Syntheses and structures of trans-di­aqua­bis­(propane-1,3-di­amine-κ²N,N′)nickel(II) salts of two isomeric naphthalene­di­sulfonates

Aqueous reactions of nickel(II) nitrate, propane-1,3-di­amine, and either naphthalene-1,5-di­sulfonic acid or disodium naphthalene-2,6-di­sulfonate produced crystals of trans-di­aqua­bis­(propane-1,3-di­amine-κ²N,N′)nickel(II) naphthalene-1,5-di­sulfonate, (I), and trans-di­aqua­bis­(propane-1,3-di­amine-κ²N,N′)nickel(II) naphthalene-2,6-di­sulfonate, (II), both [Ni(C₃H₁₀N₂)₂(H₂O)₂](C₁₀H₆O₆S₂), in high yields. (I) crystallizes in the monoclinic space group P2₁/c while (II) crystallizes in the triclinic space group P1. In both structures, the cation and anion rest on centers of inversion. The nickel cations display trans octa­hedral coordination of two water mol­ecules and two bidentate propane-1,3-di­amine mol­ecules with Ni—O/N bond distances in the ranges 2.0960 (9)–2.1205 (7) Å (I) and 2.1110 (7)–2.1181 (9) Å (II). The packing in both structures features alternating layers of complex cations and naphthalene­disulfonate anions held together by O—H⋯O and N—H⋯O hydrogen bonds between the water and amine groups of the ligands and the sulfonate groups of the anions. These are the first metal salts of naphthalene-1,5-di­sulfonate and naphthalene-2,6-di­sulfonate that contain propane-1,3-di­amine. The packing in (I) and (II) is compared to each other and to those found in other nickel salts of the anions.

1. Chemical context

Metal–organic framework (MOF) structures are of inter­est for a variety of potential applications including gas storage and drug delivery (Dey et al., 2014). Construction of MOFs using sulfonate anions as linkers has been an active area of research for the past few decades (Shimizu et al., 2009; Zhang & Fei, 2019). As part of our ongoing study of metal sulfonate structures (Doney et al., 2025), we serendipitously prepared the new compounds (I) and (II) during attempts to prepare MOFs with both sulfonate and amine bridges. In the event, the structures are composed of discrete nickel complexes and naphthalene­disulfonate anions, and belong to a family of compounds first reported twenty-five years ago (Chen et al., 2001).

2. Structural commentary

The product of the reaction of nickel nitrate hexa­hydrate, propane-1,3-di­amine (DAP), and naphthalene-1,5-di­sulfonic acid is trans-[Ni(H₂O)₂(DAP)₂](C₁₀H₆(SO₃)₂), (I). The compound crystallizes in the monoclinic space group P2₁/c with the asymmetric unit consisting of half a [Ni(H₂O)₂(DAP)₂]²⁺ cation and half a 1,5-C₁₀H₆(SO₃)₂^2– anion, both on centers of inversion. As a result of the symmetry, the nickel complex has a very regular trans octa­hedral coordination geometry (Fig. 1), with bond distances [Ni—O 2.1205 (7) Å, Ni—N 2.0961 (9), 2.1127 (9) Å] and angles [N—Ni—N 93.92 (4)^o, N—Ni—O 91.08 (3), 88.67 (3)^o] that are consistent with reported examples of this complex (Kim & Lee, 2002; Temel et al., 2009; Rusanova, 2012). The naphthalene-1,5-di­sulfonate (1,5-nds) anion shows the pattern of slightly shorter (C4—C5, C6—C7 ca. 1.37 Å) and slightly longer (C5—C6, C7—C8, C8—C8ⁱ [symmetry code: (i) −x + 2, −y + 1, −z + 1] ca. 1.40–1.42 Å) bond distances seen in [Ni(H₂O)₆](C₁₀H₆(SO₃)₂)] (Chen et al., 2001). The sulfonate groups are positioned so that O2 nearly eclipses the ring [torsion angle O2—S1—C4—C5 = 3.66 (8)°. A similar eclipsed conformation is also seen in trans-di­aqua­bis­(ethylene­di­amine)nickel(II) naph­tha­lene-1,5-di­sul­fon­ate di­hy­drate (Chen et al., 2001), perhaps indicating some resonance delocalization between the ring system and the sulfonate group. The cation and anion are linked by O—H⋯O and N—H⋯O hydrogen bonds between the water and amine groups and the sulfonate group (Table 1, Fig. 1).

Table 1
Hydrogen-bond geometry (Å, °) for (I)

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
O1W—H2W⋯O3^i	0.83 (1)	1.99 (1)	2.8095 (10)	173 (2)
O1W—H1W⋯O1	0.83 (1)	1.92 (1)	2.7324 (10)	167 (2)
N1—H1N⋯O2	0.91 (1)	2.51 (1)	3.3726 (13)	159 (1)
N2—H3N⋯O2^ii	0.90 (1)	2.34 (1)	3.1817 (13)	157 (1)
N2—H4N⋯O2^iii	0.88 (1)	2.60 (2)	3.3207 (12)	140 (1)
Symmetry codes: (i) ; (ii) ; (iii) .

Figure 1 The mol­ecular structure of (I), showing the atom-numbering scheme. Displacement ellipsoids in this and subsequent figures are shown at the 70% probability level and hydrogen atoms are shown as small spheres of arbitrary radii. Hydrogen bonds are shown as striped cylinders. Symmetry-equivalent atoms are included to show the complete cation and anion.

Compound (II), with the same chemical formula as (I), was the main product of the reaction of nickel nitrate hexa­hydrate, propane-1,3-di­amine (DAP), and the disodium salt of naphthalene-2,6-di­sulfonic acid. This compound crystallizes in the triclinic space group P (the unit cell is coincidentally biclinic as the alpha angle is within two standard uncertainties of 90^o) with half a [Ni(H₂O)₂(DAP)₂]²⁺ cation and half a 2,6-C₁₀H₆(SO₃)₂^2– anion, both on centers of inversion, in the asymmetric unit. The trans octa­hedral coordination of the nickel ion [Ni—O 2.1110 (7) Å, Ni—N 2.1151 (8), 2.1181 (9) Å, N—Ni—N 90.30 (3)^o, N—Ni—O 88.92 (3), 89.13 (3)^o] is even more regular than in (I). The naphthalene-2,6-di­sulfonate (2,6-nds) anion shows the same pattern of C–C bond distances seen in (I). The sulfonate group is rotated a little over 10^o with respect to the ring relative to that in (I) [torsion angle O3—S1—C5—C4 = 15.34 (9)°]. Similar O—H⋯O water-sulfonate and N—H⋯O amine-sulfonate hydrogen bonds occur between the cation and anion (Table 2, Fig. 2).

Table 2
Hydrogen-bond geometry (Å, °) for (II)

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
O1W—H1W⋯O1	0.83 (1)	1.88 (1)	2.7065 (10)	174 (2)
O1W—H2W⋯O3^i	0.82 (1)	1.92 (1)	2.7437 (11)	177 (2)
N1—H1N⋯O2^ii	0.87 (1)	2.22 (1)	3.0039 (11)	150 (1)
N1—H2N⋯O3^i	0.90 (1)	2.51 (1)	3.3444 (12)	155 (1)
N2—H3N⋯O2^iii	0.90 (1)	2.18 (1)	3.0533 (12)	166 (1)
Symmetry codes: (i) ; (ii) ; (iii) .

Figure 2 The mol­ecular structure of (II), showing the atom-numbering scheme. Hydrogen bonds are shown as striped cylinders. Symmetry-equivalent atoms are included to show the complete cation and anion. [Symmetry code: (#) 1 − x, 1 − y, 1 − z]

Neither structure shows direct bonding between the Ni²⁺ cation and sulfonate O atoms. This is common for transition metal sulfonate salts, however, there are examples where 1,5-nds and 2,6-nds coordinate directly to Ni²⁺ as a terminal ligand (Gándara et al., 2006) and 1,5-nds acts as a bridging ligand (Forbes & Sevov, 2009; Das et al., 2015; Wei et al., 2024), indicating its potential as a building block for MOF structures.

3. Supra­molecular features

The nickel complex cations and 1,5-nds anions in (I) are segregated into layers parallel to the bc plane that stack in an alternating fashion along the a-axis direction (Fig. 3). Adjacent columns of cations and anions running along b and c are canted with respect to each other leading to a herringbone pattern in the bc plane (Fig. 4). The structure is anchored by a network of O—H⋯O and N—H⋯O hydrogen bonds between the coordinated water molecules and DAP ligands of the complexes and the sulfonate groups of the anions (Table 1). Unlike many structures containing aromatic ring systems in which parallel rings are packed ca. 3.4 Å apart to afford π stacking inter­actions, in (I) the 1,5-nds anions are more widely separated leading to cavities of ca. 2.5 Å radius between the 1,5-nds anions in the bc plane (Fig. 5) as calculated using CrystalMaker version 11.7.1 (Palmer, 2014).

Figure 3 Packing diagram of (I) with the outline of the unit cell. The alternating layers of nickel complex cations and 1,5-nds anions are evident. O—H⋯O and N—H⋯O hydrogen bonds are shown as striped cylinders. H atoms bonded to C atoms have been omitted from all packing diagrams.

Figure 4 View of (I) perpendicular to the layers in the bc plane showing the alternating columns of cations and anions with opposite tilts of the nearest neighbors. The network of O—H⋯O and N—H⋯O hydrogen bonds (striped cylinders) is evident.

Figure 5 View of the packing in (I) showing the centroids (small green spheres) of cavities of radius ca 2.5 Å in the anion layer. Cavities in (I) and (II) were calculated using CrystalMaker (Palmer, 2014).

The packing in (I) differs from that found in the closest related compound trans-di­aquabis(ethyl­enedi­amine)­nickel(II) 1,5-nds dihydrate (Chen et al., 2001). In that compound, the naphthalene rings are all parallel to the ac plane, but the anions are not segregated from the cations in this or any of the planes corresponding to the faces of the unit cell. Rather, there are alternating layers of cations and anions parallel to ( 53 24) with the naphthalene rings slanted ca. 40^o relative to the stacking direction. Owing to this slant, the parallel ring systems are not face to face, and have ethyl­enedi­amine groups in between. The cavities seen in (I) are absent and the largest existing cavities are significantly smaller (radius ca. 1.8 Å). Evidently the hydrogen-bonding network including non-coordinated water mol­ecules is sufficiently different to drive the changes. Nevertheless, the density of (I) (1.596 Mg m⁻³) is actually about 2.2% larger than the ethyl­enedi­amine analog (1.560 Mg m⁻³), so the packing in (I) is not more open. For comparison, [Ni(H₂O)₆](1,5-nds), in which the parallel naphthalene rings are closer together and do not have groups from the ligands between them, has a calculated density of 1.795 Mg m⁻³ (Chen et al., 2001). Another related di­aquabis(di­amine) complex salt, trans-di­aquabis(o-phenyl­enedi­amine)­nickel(II) 1,5-nds (Suyunov et al., 2023) has alternating planes of cations and anions parallel to (01) with the naphthalene rings only slanted about 12^o relative to the stacking direction. In this case, the phenyl groups on the ligands project into the naphthalene­disulfonate layers, so the segregation is not as great as in (I).

Similar to (I), the cations and anions in (II) are segregated into layers parallel to one of the faces of the unit cell (ab) that stack in an alternating fashion in the direction of the remaining axis (c) (Fig. 6). All of the naphthalene rings are parallel to each other and there is an additional segregation of the cations and anions in the bc plane with alternating stacking along a (Fig. 7). Due to the dominant role of the sulfonate groups in the cation-anion inter­actions, the 2,6-nds anions are oriented with the long dimension of the ring system approximately along the stacking direction c, in contrast to the case in (I). A robust network of O—H⋯O and N—H⋯O hydrogen bonds link the cations and anions in the ab plane (Fig. 7, Table 2). As a consequence of the insertion of the DAP groups between them, the 2,6-nds anions are separated from each other sufficiently to result in cavities of radius ca. 2.5 Å centered at 0,1/2,0 between them (Fig. 8) (Palmer, 2014). The density of (II) (1.588 Mg m⁻³) is within 0.5% of the density of (I), indicating the structures are essentially equally open.

Figure 6 Packing diagram of (II) with the outline of the unit cell. The alternating layers of nickel complex cations and 2,6-nds anions are evident. O–H⋯O and N–H⋯O hydrogen bonds are shown as striped cylinders.

Figure 7 View of (II) perpendicular to the layers in the ab plane showing the alternating columns of cations and anions linked by the network of O—H⋯O and N—H⋯O hydrogen bonds (striped cylinders).

Figure 8 View of the packing in (II) showing the centroids (small green spheres) of cavities of radius ca. 2.5 Å in the anion layers.

The most closely related compound to (II) with a reported structure is trans-di­aqua­bis­(N,N′-di­methyl­ethylenedi­amine)­nickel(II) 2,6-nds (Lian & Li, 2007). In this compound there is no clean segregation of the cations and anions with the long dimension of the naphthalene rings approximately along the stacking direction as is seen in (II) (Fig. 6). The only such segregation that occurs has the naphthalene rings approximately in the plane of the anion layer. Although there is a similar assortment of hydrogen bonds in all of these nickel(II) complex naphthalene­disulfonate structures, it appears that the details of the packing arrangement are highly sensitive to the size and shape of the amine ligand and the extent to which it protrudes into the anion layer.

4. Database survey

A search of the Cambridge Structural Database (CSD, Version 6.01, update of November 2025; Groom et al., 2016) for naphthalene-1,5-di­sulfonate (1,5-nds) with any metal yielded 283 hits, of which 23 contain nickel. These comprise sixteen unique structures in which the 1,5-nds is a counter-ion only, one in which it is a terminal ligand to a single Ni²⁺ ion, and four in which it bridges two Ni²⁺ ions. Examples of the first category include hexa­aqua­nickel(II) 1,5-nds (refcode LUMVAQ; Chen et al., 2001), trans-di­aqua­bis­(ethyl­enedi­amine)­nickel(II) 1,5-nds dihydrate (refcode LUMVEU; Chen et al., 2001), bis­[bis­(2-amino­eth­yl)amine]­nickel(II) 1,5-nds dihydrate (refcode LUMVOE; Chen et al., 2001), di­aqua­[tris­(2-amino­eth­yl)amine]­nickel(II) 1,5-nds monohydrate (refcode LUMVIY; Chen et al., 2001), trans-tetra­aqua­bis­(imidazole)­nickel(II) 1,5-nds (refcode HIVDAS; Liu & Deng, 2008), tetra­aqua­(1,10-phenanthroline)nickel(II) 1,5-nds dihydrate (refcode KERBEP01; Gándara et al., 2006), di­aqua­bis­(benzene-1,2-di­amine)­nickel(II) 1,5-nds (refcode LIWBEC; Suyunov et al., 2023), and tetra­aqua­bis­(isonicotinamide)­nickel(II) 1,5-nds bis­(isonicotinamide) dihydrate (refcode TESDEC; Lian, 2012). The structure in which 1,5-nds bonds to a single Ni²⁺ ion through one of the sulfonate groups is aqua­(naphthalene-1,5-di­sulfonato-O)bis­(1,10-phenanthroline) nickel(II) (refcode GESVEG; Gándara et al., 2006). The four structures in which a 1,5-nds anion bridges two Ni²⁺ ions through separate sulfonate groups are catena-[cis(μ₂-naphthalene-1,5-di­sulfonato-O,O′)tetra­kis(imidazole)­nickel(II)] (refcode BUCTID; Forbes & Sevov, 2009), (μ-naphthalene-1,5-di­sulfonato)­hexa­aqua­bis­(4,4′-dimethyl-2,2′-bi­pyridine)­di­nickel(II) naphthalene-1,5-di­sulfonate dihydrate (refcode KONFOM; Wei et al., 2024), catena-(tetra­kis­{μ-[3,5-bis­(2-amino­eth­yl)-1,3,5-triazinan-1-yl]methano­lato}tetra­kis­(μ-hy­droxo)bis­(μ-naphthalene-1,5-di­sulfonato)­tetra­aqua­octo­nickel(II) bis­(naphthalene-1,5-di­sulfonate) docosa­hydrate (refcode KUTSUP; Das et al., 2015), and catena-[(μ₂-naphthalene-1,5-di­sulfonato-O,O′)(1,4,8,11-tetra­aza­cyclo­tetra­dec­ane-N,N′,N",N′′′)nickel(II) hydrate] (refcode UKESUY; Cai et al., 2003). None of the 283 hits also contain propane-1,3-di­amine.

A search of the Cambridge Structural Database (CSD, Version 6.01, update of November 2025; Groom et al., 2016) for naphthalene-2,6-di­sulfonate (2,6-nds) with any metal yielded 109 hits, of which ten contain nickel. These comprise nine structures in which the 2,6-nds is a counter-ion only and one in which it is a terminal ligand to a single Ni²⁺ ion. The first category includes tri­aqua­tris­(1H-imidazole)­nickel(II) 2,6-nds monohydrate (refcode RAHWEE; Zhang et al., 2011), di­aqua­bis­(ethyl­enedi­amine)­copper(II) bis­[tris­(ethyl­enedi­amine)­nickel(II)] tris­(2,6-nds) tetra­hydrate (refcode TIJGAU; Cai et al., 2001), catena-[(μ₂-4,4′-bi­pyridine)­tetra­aqua­nickel(II) 2,6-nds tetra­hydrate] (refcode TUCLOT; Kanoo et al., 2009), trans-di­aqua­bis­(N,N′-di­methyl­enedi­amine)­nickel(II) 2,6-nds (refcode XEYZEH; Lian & Li, 2007), and tris­(ethyl­enedi­amine)­nickel(II) 2,6-nds monohydrate (refcode YAFSOO; Huo et al., 2004). The one structure in which 2,6-nds bonds to a single Ni²⁺ ion through one of the sulfonate groups is aqua­(naphthalene-2,6-di­sulfonato-O)bis­(1,10-phenanthroline) nickel(II) dihydrate (refcode GESVOQ; Gandara et al., 2006). None of the 109 hits also contains propane-1,3-di­amine.

5. Synthesis and crystallization

For (I), 0.893 g (3.07 mmol) Ni(NO₃)₂^.6H₂O (Aldrich) was dissolved in 10 ml of water to give a clear green solution. A 1.126 g (3.12 mmol) sample of naphthalene-1,5-di­sulfonic acid tetra­hydrate (Aldrich, 97%) was dissolved in 50 ml of water to give a clear colorless solution. These were combined with stirring and the resulting solution was clear pale green. Approximately 0.75 ml (ca. 9 mmol) of propane-1,3-di­amine (Aldrich, 99%) was added dropwise over several minutes. The color changed gradually to blue and the solution remained clear. It was set out in a porcelain evaporating dish. Many purple crystals started forming after about one h. The remaining solution was pale blue. A majority of the solvent was allowed to evaporate over a few days and the crystals were collected by suction filtration (1.5 g, 92% yield based on Ni).

For (II), 0.904 g (3.11 mmol) Ni(NO₃)₂^.6H₂O (Aldrich) was dissolved in 10 ml of water and 1.032 g (3.11 mmol) of naphthalene-2,6-di­sulfonic acid disodium salt (Aldrich, 97%) was dissolved in 50 ml of water to give clear green and pale yellow solutions, respectively. After combining with stirring, 0.75 ml (ca. 9 mmol) of propane-1,3-di­amine (Aldrich 99%) was added dropwise over several minutes. The solution's color changed to blue and then bluish purple, but it remained clear. The solution was set out in a porcelain evaporating dish. Crystals started to grow in the bottom of the dish within a few hours. Following evaporation of the solvent, large purple crystals were collected by hand (1.5 g, 91% yield based on Ni).

6. Refinement

Crystal data, data collection and structure refinement details are summarized in Table 3. For both structures, hydrogen atoms bonded to carbon atoms were located in difference-electron density maps, constrained on idealized positions, and included in the refinement as riding atoms with C—H = 0.95 Å (aromatic) or 0.99 Å (aliphatic) and their U_iso constrained to be 1.2 times the U_eq of the bonding atom. Oxygen- and nitro­gen-bound hydrogen atoms were located in difference electron-density maps and refined with isotropic displacement parameters while the O—H and N—H distances were restrained to 0.84 (1) Å and 0.91 (1) Å, respectively.

Table 3
Experimental details

	(I)	(II)
Crystal data
Chemical formula	[Ni(C3H10N2)2(H2O)2](C10H6O6S2)	[Ni(C3H10N2)2(H2O)2](C10H6O6S2)
Mr	529.27	529.27
Crystal system, space group	Monoclinic, P21/c	Triclinic, P
Temperature (K)	150	150
a, b, c (Å)	11.3312 (15), 10.9678 (15), 8.9430 (12)	7.9530 (3), 8.1103 (3), 9.7183 (3)
α, β, γ (°)	90, 97.745 (3), 90	89.9982 (11), 81.8907 (11), 63.368 (1)
V (Å^3)	1101.3 (3)	553.32 (3)
Z	2	1
Radiation type	Mo Kα	Mo Kα
μ (mm^−1)	1.12	1.12
Crystal size (mm)	0.62 × 0.34 × 0.22	0.44 × 0.20 × 0.12
Data collection
Diffractometer	APEX duo with Photon II area detector	APEX duo with Photon II area detector
Absorption correction	Multi-scan (SADABS; Krause et al., 2015)	Multi-scan (SADABS; Krause et al., 2015)
Tmin, Tmax	0.660, 0.747	0.660, 0.747
No. of measured, independent and observed [I > 2σ(I)] reflections	51023, 4915, 4314	29051, 4211, 3850
Rint	0.033	0.028
(sin θ/λ)max (Å^−1)	0.822	0.769
Refinement
R[F^2 > 2σ(F^2)], wR(F^2), S	0.024, 0.063, 1.05	0.022, 0.058, 1.06
No. of reflections	4915	4211
No. of parameters	160	160
No. of restraints	6	6
H-atom treatment	H atoms treated by a mixture of independent and constrained refinement	H atoms treated by a mixture of independent and constrained refinement
Δρmax, Δρmin (e Å^−3)	0.49, −0.45	0.46, −0.40
Computer programs: APEX3 and SAINT (Bruker, 2015), SHELXT2018/2 (Sheldrick, 2015a), SHELXL2025/1 (Sheldrick, 2015b), and CrystalMaker (Palmer, 2014).

Supporting information

Computing details

trans-Diaquabis(propane-1,3-diamine-κ²N,N')nickel(II) naphthalene-1,5-disulfonate (I)

Crystal data

[Ni(C3H10N2)2(H2O)2](C10H6O6S2)	F(000) = 556
Mr = 529.27	Dx = 1.596 Mg m^−3
Monoclinic, P21/c	Mo Kα radiation, λ = 0.71073 Å
a = 11.3312 (15) Å	Cell parameters from 9842 reflections
b = 10.9678 (15) Å	θ = 2.6–35.0°
c = 8.9430 (12) Å	µ = 1.12 mm^−1
β = 97.745 (3)°	T = 150 K
V = 1101.3 (3) Å^3	Parallelepiped, violet
Z = 2	0.62 × 0.34 × 0.22 mm

Data collection

APEX duo with Photon II area detector diffractometer	4314 reflections with I > 2σ(I)
Radiation source: fine-focus sealed tube	Rint = 0.033
φ and ω scans	θmax = 35.7°, θmin = 2.6°
Absorption correction: multi-scan (SADABS; Krause et al., 2015)	h = −18→18
Tmin = 0.660, Tmax = 0.747	k = −17→17
51023 measured reflections	l = −14→14
4915 independent reflections

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)] = 0.024	Hydrogen site location: mixed
wR(F^2) = 0.063	H atoms treated by a mixture of independent and constrained refinement
S = 1.05	w = 1/[σ^2(Fo^2) + (0.0276P)^2 + 0.4313P] where P = (Fo^2 + 2Fc^2)/3
4915 reflections	(Δ/σ)max = 0.001
160 parameters	Δρmax = 0.49 e Å^−3
6 restraints	Δρmin = −0.45 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
Ni1	0.500000	0.500000	0.000000	0.01186 (4)
S1	0.70679 (2)	0.58894 (2)	0.49483 (2)	0.01321 (4)
O1	0.66084 (6)	0.46643 (7)	0.45862 (9)	0.02052 (13)
O2	0.64514 (6)	0.68190 (7)	0.39781 (9)	0.02174 (14)
O3	0.71298 (6)	0.61736 (7)	0.65499 (8)	0.02114 (14)
O1W	0.49621 (6)	0.41740 (7)	0.21368 (8)	0.01817 (12)
H1W	0.5388 (13)	0.4416 (15)	0.2909 (15)	0.027*
H2W	0.4313 (12)	0.4063 (14)	0.2445 (17)	0.027*
N1	0.44649 (8)	0.66749 (8)	0.08156 (10)	0.02049 (15)
H1N	0.4992 (13)	0.6929 (14)	0.1609 (16)	0.031*
H2N	0.4508 (15)	0.7228 (13)	0.0109 (16)	0.031*
N2	0.32384 (8)	0.43843 (9)	−0.06461 (10)	0.02132 (16)
H3N	0.3261 (15)	0.3583 (12)	−0.0453 (18)	0.032*
H4N	0.3126 (15)	0.4430 (16)	−0.1632 (15)	0.032*
C1	0.32692 (10)	0.67556 (9)	0.12968 (13)	0.0249 (2)
H1A	0.310814	0.761263	0.155196	0.030*
H1B	0.325386	0.625806	0.221760	0.030*
C2	0.22970 (10)	0.63152 (11)	0.00790 (13)	0.0284 (2)
H2A	0.244925	0.665585	−0.090222	0.034*
H2B	0.152384	0.664235	0.029653	0.034*
C3	0.21966 (9)	0.49362 (11)	−0.00668 (12)	0.02373 (19)
H3A	0.211983	0.458221	0.093386	0.028*
H3B	0.146609	0.473004	−0.075744	0.028*
C4	0.85697 (7)	0.58798 (8)	0.45455 (9)	0.01372 (14)
C5	0.88796 (8)	0.67320 (8)	0.35417 (10)	0.01628 (15)
H5	0.831367	0.732016	0.312373	0.020*
C6	1.00413 (8)	0.67325 (9)	0.31317 (11)	0.01825 (16)
H6	1.025026	0.732127	0.243378	0.022*
C7	1.08703 (8)	0.58934 (9)	0.37293 (10)	0.01694 (15)
H7	1.164422	0.590372	0.343242	0.020*
C8	1.05880 (7)	0.50074 (8)	0.47877 (9)	0.01321 (13)

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
Ni1	0.01178 (7)	0.01213 (7)	0.01176 (7)	−0.00176 (5)	0.00194 (5)	−0.00112 (5)
S1	0.01056 (8)	0.01543 (9)	0.01360 (8)	0.00099 (6)	0.00144 (6)	−0.00184 (6)
O1	0.0148 (3)	0.0189 (3)	0.0267 (3)	−0.0022 (2)	−0.0015 (2)	−0.0050 (3)
O2	0.0152 (3)	0.0243 (3)	0.0259 (3)	0.0069 (3)	0.0031 (2)	0.0061 (3)
O3	0.0173 (3)	0.0314 (4)	0.0154 (3)	−0.0027 (3)	0.0045 (2)	−0.0069 (3)
O1W	0.0162 (3)	0.0241 (3)	0.0140 (3)	−0.0048 (2)	0.0012 (2)	0.0015 (2)
N1	0.0253 (4)	0.0150 (3)	0.0234 (4)	−0.0025 (3)	0.0115 (3)	−0.0018 (3)
N2	0.0165 (3)	0.0268 (4)	0.0205 (4)	−0.0055 (3)	0.0021 (3)	−0.0052 (3)
C1	0.0295 (5)	0.0168 (4)	0.0322 (5)	0.0016 (4)	0.0177 (4)	−0.0005 (4)
C2	0.0225 (5)	0.0319 (5)	0.0319 (5)	0.0109 (4)	0.0083 (4)	0.0117 (4)
C3	0.0149 (4)	0.0350 (5)	0.0213 (4)	−0.0035 (4)	0.0027 (3)	0.0004 (4)
C4	0.0112 (3)	0.0158 (3)	0.0142 (3)	0.0011 (3)	0.0019 (2)	−0.0007 (3)
C5	0.0145 (3)	0.0166 (4)	0.0176 (3)	0.0016 (3)	0.0014 (3)	0.0021 (3)
C6	0.0156 (4)	0.0192 (4)	0.0203 (4)	0.0000 (3)	0.0033 (3)	0.0059 (3)
C7	0.0129 (3)	0.0198 (4)	0.0186 (4)	0.0000 (3)	0.0040 (3)	0.0038 (3)
C8	0.0115 (3)	0.0146 (3)	0.0136 (3)	0.0002 (3)	0.0018 (2)	0.0002 (3)

Geometric parameters (Å, º)

Ni1—N1^i	2.0960 (9)	C1—C2	1.5197 (18)
Ni1—N1	2.0961 (9)	C1—H1A	0.9900
Ni1—N2^i	2.1127 (9)	C1—H1B	0.9900
Ni1—N2	2.1127 (9)	C2—C3	1.5210 (18)
Ni1—O1W	2.1205 (7)	C2—H2A	0.9900
Ni1—O1W^i	2.1205 (7)	C2—H2B	0.9900
S1—O2	1.4550 (7)	C3—H3A	0.9900
S1—O3	1.4583 (7)	C3—H3B	0.9900
S1—O1	1.4614 (8)	C4—C5	1.3739 (12)
S1—C4	1.7863 (9)	C4—C8^ii	1.4353 (12)
O1W—H1W	0.831 (13)	C5—C6	1.4132 (13)
O1W—H2W	0.828 (13)	C5—H5	0.9500
N1—C1	1.4785 (13)	C6—C7	1.3710 (13)
N1—H1N	0.908 (13)	C6—H6	0.9500
N1—H2N	0.883 (13)	C7—C8	1.4227 (12)
N2—C3	1.4809 (14)	C7—H7	0.9500
N2—H3N	0.895 (13)	C8—C8^ii	1.4341 (17)
N2—H4N	0.875 (13)
N1^i—Ni1—N1	180.0	H3N—N2—H4N	104.4 (15)
N1^i—Ni1—N2^i	93.92 (4)	N1—C1—C2	112.12 (9)
N1—Ni1—N2^i	86.08 (4)	N1—C1—H1A	109.2
N1^i—Ni1—N2	86.08 (4)	C2—C1—H1A	109.2
N1—Ni1—N2	93.92 (4)	N1—C1—H1B	109.2
N2^i—Ni1—N2	180.0	C2—C1—H1B	109.2
N1^i—Ni1—O1W	88.92 (3)	H1A—C1—H1B	107.9
N1—Ni1—O1W	91.08 (3)	C1—C2—C3	114.59 (9)
N2^i—Ni1—O1W	91.33 (3)	C1—C2—H2A	108.6
N2—Ni1—O1W	88.67 (3)	C3—C2—H2A	108.6
N1^i—Ni1—O1W^i	91.08 (3)	C1—C2—H2B	108.6
N1—Ni1—O1W^i	88.92 (3)	C3—C2—H2B	108.6
N2^i—Ni1—O1W^i	88.67 (3)	H2A—C2—H2B	107.6
N2—Ni1—O1W^i	91.33 (3)	N2—C3—C2	112.49 (9)
O1W—Ni1—O1W^i	180.0	N2—C3—H3A	109.1
O2—S1—O3	113.05 (5)	C2—C3—H3A	109.1
O2—S1—O1	112.59 (5)	N2—C3—H3B	109.1
O3—S1—O1	112.50 (5)	C2—C3—H3B	109.1
O2—S1—C4	106.12 (4)	H3A—C3—H3B	107.8
O3—S1—C4	106.16 (4)	C5—C4—C8^ii	121.23 (8)
O1—S1—C4	105.70 (4)	C5—C4—S1	117.52 (7)
Ni1—O1W—H1W	122.2 (11)	C8^ii—C4—S1	121.23 (6)
Ni1—O1W—H2W	119.3 (11)	C4—C5—C6	119.92 (8)
H1W—O1W—H2W	102.2 (15)	C4—C5—H5	120.0
C1—N1—Ni1	118.24 (6)	C6—C5—H5	120.0
C1—N1—H1N	106.6 (10)	C7—C6—C5	120.78 (8)
Ni1—N1—H1N	110.5 (10)	C7—C6—H6	119.6
C1—N1—H2N	108.0 (11)	C5—C6—H6	119.6
Ni1—N1—H2N	107.9 (10)	C6—C7—C8	120.94 (8)
H1N—N1—H2N	104.8 (14)	C6—C7—H7	119.5
C3—N2—Ni1	122.81 (7)	C8—C7—H7	119.5
C3—N2—H3N	109.7 (11)	C7—C8—C8^ii	118.96 (10)
Ni1—N2—H3N	105.0 (11)	C7—C8—C4^ii	122.89 (8)
C3—N2—H4N	108.3 (11)	C8^ii—C8—C4^ii	118.16 (9)
Ni1—N2—H4N	105.1 (11)

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

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
O1W—H2W···O3^iii	0.83 (1)	1.99 (1)	2.8095 (10)	173 (2)
O1W—H1W···O1	0.83 (1)	1.92 (1)	2.7324 (10)	167 (2)
N1—H1N···O2	0.91 (1)	2.51 (1)	3.3726 (13)	159 (1)
N2—H3N···O2^iv	0.90 (1)	2.34 (1)	3.1817 (13)	157 (1)
N2—H4N···O2^i	0.88 (1)	2.60 (2)	3.3207 (12)	140 (1)

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

trans-Diaquabis(propane-1,3-diamine-κ²N,N')nickel(II) naphthalene-2,6-disulfonate (II)

Crystal data

[Ni(C3H10N2)2(H2O)2](C10H6O6S2)	Z = 1
Mr = 529.27	F(000) = 278
Triclinic, P1	Dx = 1.588 Mg m^−3
a = 7.9530 (3) Å	Mo Kα radiation, λ = 0.71073 Å
b = 8.1103 (3) Å	Cell parameters from 9894 reflections
c = 9.7183 (3) Å	θ = 2.8–33.1°
α = 89.9982 (11)°	µ = 1.12 mm^−1
β = 81.8907 (11)°	T = 150 K
γ = 63.368 (1)°	Parallelepiped, violet
V = 553.32 (3) Å^3	0.44 × 0.20 × 0.12 mm

Data collection

APEX duo with Photon II area detector diffractometer	3850 reflections with I > 2σ(I)
Radiation source: fine-focus sealed tube	Rint = 0.028
φ and ω scans	θmax = 33.2°, θmin = 2.1°
Absorption correction: multi-scan (SADABS; Krause et al., 2015)	h = −12→12
Tmin = 0.660, Tmax = 0.747	k = −12→12
29051 measured reflections	l = −14→14
4211 independent reflections

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)] = 0.022	Hydrogen site location: mixed
wR(F^2) = 0.058	H atoms treated by a mixture of independent and constrained refinement
S = 1.06	w = 1/[σ^2(Fo^2) + (0.0266P)^2 + 0.1786P] where P = (Fo^2 + 2Fc^2)/3
4211 reflections	(Δ/σ)max < 0.001
160 parameters	Δρmax = 0.46 e Å^−3
6 restraints	Δρmin = −0.40 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
Ni1	0.500000	0.500000	0.500000	0.01258 (4)
S1	0.21076 (3)	0.14345 (3)	0.33755 (2)	0.01595 (5)
O1	0.41712 (11)	0.07412 (12)	0.30570 (9)	0.02572 (16)
O2	0.10953 (11)	0.34311 (10)	0.36511 (9)	0.02322 (15)
O3	0.15378 (12)	0.04556 (12)	0.44533 (8)	0.02541 (16)
O1W	0.61858 (11)	0.22987 (10)	0.40417 (8)	0.01870 (13)
H1W	0.552 (2)	0.190 (2)	0.3720 (16)	0.028*
H2W	0.684 (2)	0.149 (2)	0.4515 (15)	0.028*
N1	0.70875 (12)	0.40258 (12)	0.63276 (9)	0.01801 (15)
H1N	0.790 (2)	0.446 (2)	0.6081 (16)	0.027*
H2N	0.783 (2)	0.2799 (18)	0.6154 (16)	0.027*
N2	0.31602 (13)	0.43491 (13)	0.64373 (9)	0.02010 (15)
H3N	0.1967 (19)	0.493 (2)	0.6252 (17)	0.030*
H4N	0.354 (2)	0.3138 (18)	0.6294 (16)	0.030*
C1	0.64342 (16)	0.44315 (14)	0.78519 (11)	0.02175 (18)
H1A	0.584826	0.578454	0.807031	0.026*
H1B	0.754942	0.384928	0.834190	0.026*
C2	0.49963 (17)	0.37299 (14)	0.83887 (10)	0.02265 (19)
H2A	0.553073	0.241033	0.806376	0.027*
H2B	0.482087	0.380444	0.941971	0.027*
C3	0.30612 (16)	0.47729 (14)	0.79356 (11)	0.02272 (19)
H3A	0.213780	0.442867	0.849048	0.027*
H3B	0.260449	0.611846	0.811525	0.027*
C4	0.01803 (13)	0.01806 (12)	0.18912 (10)	0.01534 (15)
H4	−0.030957	−0.008594	0.276542	0.018*
C5	0.14324 (13)	0.09259 (12)	0.18246 (10)	0.01522 (15)
C6	0.22107 (15)	0.13071 (14)	0.05315 (11)	0.02002 (18)
H6	0.308291	0.181511	0.050351	0.024*
C7	0.16995 (14)	0.09397 (14)	−0.06789 (11)	0.01973 (17)
H7	0.222939	0.118660	−0.154552	0.024*
C8	0.03830 (12)	0.01922 (12)	−0.06491 (9)	0.01458 (15)

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
Ni1	0.01234 (7)	0.01358 (7)	0.01365 (7)	−0.00721 (6)	−0.00296 (5)	0.00048 (5)
S1	0.01467 (10)	0.01617 (10)	0.01876 (10)	−0.00778 (8)	−0.00518 (8)	−0.00098 (7)
O1	0.0149 (3)	0.0302 (4)	0.0318 (4)	−0.0095 (3)	−0.0054 (3)	−0.0091 (3)
O2	0.0233 (3)	0.0175 (3)	0.0287 (4)	−0.0085 (3)	−0.0061 (3)	−0.0044 (3)
O3	0.0320 (4)	0.0310 (4)	0.0225 (4)	−0.0202 (3)	−0.0123 (3)	0.0083 (3)
O1W	0.0194 (3)	0.0156 (3)	0.0227 (3)	−0.0083 (3)	−0.0072 (3)	−0.0005 (2)
N1	0.0186 (4)	0.0183 (3)	0.0185 (4)	−0.0086 (3)	−0.0061 (3)	0.0002 (3)
N2	0.0172 (4)	0.0224 (4)	0.0223 (4)	−0.0104 (3)	−0.0026 (3)	0.0038 (3)
C1	0.0303 (5)	0.0198 (4)	0.0176 (4)	−0.0119 (4)	−0.0096 (4)	0.0008 (3)
C2	0.0338 (5)	0.0180 (4)	0.0159 (4)	−0.0112 (4)	−0.0050 (4)	0.0023 (3)
C3	0.0246 (5)	0.0183 (4)	0.0204 (4)	−0.0076 (4)	0.0041 (4)	0.0001 (3)
C4	0.0144 (4)	0.0157 (4)	0.0169 (4)	−0.0075 (3)	−0.0032 (3)	0.0000 (3)
C5	0.0141 (4)	0.0142 (3)	0.0184 (4)	−0.0067 (3)	−0.0046 (3)	−0.0006 (3)
C6	0.0213 (4)	0.0246 (4)	0.0217 (4)	−0.0165 (4)	−0.0047 (3)	0.0022 (3)
C7	0.0210 (4)	0.0260 (4)	0.0193 (4)	−0.0168 (4)	−0.0035 (3)	0.0022 (3)
C8	0.0132 (3)	0.0143 (3)	0.0179 (4)	−0.0074 (3)	−0.0031 (3)	0.0003 (3)

Geometric parameters (Å, º)

Ni1—O1W^i	2.1110 (7)	C1—C2	1.5227 (16)
Ni1—O1W	2.1110 (7)	C1—H1A	0.9900
Ni1—N1	2.1151 (8)	C1—H1B	0.9900
Ni1—N1^i	2.1151 (8)	C2—C3	1.5171 (16)
Ni1—N2	2.1181 (9)	C2—H2A	0.9900
Ni1—N2^i	2.1181 (9)	C2—H2B	0.9900
S1—O2	1.4534 (8)	C3—H3A	0.9900
S1—O3	1.4565 (8)	C3—H3B	0.9900
S1—O1	1.4612 (8)	C4—C5	1.3720 (12)
S1—C5	1.7769 (9)	C4—C8^ii	1.4224 (13)
O1W—H1W	0.829 (13)	C4—H4	0.9500
O1W—H2W	0.823 (13)	C5—C6	1.4177 (14)
N1—C1	1.4839 (13)	C6—C7	1.3717 (14)
N1—H1N	0.871 (13)	C6—H6	0.9500
N1—H2N	0.901 (12)	C7—C8	1.4231 (12)
N2—C3	1.4792 (14)	C7—H7	0.9500
N2—H3N	0.895 (13)	C8—C8^ii	1.4189 (18)
N2—H4N	0.893 (13)
O1W^i—Ni1—O1W	180.00 (5)	H3N—N2—H4N	106.6 (14)
O1W^i—Ni1—N1	91.08 (3)	N1—C1—C2	112.55 (8)
O1W—Ni1—N1	88.92 (3)	N1—C1—H1A	109.1
O1W^i—Ni1—N1^i	88.92 (3)	C2—C1—H1A	109.1
O1W—Ni1—N1^i	91.08 (3)	N1—C1—H1B	109.1
N1—Ni1—N1^i	180.0	C2—C1—H1B	109.1
O1W^i—Ni1—N2	90.87 (3)	H1A—C1—H1B	107.8
O1W—Ni1—N2	89.13 (3)	C3—C2—C1	114.71 (8)
N1—Ni1—N2	90.30 (3)	C3—C2—H2A	108.6
N1^i—Ni1—N2	89.70 (3)	C1—C2—H2A	108.6
O1W^i—Ni1—N2^i	89.13 (3)	C3—C2—H2B	108.6
O1W—Ni1—N2^i	90.87 (3)	C1—C2—H2B	108.6
N1—Ni1—N2^i	89.70 (3)	H2A—C2—H2B	107.6
N1^i—Ni1—N2^i	90.30 (3)	N2—C3—C2	111.08 (8)
N2—Ni1—N2^i	180.0	N2—C3—H3A	109.4
O2—S1—O3	112.75 (5)	C2—C3—H3A	109.4
O2—S1—O1	112.81 (5)	N2—C3—H3B	109.4
O3—S1—O1	112.93 (5)	C2—C3—H3B	109.4
O2—S1—C5	106.41 (4)	H3A—C3—H3B	108.0
O3—S1—C5	106.06 (4)	C5—C4—C8^ii	119.89 (8)
O1—S1—C5	105.10 (4)	C5—C4—H4	120.1
Ni1—O1W—H1W	121.5 (11)	C8^ii—C4—H4	120.1
Ni1—O1W—H2W	114.1 (11)	C4—C5—C6	121.22 (8)
H1W—O1W—H2W	105.6 (15)	C4—C5—S1	120.11 (7)
C1—N1—Ni1	117.93 (7)	C6—C5—S1	118.68 (7)
C1—N1—H1N	108.4 (10)	C7—C6—C5	119.74 (8)
Ni1—N1—H1N	108.3 (10)	C7—C6—H6	120.1
C1—N1—H2N	108.7 (10)	C5—C6—H6	120.1
Ni1—N1—H2N	110.4 (10)	C6—C7—C8	120.64 (9)
H1N—N1—H2N	101.8 (14)	C6—C7—H7	119.7
C3—N2—Ni1	117.46 (7)	C8—C7—H7	119.7
C3—N2—H3N	106.8 (10)	C8^ii—C8—C4^ii	119.26 (10)
Ni1—N2—H3N	110.3 (10)	C8^ii—C8—C7	119.24 (10)
C3—N2—H4N	108.5 (10)	C4^ii—C8—C7	121.50 (8)
Ni1—N2—H4N	106.7 (10)

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

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
O1W—H1W···O1	0.83 (1)	1.88 (1)	2.7065 (10)	174 (2)
O1W—H2W···O3^iii	0.82 (1)	1.92 (1)	2.7437 (11)	177 (2)
N1—H1N···O2^i	0.87 (1)	2.22 (1)	3.0039 (11)	150 (1)
N1—H2N···O3^iii	0.90 (1)	2.51 (1)	3.3444 (12)	155 (1)
N2—H3N···O2^iv	0.90 (1)	2.18 (1)	3.0533 (12)	166 (1)

Symmetry codes: (i) −x+1, −y+1, −z+1; (iii) −x+1, −y, −z+1; (iv) −x, −y+1, −z+1.