Tris(2,2′-bipyridine-κ2 N:N′)cobalt(III) trichloride tetra­hydrate

Wen Liu; Wei Xu; Jian-Li Lin; Hong-Zhen Xie

doi:10.1107/S1600536808038154

. 2008 Nov 22;64(Pt 12):m1586. doi: 10.1107/S1600536808038154

Tris(2,2′-bipyridine-κ² N:N′)cobalt(III) trichloride tetrahydrate

Wen Liu ^a, Wei Xu ^a,^*, Jian-Li Lin ^a, Hong-Zhen Xie ^a

PMCID: PMC2959986 PMID: 21581186

Abstract

The title compound, [Co(C₁₀H₈N₂)₃]Cl₃·4H₂O, contains discrete [Co(bpy)₃]³⁺ cations (bpy is 2,2′-bipyridine), Cl⁻ anions and water molecules. The [Co(bpy)₃]³⁺ complex cation exhibits C ₂ symmetry with the twofold axis through the central Co atom and bisecting one bpy ligand and one of the Cl⁻ anions. The four solvent water molecules and the remaining two Cl⁻ anions lie on a mirror plane. Hydrogen-bond interactions define a two-dimensional layer structure parallel to (100), which consists of seven-membered [Cl₂(H₂O)₅], eight-membered [Cl₄(H₂O)₄] and ten-membered [Cl₂(H₂O)₈] rings.

Related literature

For general background, see: Liu et al. (1996 ▶); Nauta & Miller (2000 ▶); Ludwig (2001 ▶); Saha & Bernal (2005 ▶); Reger et al. (2006 ▶); Li et al. (2007 ▶); Mir & Vittal (2007 ▶). For related structures, see: Hernández-Molina et al. (1998 ▶).

Experimental

Crystal data

[Co(C₁₀H₈N₂)₃]Cl₃·4H₂O
M _r = 705.90
Orthorhombic,
a = 20.171 (4) Å
b = 23.170 (5) Å
c = 13.316 (3) Å
V = 6223 (2) Å³
Z = 8
Mo Kα radiation
μ = 0.86 mm⁻¹
T = 295 (2) K
0.12 × 0.10 × 0.08 mm

Data collection

Bruker P4 diffractometer
Absorption correction: ψ scan (XSCANS; Siemens, 1996 ▶) T _min = 0.905, T _max = 0.929
3430 measured reflections
2824 independent reflections
1980 reflections with I > 2σ(I)
R _int = 0.049
3 standard reflections every 97 reflections intensity decay: none

Refinement

R[F ² > 2σ(F ²)] = 0.056
wR(F ²) = 0.162
S = 1.03
2824 reflections
225 parameters
12 restraints
H atoms treated by a mixture of independent and constrained refinement
Δρ_max = 1.01 e Å⁻³
Δρ_min = −0.66 e Å⁻³

Data collection: XSCANS (Siemens, 1996 ▶); cell refinement: XSCANS; data reduction: XSCANS; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008 ▶); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008 ▶); molecular graphics: XP in SHELXTL (Sheldrick, 2008 ▶); software used to prepare material for publication: SHELXL97.

Supplementary Material

Crystal structure: contains datablocks global, I. DOI: 10.1107/S1600536808038154/bg2219sup1.cif

e-64-m1586-sup1.cif^{(19.8KB, cif)}

Structure factors: contains datablocks I. DOI: 10.1107/S1600536808038154/bg2219Isup2.hkl

e-64-m1586-Isup2.hkl^{(138.9KB, hkl)}

Additional supplementary materials: crystallographic information; 3D view; checkCIF report

Table 1. Hydrogen-bond geometry (Å, °).

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
O1—H1W2⋯O2	0.85 (4)	2.04 (5)	2.885 (9)	176 (9)
O1—H1W1⋯Cl1	0.83 (4)	2.30 (4)	3.127 (7)	180 (9)
O2—H2W1⋯Cl1ⁱ	0.84 (4)	2.48 (4)	3.317 (7)	175 (6)
O2—H2W2⋯Cl2	0.84 (3)	2.33 (3)	3.165 (5)	173 (7)
O3—H3W1⋯Cl1ⁱⁱ	0.85 (6)	2.33 (6)	3.161 (5)	166 (6)
O3—H3W2⋯Cl2ⁱⁱⁱ	0.84 (4)	2.27 (5)	3.095 (5)	170 (7)
O4—H4W1⋯O1	0.79 (5)	2.06 (5)	2.841 (8)	169 (5)
O4—H4W2⋯O3	0.81 (3)	2.00 (3)	2.795 (8)	168 (7)

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Symmetry codes: (i) Inline graphic ; (ii) ; (iii) ; (iv) ; (v) .

Acknowledgments

This project was sponsored by the K. C. Wong Magna Fund of Ningbo University, the Expert Project of Key Basic Research of the Ministry of Science and Technology of China (grant No. 2003CCA00800), the Ningbo Municipal Natural Science Foundation (grant No. 2006 A610061), and the Newer Training Program Foundation for Talent of the Science and Technology Department of Zhejiang Province (grant No. 2007R40G2070020).

supplementary crystallographic information

Comment

Due to the central role that water plays in biological and chemical processes, research on its structure, properties and functions has attracted the scientist's attention (Liu, et al., 1996; Nauta & Miller, 2000; Ludwig, 2001; Mir & Vittal, 2007). However, there are only a few reports focused on the experimental identificaion and analysis of hydrogen-bond networks between water of crystallization and chloride counterions in crystalline materials. As a few examples we can mention [cis-α-(trine)CoCl₂]Cl.3H₂O (Saha & Bernal, 2005) where a two-dimensional layered structure containing [Cl₂(H₂O)₄] six-membered rings build up. In the crystal structure of {p-C₆H₄[CH₂OCH₂C(pz)₃]₂[Ru(p-cymene)]₂}Cl₄.14H₂O two-dimensional layers built from four-membered [Cl(H₂O)₃], five-membered [Cl(H₂O)₄], six-membered [Cl(H₂O)₅] and seven-membered [Cl₃(H₂O)₄] rings formed through hydrogen bond self-assembly (Reger, et al., 2006). A hybrid water-chloride structure of 14 water molecules and 4 Cl^- anions connected into layers is formed in the crystal structure of an europium complex [Eu₃(BDC)₃(phen)₃Cl(H₂O)₆]Cl₂.4H₂O (Li, et al., 2007). The references suggest that a great variety of mixed water-chloride supramolecular self-assemblies is possible. Herein, we describe a structure of a cobalt(III) complex containing discrete tris(2,2'-bipyridine)cobalt(III) cations and infinite layers of water and chloride anions, and where seven-membered (Cl₂(H₂O)₅), eight-membered (Cl₄(H₂O)₄) and ten-membered (Cl₂(H₂O)₈) rings can be found.

The crystal structure of the title compound is composed of [Co(bpy)₃]³⁺ complex cations, Cl^- anions and crystal H₂O molecules (Fig. 1). Within the trivalent complex cations, the Co atoms are each surrounded by six N atoms of three chelating bpy ligands to complete a distorted octahedral coordination with d(Co—N) = 1,928 (3)–1.939 (3) Å, the cis and trans N—Co—N bond angles in the range 83.50 (19)–93.82 (14) and 175.23 (14)–176.38 (19)°, respectively. Such distances are similar to those found in other related structures (Hernández-Molina, et al., 1998). The complex cation exhibits C₂ symmetry with the twofold axis through the central Co atom and bisecting the C5—C5ⁱ bond of one bpy ligand (i = -x + 1/2, y, -z + 3/2), as well as one of the Cl^- anions (Cl3). Through a C—H···Cl weak hydrogen bond the [Co(phen)₃]³⁺ moieties are interlink into one-dimensional chains along the [001] direction (Fig.2). There are no π-π stacking interactions in the chains.

The most starling feature of the solid-state structure of 1 is the hydrogen-bonding interactions of the four water molecules and the remaining two Cl^- anions (Cl1 and Cl2), which lay on a mirror plane. The four crystal water molecules (O1, O2, O3,and O4) locate at the crystallographic 8f position and through intermolecular hydrogen bonds determine a linear water tetramer (H₂O)₄. The O···O distances span the range 2.795 (8)–2.885 (9) Å. Interestingly, such tetrameric water groups are further hydrogen-bond-interacting with the Cl^- anions to complete a two-dimensional water-chloride framework parallel to (100). As Shown in Fig. 3, the two-dimensional layers are composed by seven- (five water molecules and two Cl^- anions), eight- (four water molecules and four Cl^- anions) and ten-membered (eight water molecules and two Cl^- anions) rings through O—H···O and O—H···Cl interactions (Table 1). The O···Cl distances range from 3.095 (5) to 3.317 (7) Å and O—H···Cl angles span the range 166 (6) to 180 (9)°. The water-chloride layer can be viewed as building blocks, which are pillared by [Co(bpy)₃]³⁺ spacers to produce an infinite three-dimensional supramolecular edifice. In this sense, the layer is different from already reported water clusters and other morphologies, which are situated within the host cavities or channels generated by organic and inorganic moieties (Fig. 4).

Experimental

Addition of 10 ml CH₃OH containing 0.162 g (1.04 mmol) 2,2'-bipyridine (bpy) to an aqueous solution of 0.238 g (1.00 mmol) CoCl₂.6H₂O in 10 ml H₂O gave a yellow solution, then dropwise added 3 ml 30% H₂O₂ solution to the mixture, stirred for ca half an hour. The resulting light-yellow solution (PH = 6.48) was allowed to stand at room temperature. After 8 days, a small amount of yellow block crystals had grown.