Piperazinium hexa­aqua­cobalt(II) di­sulfate

The crystal structure of the title compound, (C₄H₁₂N₂)[Co(H₂O)₆](SO₄)₂, is built of [Co(H₂O)₆]²⁺ cations, diproton­ated piperazinium cations (each of the two crystallographic­ally independent piperazinium cations occupies a special position on an inversion centre) and sulfate anions. The Co atom is coordinated by six water mol­ecules in a slightly distorted octahedral geometry. The cations are linked to anions by N—H...O and O—H...O hydrogen bonds, forming an extensive three-dimensional hydrogen-bond network in the crystal structure.

Key indicators

• Single-crystal X-ray study
• T = 293 K
• Mean [sigma](C-C) = 0.007 Å
• R factor = 0.043
• wR factor = 0.112
• Data-to-parameter ratio = 11.4

checkCIF results

No syntax errors found

ADDSYM reports no extra symmetry


 Alert Level C:



PLAT_354  Alert C Short   O-H Bond (0.82A)   O(3W)  -   H(32)  =       0.70 Ang.

PLAT_354  Alert C Short   O-H Bond (0.82A)   O(6W)  -   H(61)  =       0.69 Ang.


 0 Alert Level A = Potentially serious problem

 0 Alert Level B = Potential problem

 2 Alert Level C = Please check

---

S1. Comment

Intermolecular interactions, such as hydrogen bonds or aromatic π–π stacking, play a dominant role in molecular recognition in nature, and in designing molecular aggregates (Juan et al., 2002). One of the important aspects of cobalt sulfate hydrate structures is the existence of extensive hydrogen-bonding interactions. Up until now, a series of such compounds have been reported in the literature, e.g. CoSO₄·7D₂O (Olovsson et al., 1991), CoSO₄·four-dimensional₂O (Kellersohn, 1992) and CoSO₄·six-dimensional₂O (Olovsson et al., 1993). In the course of our studies of transition metal borophosphates, we tried to prepare a novel cobalt borophosphate containing piperazine as a template. Unfortunately, borophosphate salt was not isolated; instead, single crystals of the title double salt, (I), were obtained.

The crystal structure of (I) consists of discrete [Co(H₂O)₆]²⁺ cations, diprotonated piperazinium cations and sulfate anions. All crystallographically independent chemical residues in the crystal of the title compound are shown in Fig. 1. Within the [Co(H₂O)₆]²⁺ cation, the Co atom is coordinated by six water molecules in the vertices of a slightly distorted octahedron. The Co—O bond lengths range from 2.052 (4) to 2.124 (3) Å and the O—Co—O bond angles span the intervals of 84.7–93.8 and 177.3–178.8°.

The anions and cations in the crystal are linked via N—H···O and O—H···O hydrogen bonds into an extensive three-dimensional infinite framework. Each cation acts as a donor of hydrogen bonds and each anion acts as an acceptor. The packing diagram of the title compound showing the hydrogen-bonding framework is presented in Fig. 2. Intermolecular N—H···O and O—H···O hydrogen bonds lengths are in the ranges 2.720 (5)–3.239 (5) and 2.689 (5)–3.049 (6) Å, respectively.

S2. Experimental

The title compound was prepared by hydrothermal synthesis from a mixture of CoSO₄·7H₂O (0.562 g, 2 mmol), H₃BO₃ (0.124 g, 2 mmol), piperazine (0.172 g, 2 mmol), 85% H₃PO₄ (0.27 ml, 4 mmol) and 37% HCl (1 ml) in H₂O (5 ml). The mixture was sealed in a Teflon autoclave, heated at 438 K for 5 d and cooled. After filtration, the red filtrate was allowed to stand in air for 2 d, whereupon red crystals were obtained.

S3. Refinement

The aqua H atoms were located in the difference Fourier maps and their positions and isotropic displacement parameters were refined. H atoms bonded to C and N atoms were positioned geometrically (the C—H and N—H bonds were fixed at 0.97 and 0.90 Å, respectively) and allowed to ride on their parent atoms.

Computing details

Data collection: SMART (Siemens, 1996); cell refinement: SMART; data reduction: SAINT (Siemens, 1994); program(s) used to solve structure: SHELXS97 (Sheldrick, 1990); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: SHELXTL (Bruker, 1997); software used to prepare material for publication: SHELXTL.

Figures

	Fig. 1. The cations and anions in the structure of the title compound, with the atom-numbering scheme and displacement ellipsoids shown at the 50% probability level [symmetry codes: (i) 1 − x, 2 − y, −z; (ii) 1 − x, 2 − y, 1 − z].
	Fig. 2. Packing diagram viewed down the c axis of the unit cell, showing N—H···O and O—H···O hydrogen bonds.

Piperazinium hexaaquacobalt disulfate

Crystal data

(C4H12N2)[Co(H2O)6](SO4)2	F(000) = 932
Mr = 447.30	Dx = 1.775 Mg m^−3
Monoclinic, P21/n	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2yn	Cell parameters from 68 reflections
a = 12.8796 (6) Å	θ = 1.8–25.1°
b = 10.6984 (6) Å	µ = 1.34 mm^−1
c = 13.3098 (7) Å	T = 293 K
β = 114.118 (2)°	Polyhedron, red
V = 1673.88 (15) Å^3	0.34 × 0.26 × 0.24 mm
Z = 4

Data collection

Siemens SMART CCD diffractometer	2914 independent reflections
Radiation source: fine-focus sealed tube	2163 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.026
ϕ and ω scans	θmax = 25.1°, θmin = 1.8°
Absorption correction: empirical (using intensity measurements) (SADABS; Sheldrick, 1996)	h = −6→15
Tmin = 0.639, Tmax = 0.724	k = −8→12
5044 measured reflections	l = −15→12

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)] = 0.043	Hydrogen site location: inferred from neighbouring sites
wR(F^2) = 0.112	H atoms treated by a mixture of independent and constrained refinement
S = 1.07	w = 1/[σ^2(Fo^2) + (0.0415P)^2 + 3.1275P] where P = (Fo^2 + 2Fc^2)/3
2914 reflections	(Δ/σ)max = 0.001
256 parameters	Δρmax = 0.40 e Å^−3
0 restraints	Δρmin = −0.51 e Å^−3

Special details

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
Co	0.4965 (1)	0.5071 (1)	0.2440 (1)	0.0287 (2)
S1	0.7925 (1)	0.3710 (1)	0.1303 (1)	0.0280 (3)
S2	0.2483 (1)	0.6485 (1)	0.3966 (1)	0.0292 (3)
O1	0.7219 (3)	0.4818 (3)	0.0949 (3)	0.0529 (9)
O2	0.9131 (3)	0.4082 (3)	0.1798 (2)	0.0489 (9)
O3	0.7760 (3)	0.2901 (3)	0.0360 (2)	0.0412 (8)
O4	0.7679 (3)	0.3038 (3)	0.2139 (3)	0.0465 (8)
O5	0.2532 (3)	0.5142 (3)	0.3851 (3)	0.0580 (9)
O6	0.2503 (3)	0.7144 (3)	0.3005 (2)	0.0402 (8)
O7	0.3459 (3)	0.6916 (4)	0.4933 (3)	0.0694 (9)
O8	0.1440 (3)	0.6790 (3)	0.4103 (3)	0.0482 (9)
N1	0.4701 (3)	0.8778 (3)	0.4530 (3)	0.0353 (9)
H1A	0.5119	0.8715	0.4131	0.042*
H1B	0.4308	0.8062	0.4448	0.042*
N2	0.5033 (3)	0.9896 (4)	0.1071 (3)	0.0380 (9)
H2A	0.5317	0.9546	0.1745	0.046*
H2B	0.4508	1.0464	0.1049	0.046*
C1	0.5959 (4)	1.0536 (5)	0.0891 (4)	0.0454 (12)
H1C	0.6563	0.9945	0.0984	0.055*
H1D	0.6272	1.1196	0.1430	0.055*
C2	0.4482 (4)	0.8922 (4)	0.0242 (4)	0.0440 (12)
H2C	0.3859	0.8555	0.0370	0.053*
H2D	0.5027	0.8267	0.0308	0.053*
C3	0.5472 (4)	0.8944 (4)	0.5709 (3)	0.0394 (11)
H3A	0.6012	0.8260	0.5945	0.047*
H3B	0.5030	0.8926	0.6150	0.047*
C4	0.3894 (4)	0.9833 (4)	0.4108 (4)	0.0385 (11)
H4A	0.3387	0.9849	0.4483	0.046*
H4B	0.3436	0.9718	0.3328	0.046*
O1W	0.4295 (3)	0.4177 (4)	0.0941 (3)	0.0471 (10)
O2W	0.6073 (3)	0.3549 (4)	0.2940 (3)	0.0515 (10)
O3W	0.5676 (3)	0.5918 (4)	0.4021 (3)	0.0424 (9)
O4W	0.5988 (3)	0.6047 (4)	0.1871 (3)	0.0463 (9)
O5W	0.3791 (3)	0.6551 (3)	0.1879 (3)	0.0420 (8)
O6W	0.3955 (3)	0.4077 (4)	0.3049 (3)	0.0384 (8)
H11	0.378 (5)	0.452 (6)	0.040 (5)	0.08 (2)*
H12	0.401 (4)	0.358 (5)	0.085 (4)	0.040 (17)*
H21	0.662 (5)	0.350 (6)	0.279 (5)	0.08 (2)*
H22	0.628 (4)	0.333 (5)	0.359 (5)	0.053 (16)*
H31	0.623 (8)	0.648 (10)	0.424 (8)	0.19 (5)*
H32	0.595 (5)	0.548 (6)	0.444 (5)	0.06 (2)*
H41	0.637 (5)	0.661 (6)	0.213 (5)	0.06 (2)*
H42	0.633 (4)	0.566 (5)	0.163 (4)	0.049 (18)*
H51	0.338 (5)	0.664 (6)	0.125 (5)	0.08 (2)*
H52	0.345 (4)	0.666 (5)	0.223 (4)	0.047 (18)*
H61	0.363 (5)	0.359 (6)	0.274 (5)	0.05 (2)*
H62	0.352 (4)	0.444 (5)	0.326 (4)	0.047 (17)*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
Co	0.0282 (3)	0.0302 (3)	0.0269 (3)	0.0004 (2)	0.0106 (2)	0.0004 (2)
S1	0.0298 (5)	0.0297 (6)	0.0250 (5)	0.0032 (4)	0.0116 (4)	0.0019 (4)
S2	0.0306 (5)	0.0280 (6)	0.0305 (5)	−0.0001 (5)	0.0140 (4)	0.0029 (4)
O1	0.075 (2)	0.046 (2)	0.0423 (19)	0.0315 (9)	0.0293 (9)	0.0158 (9)
O2	0.0368 (9)	0.078 (3)	0.0336 (9)	−0.0151 (9)	0.0161 (9)	−0.0164 (9)
O3	0.0444 (9)	0.0426 (9)	0.0331 (9)	0.0003 (9)	0.0122 (9)	−0.0101 (9)
O4	0.055 (2)	0.047 (2)	0.054 (2)	0.0148 (16)	0.0383 (17)	0.0203 (17)
O5	0.082 (3)	0.0298 (19)	0.091 (3)	0.0125 (18)	0.065 (2)	0.0119 (18)
O6	0.0505 (19)	0.0409 (19)	0.0321 (16)	0.0090 (15)	0.0200 (15)	0.0117 (14)
O7	0.054 (2)	0.113 (4)	0.0288 (18)	−0.040 (2)	0.0040 (16)	0.009 (2)
O8	0.047 (2)	0.0312 (18)	0.082 (2)	−0.0010 (15)	0.0419 (19)	0.0015 (17)
N1	0.0337 (19)	0.035 (2)	0.040 (2)	−0.0070 (17)	0.0177 (17)	−0.0056 (17)
N2	0.039 (2)	0.049 (2)	0.0288 (18)	0.0177 (19)	0.0160 (16)	0.0115 (18)
C1	0.035 (3)	0.056 (3)	0.038 (3)	−0.008 (2)	0.007 (2)	−0.007 (2)
C2	0.043 (3)	0.034 (3)	0.058 (3)	−0.005 (2)	0.024 (2)	0.006 (2)
C3	0.041 (3)	0.042 (3)	0.033 (2)	0.004 (2)	0.013 (2)	0.009 (2)
C4	0.027 (2)	0.049 (3)	0.032 (2)	0.001 (2)	0.0047 (18)	−0.001 (2)
O1W	0.063 (3)	0.033 (2)	0.0332 (19)	−0.009 (2)	0.0072 (18)	−0.0008 (17)
O2W	0.049 (2)	0.075 (3)	0.037 (2)	0.0259 (19)	0.0239 (18)	0.0188 (19)
O3W	0.052 (2)	0.040 (2)	0.0298 (18)	−0.0039 (19)	0.0110 (17)	0.0010 (17)
O4W	0.053 (2)	0.044 (2)	0.056 (2)	−0.016 (2)	0.037 (2)	−0.0201 (19)
O5W	0.042 (2)	0.047 (2)	0.038 (2)	0.0124 (16)	0.0168 (19)	0.0093 (17)
O6W	0.038 (2)	0.035 (2)	0.047 (2)	−0.0077 (18)	0.0219 (18)	−0.0076 (17)

Geometric parameters (Å, º)

Co—O1W	2.057 (4)	N1—H1B	0.9000
Co—O2W	2.087 (4)	N2—H2A	0.9000
Co—O3W	2.124 (3)	N2—H2B	0.9000
Co—O4W	2.052 (4)	C1—H1C	0.9700
Co—O5W	2.105 (4)	C1—H1D	0.9700
Co—O6W	2.085 (3)	C2—H2C	0.9700
S1—O1	1.451 (3)	C2—H2D	0.9700
S1—O2	1.473 (3)	C3—H3A	0.9700
S1—O3	1.467 (3)	C3—H3B	0.9700
S1—O4	1.463 (3)	C4—H4A	0.9700
S2—O5	1.449 (3)	C4—H4B	0.9700
S2—O6	1.472 (3)	O1W—H11	0.83 (6)
S2—O7	1.458 (3)	O1W—H12	0.73 (5)
S2—O8	1.463 (3)	O2W—H21	0.81 (6)
N1—C3	1.486 (5)	O2W—H22	0.83 (5)
N1—C4	1.481 (6)	O3W—H31	0.88 (6)
N2—C1	1.477 (6)	O3W—H32	0.70 (6)
N2—C2	1.472 (6)	O4W—H41	0.76 (6)
C1—C2^i	1.494 (6)	O4W—H42	0.77 (6)
C2—C1^i	1.494 (6)	O5W—H51	0.79 (6)
C3—C4^ii	1.509 (6)	O5W—H52	0.77 (6)
C4—C3^ii	1.509 (6)	O6W—H61	0.69 (6)
N1—H1A	0.9000	O6W—H62	0.81 (6)
O1W—Co—O2W	84.7 (2)	N2—C1—H1D	109.6
O1W—Co—O3W	177.5 (2)	C2^i—C1—H1C	109.6
O1W—Co—O5W	92.9 (2)	C2^i—C1—H1D	109.6
O1W—Co—O6W	93.4 (2)	H1C—C1—H1D	108.2
O2W—Co—O3W	93.2 (2)	N2—C2—C1^i	110.5 (4)
O2W—Co—O5W	177.3 (2)	N2—C2—H2C	109.6
O4W—Co—O1W	87.6 (2)	N2—C2—H2D	109.6
O4W—Co—O2W	93.2 (2)	C1^i—C2—H2C	109.6
O4W—Co—O3W	93.8 (2)	C1^i—C2—H2D	109.6
O4W—Co—O5W	87.9 (2)	H2C—C2—H2D	108.1
O4W—Co—O6W	178.8 (2)	N1—C3—C4^ii	111.0 (4)
O5W—Co—O3W	89.3 (2)	N1—C3—H3A	109.4
O6W—Co—O2W	86.1 (2)	N1—C3—H3B	109.4
O6W—Co—O3W	85.2 (2)	C4^ii—C3—H3A	109.4
O6W—Co—O5W	92.8 (2)	C4^ii—C3—H3B	109.4
O1—S1—O2	109.3 (2)	H3A—C3—H3B	108.0
O1—S1—O3	110.6 (2)	N1—C4—C3^ii	110.4 (3)
O1—S1—O4	110.3 (2)	N1—C4—H4A	109.6
O3—S1—O2	107.4 (2)	N1—C4—H4B	109.6
O4—S1—O2	108.0 (2)	C3^ii—C4—H4A	109.6
O4—S1—O3	111.1 (2)	C3^ii—C4—H4B	109.6
O5—S2—O6	111.4 (2)	H4A—C4—H4B	108.1
O5—S2—O7	110.4 (3)	Co—O1W—H11	120 (5)
O5—S2—O8	108.5 (2)	Co—O1W—H12	124 (4)
O7—S2—O6	107.4 (2)	H11—O1W—H12	94 (6)
O7—S2—O8	109.0 (2)	Co—O2W—H21	122 (5)
O8—S2—O6	110.1 (2)	Co—O2W—H22	116 (4)
C4—N1—C3	111.8 (3)	H21—O2W—H22	107 (5)
C3—N1—H1A	109.2	Co—O3W—H31	126 (7)
C3—N1—H1B	109.2	Co—O3W—H32	112 (5)
C4—N1—H1A	109.2	H31—O3W—H32	96 (7)
C4—N1—H1B	109.2	Co—O4W—H41	129 (4)
H1A—N1—H1B	107.9	Co—O4W—H42	116 (4)
C2—N2—C1	112.3 (4)	H41—O4W—H42	104 (6)
C1—N2—H2A	109.1	Co—O5W—H51	123 (5)
C1—N2—H2B	109.1	Co—O5W—H52	114 (4)
C2—N2—H2A	109.1	H51—O5W—H52	108 (6)
C2—N2—H2B	109.1	Co—O6W—H61	118 (5)
H2A—N2—H2B	107.9	Co—O6W—H62	121 (4)
N2—C1—C2^i	110.1 (4)	H61—O6W—H62	103 (6)
N2—C1—H1C	109.6

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

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
N1—H1A···O2^iii	0.90	1.89	2.768 (5)	163
N1—H1B···O6	0.90	2.53	3.239 (5)	136
N1—H1B···O7	0.90	1.92	2.741 (5)	151
N2—H2A···O2^iii	0.90	1.84	2.733 (4)	171
N2—H2B···O8^iv	0.90	1.83	2.720 (5)	170
O1W—H11···O1^v	0.83 (6)	1.87 (7)	2.698 (5)	169 (6)
O1W—H12···O8^vi	0.73 (5)	2.01 (5)	2.716 (5)	166 (6)
O2W—H21···O4	0.81 (6)	1.95 (7)	2.742 (5)	164 (6)
O2W—H22···O7^vii	0.83 (5)	1.87 (6)	2.689 (5)	168 (5)
O3W—H31···O3^iii	0.88 (8)	1.94 (9)	2.808 (5)	171 (7)
O3W—H32···O5^vii	0.70 (6)	2.41 (6)	3.049 (6)	152 (6)
O4W—H41···O4^iii	0.76 (6)	1.95 (6)	2.715 (5)	176 (6)
O4W—H42···O1	0.77 (6)	1.95 (6)	2.710 (5)	174 (6)
O5W—H51···O3^v	0.79 (6)	2.11 (6)	2.888 (5)	173 (7)
O5W—H52···O6	0.77 (6)	1.96 (6)	2.726 (5)	172 (6)
O6W—H61···O6^vi	0.69 (6)	2.08 (6)	2.760 (5)	170 (6)
O6W—H62···O5	0.81 (6)	1.91 (6)	2.719 (5)	174 (5)

Symmetry codes: (iii) −x+3/2, y+1/2, −z+1/2; (iv) −x+1/2, y+1/2, −z+1/2; (v) −x+1, −y+1, −z; (vi) −x+1/2, y−1/2, −z+1/2; (vii) −x+1, −y+1, −z+1.