Inter­actions between dimers of {1,1′-[o-phenyl­enebis(nitrilo­methyli­dyne)]di-2-naphtholato-κ⁴O,N,N′,O′}­nickel(II)

In the title compound, [Ni(C₂₈H₁₈N₂O₂)], the Ni^II centre has a square-planar coordination geometry in which the Schiff base ligand acts as a cis-O,N,N′,O′-tetra­dentate ligand. The crystal structure is built up of centrosymmetric dimer units stacked into chains along the [010] direction. Adjacent chains associate via C—H...O hydrogen bonding only, leading to a two-dimensional sheet-like structure consisting of layers parallel to (10). The cofacial dimeric complex contains an Ni...Ni contact of 3.291 (4) Å.

S1. Comment

Polydentate Schiff base ligands and their metal complexes have been extensively studied because of their preparative availability and structural variability (Dodziuk, 2002). Compounds of this type having a delocalized system of conjugated π electrons play an important role as building blocks in new materials for nonlinear optical applications (Schalley, 2007). Schiff bases are electronically and sterically tunable, which makes them versatile ligands for investigating the effects of ligand flexibility on the reactivity of complexes containg these ligands (Szłyk et al., 1999). Tetradentate Schiff base metal complexes may form trans or cis planar or tetrahedral structures (Elmali et al., 2000). Nickel(II) complexes of aromatic diamine Schiff bases generally display either square-planar or slightly distorted square-planar coordination (Fun et al., 2008). In comparison with salicylaldimine metal complexes, structural data for naphthaldimines and relatedcomplexes are quite rare. So far the coordination compounds of 2-hydroxy-1-naphthaldimine derivatives of tin (Teoh et al., 1997), iron (Elerman et al., 1997), chromium (Wang et al., 2006), ruthenium (Prabhakaran et al., 2006) and copper (Xue et al., 2007) have been reported.

We report here the novel structure of a nickel(II) complex with a naphthaldiminate-type ligand (Fig. 1) in which π–π stacking interactions and C—H···O hydrogen bonding lead to a two-dimensional supramolecular network. Upon coordination to the metal centre the ligand undergoes a substantial stereochemical change from significantly nonplanar to an almost planar configuration. It has been found that the free ligand in the solid state exists in both enol–imine and keto–amine forms (Popović et al., 2001; Blagus; 2005), while in complex (I), the two chelating rings apparently contain delocalized electrons.

Comparison of the bond lengths observed in free (Popović et al., 2001) and Ni-coordinated ligands (Table 1) shows no significant differences except in the case of C_ar—O and C═N imino bond distances. In complex (I) the Cn11—Nn1 distances are slightly longer than the standard imine C═N double bond (1.28 Å; Allen et al., 1987), and the Cn2—On1 bond lengths are shorter than the typical C—O single bond (1.34 Å; n = 1 or 2). Both the C—N and C—O bond distances in the coordinated ligand are intermediate between single- and double-bond values. The remaining bond lengths and angles are all typical of their types (Allen et al., 1987).

The coordination of the Ni^II ion is square-planar, with a cis-O,N,N',O' donor set. The Ni—N and Ni—O bond lengths are within the ranges expected for square-planar Schiff base Ni complexes (Szłyk et al.,1999; de Castro et al., 2001). Similar coordination geometry has been observed in analogous nickel complexes with Schiff bases derived from o-phenylenediamine and salicylaldehyde (Wang et al., 1994, 2003). The Ni—N distances are longer then the Ni—O distances for complexes with ligands in which the diimine bridge is aromatic, whereas for those with two aliphatic C atoms the opposite is observed (Azevedo et al., 1994). Ni—N bond distances in Ni(salen) complexes are slightly longer than those in Ni(naphthen) complexes (Wojtczak et al., 1997).

In the title compound, the Ni atom is displaced from the least-squares plane through the N,N,O,O atoms by only 0.0082 (3) Å, and this planarity permits extensive π-electron delocalization. In spite of that, the terminal naphthalene moieties maintain the genuine quinoidal bond-length arrangement [Cn3—Cn4 = 1.352 (3) and 1.359 (3) Å, respectively; n = 1, 2; Allen et al., 1987]. The dihedral angle between the two chelate rings is 1.25°.

The molecules of (I) form centrosymmetric dimers through a weak metal–metal interaction with an Ni···Ni distance of 3.291 (4) Å. This contact is out of the range for bond-length values usually accepted for the Ni—Ni bond distance (2.38-2.81 Å; Peng & Goedken, 1976, and references therein). The bond between two Ni atoms was first proposed in 1953 to explain the seemingly anomalous insolubility of nickel(II)bis(dimethylglyoxime) as compared with its copper analogue (Godycki & Rundle, 1953). This interaction is not common, occurring only rarely in the numerous Ni structures in the Cambridge Structural Database (CSD). The reported Ni—Ni distances in the CSD, based on a search for bonded Ni atoms in tetracoordinated complexes with a set of either N₄ or N₂O₂ nonbridged donor atoms, range from 2.808 to 3.336 Å. The shorter Ni—Ni distances are observed in structures for which nonbonding repulsions of the ligands are minimal (Berry et al., 2006). In the present case the d⁸–d⁸ Ni···Ni interaction is weak, being a consequence of other types of stronger intermolecular interactions. Such Ni···Ni interactions are weaker than most covalent or ionic bonds, but they are stronger than other van der Waals interactions, and are roughly comparable in strength to typical hydrogen bonds (Pyykkö, 1997). Similar Ni···Ni distances [Ni···Ni = 3.3244 (4) Å] are found in a naphthaldimine nickel(II) complex with an aliphatic bridging diamine unit (Akhtar, 1981) and in a range of analogous nickel Schiff base complexes [3.201 (1)–3.582 (1) Å] with metal–metal interactions (Chakraborty et al., 2004).

The aromatic rings within the dimer complexes are arranged face-to- face and there are indeed net repulsive interactions between the π systems. If the adjacent dimer molecules are well laterally offset with regard to each other this offset geometry increases the attractive forces between the π systems to the extent that they can become more significant than the repulsive forces (Hunter & Sanders 1990).

In our case, the only attraction within the dimer is the metal–metal interaction, whereas the peripheral atoms show significantly larger separation than those more centrally located, e.g. the four donor atoms. The interplanar distance between the least-squares planes defined by the N,N,O,O atoms of 3.163 Å is in the repulsive range for nonbonding interactions (Williams et al., 1968). The apparent nonbonding repulsion of the peripheral naphthalene rings is observed, as indicated by the C17—C28* [the star denotes the symmetry code (-x, -y, -z +1)] separation of ca 3.677 Å and C18—C27* separation of ca 3.582 Å, respectively. The influence of the mutually repulsive interactions of the peripheral naphthalene rings leads to a slightly saddle-shaped conformation of particular dimeric molecules. The adjacent dimers have such a staggered arrangement that minimizes repulsive interactions. The later is shown by an interplanar separation shorter than that in graphite (3.35 Å), amounting ca 3.251 Å. These interactions (clearly visible in Fig. 2) could be recognized as offset π–π attraction forces existing between the dimer molecules exclusively and linking the dimers in parallel columns spreading along [010].

The crystals are built up of parallel (101) layers formed by [010] columns linked by the C—H···O hydrogen bond (Fig. 3 and Table 2). The apparent herringbone packing pattern typical for arrays of fused aromatic rings (Desiraju & Gavezzotti, 1989) is shown in Fig. 2.

Related literature

For related literature, see: Akhtar (1981); Allen et al. (1987); Azevedo et al. (1994); Blagus (2005); Castro et al. (2001); Desiraju & Gavezzotti (1989); Dodziuk (2002); Elerman et al. (1997); Elmali et al. (2000); Fun et al. (2008); Godycki & Rundle (1953); Hunter & Sanders (1990); Peng & Goedken (1976); Popović et al. (2001); Prabhakaran et al. (2006); Schalley (2007); Szłyk et al. (1999); Teoh et al. (1997); Wang et al. (1994, 2003, 2006); Williams et al. (1968); Xue et al. (2007).

S2. Experimental

The nickel complex was synthesized by template synthesis. A solution of nickel(II) chloride hexahydrate (1 mmol) and 2-hydroxy-1-naphthaldehyde (2 mmol) in absolute ethanol and an ethanol solution of 1,2-phenylenediamine (1 mmol) were allowed to mix by slow diffusion through chloroform. After one week red crystals had been formed.

S3. Refinement

All H atoms were located in a difference map and then treated as riding in geometrically idealized positions, with C—H = 0.95 Å and U_iso(H) = 1.2U_eq(C).

Computing details

Data collection: CrysAlis CCD (Oxford Diffraction, 2003); cell refinement: CrysAlis RED (Oxford Diffraction, 2003); data reduction: CrysAlis RED (Oxford Diffraction, 2003); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: ORTEP-3 (Farrugia, 1997); software used to prepare material for publication: WinGX (Farrugia, 1999), PARST97 (Nardelli, 1996) and Mercury (Version 1.4; Macrae et al., 2006).

Figures

	Fig. 1. (a) The molecular structure of the dimeric nickel(II) complex, with the atom-numbering scheme. Displacement ellipsoids are drawn at the 50% probability level and H atoms are shown as small spheres of arbitrary radius. (b) A perpendicular projection of the dimer complex molecule, showing the offset arrangement of the monomeric moieties.
	Fig. 2. A projection of the crystal packing along the a axis, showing the herringbone arrangement of the complex molecules. The dimers stack by weak π–π interactions in columns spreading along the y axis. The shortest dimer-to-dimer contacts are represented as dotted lines.
	Fig. 3. A view of the crystal packing, showing the interconnection of the parallel (010) columns into (101) layers through the C24—H24···O21(-x + 3/2, y - 1/2, -z + 3/2) hydrogen bond.

{1,1'-[o-phenylenebis(nitrilomethylidyne)]di-2-naphtholato- κ⁴O,N,N',O'}nickel(II)

Crystal data

[Ni(C28H18N2O2)]	F(000) = 976
Mr = 473.15	Dx = 1.609 Mg m^−3
Monoclinic, P21/n	Mo Kα radiation, λ = 0.71069 Å
Hall symbol: -P 2yn	Cell parameters from 4227 reflections
a = 15.8669 (3) Å	θ = 3.8–27°
b = 7.5765 (1) Å	µ = 1.03 mm^−1
c = 16.4065 (2) Å	T = 100 K
β = 97.9769 (13)°	Lath, red
V = 1953.23 (5) Å^3	0.6 × 0.2 × 0.02 mm
Z = 4

Data collection

Oxford Diffraction Xcalibur CCD diffractometer	4227 independent reflections
Radiation source: fine-focus sealed tube	3694 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.024
ω scan	θmax = 27.1°, θmin = 3.8°
Absorption correction: analytical (Alcock, 1970)	h = −20→20
Tmin = 0.667, Tmax = 0.936	k = −9→9
11136 measured reflections	l = −12→21

Refinement

Refinement on F^2	Primary atom site location: structure-invariant direct methods
Least-squares matrix: full	Secondary atom site location: difference Fourier map
R[F^2 > 2σ(F^2)] = 0.039	Hydrogen site location: inferred from neighbouring sites
wR(F^2) = 0.094	H-atom parameters constrained
S = 1.16	w = 1/[σ^2(Fo^2) + (0.0321P)^2 + 3.1247P] where P = (Fo^2 + 2Fc^2)/3
4227 reflections	(Δ/σ)max = 0.001
298 parameters	Δρmax = 0.42 e Å^−3
0 restraints	Δρmin = −0.38 e Å^−3

Special details

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

Refinement. Refinement of F² against ALL reflections. The weighted R-factor wR and goodness of fit S are based on F², conventional R-factors R are based on F, with F set to zero for negative F². The threshold expression of F² > σ(F²) is used only for calculating R-factors(gt) etc. and is not relevant to the choice of reflections for refinement. R-factors based on F² are statistically about twice as large as those based on F, and R- factors based on ALL data will be even larger.

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

	x	y	z	Uiso*/Ueq
Ni1	0.540051 (19)	0.67592 (4)	0.549938 (18)	0.01128 (10)
O11	0.62156 (11)	0.7567 (2)	0.48965 (10)	0.0142 (4)
O21	0.63069 (10)	0.5795 (2)	0.61572 (10)	0.0131 (3)
N11	0.45013 (13)	0.7745 (3)	0.48150 (12)	0.0113 (4)
N21	0.46072 (12)	0.5965 (3)	0.61416 (12)	0.0112 (4)
C11	0.53092 (15)	0.8974 (3)	0.37945 (14)	0.0118 (5)
C12	0.61032 (15)	0.8406 (3)	0.42004 (14)	0.0122 (5)
C13	0.68628 (16)	0.8776 (3)	0.38354 (14)	0.0150 (5)
H13	0.7397	0.8350	0.4094	0.018*
C14	0.68241 (16)	0.9720 (3)	0.31318 (14)	0.0161 (5)
H14	0.7335	0.9961	0.2912	0.019*
C15	0.60357 (16)	1.0366 (3)	0.27089 (14)	0.0140 (5)
C16	0.60094 (17)	1.1400 (3)	0.19886 (14)	0.0162 (5)
H16	0.6525	1.1683	0.1785	0.019*
C17	0.52505 (17)	1.2003 (3)	0.15783 (14)	0.0178 (5)
H17	0.5241	1.2710	0.1099	0.021*
C18	0.44917 (16)	1.1563 (3)	0.18737 (14)	0.0165 (5)
H18	0.3964	1.1953	0.1585	0.020*
C19	0.45005 (16)	1.0570 (3)	0.25780 (14)	0.0154 (5)
H19	0.3977	1.0285	0.2766	0.019*
C110	0.52682 (15)	0.9969 (3)	0.30261 (14)	0.0125 (5)
C111	0.45504 (15)	0.8625 (3)	0.41323 (14)	0.0122 (5)
H111	0.4034	0.9064	0.3841	0.015*
C21	0.55857 (15)	0.4600 (3)	0.72329 (14)	0.0118 (5)
C22	0.63151 (15)	0.4953 (3)	0.68493 (14)	0.0123 (5)
C23	0.71326 (15)	0.4379 (3)	0.72309 (14)	0.0142 (5)
H23	0.7616	0.4572	0.6960	0.017*
C24	0.72314 (15)	0.3560 (3)	0.79749 (15)	0.0143 (5)
H24	0.7784	0.3213	0.8220	0.017*
C25	0.65156 (15)	0.3211 (3)	0.83959 (14)	0.0128 (5)
C26	0.66440 (16)	0.2330 (3)	0.91627 (14)	0.0156 (5)
H26	0.7202	0.1988	0.9396	0.019*
C27	0.59655 (16)	0.1969 (4)	0.95717 (15)	0.0181 (5)
H27	0.6050	0.1367	1.0084	0.022*
C28	0.51464 (17)	0.2495 (4)	0.92264 (15)	0.0185 (5)
H28	0.4679	0.2267	0.9515	0.022*
C29	0.50073 (16)	0.3338 (3)	0.84752 (14)	0.0163 (5)
H29	0.4445	0.3665	0.8251	0.020*
C210	0.56893 (15)	0.3726 (3)	0.80313 (14)	0.0123 (5)
C211	0.47711 (15)	0.5115 (3)	0.68432 (14)	0.0120 (5)
H211	0.4299	0.4818	0.7114	0.014*
C31	0.37040 (15)	0.7450 (3)	0.50902 (14)	0.0117 (5)
C32	0.37626 (15)	0.6448 (3)	0.58151 (13)	0.0110 (5)
C33	0.30246 (16)	0.6023 (3)	0.61474 (14)	0.0155 (5)
H33	0.3060	0.5316	0.6629	0.019*
C34	0.22469 (15)	0.6627 (3)	0.57778 (15)	0.0157 (5)
H34	0.1747	0.6343	0.6009	0.019*
C35	0.21868 (16)	0.7657 (3)	0.50642 (15)	0.0162 (5)
H35	0.1648	0.8082	0.4817	0.019*
C36	0.29115 (15)	0.8058 (3)	0.47182 (14)	0.0154 (5)
H36	0.2870	0.8743	0.4229	0.018*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
Ni1	0.00783 (15)	0.01446 (17)	0.01127 (15)	−0.00006 (13)	0.00034 (10)	0.00048 (12)
O11	0.0103 (8)	0.0188 (9)	0.0131 (8)	−0.0013 (7)	0.0000 (6)	0.0015 (7)
O21	0.0102 (8)	0.0172 (9)	0.0115 (7)	−0.0003 (7)	0.0004 (6)	0.0018 (6)
N11	0.0101 (10)	0.0124 (10)	0.0110 (9)	−0.0012 (8)	0.0006 (7)	−0.0012 (7)
N21	0.0082 (10)	0.0133 (10)	0.0118 (9)	0.0002 (8)	−0.0001 (7)	−0.0021 (8)
C11	0.0121 (12)	0.0113 (11)	0.0122 (10)	−0.0011 (9)	0.0023 (8)	−0.0033 (9)
C12	0.0134 (12)	0.0118 (11)	0.0117 (10)	−0.0009 (10)	0.0031 (9)	−0.0044 (9)
C13	0.0104 (12)	0.0185 (12)	0.0159 (11)	0.0012 (10)	0.0011 (9)	−0.0015 (9)
C14	0.0132 (12)	0.0188 (12)	0.0172 (11)	−0.0019 (10)	0.0061 (9)	−0.0019 (10)
C15	0.0165 (12)	0.0135 (12)	0.0121 (10)	−0.0012 (10)	0.0023 (9)	−0.0027 (9)
C16	0.0198 (13)	0.0167 (12)	0.0135 (11)	−0.0023 (10)	0.0067 (9)	−0.0015 (9)
C17	0.0247 (14)	0.0187 (13)	0.0104 (10)	−0.0002 (11)	0.0034 (9)	0.0006 (9)
C18	0.0164 (12)	0.0191 (13)	0.0128 (11)	0.0027 (11)	−0.0019 (9)	−0.0014 (9)
C19	0.0153 (12)	0.0166 (12)	0.0144 (11)	−0.0008 (10)	0.0022 (9)	−0.0021 (9)
C110	0.0158 (12)	0.0096 (11)	0.0121 (10)	−0.0007 (9)	0.0018 (9)	−0.0028 (8)
C111	0.0113 (11)	0.0134 (12)	0.0114 (10)	0.0001 (9)	−0.0003 (8)	−0.0016 (9)
C21	0.0113 (11)	0.0105 (11)	0.0127 (10)	0.0009 (9)	−0.0009 (8)	−0.0008 (9)
C22	0.0115 (11)	0.0110 (11)	0.0137 (10)	0.0006 (9)	−0.0010 (8)	−0.0019 (9)
C23	0.0098 (12)	0.0146 (12)	0.0179 (11)	−0.0014 (10)	0.0011 (9)	−0.0006 (9)
C24	0.0098 (11)	0.0144 (12)	0.0176 (11)	0.0014 (10)	−0.0021 (9)	−0.0007 (9)
C25	0.0126 (11)	0.0118 (11)	0.0131 (10)	0.0013 (10)	−0.0010 (8)	−0.0016 (9)
C26	0.0142 (12)	0.0190 (12)	0.0125 (11)	0.0018 (10)	−0.0024 (9)	−0.0001 (9)
C27	0.0179 (13)	0.0237 (14)	0.0122 (11)	0.0012 (11)	0.0007 (9)	0.0023 (10)
C28	0.0167 (13)	0.0242 (14)	0.0155 (11)	0.0001 (11)	0.0050 (9)	0.0018 (10)
C29	0.0115 (11)	0.0214 (13)	0.0152 (11)	0.0023 (10)	−0.0011 (9)	0.0000 (10)
C210	0.0112 (11)	0.0127 (11)	0.0127 (10)	0.0010 (9)	0.0005 (8)	−0.0020 (9)
C211	0.0120 (11)	0.0114 (11)	0.0127 (10)	−0.0012 (9)	0.0018 (8)	−0.0024 (9)
C31	0.0106 (12)	0.0132 (11)	0.0109 (10)	−0.0018 (9)	0.0001 (8)	−0.0037 (9)
C32	0.0100 (11)	0.0104 (11)	0.0120 (10)	−0.0001 (9)	−0.0014 (8)	−0.0029 (8)
C33	0.0147 (12)	0.0183 (12)	0.0136 (11)	−0.0010 (10)	0.0022 (9)	0.0020 (9)
C34	0.0102 (11)	0.0199 (13)	0.0171 (11)	−0.0033 (10)	0.0019 (9)	−0.0015 (10)
C35	0.0085 (11)	0.0206 (13)	0.0183 (12)	0.0014 (10)	−0.0026 (9)	−0.0010 (10)
C36	0.0139 (12)	0.0195 (13)	0.0123 (10)	0.0001 (10)	0.0004 (9)	0.0004 (9)

Geometric parameters (Å, º)

Ni1—O21	1.8266 (17)	C21—C211	1.415 (3)
Ni1—O11	1.8385 (17)	C21—C22	1.417 (3)
Ni1—N11	1.846 (2)	C21—C210	1.457 (3)
Ni1—N21	1.851 (2)	C22—C23	1.428 (3)
O11—C12	1.298 (3)	C23—C24	1.359 (3)
O21—C22	1.301 (3)	C23—H23	0.9500
N11—C111	1.315 (3)	C24—C25	1.433 (3)
N11—C31	1.419 (3)	C24—H24	0.9500
N21—C211	1.313 (3)	C25—C26	1.413 (3)
N21—C32	1.421 (3)	C25—C210	1.418 (3)
C11—C12	1.408 (3)	C26—C27	1.373 (3)
C11—C111	1.418 (3)	C26—H26	0.9500
C11—C110	1.463 (3)	C27—C28	1.402 (4)
C12—C13	1.446 (3)	C27—H27	0.9500
C13—C14	1.352 (3)	C28—C29	1.378 (3)
C13—H13	0.9500	C28—H28	0.9500
C14—C15	1.430 (3)	C29—C210	1.416 (3)
C14—H14	0.9500	C29—H29	0.9500
C15—C16	1.413 (3)	C211—H211	0.9500
C15—C110	1.421 (3)	C31—C36	1.397 (3)
C16—C17	1.373 (4)	C31—C32	1.403 (3)
C16—H16	0.9500	C32—C33	1.396 (3)
C17—C18	1.399 (4)	C33—C34	1.376 (3)
C17—H17	0.9500	C33—H33	0.9500
C18—C19	1.377 (3)	C34—C35	1.399 (3)
C18—H18	0.9500	C34—H34	0.9500
C19—C110	1.408 (3)	C35—C36	1.385 (3)
C19—H19	0.9500	C35—H35	0.9500
C111—H111	0.9500	C36—H36	0.9500
O21—Ni1—O11	84.04 (7)	C22—C21—C210	119.2 (2)
O21—Ni1—N11	178.60 (8)	O21—C22—C21	124.8 (2)
O11—Ni1—N11	94.60 (8)	O21—C22—C23	115.5 (2)
O21—Ni1—N21	94.32 (8)	C21—C22—C23	119.7 (2)
O11—Ni1—N21	177.87 (8)	C24—C23—C22	121.2 (2)
N11—Ni1—N21	87.05 (9)	C24—C23—H23	119.4
C12—O11—Ni1	127.99 (16)	C22—C23—H23	119.4
C22—O21—Ni1	128.58 (15)	C23—C24—C25	121.1 (2)
C111—N11—C31	120.8 (2)	C23—C24—H24	119.4
C111—N11—Ni1	126.21 (17)	C25—C24—H24	119.4
C31—N11—Ni1	113.00 (15)	C26—C25—C210	121.0 (2)
C211—N21—C32	121.3 (2)	C26—C25—C24	119.3 (2)
C211—N21—Ni1	126.23 (17)	C210—C25—C24	119.6 (2)
C32—N21—Ni1	112.45 (15)	C27—C26—C25	120.2 (2)
C12—C11—C111	120.7 (2)	C27—C26—H26	119.9
C12—C11—C110	119.7 (2)	C25—C26—H26	119.9
C111—C11—C110	119.6 (2)	C26—C27—C28	119.4 (2)
O11—C12—C11	124.8 (2)	C26—C27—H27	120.3
O11—C12—C13	116.0 (2)	C28—C27—H27	120.3
C11—C12—C13	119.2 (2)	C29—C28—C27	121.2 (2)
C14—C13—C12	121.0 (2)	C29—C28—H28	119.4
C14—C13—H13	119.5	C27—C28—H28	119.4
C12—C13—H13	119.5	C28—C29—C210	121.1 (2)
C13—C14—C15	121.9 (2)	C28—C29—H29	119.4
C13—C14—H14	119.1	C210—C29—H29	119.4
C15—C14—H14	119.1	C29—C210—C25	117.0 (2)
C16—C15—C110	119.7 (2)	C29—C210—C21	123.9 (2)
C16—C15—C14	121.2 (2)	C25—C210—C21	119.1 (2)
C110—C15—C14	119.1 (2)	N21—C211—C21	126.1 (2)
C17—C16—C15	121.1 (2)	N21—C211—H211	117.0
C17—C16—H16	119.5	C21—C211—H211	117.0
C15—C16—H16	119.5	C36—C31—C32	119.9 (2)
C16—C17—C18	119.3 (2)	C36—C31—N11	126.7 (2)
C16—C17—H17	120.4	C32—C31—N11	113.4 (2)
C18—C17—H17	120.4	C33—C32—C31	119.7 (2)
C19—C18—C17	120.8 (2)	C33—C32—N21	126.3 (2)
C19—C18—H18	119.6	C31—C32—N21	114.0 (2)
C17—C18—H18	119.6	C34—C33—C32	120.0 (2)
C18—C19—C110	121.5 (2)	C34—C33—H33	120.0
C18—C19—H19	119.3	C32—C33—H33	120.0
C110—C19—H19	119.3	C33—C34—C35	120.5 (2)
C19—C110—C15	117.6 (2)	C33—C34—H34	119.8
C19—C110—C11	123.3 (2)	C35—C34—H34	119.8
C15—C110—C11	119.1 (2)	C36—C35—C34	120.1 (2)
N11—C111—C11	125.5 (2)	C36—C35—H35	120.0
N11—C111—H111	117.2	C34—C35—H35	120.0
C11—C111—H111	117.2	C35—C36—C31	119.8 (2)
C211—C21—C22	119.9 (2)	C35—C36—H36	120.1
C211—C21—C210	120.9 (2)	C31—C36—H36	120.1
O21—Ni1—O11—C12	174.9 (2)	C211—C21—C22—C23	−177.9 (2)
N11—Ni1—O11—C12	−4.8 (2)	C210—C21—C22—C23	2.8 (3)
O11—Ni1—O21—C22	175.4 (2)	O21—C22—C23—C24	176.8 (2)
N21—Ni1—O21—C22	−3.3 (2)	C21—C22—C23—C24	−2.7 (4)
O11—Ni1—N11—C111	2.3 (2)	C22—C23—C24—C25	1.3 (4)
N21—Ni1—N11—C111	−179.0 (2)	C23—C24—C25—C26	179.0 (2)
O11—Ni1—N11—C31	−178.37 (16)	C23—C24—C25—C210	0.0 (4)
N21—Ni1—N11—C31	0.28 (16)	C210—C25—C26—C27	−0.4 (4)
O21—Ni1—N21—C211	3.8 (2)	C24—C25—C26—C27	−179.4 (2)
N11—Ni1—N21—C211	−176.5 (2)	C25—C26—C27—C28	−0.6 (4)
O21—Ni1—N21—C32	−179.17 (15)	C26—C27—C28—C29	1.3 (4)
N11—Ni1—N21—C32	0.55 (16)	C27—C28—C29—C210	−1.0 (4)
Ni1—O11—C12—C11	4.7 (3)	C28—C29—C210—C25	−0.1 (4)
Ni1—O11—C12—C13	−175.85 (16)	C28—C29—C210—C21	179.5 (2)
C111—C11—C12—O11	−1.0 (4)	C26—C25—C210—C29	0.8 (3)
C110—C11—C12—O11	177.7 (2)	C24—C25—C210—C29	179.7 (2)
C111—C11—C12—C13	179.6 (2)	C26—C25—C210—C21	−178.9 (2)
C110—C11—C12—C13	−1.7 (3)	C24—C25—C210—C21	0.1 (3)
O11—C12—C13—C14	−176.7 (2)	C211—C21—C210—C29	−0.5 (4)
C11—C12—C13—C14	2.8 (4)	C22—C21—C210—C29	178.9 (2)
C12—C13—C14—C15	−1.2 (4)	C211—C21—C210—C25	179.2 (2)
C13—C14—C15—C16	177.9 (2)	C22—C21—C210—C25	−1.5 (3)
C13—C14—C15—C110	−1.5 (4)	C32—N21—C211—C21	−178.7 (2)
C110—C15—C16—C17	−1.3 (4)	Ni1—N21—C211—C21	−1.8 (3)
C14—C15—C16—C17	179.3 (2)	C22—C21—C211—N21	−2.0 (4)
C15—C16—C17—C18	−0.9 (4)	C210—C21—C211—N21	177.4 (2)
C16—C17—C18—C19	1.5 (4)	C111—N11—C31—C36	−2.1 (4)
C17—C18—C19—C110	0.2 (4)	Ni1—N11—C31—C36	178.5 (2)
C18—C19—C110—C15	−2.3 (3)	C111—N11—C31—C32	178.3 (2)
C18—C19—C110—C11	177.4 (2)	Ni1—N11—C31—C32	−1.1 (3)
C16—C15—C110—C19	2.8 (3)	C36—C31—C32—C33	1.8 (3)
C14—C15—C110—C19	−177.7 (2)	N11—C31—C32—C33	−178.6 (2)
C16—C15—C110—C11	−176.9 (2)	C36—C31—C32—N21	−178.1 (2)
C14—C15—C110—C11	2.5 (3)	N11—C31—C32—N21	1.5 (3)
C12—C11—C110—C19	179.4 (2)	C211—N21—C32—C33	−3.9 (4)
C111—C11—C110—C19	−2.0 (3)	Ni1—N21—C32—C33	178.8 (2)
C12—C11—C110—C15	−0.9 (3)	C211—N21—C32—C31	176.0 (2)
C111—C11—C110—C15	177.8 (2)	Ni1—N21—C32—C31	−1.3 (2)
C31—N11—C111—C11	−179.1 (2)	C31—C32—C33—C34	−1.8 (4)
Ni1—N11—C111—C11	0.2 (3)	N21—C32—C33—C34	178.0 (2)
C12—C11—C111—N11	−1.6 (4)	C32—C33—C34—C35	0.5 (4)
C110—C11—C111—N11	179.8 (2)	C33—C34—C35—C36	0.8 (4)
Ni1—O21—C22—C21	0.6 (3)	C34—C35—C36—C31	−0.9 (4)
Ni1—O21—C22—C23	−178.87 (16)	C32—C31—C36—C35	−0.4 (4)
C211—C21—C22—O21	2.6 (4)	N11—C31—C36—C35	−180.0 (2)
C210—C21—C22—O21	−176.7 (2)

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
C24—H24···O21^i	0.95	2.46	3.298 (3)	147

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