (iii), forming chains along the crystallographic a axis. Additional type (i) inter­linking along the b axis generates layers, which are oriented parallel to the ab plane (Fig. 3a). Similarly, the cations of Ge2 form chains along the a axis via inter­action types (i), (ii) and (iv). Further inter­linking by type (i) hydrogen bonds along b results again in the formation of layers parallel to the ab plane (Fig. 3b). Finally, inter­linking of the two different cationic species (Ge1 and Ge2) by all four inter­action types constitutes layers oriented parallel to the bc plane (Fig. 3c). The four inter­action types give rise to the formation of a variety of different cyclic patterns. Some of them are displayed in Fig. 4. The first example (Fig. 4a) shows the direct inter­linking of [Ge1(taci)₂](H₂O)₆⁴⁺ aggregates via type-B-bonded H₂O molecules. In terms of a graph-set description, the type-B binding comprises two individual finite hydrogen bonds and the corresponding first-level (N₁) descriptor is DD. The cyclic nature of this arrangement becomes evident from the second level (N₂) analysis with the descriptor R₂²(7). This pattern is further extended to chains of the type C₁²(9) along the a axis considering the additional hydrogen bond from O3W to O7, and the combination of two symmetry-related C₁²(9) patterns finally constitute large rings of the type R₄²(24). The inter­linking of type-A-bonded water molecules, as observed for Ge2, takes place by a somewhat different mechanism (Fig. 4b). Again, the type-A binding comprises two finite hydrogen bonds (N₁: DD). The emerging ring pattern (N₂) is, however, R₂²(9). The formation of C₁²(9) chains follows again from the additional hydrogen bonding (O3W···O7) to a neighbouring cation, and the combination of symmetry-related C₁²(9) chains generates R₄²(8) and (more complex) R₄⁴(24) rings. It has been pointed out by Bernstein et al. that the R₄²(8) pattern is quite common for hydrogen bonding and is observed in a variety of different structures. The archetypal nature of the R₄²(8) pattern is also evident in the title compound. It is not only found for the abovementioned Ge2-cation···water inter­linking along [100] (Fig. 4b), but also for the cation–chloride inter­actions of Ge1 along [110] (Fig. 4c). Further cyclic patterns containing ammonium groups and chloride anions with larger rings are obtained as some parts of the ligand skeleton is included within the loop. Fig. 4(d) shows the alignment of Ge1 along the b axis, forming R₄²(16)-rings, whereas connection of the Ge1 cations along the a axis is not only mediated via water molecules (Fig. 4a), but also via chloride anions (Fig. 4e), forming R₄²(12) and large R₄³(24) patterns. The latter are again obtained by combining two symmetry-related R₄²(12) motifs within the Ge1···Ge1 chain. Finally, even more complex structures evolve, if both H₂O and Cl^- are included within the cycle. Such an example, comprising two chloride anions and four water molecules, adding up to R₈⁶(22) (for a loop via N—H···OH₂) or R₈⁶(20) (for a loop via H—O—H···O_alkoxo) is shown for the Ge2···Ge2 inter­action along the b axis in Fig. 4(f).

With regard to the counter-ions (Fig. 5), Cl1 accepts one N—H and four H—O (water) hydrogens, thus having a coordination number of five. It is engaged by the inter­connection from three cations (two Ge2 and one Ge1). Cl2 accepts three N—H hydrogens from three cations (two Ge1 and one Ge2), Cl3 accepts four N—H hydrogens from four cations (three Ge2 and one Ge1) and Cl4 accepts three N—H hydrogens and one water H atom, inter­linking three cations of Ge1. As can be seen in Fig. 5, the geometry of the corresponding Cl1H₅, Cl2H₃, Cl3H₄ and Cl4H₄ polyhedra is strongly irregular throughout.

The title compound exhibits a remarkably complex three-dimensional network of hydrogen bonds. Although a waste variety of different types of inter­actions are formed, direct taci–taci contacts, such as N—H···O_alkoxo, are not observed. It is obvious that bis-taci complexes with a zwitterionic form of the ligand display a completely different behaviour than the free ligand, its protonation products and metal complexes with the ligand in a nonzwitterionic form (Neis et al., 2014). In addition, no direct inter­actions between the hydro­phobic poles of the [Ge(taci)₂]⁴⁺ cations in the form of C—H···H—C van der Waals contacts are observed. As can be seen in Figs. 3(b) and 3(c), the nearest neighbours of the hydro­phobic poles are either water molecules or chloride ions, with H···O distances around 2.5 Å and H···Cl distances in the range from 2.6–2.8 Å. It remains questionable whether these inter­actions could be regarded as additional weak C—H···X hydrogen bonds. Inspection of this structure also supports the conclusion that simple electrostatic inter­actions contribute extensively to its stability. The non-observance of direct N—H···O_alkoxo inter­actions could be explained by the considerable Coulombic repulsion between the fourfold cations. On the other hand, cation–anion attraction, which of course results in a general Madelung-type stabilization, is directly visible (Fig. 5d), displaying a `salt bridge' with an ammonium group (N8) where all three H atoms (N8) are directed towards Cl4 [N8···Cl4 separation = 3.2(?) Å]. It is also noteworthy that in contrast to the well balanced pairing of vicinal HO—CH—CH—NH₂ groups mentioned above, the hydrogen-bonding scheme in the title compound remains unbalanced. One of the water H atoms (H3W—O2W), as an example, remains without an acceptor (Fig. 3c).

Synthesis and crystallization

1,3,5-Tri­amino-1,3,5-tri­deoxy-cis-inositol (taci) was prepared as described by Hegetschweiler et al. (1990). The title compound, i.e. [Ge(taci)₂]₂Cl₈.12H₂O, was prepared by combining solutions of GeCl₄ (0.50 g, 2.33 mmol in 5 ml of MeOH) and taci (0.82 g, 4.63 mmol in 25 ml of MeOH) following the protocol given by Ghisletta (1994). Colourless single crystals suitable for X-ray analysis were grown from an aqueous solution by slow evaporation at ambient temperature. ¹H NMR (D₂O): δ 4.53, 3.53; ¹³C NMR (D₂O): δ 75.3, 54.7.

The crystals effloresce under ambient conditions when exposed to the air and lose two of the six equivalents of water, forming the terahydrate [Ge(taci)₂]Cl₄.4H₂O. Elemental analysis calculated (%) for C₁₂H₃₈Cl₄GeN₆O₁₀: C 22.49, H 5.98, Cl 22.13, Ge 11.33, N, 13.11; found: C 22.52, H 5.69, Cl 22.62, Ge 11.25, N, 12.80. Ge was determined by ICP–MS (inductively coupled plasma mass spectrometry) and Cl was determined by argentometric titrations.

Refinement details

Crystal data, data collection and structure refinement details are summarized in Table 1. All H atoms were located in a difference Fourier map and were treated as recommended by Müller et al. (2006). A riding model was used for the C-bonded H atoms. The positional parameters of the O- and N-bonded H atoms were refined using isotropic displacement parameters which were set at 1.5×U_eq of the pivot atom. In addition, restraints of 0.84 and 0.88 Å were used for the O—H and N—H bond lengths, respectively.

Computing details

Data collection: APEX2 (Bruker, 2010); cell refinement: SAINT (Bruker, 2010); data reduction: SAINT (Bruker, 2010); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL2014 (Sheldrick, 2015); molecular graphics: DIAMOND (Brandenburg, 2012); software used to prepare material for publication: SHELXL2014 (Sheldrick, 2015).

Figures

	Fig. 1. Digonal distortion of the two crystallographically independent [Ge(taci)2]^4+ cations from D3d to C2h. Intraligand O···O and interligand O···O separations (in Å) are given in red and blue, respectively. Of each pair, the first number refers to Ge1 and the second (in italics) to Ge2. The relevant symmetry elements and pseudosymmetry elements are displayed in green.
	Fig. 2. The molecular structure and atom-numbering scheme for the two [Ge(taci)2](H2O)6^4+ cations of (I). The cyclohexane frame is shown as a stick model. N (dark blue), alkoxo O (red), water O (orange), Ge (light blue), and N– and O-bonded H (white) atoms are shown as spheres of arbitrary size, while C-bonded H atoms have been omitted for clarity. N—H···O (blue) and O—H···O (orange) hydrogen bonds are represented by thin broken lines.
	Fig. 3. Sections of the hydrogen-bonding pattern in (I). (a)/(b) The layers parallel to the ab plane formed by the interlinking of symmetry-related cations of Ge1 and Ge2, respectively. (c) A layer parallel to the bc plane formed by the mutual interlinking of the cations of Ge1 and Ge2. The colour code is as used in Fig. 1. In addition, the chloride counter-anions are shown as green spheres and N—H···Cl and O—H···Cl hydrogen bonds are represented as thin broken green lines. Weak C—H···Cl and C—H···Cl contacts are shown as thin broken black lines. C– and N-bonded H atoms, as well as ammonium groups, which are not involved in the intermolecular hydrogen-bonding scheme shown explicitely in the figure have been omitted for clarity.
	Fig. 4. A selection of cyclic motifs, emerging from the various linking interactions between neighbouring cations. The representation of atoms and bonds is as in Fig. 2. (a) R4^4(18), R4^4(21) and R4^4(24) rings which are formed within the chains of Ge1 cations aligned along the a axis. (b)/(c) The R2^4(8) motif observed for the Ge2···Ge2 and Ge1···Ge1 interactions, respectively. (d)/(e) The R2^4(16), R2^4(12) and R2^4(24) ring observed for the interlinking of Ge1. Complex R4^8(24) rings which are observed for the Ge2···Ge2 interconnection, comprising four ammonium groups, four water molecules and two chloride anions. Atoms and bonds are as represented in Fig. 2.
	Fig. 5. The chloride anions with their environments. Atoms and bonds are as represented in Fig. 2.

Bis[2,4,6-triazaniumylcyclohexane-1,3,5-tris(olate)-κ³O,O',O'']germanium(IV) tetrachloride hexahydrate

Crystal data

C12H30GeN6O6^4+·4Cl^−·6H2O	Z = 2
Mr = 676.90	F(000) = 704
Triclinic, P1	Dx = 1.730 Mg m^−3
a = 8.5247 (5) Å	Mo Kα radiation, λ = 0.71073 Å
b = 10.9152 (6) Å	Cell parameters from 9303 reflections
c = 15.1592 (8) Å	θ = 2.5–33.3°
α = 82.980 (2)°	µ = 1.66 mm^−1
β = 79.248 (2)°	T = 123 K
γ = 70.022 (2)°	Block, colourless
V = 1299.78 (13) Å^3	0.55 × 0.45 × 0.45 mm

Data collection

Bruker X8 APEX/Nonius KappaCCD diffractometer	5520 reflections with I > 2σ(I)
φ and ω scans	Rint = 0.021
Absorption correction: multi-scan (SADABS; Bruker, 2010)	θmax = 27.0°, θmin = 2.0°
Tmin = 0.620, Tmax = 0.747	h = −10→10
29040 measured reflections	k = −13→13
5652 independent reflections	l = −15→19

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)] = 0.018	Hydrogen site location: inferred from neighbouring sites
wR(F^2) = 0.048	H atoms treated by a mixture of independent and constrained refinement
S = 1.07	w = 1/[σ^2(Fo^2) + (0.020P)^2 + 1.016P] where P = (Fo^2 + 2Fc^2)/3
5652 reflections	(Δ/σ)max = 0.001
411 parameters	Δρmax = 0.60 e Å^−3
30 restraints	Δρmin = −0.53 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
Ge1	0.5000	0.0000	0.5000	0.00507 (5)
Cl1	0.34505 (5)	0.53186 (4)	0.29724 (2)	0.01918 (8)
O1	0.26716 (11)	0.08331 (9)	0.53532 (6)	0.00782 (17)
C1	0.21252 (16)	0.18593 (12)	0.59443 (8)	0.0079 (2)
H1	0.0862	0.2185	0.6053	0.009*
Ge2	0.0000	0.5000	1.0000	0.00523 (5)
Cl2	0.16658 (4)	0.89804 (3)	0.18156 (2)	0.01299 (7)
N2	0.21771 (15)	0.02494 (11)	0.72309 (8)	0.0104 (2)
H2C	0.1080 (12)	0.0512 (17)	0.7434 (11)	0.016*
H2B	0.273 (2)	−0.0190 (16)	0.7674 (9)	0.016*
H2A	0.235 (2)	−0.0291 (15)	0.6808 (10)	0.016*
C2	0.27454 (16)	0.13831 (12)	0.68518 (9)	0.0086 (2)
H2	0.2248	0.2103	0.7273	0.010*
Cl3	0.58198 (4)	0.09882 (3)	0.11571 (2)	0.01123 (7)
O3	0.54265 (11)	−0.01265 (9)	0.61961 (6)	0.00764 (17)
C3	0.46737 (16)	0.09543 (12)	0.67402 (8)	0.0078 (2)
H3	0.5028	0.0695	0.7347	0.009*
Cl4	0.15020 (4)	0.64858 (3)	0.53102 (2)	0.01232 (7)
C4	0.52395 (16)	0.21148 (12)	0.63282 (9)	0.0083 (2)
H4	0.4726	0.2846	0.6740	0.010*
N4	0.71145 (14)	0.17095 (11)	0.62418 (8)	0.0103 (2)
H4C	0.741 (2)	0.1627 (17)	0.6779 (8)	0.015*
H4B	0.751 (2)	0.2279 (14)	0.5878 (10)	0.015*
H4A	0.761 (2)	0.0953 (12)	0.5987 (11)	0.015*
O5	0.54073 (11)	0.16181 (9)	0.47733 (6)	0.00759 (17)
C5	0.46765 (16)	0.25862 (12)	0.54107 (9)	0.0080 (2)
H5	0.5026	0.3367	0.5178	0.010*
C7	−0.14445 (16)	0.74172 (12)	0.89916 (8)	0.0082 (2)
H7	−0.2369	0.7875	0.8628	0.010*
O7	−0.15275 (11)	0.61525 (9)	0.92760 (6)	0.00795 (18)
C8	0.02392 (16)	0.73851 (12)	0.84157 (8)	0.0084 (2)
H8	0.0216	0.8307	0.8258	0.010*
N8	0.04825 (15)	0.67499 (11)	0.75618 (8)	0.0101 (2)
H8A	−0.0396 (17)	0.7159 (16)	0.7290 (11)	0.015*
H8C	0.1404 (16)	0.6826 (17)	0.7210 (10)	0.015*
H8B	0.057 (2)	0.5923 (10)	0.7650 (12)	0.015*
C9	0.16852 (16)	0.67069 (12)	0.89530 (8)	0.0079 (2)
H9	0.2772	0.6711	0.8567	0.010*
O9	0.18025 (11)	0.53983 (9)	0.92401 (6)	0.00786 (18)
C12	−0.16892 (16)	0.82192 (12)	0.97956 (9)	0.0086 (2)
H12	−0.1657	0.9111	0.9567	0.010*
O1W	−0.02517 (14)	0.57481 (10)	0.25090 (7)	0.0154 (2)
H1W	0.0704 (15)	0.5636 (19)	0.2642 (13)	0.023*
H2W	−0.020 (2)	0.5953 (18)	0.1955 (7)	0.023*
O2W	0.27293 (13)	0.22936 (10)	0.30544 (7)	0.0152 (2)
H3W	0.343 (2)	0.2516 (18)	0.2675 (11)	0.023*
H4W	0.328 (2)	0.1569 (12)	0.3276 (12)	0.023*
O3W	0.41176 (13)	0.44012 (10)	0.09881 (7)	0.0164 (2)
H5W	0.3296 (18)	0.4169 (19)	0.0941 (13)	0.025*
H6W	0.402 (3)	0.4533 (19)	0.1530 (7)	0.025*
O5W	0.97249 (14)	0.05039 (11)	0.40190 (7)	0.0188 (2)
H9W	0.903 (2)	0.0194 (19)	0.4347 (12)	0.028*
H10W	0.952 (3)	0.1225 (12)	0.4217 (13)	0.028*
O4W	0.64995 (14)	0.26799 (11)	0.31329 (7)	0.0164 (2)
H7W	0.5723 (19)	0.3392 (13)	0.3084 (13)	0.025*
H8W	0.623 (2)	0.2403 (18)	0.3652 (8)	0.025*
O6W	0.59307 (17)	0.65553 (12)	0.16287 (9)	0.0345 (3)
H11W	0.658 (3)	0.5880 (16)	0.1386 (16)	0.052*
H12W	0.509 (2)	0.636 (2)	0.1882 (16)	0.052*
N12	−0.33744 (14)	0.83462 (11)	1.03432 (8)	0.0099 (2)
H12A	−0.4124 (18)	0.8493 (17)	0.9983 (10)	0.015*
H12B	−0.342 (2)	0.7663 (13)	1.0710 (10)	0.015*
H12C	−0.371 (2)	0.9038 (13)	1.0660 (11)	0.015*
C11	−0.02864 (16)	0.75855 (12)	1.03694 (9)	0.0082 (2)
H11	−0.0456	0.8162	1.0868	0.010*
O11	−0.02991 (11)	0.63406 (9)	1.07497 (6)	0.00779 (17)
C10	0.13823 (16)	0.75255 (12)	0.97592 (9)	0.0084 (2)
H10	0.1332	0.8434	0.9529	0.010*
H10B	0.270 (2)	0.7446 (16)	1.0706 (9)	0.018 (4)*
N10	0.28346 (14)	0.69589 (11)	1.02618 (8)	0.0102 (2)
H10C	0.3764 (16)	0.6924 (17)	0.9882 (10)	0.015*
H10A	0.298 (2)	0.6147 (10)	1.0483 (11)	0.015*
C6	0.27445 (16)	0.30084 (12)	0.55631 (8)	0.0086 (2)
H6	0.2287	0.3709	0.6000	0.010*
N6	0.21305 (15)	0.35440 (11)	0.46944 (8)	0.0100 (2)
H6A	0.264 (2)	0.3019 (15)	0.4259 (9)	0.015*
H6B	0.1050 (13)	0.3638 (17)	0.4739 (12)	0.015*
H6C	0.225 (2)	0.4310 (11)	0.4543 (12)	0.015*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
Ge1	0.00563 (9)	0.00489 (9)	0.00471 (9)	−0.00180 (7)	−0.00080 (6)	−0.00011 (6)
Cl1	0.02134 (18)	0.02079 (18)	0.01659 (16)	−0.01033 (14)	−0.00246 (13)	0.00375 (13)
O1	0.0070 (4)	0.0074 (4)	0.0088 (4)	−0.0018 (3)	−0.0006 (3)	−0.0022 (3)
C1	0.0070 (6)	0.0072 (6)	0.0087 (6)	−0.0015 (5)	−0.0005 (4)	−0.0010 (5)
Ge2	0.00552 (9)	0.00493 (9)	0.00533 (9)	−0.00180 (7)	−0.00099 (6)	−0.00017 (6)
Cl2	0.01460 (16)	0.01298 (15)	0.01089 (14)	−0.00306 (12)	−0.00292 (12)	−0.00167 (11)
N2	0.0105 (5)	0.0116 (5)	0.0092 (5)	−0.0048 (4)	−0.0009 (4)	0.0012 (4)
C2	0.0097 (6)	0.0083 (6)	0.0080 (6)	−0.0036 (5)	0.0000 (5)	−0.0008 (4)
Cl3	0.01186 (15)	0.01079 (15)	0.01166 (14)	−0.00423 (12)	−0.00366 (11)	0.00135 (11)
O3	0.0095 (4)	0.0066 (4)	0.0063 (4)	−0.0012 (3)	−0.0019 (3)	−0.0014 (3)
C3	0.0088 (6)	0.0085 (6)	0.0062 (5)	−0.0028 (5)	−0.0009 (4)	−0.0015 (4)
Cl4	0.01222 (15)	0.01241 (15)	0.01334 (15)	−0.00581 (12)	−0.00138 (11)	−0.00031 (11)
C4	0.0076 (6)	0.0086 (6)	0.0089 (6)	−0.0026 (5)	−0.0013 (5)	−0.0019 (5)
N4	0.0099 (5)	0.0118 (6)	0.0104 (5)	−0.0048 (4)	−0.0030 (4)	0.0008 (4)
O5	0.0094 (4)	0.0063 (4)	0.0071 (4)	−0.0030 (3)	−0.0001 (3)	−0.0012 (3)
C5	0.0095 (6)	0.0061 (6)	0.0088 (6)	−0.0028 (5)	−0.0016 (5)	−0.0009 (4)
C7	0.0090 (6)	0.0069 (6)	0.0081 (6)	−0.0019 (5)	−0.0021 (5)	0.0008 (4)
O7	0.0084 (4)	0.0064 (4)	0.0095 (4)	−0.0029 (3)	−0.0027 (3)	0.0010 (3)
C8	0.0103 (6)	0.0078 (6)	0.0071 (6)	−0.0032 (5)	−0.0012 (5)	0.0001 (4)
N8	0.0109 (5)	0.0114 (5)	0.0074 (5)	−0.0032 (4)	−0.0014 (4)	0.0002 (4)
C9	0.0088 (6)	0.0073 (6)	0.0079 (6)	−0.0034 (5)	−0.0010 (5)	0.0008 (4)
O9	0.0077 (4)	0.0061 (4)	0.0090 (4)	−0.0025 (3)	0.0004 (3)	0.0002 (3)
C12	0.0088 (6)	0.0068 (6)	0.0090 (6)	−0.0019 (5)	−0.0004 (5)	−0.0002 (5)
O1W	0.0191 (5)	0.0162 (5)	0.0094 (5)	−0.0040 (4)	−0.0017 (4)	−0.0007 (4)
O2W	0.0148 (5)	0.0134 (5)	0.0148 (5)	−0.0015 (4)	−0.0050 (4)	0.0036 (4)
O3W	0.0125 (5)	0.0173 (5)	0.0223 (5)	−0.0072 (4)	−0.0056 (4)	−0.0010 (4)
O5W	0.0194 (5)	0.0169 (5)	0.0207 (5)	−0.0076 (4)	0.0015 (4)	−0.0057 (4)
O4W	0.0171 (5)	0.0199 (5)	0.0114 (5)	−0.0076 (4)	0.0015 (4)	0.0006 (4)
O6W	0.0347 (7)	0.0131 (6)	0.0414 (8)	−0.0053 (5)	0.0264 (6)	−0.0047 (5)
N12	0.0087 (5)	0.0096 (5)	0.0100 (5)	−0.0011 (4)	−0.0011 (4)	−0.0013 (4)
C11	0.0100 (6)	0.0067 (6)	0.0084 (6)	−0.0032 (5)	−0.0017 (5)	−0.0010 (4)
O11	0.0104 (4)	0.0062 (4)	0.0073 (4)	−0.0036 (3)	−0.0013 (3)	−0.0001 (3)
C10	0.0086 (6)	0.0078 (6)	0.0098 (6)	−0.0032 (5)	−0.0030 (5)	0.0004 (5)
N10	0.0097 (5)	0.0110 (5)	0.0108 (5)	−0.0038 (4)	−0.0026 (4)	−0.0012 (4)
C6	0.0102 (6)	0.0072 (6)	0.0082 (6)	−0.0020 (5)	−0.0027 (5)	0.0000 (5)
N6	0.0104 (5)	0.0081 (5)	0.0114 (5)	−0.0027 (4)	−0.0035 (4)	0.0013 (4)

Geometric parameters (Å, º)

Ge1—O1	1.8822 (9)	C8—C9	1.5280 (17)
Ge1—O3	1.8946 (9)	C8—H8	1.0000
Ge1—O5	1.8933 (9)	N8—H8A	0.878 (9)
Ge1—O1^i	1.8822 (9)	N8—H8C	0.886 (9)
Ge1—O3^i	1.8946 (9)	N8—H8B	0.876 (9)
Ge1—O5^i	1.8932 (9)	C9—O9	1.4165 (15)
O1—C1	1.4169 (15)	C9—C10	1.5330 (17)
C1—C6	1.5321 (17)	C9—H9	1.0000
C1—C2	1.5333 (17)	C12—N12	1.4897 (17)
C1—H1	1.0000	C12—C11	1.5300 (17)
Ge2—O7	1.8866 (9)	C12—H12	1.0000
Ge2—O9	1.8843 (9)	O1W—H1W	0.841 (9)
Ge2—O11	1.8818 (9)	O1W—H2W	0.839 (9)
Ge2—O7^ii	1.8866 (9)	O2W—H3W	0.827 (9)
Ge2—O9^ii	1.8844 (9)	O2W—H4W	0.837 (9)
Ge2—O11^ii	1.8817 (9)	O3W—H5W	0.839 (9)
N2—C2	1.4927 (16)	O3W—H6W	0.835 (9)
N2—H2C	0.884 (9)	O5W—H9W	0.833 (9)
N2—H2B	0.887 (9)	O5W—H10W	0.828 (9)
N2—H2A	0.882 (9)	O4W—H7W	0.837 (9)
C2—C3	1.5296 (17)	O4W—H8W	0.828 (9)
C2—H2	1.0000	O6W—H11W	0.834 (10)
O3—C3	1.4166 (15)	O6W—H12W	0.832 (10)
C3—C4	1.5293 (17)	N12—H12A	0.879 (9)
C3—H3	1.0000	N12—H12B	0.882 (9)
C4—N4	1.4902 (16)	N12—H12C	0.879 (9)
C4—C5	1.5281 (17)	C11—O11	1.4125 (15)
C4—H4	1.0000	C11—C10	1.5310 (18)
N4—H4C	0.880 (9)	C11—H11	1.0000
N4—H4B	0.891 (9)	C10—N10	1.4864 (16)
N4—H4A	0.888 (9)	C10—H10	1.0000
O5—C5	1.4190 (15)	N10—H10B	0.877 (9)
C5—C6	1.5309 (17)	N10—H10C	0.881 (9)
C5—H5	1.0000	N10—H10A	0.884 (9)
C7—O7	1.4165 (15)	C6—N6	1.4865 (16)
C7—C8	1.5261 (18)	C6—H6	1.0000
C7—C12	1.5286 (17)	N6—H6A	0.877 (9)
C7—H7	1.0000	N6—H6B	0.882 (9)
C8—N8	1.4900 (16)	N6—H6C	0.875 (9)
O1—Ge1—O3	91.81 (4)	O5—C5—H5	108.5
O1—Ge1—O3^i	88.19 (4)	C4—C5—H5	108.5
O1—Ge1—O5	91.89 (4)	C6—C5—H5	108.5
O1—Ge1—O5^i	88.11 (4)	O7—C7—C8	112.67 (10)
O5—Ge1—O3	90.74 (4)	O7—C7—C12	111.21 (10)
O5—Ge1—O3^i	89.26 (4)	C8—C7—C12	107.48 (10)
O9—Ge2—O7	89.88 (4)	O7—C7—H7	108.5
O9^ii—Ge2—O7	90.12 (4)	C8—C7—H7	108.5
O11—Ge2—O7	91.30 (4)	C12—C7—H7	108.5
O11^ii—Ge2—O7	88.70 (4)	N8—C8—C7	110.83 (10)
O11—Ge2—O9	91.61 (4)	N8—C8—C9	111.87 (10)
O11^ii—Ge2—O9	88.39 (4)	C7—C8—C9	110.04 (10)
C1—O1—Ge1	119.50 (8)	N8—C8—H8	108.0
C3—O3—Ge1	120.50 (7)	C7—C8—H8	108.0
C5—O5—Ge1	119.77 (7)	C9—C8—H8	108.0
C7—O7—Ge2	120.91 (8)	C8—N8—H8A	108.1 (12)
C9—O9—Ge2	121.04 (8)	C8—N8—H8C	109.3 (12)
C11—O11—Ge2	120.10 (8)	H8A—N8—H8C	108.9 (16)
O1^i—Ge1—O1	180.0	C8—N8—H8B	112.8 (12)
O1^i—Ge1—O5^i	91.89 (4)	H8A—N8—H8B	108.2 (16)
O1^i—Ge1—O5	88.11 (4)	H8C—N8—H8B	109.4 (16)
O5^i—Ge1—O5	180.000 (13)	O9—C9—C8	112.89 (10)
O1^i—Ge1—O3^i	91.81 (4)	O9—C9—C10	110.99 (10)
O5^i—Ge1—O3^i	90.74 (4)	C8—C9—C10	106.82 (10)
O1^i—Ge1—O3	88.19 (4)	O9—C9—H9	108.7
O5^i—Ge1—O3	89.26 (4)	C8—C9—H9	108.7
O3^i—Ge1—O3	180.0	C10—C9—H9	108.7
O1—C1—C6	112.77 (10)	N12—C12—C7	109.07 (10)
O1—C1—C2	111.31 (10)	N12—C12—C11	110.52 (10)
C6—C1—C2	107.57 (10)	C7—C12—C11	111.06 (10)
O1—C1—H1	108.4	N12—C12—H12	108.7
C6—C1—H1	108.4	C7—C12—H12	108.7
C2—C1—H1	108.4	C11—C12—H12	108.7
O11^ii—Ge2—O11	180.00 (3)	H1W—O1W—H2W	106.9 (19)
O11^ii—Ge2—O9^ii	91.61 (4)	H3W—O2W—H4W	104.4 (19)
O11—Ge2—O9^ii	88.39 (4)	H5W—O3W—H6W	106.1 (19)
O9—Ge2—O9^ii	180.0	H9W—O5W—H10W	104 (2)
O11^ii—Ge2—O7^ii	91.30 (4)	H7W—O4W—H8W	102.5 (19)
O11—Ge2—O7^ii	88.70 (4)	H11W—O6W—H12W	105 (2)
O9—Ge2—O7^ii	90.12 (4)	C12—N12—H12A	109.3 (12)
O9^ii—Ge2—O7^ii	89.88 (4)	C12—N12—H12B	115.1 (12)
O7—Ge2—O7^ii	180.0	H12A—N12—H12B	107.9 (16)
C2—N2—H2C	110.8 (12)	C12—N12—H12C	109.6 (12)
C2—N2—H2B	111.6 (12)	H12A—N12—H12C	105.8 (16)
H2C—N2—H2B	109.0 (16)	H12B—N12—H12C	108.7 (16)
C2—N2—H2A	110.3 (12)	O11—C11—C12	111.99 (10)
H2C—N2—H2A	106.7 (16)	O11—C11—C10	112.17 (10)
H2B—N2—H2A	108.3 (16)	C12—C11—C10	106.74 (10)
N2—C2—C3	109.12 (10)	O11—C11—H11	108.6
N2—C2—C1	108.55 (10)	C12—C11—H11	108.6
C3—C2—C1	110.99 (10)	C10—C11—H11	108.6
N2—C2—H2	109.4	N10—C10—C11	111.14 (10)
C3—C2—H2	109.4	N10—C10—C9	108.63 (10)
C1—C2—H2	109.4	C11—C10—C9	111.45 (10)
O3—C3—C4	110.91 (10)	N10—C10—H10	108.5
O3—C3—C2	111.09 (10)	C11—C10—H10	108.5
C4—C3—C2	108.52 (10)	C9—C10—H10	108.5
O3—C3—H3	108.8	C10—N10—H10B	109.4 (12)
C4—C3—H3	108.8	C10—N10—H10C	107.9 (12)
C2—C3—H3	108.8	H10B—N10—H10C	111.3 (17)
N4—C4—C5	110.44 (10)	C10—N10—H10A	114.4 (12)
N4—C4—C3	108.59 (10)	H10B—N10—H10A	108.5 (16)
C5—C4—C3	111.12 (10)	H10C—N10—H10A	105.3 (16)
N4—C4—H4	108.9	N6—C6—C5	108.99 (10)
C5—C4—H4	108.9	N6—C6—C1	110.10 (10)
C3—C4—H4	108.9	C5—C6—C1	111.10 (10)
C4—N4—H4C	109.5 (12)	N6—C6—H6	108.9
C4—N4—H4B	110.7 (12)	C5—C6—H6	108.9
H4C—N4—H4B	111.4 (16)	C1—C6—H6	108.9
C4—N4—H4A	111.5 (12)	C6—N6—H6A	112.6 (12)
H4C—N4—H4A	108.6 (16)	C6—N6—H6B	110.5 (12)
H4B—N4—H4A	105.0 (16)	H6A—N6—H6B	104.9 (16)
O5—C5—C4	112.44 (10)	C6—N6—H6C	110.5 (12)
O5—C5—C6	111.73 (10)	H6A—N6—H6C	110.0 (16)
C4—C5—C6	107.00 (10)	H6B—N6—H6C	108.0 (16)
O5^i—Ge1—O1—C1	134.59 (9)	O7—C7—C8—C9	−60.63 (13)
O5—Ge1—O1—C1	−45.41 (9)	C12—C7—C8—C9	62.23 (13)
O3^i—Ge1—O1—C1	−134.60 (9)	N8—C8—C9—O9	−63.31 (14)
O3—Ge1—O1—C1	45.40 (9)	C7—C8—C9—O9	60.36 (13)
Ge1—O1—C1—C6	59.68 (12)	N8—C8—C9—C10	174.43 (10)
Ge1—O1—C1—C2	−61.33 (12)	C7—C8—C9—C10	−61.90 (13)
O1—C1—C2—N2	−55.20 (13)	C8—C9—O9—Ge2	−60.42 (12)
C6—C1—C2—N2	−179.21 (10)	C10—C9—O9—Ge2	59.47 (12)
O1—C1—C2—C3	64.72 (13)	O11^ii—Ge2—O9—C9	134.69 (9)
C6—C1—C2—C3	−59.29 (13)	O11—Ge2—O9—C9	−45.31 (9)
O1^i—Ge1—O3—C3	135.26 (9)	O7—Ge2—O9—C9	45.98 (9)
O1—Ge1—O3—C3	−44.74 (9)	O7^ii—Ge2—O9—C9	−134.02 (9)
O5^i—Ge1—O3—C3	−132.83 (9)	O7—C7—C12—N12	−59.90 (13)
O5—Ge1—O3—C3	47.17 (9)	C8—C7—C12—N12	176.34 (10)
Ge1—O3—C3—C4	−61.58 (12)	O7—C7—C12—C11	62.13 (13)
Ge1—O3—C3—C2	59.20 (12)	C8—C7—C12—C11	−61.62 (13)
N2—C2—C3—O3	56.33 (13)	N12—C12—C11—O11	58.16 (14)
C1—C2—C3—O3	−63.25 (13)	C7—C12—C11—O11	−63.03 (13)
N2—C2—C3—C4	178.51 (10)	N12—C12—C11—C10	−178.72 (10)
C1—C2—C3—C4	58.93 (13)	C7—C12—C11—C10	60.09 (13)
O3—C3—C4—N4	−59.22 (13)	C12—C11—O11—Ge2	60.37 (12)
C2—C3—C4—N4	178.49 (10)	C10—C11—O11—Ge2	−59.63 (12)
O3—C3—C4—C5	62.44 (13)	O9—Ge2—O11—C11	44.76 (9)
C2—C3—C4—C5	−59.85 (13)	O9^ii—Ge2—O11—C11	−135.24 (9)
O1^i—Ge1—O5—C5	−133.85 (9)	O7—Ge2—O11—C11	−45.16 (9)
O1—Ge1—O5—C5	46.15 (9)	O7^ii—Ge2—O11—C11	134.84 (9)
O3^i—Ge1—O5—C5	134.32 (9)	O11—C11—C10—N10	−58.74 (14)
O3—Ge1—O5—C5	−45.68 (9)	C12—C11—C10—N10	178.25 (10)
Ge1—O5—C5—C4	60.05 (12)	O11—C11—C10—C9	62.59 (13)
Ge1—O5—C5—C6	−60.29 (12)	C12—C11—C10—C9	−60.43 (13)
N4—C4—C5—O5	58.15 (13)	O9—C9—C10—N10	61.00 (13)
C3—C4—C5—O5	−62.43 (13)	C8—C9—C10—N10	−175.56 (10)
N4—C4—C5—C6	−178.81 (10)	O9—C9—C10—C11	−61.78 (13)
C3—C4—C5—C6	60.60 (13)	C8—C9—C10—C11	61.66 (13)
C8—C7—O7—Ge2	61.04 (12)	O5—C5—C6—N6	−59.57 (13)
C12—C7—O7—Ge2	−59.71 (12)	C4—C5—C6—N6	176.95 (10)
O11^ii—Ge2—O7—C7	−134.70 (9)	O5—C5—C6—C1	61.91 (13)
O11—Ge2—O7—C7	45.30 (9)	C4—C5—C6—C1	−61.56 (13)
O9—Ge2—O7—C7	−46.31 (9)	O1—C1—C6—N6	58.82 (13)
O9^ii—Ge2—O7—C7	133.69 (9)	C2—C1—C6—N6	−178.07 (10)
O7—C7—C8—N8	63.64 (13)	O1—C1—C6—C5	−62.01 (13)
C12—C7—C8—N8	−173.50 (10)	C2—C1—C6—C5	61.10 (13)

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

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
N2—H2C···Cl2^iii	0.88	2.31	3.1900 (12)	171
N2—H2B···Cl3^i	0.89	2.27	3.1443 (12)	170
N2—H2A···O5W^i	0.88	2.44	3.0550 (16)	128
N2—H2A···O4W^i	0.88	2.45	3.088 (16)	130
N4—H4C···Cl2^iv	0.88	2.35	3.2225 (12)	170
N4—H4B···Cl4^iv	0.89	2.32	3.1978 (12)	168
N4—H4A···O5W^v	0.89	2.28	2.9395 (16)	131
N8—H8A···O2W^iii	0.88	2.02	2.8674 (16)	161
N8—H8C···O4W^iv	0.89	2.00	2.8352 (16)	157
N8—H8C···Cl4	0.89	2.93	3.3840 (12)	114
N8—H8B···O1W^iii	0.88	1.98	2.8161 (16)	159
O1W—H1W···Cl1	0.84	2.39	3.2264 (12)	178
O1W—H2W···O11^vi	0.84	1.84	2.6708 (14)	173
O2W—H4W···O3^i	0.84	1.78	2.6126 (13)	173
O3W—H5W···O7^iii	0.84	1.76	2.5888 (14)	172
O3W—H6W···Cl1	0.84	2.35	3.1755 (12)	169
O5W—H9W···O1^i	0.83	2.08	2.8603 (14)	156
O5W—H10W···Cl4^iv	0.83	2.50	3.3160 (11)	171
O4W—H7W···Cl1	0.84	2.34	3.1716 (12)	177
O4W—H8W···O5	0.83	1.93	2.7501 (14)	171
O6W—H11W···O9^iv	0.83	1.81	2.6338 (15)	170
O6W—H12W···Cl1	0.83	2.39	3.1801 (12)	158
N12—H12A···Cl3^iii	0.88	2.35	3.2212 (12)	171
N12—H12B···O6W^vii	0.88	1.86	2.7202 (17)	164
N12—H12C···Cl3^viii	0.88	2.23	3.0838 (12)	165
N10—H10B···Cl2^ix	0.88	2.35	3.2097 (12)	166
N10—H10C···O3W^iv	0.88	2.21	2.9597 (16)	143
N10—H10C···Cl3^iv	0.88	2.70	3.2591 (12)	123
N10—H10A···O3W^ix	0.88	1.95	2.7953 (16)	159
N6—H6A···O2W	0.88	2.05	2.8606 (16)	153
N6—H6B···Cl4^iii	0.88	2.24	3.1091 (12)	168
N6—H6C···Cl4	0.88	2.60	3.2924 (12)	137
N6—H6C···Cl1	0.88	2.67	3.3150 (12)	131

Symmetry codes: (i) −x+1, −y, −z+1; (iii) −x, −y+1, −z+1; (iv) −x+1, −y+1, −z+1; (v) −x+2, −y, −z+1; (vi) x, y, z−1; (vii) x−1, y, z+1; (viii) x−1, y+1, z+1; (ix) x, y, z+1.