Crystal structure of a nickel compound comprising two nickel(II) complexes with different ligand environments: [Ni(tren)(H2O)2][Ni(H2O)6](SO4)2.

The title compound, di-aqua-[tris-(2-amino-eth-yl)amine]-nickel(II) hexa-aqua-nickel(II) bis-(sulfate), [Ni(C6H18N4)(H2O)2][Ni(H2O)6](SO4)2 or [Ni(tren)(H2O)2][Ni(H2O)6](SO4)2, consists of two octa-hedral nickel complexes within the same unit cell. These metal complexes are formed from the reaction of [Ni(H2O)6](SO4) and the ligand tris-(2-amino-eth-yl)amine (tren). The crystals of the title compound are purple, different from those of the starting complex [Ni(H2O)6](SO4), which are turquoise. The reaction was performed both in a 1:1 and 1:2 metal-ligand molar ratio, always yielding the co-precipitation of the two types of crystals. The asymmetric unit of the title compound, which crystallizes in the space group Pnma, consists of two half NiII complexes and a sulfate counter-anion. The mononuclear cationic complex [Ni(tren)(H2O)2]2+ comprises an Ni ion, the tren ligand and two water mol-ecules, while the mononuclear complex [Ni(H2O)6]2+ consists of another Ni ion surrounded by six coordinated water mol-ecules. The [Ni(tren)(H2O)2] and [Ni(H2O)6] subunits are connected to the SO4 2- counter-anions through hydrogen bonding, thus consolidating the crystal structure. © Gonzalez Nieves and Piñero Cruz 2020.

Chemical context

Tris(2-amino­eth­yl)amine (tren) has been used extensively as an ancillary tripodal ligand for capping transition metals to form mononuclear and polynuclear complexes. The tren ligand has the capacity to chelate metal ions through its central tertiary amine and through its three terminal amine groups in a spider-like conformation, leaving one or two positions available for additional ligand coordination (Marzotto et al., 1993 ▸; Albertin et al., 1975 ▸; Blackman, 2005 ▸; Brines et al., 2007 ▸). Metal complexes with a variety of ligands in which also tren is coordinating to the metal center have been proposed for applications in catalysis (Ruffin et al., 2017 ▸), sensors, and as precursors of bioinorganic reactions (Sakai et al., 1996 ▸). For instance, Ni(tren) complexes have been proposed for applications in biological systems (Salam & Aoki, 2001 ▸) or as a model to study enanti­oselective synthesis or asymmetric catalysis (Rao et al., 2009 ▸), and as coordination polymers in magnetism, electrical conductivity and ion exchange (Park et al., 2001 ▸; Tanase et al., 1996 ▸). [Ni(tren)(H2O)2] was reported previously (Chen et al., 2001 ▸; Pedersen et al., 2014 ▸); however, to our knowledge, this is the first report of it co-crystallizing with the hexa­aquo nickel complex [Ni(H2O)6](SO4).

Structural commentary

Fig. 1 ▸ shows the molecular structure of the title compound, which crystallizes in the space group Pnma. Its asymmetric unit comprises two half NiII complexes and a sulfate counter-anion. Each Ni complex shows a different ligand environment: (i) the mononuclear cationic complex [Ni(tren)(H2O)2]2+ includes Ni1, the tren ligand and two water mol­ecules; (ii) the mononuclear complex [Ni(H2O)6]2+ consists of Ni2 surrounded by six coordinated water mol­ecules.

Figure 1

View of the mol­ecular structure of the title compound with displacement ellipsoids drawn at the 20% probability level and labeling scheme for the symmetry-independent atoms. The CH2 hydrogen atoms have been omitted for clarity. The symmetry operations generating the equivalent atoms are 1 − x, 1 − y, 2 − z and x,  − y, z for [Ni(H2O)6]2+ and [Ni(tren)(H2O)2]2+, respectively.

Ni1 exhibits an octa­hedral geometry of the type N4O2, with the central N1 atom of the tren ligand occupying one of the axial positions and atoms N2, N3 and N2i occupying three of the equatorial positions [symmetry code: (i) x, −y + , z]. The remaining two positions, one axial (O2) and one equatorial (O1), are occupied by two oxygen atoms from the two water mol­ecules. The bond lengths are similar for the Ni1—N bonds that are trans to oxygen atoms; for instance, Ni1—N1ax is 2.064 (2) Å and Ni1—N3eq is 2.069 (2) Å; a longer bond distance is observed between Ni1—N2eq, 2.122 (2), which is trans by symmetry to another nitro­gen atom, N2i. The nickel–oxygen bond length is shorter for Ni1—O2ax at 2.094 (2) Å, in comparison to Ni1—O1eq, which is 2.140 (2) Å. The N3 and C3 atoms of the tren ligand lie on a mirror plane perpendicular to [010]. This results in a symmetry-induced disorder of the N3/C4/C3 fragment. The octa­hedral geometry around the Ni1 ion is reflected by the angles N1—Ni1—O2 = 178.42 (8)°, N2—Ni1—N2i = 164.74 (9)°, and N3—Ni1—O1 = 177.27 (8)°.

The Ni2 ion of the mononuclear complex [Ni(H2O)6]2+ also shows an octa­hedral geometry. In the asymmetric unit, the atom Ni2 sits on an inversion center on a screw axis along the b-axis direction. The Ni2—Owater bond lengths with O3, O4 and O5 range between 2.051 (1) and 2.074 (1) Å, respectively, with angles of 180° due to symmetry.

Supra­molecular features

The crystal structure of the title compound is consolidated through inter­molecular hydrogen bonding between the water mol­ecules from the [Ni(tren)(H2O)2] complex, the sulfate oxygen atoms and the water mol­ecules from the [Ni(H2O)6] complex (Fig. 2 ▸ and Table 1 ▸). In particular, the two water mol­ecules of [Ni(tren)(H2O)2] form O1—H1⋯O8i and O2—H2⋯O6 hydrogen bonds of 2.05 (2) and 1.96 (2) Å respectively, involving two neighboring SO4 2− anions [symmetry code: (i) x + , y, −z + ). The [Ni(H2O)6] complex is hydrogen bonded to adjacent SO4 2− anions through O3—H3E⋯O9ii, O3—H3F⋯O7i, O4—H4C⋯O6, O4—H4D⋯O8i, O5—H5B⋯O7, O5—H5A⋯O7iii contacts [symmetry codes: (ii) −x + , −y + 1, z − ; (iii) −x + , −y + 1, z + ]. These hydrogen-bond distances range from 1.905 (15) to 2.047 (18) Å. Additional weak hydrogen bonds are formed between the hydrogen atoms from the primary amine groups of the tren ligand and the sulfate oxygen atoms.

Figure 2

The hydrogen-bonding network (cyan dotted lines) in the title compound. Symmetry codes: (i) x + , y, −z + ; (ii) −x + , −y + 1, z − ; (iii) −x + , −y + 1, z + .

Table 1

Hydrogen-bond geometry (Å, °)

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
O1—H1⋯O8i	0.78 (2)	2.05 (2)	2.8212 (16)	172 (2)
O2—H2⋯O6	0.81 (2)	1.96 (2)	2.7342 (15)	162 (3)
O3—H3E⋯O9ii	0.81 (2)	1.94 (2)	2.731 (2)	167 (2)
O3—H3F⋯O7i	0.85 (2)	2.05 (2)	2.8403 (18)	155 (2)
O4—H4C⋯O6	0.83 (2)	1.91 (2)	2.7249 (18)	171 (2)
O4—H4D⋯O8i	0.83 (2)	1.95 (2)	2.7810 (18)	179 (2)
O5—H5A⋯O7iii	0.88	2.02	2.8125 (19)	150
O5—H5B⋯O7	0.88	1.95	2.7826 (17)	160

Symmetry codes: (i) ; (ii) ; (iii) .

Database survey

A search for tris­(2-amino­eth­yl)aminenickel complexes in the Cambridge Structural Database (CSD version 5.38, updated February 2019; Groom et al., 2016 ▸) yielded 222 hits. Among these results, 124 hits contained the ligand tris­(2-amino­eth­yl)amine capping the nickel ion, along with other types of ligands on the remaining coordination sites. Only two hits contain the di­aqua[tris­(2-amino­eth­yl)amine]nickel(II) complex, [Ni(tren)(H2O)2] (LUMVIY; Chen et al., 2001 ▸; TIYQAT; Tanase et al., 1996 ▸). More precisely, the asymmetric unit in LUMVIY comprises the [Ni(tren)(H2O)2]2+ cation with two independent halves of a 1,5-naphthalene­disulfonate (1,5nds) ligand as counter-anion. A common feature of this structure with the title compound is the hydrogen bond network formed between the water mol­ecules on the Ni(tren) motif with the counter anions. However, in the title compound, also the hydrogen atoms on the primary amine groups form hydrogen bonds with the sulfate anions, albeit quite weak. In TIYQAT, sulfate anions act as counter-ions for the [Ni(tren)(H2O)2]2+ complex, and uncoordinated water mol­ecules are included in the crystal lattice. The angle between the Ni center and the two oxygen atoms from the coordinated water mol­ecules are 86.52 (5)° (O7—Ni1—O8) and 86.9 (4)° (O5—Ni1—O6) for LUMVIY and TIYQAT, respectively. The corresponding angle O2—Ni—O1 in the tittle compound has a value of 88.70 (8)°, which is in good agreement with the reported values. The title compound is the first example of a crystal structure of [Ni(tren)(H2O)2]2+ co-crystallizing with the [Ni(H2O)6]2+ complex.

Synthesis and crystallization

The synthesis of the title compound is summarized in the reaction scheme shown in Fig. 3 ▸. NiSO4·6H2O and tris­(2-amino­eth­yl)amine (tren) were used without further purification. A methano­lic solution of NiSO4·6H2O (0.0265 g, 0.1 mmol) was added slowly to a tren (0.0146 g, 0.1 mmol) solution (4 mL MeOH) at room temperature. The resulting solution was stirred for two h and it changed color from light green to purple. The solution was then filtered through celite and evaporated under reduced pressure. Single crystals of the title compound were obtained by vapor diffusion of methanol into 2-propanol. In the crystallization process, two types of crystal were formed: the starting reagent hexa­hydrate nickel (II) complex (turquoise crystals) and the nickel(II) tren complex (purple crystals, Fig. 4 ▸). The reaction was performed both in a 1:1 and 1:2 metal–ligand molar ratio, always yielding the title compound. IR data: 3265 (m), 3171 (m), 2937 (w), 2891 (w), 1607 (m), 1472 (w) 1338 (w), 1054 (s), 984 (m), 885 (m), 750 (w), 685 (w).

Figure 3

Reaction scheme for the synthesis of [Ni(tren)(H2O)2][Ni(H2O)6](SO4)2.

Figure 4

Crystallization of [Ni(tren)(H2O)2][Ni(H2O)6](SO4)2 and [Ni(H2O)6]SO4 in the same reaction vial.

Refinement

Crystal data, data collection and structure refinement details are summarized in Table 2 ▸. H atoms were included in geometrically calculated positions for the alkyl and amine groups using a riding model: C—H = 0.97 Å and N—H = 0.89 Å with U iso(H) =1.2U eq(C, N). The hydrogen atoms of the water mol­ecules were located from the difference-Fourier map; they were refined freely in the case of O1 and O2, with a DFIX of 0.85 (2) Å and U iso(H) =1.5U eq(O) in the case of O3 and O4, and riding with O—H = 0.88 Å and U iso(H) =1.5U eq(O) in the case of O5.

Table 2

Experimental details

Crystal data
Chemical formula	[Ni(C6H18N4)(H2O)2][Ni(H2O)6](SO4)2
M r	599.91
Crystal system, space group	Orthorhombic, P n m a
Temperature (K)	293
a, b, c (Å)	11.8937 (1), 21.3933 (2), 8.4468 (1)
V (Å3)	2149.25 (4)
Z	4
Radiation type	Cu Kα
μ (mm−1)	4.76
Crystal size (mm)	0.28 × 0.21 × 0.09
Data collection
Diffractometer	Rigaku Oxford Diffraction SuperNova, Single source at offset/far, HyPix3000
Absorption correction	Multi-scan (CrysAlis PRO; Rigaku OD, 2015 ▸)
T min, T max	0.353, 0.661
No. of measured, independent and observed [I > 2σ(I)] reflections	17858, 2044, 1996
R int	0.023
(sin θ/λ)max (Å−1)	0.605
Refinement
R[F 2 > 2σ(F 2)], wR(F 2), S	0.023, 0.063, 1.12
No. of reflections	2044
No. of parameters	173
No. of restraints	8
H-atom treatment	All H-atom parameters refined
Δρmax, Δρmin (e Å−3)	0.37, −0.35

Computer programs: CrysAlis PRO (Rigaku OD, 2015 ▸), olex2.solve (Bourhis et al., 2015 ▸), SHELXL2016 (Sheldrick, 2015 ▸) and OLEX2 (Dolomanov et al., 2009 ▸).

The N3 and C3 atoms of the tren ligand lie on a mirror plane perpendicular to [010]. This results in a symmetry-induced disorder of the N3/C4/C3 fragment.

Crystal structure: contains datablock(s) I. DOI: 10.1107/S2056989020001358/xi2016sup1.cif

CCDC reference: 1911584

Additional supporting information: crystallographic information; 3D view; checkCIF report

[Ni(C6H18N4)(H2O)2][Ni(H2O)6](SO4)2	Dx = 1.854 Mg m−3
Mr = 599.91	Cu Kα radiation, λ = 1.54184 Å
Orthorhombic, Pnma	Cell parameters from 14387 reflections
a = 11.8937 (1) Å	θ = 3.7–68.8°
b = 21.3933 (2) Å	µ = 4.76 mm−1
c = 8.4468 (1) Å	T = 293 K
V = 2149.25 (4) Å3	Block, clear violet
Z = 4	0.28 × 0.21 × 0.09 mm
F(000) = 1256

Rigaku Oxford Diffraction SuperNova, Single source at offset/far, HyPix3000 diffractometer	1996 reflections with I > 2σ(I)
ω scans	Rint = 0.023
Absorption correction: multi-scan (CrysAlis PRO; Rigaku OD, 2015)	θmax = 68.9°, θmin = 4.1°
Tmin = 0.353, Tmax = 0.661	h = −14→14
17858 measured reflections	k = −25→25
2044 independent reflections	l = −10→10

Refinement on F2	Secondary atom site location: difference Fourier map
Least-squares matrix: full	Hydrogen site location: mixed
R[F2 > 2σ(F2)] = 0.023	All H-atom parameters refined
wR(F2) = 0.063	w = 1/[σ2(Fo2) + (0.0312P)2 + 1.2986P] where P = (Fo2 + 2Fc2)/3
S = 1.12	(Δ/σ)max < 0.001
2044 reflections	Δρmax = 0.37 e Å−3
173 parameters	Δρmin = −0.35 e Å−3
8 restraints	Extinction correction: SHELXL2016 (Sheldrick, 2015), Fc*=kFc[1+0.001xFc2λ3/sin(2θ)]-1/4
Primary atom site location: dual	Extinction coefficient: 0.00044 (5)

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.

	x	y	z	Uiso*/Ueq	Occ. (<1)
Ni1	0.31517 (3)	0.250000	0.58049 (4)	0.01987 (12)
O1	0.49430 (15)	0.250000	0.5573 (2)	0.0285 (4)
H1	0.523 (2)	0.2795 (11)	0.592 (3)	0.042 (7)*
O2	0.33527 (17)	0.250000	0.8268 (2)	0.0315 (4)
H2	0.304 (2)	0.2795 (11)	0.867 (3)	0.056 (8)*
N1	0.29062 (16)	0.250000	0.3386 (2)	0.0237 (4)
N2	0.32729 (13)	0.34830 (7)	0.55183 (18)	0.0291 (3)
H2A	0.275056	0.367313	0.609911	0.035*
H2B	0.394537	0.361563	0.583583	0.035*
N3	0.14137 (18)	0.250000	0.5913 (3)	0.0330 (5)
H3A	0.116429	0.211740	0.613150	0.040*	0.5
H3B	0.118127	0.275722	0.667351	0.040*	0.5
C1	0.34686 (17)	0.30780 (9)	0.2826 (2)	0.0336 (4)
H1A	0.327506	0.315269	0.172689	0.040*
H1B	0.427761	0.302752	0.289509	0.040*
C2	0.31074 (17)	0.36314 (9)	0.3821 (2)	0.0362 (4)
H2C	0.354856	0.399608	0.353854	0.043*
H2D	0.232177	0.372476	0.362353	0.043*
C3	0.1684 (2)	0.250000	0.3008 (3)	0.0344 (6)
H3C	0.145952	0.208172	0.269741	0.041*	0.5
H3D	0.154994	0.277594	0.211689	0.041*	0.5
C4	0.0975 (3)	0.27067 (19)	0.4375 (5)	0.0384 (10)	0.5
H4A	0.092804	0.315934	0.437065	0.046*	0.5
H4B	0.022018	0.254369	0.424014	0.046*	0.5
Ni2	0.500000	0.500000	1.000000	0.02058 (12)
O3	0.46413 (12)	0.51163 (6)	0.76229 (15)	0.0337 (3)
H3E	0.4398 (19)	0.5433 (9)	0.723 (2)	0.051*
H3F	0.5103 (18)	0.4984 (11)	0.693 (2)	0.051*
O4	0.47512 (11)	0.40611 (6)	0.96546 (16)	0.0291 (3)
H4C	0.4079 (14)	0.3972 (9)	0.956 (3)	0.044*
H4D	0.5051 (17)	0.3935 (9)	0.883 (2)	0.044*
O5	0.33269 (10)	0.51618 (6)	1.05567 (15)	0.0309 (3)
H5A	0.320545	0.510448	1.156884	0.046*
H5B	0.288625	0.490680	1.003402	0.046*
S1	0.14894 (3)	0.39419 (2)	0.92733 (4)	0.02016 (12)
O6	0.26060 (10)	0.36508 (6)	0.92041 (16)	0.0339 (3)
O7	0.15935 (10)	0.46130 (5)	0.88353 (15)	0.0297 (3)
O8	0.07525 (11)	0.36247 (6)	0.81077 (16)	0.0341 (3)
O9	0.10124 (13)	0.38801 (6)	1.08500 (15)	0.0408 (4)

	U11	U22	U33	U12	U13	U23
Ni1	0.0238 (2)	0.0199 (2)	0.0160 (2)	0.000	−0.00128 (15)	0.000
O1	0.0262 (9)	0.0235 (9)	0.0357 (10)	0.000	−0.0058 (8)	0.000
O2	0.0465 (11)	0.0277 (10)	0.0203 (9)	0.000	−0.0002 (8)	0.000
N1	0.0257 (10)	0.0280 (10)	0.0172 (9)	0.000	−0.0027 (8)	0.000
N2	0.0326 (8)	0.0234 (7)	0.0313 (8)	0.0027 (6)	−0.0018 (6)	−0.0024 (6)
N3	0.0275 (11)	0.0381 (12)	0.0335 (12)	0.000	0.0076 (9)	0.000
C1	0.0396 (10)	0.0397 (11)	0.0214 (9)	−0.0057 (8)	0.0016 (8)	0.0098 (8)
C2	0.0439 (10)	0.0254 (9)	0.0392 (11)	−0.0015 (8)	−0.0059 (9)	0.0115 (8)
C3	0.0316 (13)	0.0423 (15)	0.0292 (13)	0.000	−0.0114 (11)	0.000
C4	0.0252 (16)	0.046 (2)	0.044 (2)	0.0077 (14)	−0.0074 (15)	−0.0045 (16)
Ni2	0.0226 (2)	0.0206 (2)	0.0185 (2)	−0.00029 (15)	−0.00085 (15)	−0.00050 (15)
O3	0.0442 (8)	0.0364 (7)	0.0206 (6)	0.0102 (6)	−0.0007 (6)	0.0031 (5)
O4	0.0297 (6)	0.0264 (6)	0.0312 (7)	−0.0037 (5)	0.0030 (6)	−0.0036 (5)
O5	0.0258 (6)	0.0392 (7)	0.0279 (6)	−0.0029 (5)	0.0000 (5)	−0.0073 (6)
S1	0.0224 (2)	0.0187 (2)	0.0193 (2)	−0.00018 (14)	−0.00065 (14)	0.00073 (14)
O6	0.0255 (6)	0.0294 (7)	0.0468 (8)	0.0032 (5)	−0.0021 (6)	−0.0059 (6)
O7	0.0369 (7)	0.0207 (6)	0.0316 (7)	−0.0039 (5)	−0.0083 (5)	0.0049 (5)
O8	0.0378 (7)	0.0280 (6)	0.0364 (7)	−0.0079 (5)	−0.0130 (6)	0.0017 (5)
O9	0.0594 (9)	0.0344 (7)	0.0284 (7)	0.0040 (7)	0.0168 (6)	0.0024 (6)

Ni1—O1	2.1395 (18)	C2—H2D	0.9700
Ni1—O2	2.0940 (19)	C3—H3C	0.9700
Ni1—N1	2.0640 (19)	C3—H3Ci	0.9700
Ni1—N2	2.1217 (15)	C3—H3D	0.9700
Ni1—N2i	2.1217 (15)	C3—H3Di	0.9700
Ni1—N3	2.069 (2)	C3—C4	1.496 (4)
O1—H1	0.78 (2)	C4—H4A	0.9700
O1—H1i	0.78 (2)	C4—H4B	0.9700
O2—H2	0.81 (2)	Ni2—O3ii	2.0678 (13)
O2—H2i	0.81 (2)	Ni2—O3	2.0678 (13)
N1—C1	1.483 (2)	Ni2—O4ii	2.0511 (13)
N1—C1i	1.483 (2)	Ni2—O4	2.0511 (13)
N1—C3	1.488 (3)	Ni2—O5	2.0739 (12)
N2—H2A	0.8900	Ni2—O5ii	2.0739 (12)
N2—H2B	0.8900	O3—H3E	0.808 (15)
N2—C2	1.481 (2)	O3—H3F	0.851 (15)
N3—H3Ai	0.8900	O4—H4C	0.826 (15)
N3—H3A	0.8900	O4—H4D	0.830 (15)
N3—H3B	0.8900	O5—H5A	0.8756
N3—H3Bi	0.8900	O5—H5B	0.8759
N3—C4	1.468 (4)	S1—O6	1.4679 (13)
C1—H1A	0.9700	S1—O7	1.4878 (12)
C1—H1B	0.9700	S1—O8	1.4826 (12)
C1—C2	1.514 (3)	S1—O9	1.4537 (13)
C2—H2C	0.9700
O2—Ni1—O1	88.70 (8)	C1—C2—H2D	109.8
O2—Ni1—N2	96.06 (4)	H2C—C2—H2D	108.2
O2—Ni1—N2i	96.06 (4)	N1—C3—H3Ci	109.06 (3)
N1—Ni1—O1	92.87 (8)	N1—C3—H3C	109.1
N1—Ni1—O2	178.42 (8)	N1—C3—H3Di	109.07 (10)
N1—Ni1—N2i	84.07 (4)	N1—C3—H3D	109.1
N1—Ni1—N2	84.07 (4)	N1—C3—C4	112.6 (2)
N1—Ni1—N3	84.39 (9)	H3C—C3—H3Ci	134.6
N2i—Ni1—O1	85.52 (4)	H3Ci—C3—H3Di	107.8
N2—Ni1—O1	85.52 (4)	H3C—C3—H3D	107.8
N2i—Ni1—N2	164.74 (9)	H3C—C3—H3Di	35.2
N3—Ni1—O1	177.27 (8)	H3D—C3—H3Ci	35.2
N3—Ni1—O2	94.03 (9)	H3D—C3—H3Di	75.0
N3—Ni1—N2i	94.18 (4)	C4—C3—H3C	109.1
N3—Ni1—N2	94.18 (4)	C4—C3—H3Ci	77.37 (16)
Ni1—O1—H1i	113.6 (18)	C4—C3—H3Di	133.34 (17)
Ni1—O1—H1	113.6 (18)	C4—C3—H3D	109.1
H1—O1—H1i	109 (3)	N3—C4—H3Ai	34.21 (10)
Ni1—O2—H2	111.3 (19)	N3—C4—C3	113.2 (3)
Ni1—O2—H2i	111.3 (19)	N3—C4—H4A	108.9
H2—O2—H2i	103 (4)	N3—C4—H4B	108.9
C1i—N1—Ni1	104.58 (11)	C3—C4—H3Ai	136.9 (3)
C1—N1—Ni1	104.58 (11)	C3—C4—H4A	108.9
C1—N1—C1i	113.0 (2)	C3—C4—H4B	108.9
C1—N1—C3	111.85 (12)	H4A—C4—H3Ai	76.7
C1i—N1—C3	111.85 (12)	H4A—C4—H4B	107.8
C3—N1—Ni1	110.50 (15)	H4B—C4—H3Ai	109.6
Ni1—N2—H2A	110.0	O3ii—Ni2—O3	180.0
Ni1—N2—H2B	110.0	O3ii—Ni2—O5	89.88 (5)
H2A—N2—H2B	108.4	O3—Ni2—O5	90.12 (5)
C2—N2—Ni1	108.29 (11)	O3ii—Ni2—O5ii	90.12 (5)
C2—N2—H2A	110.0	O3—Ni2—O5ii	89.88 (5)
C2—N2—H2B	110.0	O4—Ni2—O3ii	92.87 (5)
Ni1—N3—H3A	110.0	O4ii—Ni2—O3	92.87 (5)
Ni1—N3—H3Ai	110.008 (12)	O4—Ni2—O3	87.13 (5)
Ni1—N3—H3Bi	110.01 (5)	O4ii—Ni2—O3ii	87.13 (5)
Ni1—N3—H3B	110.0	O4ii—Ni2—O4	180.0
H3A—N3—H3Ai	133.8	O4ii—Ni2—O5ii	93.28 (5)
H3A—N3—H3B	108.4	O4ii—Ni2—O5	86.72 (5)
H3A—N3—H3Bi	34.7	O4—Ni2—O5ii	86.72 (5)
H3Ai—N3—H3Bi	108.4	O4—Ni2—O5	93.28 (5)
H3B—N3—H3Ai	34.7	O5—Ni2—O5ii	180.00 (7)
H3B—N3—H3Bi	76.4	Ni2—O3—H3E	124.9 (15)
C4—N3—Ni1	108.42 (19)	Ni2—O3—H3F	119.7 (15)
C4—N3—H3A	110.0	H3E—O3—H3F	103 (2)
C4—N3—H3Ai	77.77 (16)	Ni2—O4—H4C	112.3 (14)
C4—N3—H3B	110.0	Ni2—O4—H4D	112.1 (14)
C4—N3—H3Bi	135.62 (17)	H4C—O4—H4D	105 (2)
N1—C1—H1A	109.6	Ni2—O5—H5A	110.9
N1—C1—H1B	109.6	Ni2—O5—H5B	110.8
N1—C1—C2	110.31 (15)	H5A—O5—H5B	107.8
H1A—C1—H1B	108.1	O6—S1—O7	108.92 (8)
C2—C1—H1A	109.6	O6—S1—O8	108.32 (8)
C2—C1—H1B	109.6	O8—S1—O7	109.01 (7)
N2—C2—C1	109.38 (14)	O9—S1—O6	110.55 (9)
N2—C2—H2C	109.8	O9—S1—O7	110.37 (8)
N2—C2—H2D	109.8	O9—S1—O8	109.63 (8)
C1—C2—H2C	109.8
Ni1—N1—C1—C2	−48.90 (17)	N1—C3—C4—N3	−35.8 (3)
Ni1—N1—C3—C4	18.68 (18)	C1i—N1—C1—C2	−162.01 (12)
Ni1—N2—C2—C1	−27.22 (18)	C1—N1—C3—C4	−97.4 (2)
Ni1—N3—C4—C3	34.2 (3)	C1i—N1—C3—C4	134.7 (2)
N1—C1—C2—N2	52.2 (2)	C3—N1—C1—C2	70.7 (2)

D—H···A	D—H	H···A	D···A	D—H···A
O1—H1···O8iii	0.78 (2)	2.05 (2)	2.8212 (16)	172 (2)
O2—H2···O6	0.81 (2)	1.96 (2)	2.7342 (15)	162 (3)
O3—H3E···O9iv	0.81 (2)	1.94 (2)	2.731 (2)	167 (2)
O3—H3F···O7iii	0.85 (2)	2.05 (2)	2.8403 (18)	155 (2)
O4—H4C···O6	0.83 (2)	1.91 (2)	2.7249 (18)	171 (2)
O4—H4D···O8iii	0.83 (2)	1.95 (2)	2.7810 (18)	179 (2)
O5—H5A···O7v	0.88	2.02	2.8125 (19)	150
O5—H5B···O7	0.88	1.95	2.7826 (17)	160