Diaquabis(propane-1,2-diamine-N,N')nickel(II) bis(p-toluenesulfonate)

The crystal structure of the title compound, [Ni(C₃H₁₀N₂)₂(H₂O)₂](C₇H₇O₃S)₂ or [Ni(H₂O)₂{NH₂CH₂CH­(NH₂)CH₃}₂](CH₃C₆H₄SO₃)₂, exhibits a layered structure in which the complex cations and the p-toluene­sulfonate anions form alternating layers. The central Ni^II atom of the cation resides on a crystallographic inversion centre and has a slightly distorted octahedral coordination composed of the water ligands bonding through oxy­gen in a trans arrangement and the N,N'-bidentate propane­di­amine ligands. The p-toluene­sulfonate anions are arranged with the sulfonate groups turned alternately towards opposite sides of the layers. The structure of the layers is stabilized by a network of hydrogen bonds between the sulfonate O atoms, water mol­ecules and the propane­di­amine N atoms.

S1. Comment

Compounds forming layered structures have been of great interest in both academic research and industrial applications, because of their possible use as ion exchangers and intercalation materials (Clearfield, 1988; Suib, 1993). Particularly, metal phosphate and phosphonate compounds, such as zirconium and titanium phosphates and phosphonates, have been extensively studied as a new family of layered materials (Clearfield & Costantino, 1996; Alberti, 1996). Most commonly, these mixed inorganic-organic two-dimensional compounds contain covalent metal-oxygen-phosphorus frameworks. In recent years, Squattrito and co-workers have studied metal organosulfonate compounds (Gunderman & Squattrito, 1995; Benedetto et al., 1997), and they have reported two-dimensional materials with layered structures analogous to the recently reported metal phosphonate structures. In our group, research has been directed towards the development of new layered and porous materials (Kim & Lee, 2000), using weaker metal sulfonate interactions. This approach takes advantage of the flexible coordination behaviour of the SO₃^- group to obtain structures. In this paper, we report the preparation and crystal structure of the title nickel(II) sulfonate complex, (I), which is chelated by propanediamine ligands. \sch

As shown in Fig 1, the Ni^II cation of (I) lies on a crystallographic inversion centre and is six-coordinate, with two propanediamine ligands attached at the equatorial positions and two water molecules at the axial positions. Its coordination geometry can be described as a slightly distorted octahedral arrangement. The Ni—N distances range from 2.074 (2) to 2.099 (2) Å and the Ni—O distance is 2.152 (2) Å. The inter-ligand N—Ni—N angle is 82.54 (8)° and the N—Ni—O angles are in the range 86.95 (7)–88.23 (7)°.

The S—O_sulfonate bond lengths in the p-toluenesulfonate anion range from 1.426 (2) to 1.446 (2) Å and the S—C bond length is 1.768 (2) Å. The O_sulfonate—S—O_sulfonate and O_sulfonate—S—C bond angles are in the range 110.6 (2) to 112.9 (2)° and 106.6 (1) to 106.8 (1)°, respectively. The geometrical data for this anion are consistent with those previously reported by Rogers et al. (1991).

As shown in Fig. 2, compound (I) forms a layered structure consisting of dicationic [Ni(H₂O)₂{NH₂CH₂CH(NH₂)CH₃}₂]²⁺ layers and anionic CH₃C₆H₄SO₃^- layers. The arrangement of the p-toluenesulfonate anions has the sulfonate groups turned alternately toward opposite sides of the layers. The water molecules coordinated to the Ni^II cations and most of the O atoms of the p-toluenesulfonate anions are linked together in hydrogen-bonded chains along [001], with strong O_water—H···O_sulfonate hydrogen bonds (O30—H30A···O2 and O30—H30B···O3; Table 1). These chains are cross-linked in the (011) plane by the N_diamine—H···O_sulfonate hydrogen-bonding interactions formed between the amine H atoms of the propanediamine ligands and the sulfonate O atoms of the p-toluenesulfonate anions (N20—H20A···O1, N20—H20B···O1, N10—H10B···O2 and N10—H10A···O3; Table 1). Thus, all hydrogen bonds are formed by contacts between cations and anions, and so all contribute to the stabilization of the crystal structure.

In conclusion, the crystal structure of (I) consists of a highly layered two-dimensional network, with hydrophilic and hydrophobic sections alternating along [100]. The crystal structure is stabilized through hydrogen bonding. There is no direct bonding between the Ni^II cation and the sulfonate O atoms of the anion. Therefore, this Ni^II sulfonate compound is quite different in structure from the reported metal phosphonates (Clearfield & Costantino, 1996; Alberti, 1996).

Related literature

For related literature, see: Alberti (1996); Benedetto et al. (1997); Clearfield (1988); Clearfield & Costantino (1996); Gunderman & Squattrito (1995); Kim & Lee (2000); Rogers et al. (1991); Suib (1993).

S2. Experimental

To an aqueous solution (50 ml) of NiCl₂·6H₂O (2.38 g, 10 mmol) was added p-toluenesulfonic acid (1.90 g, 10 mmol) with stirring at room temperature, followed by dropwise addition of neat propanediamine (0.74 g, 10 mmol). The resulting solution was kept in a refrigerator at 278 K. Blue block crystals of (I) suitable for X-ray analysis were obtained after a few weeks. Analysis calculated for C₂₀H₃₈N₄O₈S₂Ni: C 41.04, H 6.54, N 9.57, O 21.86, S 10.96, Ni 10.03%; found: C 41.35, H 6.69, N 9.64, O 21.08, S 10.93, Ni 10.18%.

S3. Refinement

The H atoms of the water molecules were freely refined. All other H atoms were treated as riding, with C—H = 0.93–0.98 Å and N—H = 0.90 Å, and U_iso(H) = 1.2U_eq of the parent atom. Are these the correct constraints?

Computing details

Data collection: XSCANS (Siemens, 1996); cell refinement: XSCANS; data reduction: SHELXTL (Siemens, 1997); program(s) used to solve structure: SHELXS97 (Sheldrick, 1990); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: SHELXTL; software used to prepare material for publication: SHELXTL.

Figures

	Fig. 1. The molecular structure of (I) with the atomic numbering scheme and displacement ellipsoids at the 30% probability level. H atoms are shown as small spheres of arbitrary radii.
	Fig. 2. A perspective view of the unit cell of (I) along the b axis; hydrogen bonds are shown by broken lines and H atoms have been omitted for clarity.

Diaquabis(propane-1,2-diamine-N,N')nickel(II) bis(p-toluenesulfonate)

Crystal data

[Ni(H2O)2(C3H10N2)2]2C7H7SO3	? # Insert any comments here.
Mr = 585.37	Dx = 1.395 Mg m^−3 Dm = 1.40 Mg m^−3 Dm measured by flotation in mesitylene-bromoform
Monoclinic, P21/c	Mo Kα radiation, λ = 0.71073 Å
a = 13.060 (2) Å	Cell parameters from 42 reflections
b = 7.3266 (11) Å	θ = 5.4–12.5°
c = 15.0029 (18) Å	µ = 0.89 mm^−1
β = 103.842 (10)°	T = 295 K
V = 1393.9 (3) Å^3	Block, blue
Z = 2	0.40 × 0.32 × 0.23 mm
F(000) = 620

Data collection

Siemens P4 diffractometer	2697 reflections with I > 2σ(I)
Radiation source: fine-focus sealed tube	Rint = 0.028
Graphite monochromator	θmax = 27.5°, θmin = 2.8°
ω/2θ scans	h = −16→1
Absorption correction: empirical (using intensity measurements) (North et al., 1968)	k = −9→1
Tmin = 0.280, Tmax = 0.339	l = −19→19
4187 measured reflections	3 standard reflections every 97 reflections
3216 independent reflections	intensity decay: none

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) = 0.112	H atoms treated by a mixture of independent and constrained refinement
S = 1.06	w = 1/[σ^2(Fo^2) + (0.0577P)^2 + 0.4802P] where P = (Fo^2 + 2Fc^2)/3
3216 reflections	(Δ/σ)max < 0.001
168 parameters	Δρmax = 0.73 e Å^−3
2 restraints	Δρmin = −0.53 e Å^−3

Special details

Experimental. ? #Insert any special details here.

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	0.0000	0.0000	0.0000	0.03226 (12)
S1	0.18045 (4)	0.13246 (9)	−0.27123 (3)	0.04218 (16)
O1	0.1217 (2)	0.0335 (4)	−0.34848 (17)	0.0990 (10)
O2	0.12423 (15)	0.1555 (3)	−0.20046 (13)	0.0646 (5)
O3	0.21797 (17)	0.3063 (3)	−0.29616 (18)	0.0803 (7)
C1	0.29349 (18)	0.0004 (3)	−0.22309 (15)	0.0427 (5)
C2	0.3816 (2)	0.0833 (5)	−0.1689 (2)	0.0616 (7)
H2B	0.3826	0.2086	−0.1588	0.074*
C3	0.4684 (2)	−0.0228 (5)	−0.1297 (2)	0.0740 (10)
H3B	0.5279	0.0328	−0.0934	0.089*
C4	0.4689 (2)	−0.2084 (5)	−0.1433 (2)	0.0678 (9)
C5	0.3801 (2)	−0.2882 (5)	−0.1987 (2)	0.0624 (7)
H5A	0.3796	−0.4132	−0.2096	0.075*
C6	0.2921 (2)	−0.1851 (4)	−0.23830 (17)	0.0504 (6)
H6A	0.2327	−0.2406	−0.2748	0.061*
C7	0.5635 (3)	−0.3241 (7)	−0.0987 (3)	0.1008 (14)
H7A	0.6176	−0.2475	−0.0630	0.151*
H7B	0.5898	−0.3847	−0.1454	0.151*
H7C	0.5429	−0.4134	−0.0595	0.151*
N10	−0.15659 (14)	−0.0601 (3)	0.00195 (12)	0.0406 (4)
H10A	−0.1867	−0.1288	−0.0471	0.049*
H10B	−0.1583	−0.1230	0.0531	0.049*
N20	−0.04730 (15)	0.2643 (2)	0.01926 (12)	0.0386 (4)
H20A	0.0043	0.3231	0.0596	0.046*
H20B	−0.0605	0.3255	−0.0343	0.046*
C11	−0.21463 (18)	0.1131 (4)	−0.00016 (16)	0.0476 (5)
H11A	−0.2755	0.0945	0.0252	0.057*
H11B	−0.2394	0.1539	−0.0632	0.057*
C12	−0.14405 (19)	0.2568 (3)	0.05474 (15)	0.0446 (5)
H12A	−0.1238	0.2160	0.1188	0.053*
C13	−0.1976 (3)	0.4417 (5)	0.0524 (2)	0.0742 (9)
H13A	−0.1494	0.5274	0.0886	0.111*
H13B	−0.2588	0.4302	0.0770	0.111*
H13C	−0.2186	0.4842	−0.0098	0.111*
O30	−0.05333 (14)	0.0500 (3)	−0.14507 (11)	0.0455 (4)
H30A	−0.008 (2)	0.069 (5)	−0.181 (2)	0.070 (9)*
H30B	−0.103 (2)	−0.021 (4)	−0.180 (2)	0.086 (12)*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
Ni1	0.0353 (2)	0.0332 (2)	0.02864 (19)	−0.00217 (14)	0.00832 (13)	0.00087 (14)
S1	0.0463 (3)	0.0521 (3)	0.0276 (2)	0.0085 (2)	0.0078 (2)	0.0040 (2)
O1	0.0992 (18)	0.104 (2)	0.0644 (14)	0.0497 (15)	−0.0380 (13)	−0.0361 (13)
O2	0.0602 (11)	0.0904 (15)	0.0500 (10)	0.0144 (11)	0.0267 (8)	0.0151 (10)
O3	0.0664 (13)	0.0778 (15)	0.1020 (17)	0.0139 (11)	0.0308 (12)	0.0482 (14)
C1	0.0421 (11)	0.0539 (13)	0.0314 (9)	0.0054 (10)	0.0075 (8)	0.0069 (9)
C2	0.0575 (15)	0.0607 (17)	0.0584 (15)	−0.0028 (14)	−0.0020 (12)	0.0084 (14)
C3	0.0457 (15)	0.096 (3)	0.0697 (19)	−0.0071 (15)	−0.0063 (13)	0.0155 (17)
C4	0.0476 (14)	0.101 (3)	0.0573 (15)	0.0220 (16)	0.0178 (12)	0.0267 (16)
C5	0.0666 (17)	0.0630 (17)	0.0612 (16)	0.0190 (14)	0.0225 (13)	0.0088 (14)
C6	0.0516 (13)	0.0559 (15)	0.0436 (12)	0.0064 (11)	0.0108 (10)	0.0019 (11)
C7	0.0645 (19)	0.150 (4)	0.089 (2)	0.048 (2)	0.0205 (18)	0.044 (3)
N10	0.0404 (9)	0.0458 (10)	0.0358 (9)	−0.0068 (8)	0.0097 (7)	0.0011 (8)
N20	0.0458 (10)	0.0370 (9)	0.0315 (8)	−0.0010 (8)	0.0059 (7)	0.0028 (7)
C11	0.0392 (11)	0.0602 (15)	0.0450 (12)	0.0042 (11)	0.0132 (9)	0.0095 (11)
C12	0.0567 (13)	0.0436 (12)	0.0365 (10)	0.0091 (10)	0.0170 (9)	0.0061 (9)
C13	0.099 (2)	0.0563 (16)	0.080 (2)	0.0280 (18)	0.0457 (19)	0.0127 (16)
O30	0.0512 (9)	0.0521 (9)	0.0326 (7)	−0.0056 (8)	0.0090 (7)	0.0027 (7)

Geometric parameters (Å, º)

Ni1—N20	2.0736 (18)	C6—H6A	0.9300
Ni1—N20^i	2.0736 (18)	C7—H7A	0.9600
Ni1—N10^i	2.0991 (18)	C7—H7B	0.9600
Ni1—N10	2.0991 (18)	C7—H7C	0.9600
Ni1—O30	2.1521 (16)	N10—C11	1.475 (3)
Ni1—O30^i	2.1521 (16)	N10—H10A	0.9000
S1—O1	1.426 (2)	N10—H10B	0.9000
S1—O2	1.4380 (18)	N20—C12	1.485 (3)
S1—O3	1.446 (2)	N20—H20A	0.9000
S1—C1	1.768 (2)	N20—H20B	0.9000
C1—C6	1.378 (4)	C11—C12	1.507 (4)
C1—C2	1.381 (4)	C11—H11A	0.9700
C2—C3	1.385 (4)	C11—H11B	0.9700
C2—H2B	0.9300	C12—C13	1.522 (4)
C3—C4	1.375 (5)	C12—H12A	0.9800
C3—H3B	0.9300	C13—H13A	0.9600
C4—C5	1.384 (5)	C13—H13B	0.9600
C4—C7	1.516 (4)	C13—H13C	0.9600
C5—C6	1.385 (4)	O30—H30A	0.902 (18)
C5—H5A	0.9300	O30—H30B	0.893 (18)
N20—Ni1—N20^i	180.00 (12)	C4—C7—H7A	109.5
N20—Ni1—N10^i	97.46 (8)	C4—C7—H7B	109.5
N20^i—Ni1—N10^i	82.54 (8)	H7A—C7—H7B	109.5
N20—Ni1—N10	82.54 (8)	C4—C7—H7C	109.5
N20^i—Ni1—N10	97.46 (8)	H7A—C7—H7C	109.5
N10^i—Ni1—N10	180.00 (10)	H7B—C7—H7C	109.5
N20—Ni1—O30	86.95 (7)	C11—N10—Ni1	108.46 (14)
N20^i—Ni1—O30	93.05 (7)	C11—N10—H10A	110.0
N10^i—Ni1—O30	91.77 (7)	Ni1—N10—H10A	110.0
N10—Ni1—O30	88.23 (7)	C11—N10—H10B	110.0
N20—Ni1—O30^i	93.05 (7)	Ni1—N10—H10B	110.0
N20^i—Ni1—O30^i	86.95 (7)	H10A—N10—H10B	108.4
N10^i—Ni1—O30^i	88.23 (7)	C12—N20—Ni1	108.83 (13)
N10—Ni1—O30^i	91.77 (7)	C12—N20—H20A	109.9
O30—Ni1—O30^i	180.00 (3)	Ni1—N20—H20A	109.9
O1—S1—O2	112.91 (18)	C12—N20—H20B	109.9
O1—S1—O3	112.81 (19)	Ni1—N20—H20B	109.9
O2—S1—O3	110.62 (15)	H20A—N20—H20B	108.3
O1—S1—C1	106.75 (13)	N10—C11—C12	110.20 (18)
O2—S1—C1	106.65 (11)	N10—C11—H11A	109.6
O3—S1—C1	106.63 (12)	C12—C11—H11A	109.6
C6—C1—C2	120.5 (2)	N10—C11—H11B	109.6
C6—C1—S1	119.7 (2)	C12—C11—H11B	109.6
C2—C1—S1	119.8 (2)	H11A—C11—H11B	108.1
C1—C2—C3	119.0 (3)	N20—C12—C11	106.95 (18)
C1—C2—H2B	120.5	N20—C12—C13	112.6 (2)
C3—C2—H2B	120.5	C11—C12—C13	113.0 (2)
C4—C3—C2	121.7 (3)	N20—C12—H12A	108.0
C4—C3—H3B	119.2	C11—C12—H12A	108.0
C2—C3—H3B	119.2	C13—C12—H12A	108.0
C3—C4—C5	118.3 (3)	C12—C13—H13A	109.5
C3—C4—C7	121.3 (4)	C12—C13—H13B	109.5
C5—C4—C7	120.4 (4)	H13A—C13—H13B	109.5
C4—C5—C6	121.1 (3)	C12—C13—H13C	109.5
C4—C5—H5A	119.4	H13A—C13—H13C	109.5
C6—C5—H5A	119.4	H13B—C13—H13C	109.5
C1—C6—C5	119.4 (3)	Ni1—O30—H30A	122 (2)
C1—C6—H6A	120.3	Ni1—O30—H30B	120 (3)
C5—C6—H6A	120.3	H30A—O30—H30B	103 (3)
O1—S1—C1—C6	−23.5 (3)	C4—C5—C6—C1	0.8 (4)
O2—S1—C1—C6	97.4 (2)	N20—Ni1—N10—C11	9.26 (13)
O3—S1—C1—C6	−144.3 (2)	N20^i—Ni1—N10—C11	−170.74 (13)
O1—S1—C1—C2	157.9 (3)	O30—Ni1—N10—C11	−77.90 (14)
O2—S1—C1—C2	−81.1 (2)	O30^i—Ni1—N10—C11	102.10 (14)
O3—S1—C1—C2	37.1 (2)	N10^i—Ni1—N20—C12	−160.83 (14)
C6—C1—C2—C3	−0.2 (4)	N10—Ni1—N20—C12	19.17 (14)
S1—C1—C2—C3	178.3 (2)	O30—Ni1—N20—C12	107.79 (14)
C1—C2—C3—C4	−0.2 (5)	O30^i—Ni1—N20—C12	−72.21 (14)
C2—C3—C4—C5	0.9 (5)	Ni1—N10—C11—C12	−36.2 (2)
C2—C3—C4—C7	−178.8 (3)	Ni1—N20—C12—C11	−43.32 (19)
C3—C4—C5—C6	−1.2 (4)	Ni1—N20—C12—C13	−168.1 (2)
C7—C4—C5—C6	178.5 (3)	N10—C11—C12—N20	53.2 (2)
C2—C1—C6—C5	0.0 (4)	N10—C11—C12—C13	177.7 (2)
S1—C1—C6—C5	−178.59 (19)

Symmetry code: (i) −x, −y, −z.

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
N10—H10A···O3^ii	0.90	2.34	3.154 (3)	151
N10—H10B···O2^i	0.90	2.16	2.989 (3)	153
N20—H20A···O1^iii	0.90	2.08	2.984 (3)	178
N20—H20A···S1^iii	0.90	3.01	3.8505 (19)	157
N20—H20B···O1^iv	0.90	2.32	3.195 (3)	164
O30—H30A···O2	0.90 (2)	1.93 (2)	2.755 (3)	151 (3)
O30—H30B···O3^ii	0.89 (2)	1.93 (2)	2.772 (3)	156 (4)
O30—H30B···S1^ii	0.89 (2)	2.77 (2)	3.563 (2)	149 (3)

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