Crystal structure of catena-poly[[[di­aqua­cobalt(II)]-bis­(μ-hex-3-enedi­nitrile-κ2 N:N′)] bis­(tetra­fluorido­borate)]

Jung-Su Son; Sung-Chul Lim; Hochun Lee; Seung-Tae Hong

doi:10.1107/S2056989015009548

. 2015 May 23;71(Pt 6):m135–m136. doi: 10.1107/S2056989015009548

Crystal structure of catena-poly[[[diaquacobalt(II)]-bis(μ-hex-3-enedinitrile-κ² N:N′)] bis(tetrafluoridoborate)]

Jung-Su Son ^a,^‡, Sung-Chul Lim ^a,^‡, Hochun Lee ^a,^*, Seung-Tae Hong ^a,^*

PMCID: PMC4459353 PMID: 26090169

Abstract

In the structure of the title salt, [Co(C₆H₆N₂)₂(H₂O)₂](BF₄)₂, the Co^II atom is located on an inversion centre. The transition metal is in a slightly distorted octahedral coordination environment, defined by the cyano N atoms of four hex-3-enedinitrile ligands in equatorial positions and the O atoms of two water molecules in axial positions. The bridging mode of the hex-3-enedinitrile ligands leads to the formation of cationic chains extending parallel to [1-10]. The BF₄ ⁻ counter-anion is disordered over two sets of sites [occupancy ratio = 0.512 (19):0.489 (19)]. It is located in the voids between the cationic chains and is connected to the aqua ligands of the latter through O—H⋯F hydrogen bonds. One methylene H atom of the hex-3-enedinitrile ligand forms another and weak C—H⋯O hydrogen bond with a water O atom of a neighbouring chain, thus consolidating the three-dimensional network structure.

Keywords: crystal structure, cobalt, hex-3-enedinitrile, hydrogen bonding

Related literature

Aliphatic dinitriles have gained much attention not only due to their rich coordination chemistry with transition-metal ions (Storhoff & Lewis, 1977 ▸; Heller & Sheldrick, 2004 ▸; Blount et al., 1969 ▸), but also due to their applications as functional electrolyte additives for lithium ion batteries (Kim et al., 2011 ▸, 2014a ▸,b ▸). While the coordination complexes of saturated aliphatic dinitrile ligands have been extensively studied (Storhoff & Lewis, 1977 ▸; Heller & Sheldrick, 2004 ▸; Blount et al., 1969 ▸), those of unsaturated dinitrile ligands like in the title compound have hardly been reported so far. graphic file with name e-71-0m135-scheme1.jpg

Experimental

Crystal data

[Co(C₆H₆N₂)(H₂O)₂](BF₄)₂
M _r = 480.84
Triclinic,
a = 7.9839 (11) Å
b = 8.3434 (11) Å
c = 8.8441 (13) Å
α = 71.380 (5)°
β = 88.458 (5)°
γ = 66.184 (4)°
V = 507.21 (12) Å³
Z = 1
Mo Kα radiation
μ = 0.93 mm⁻¹
T = 103 K
0.20 × 0.20 × 0.20 mm

Data collection

Bruker APEXII CCD diffractometer
Absorption correction: multi-scan (SADABS; Bruker, 2006 ▸) T _min = 0.60, T _max = 0.75
14705 measured reflections
2501 independent reflections
2233 reflections with I > 2σ(I)
R _int = 0.038

Refinement

R[F ² > 3σ(F ²)] = 0.033
wR(F ²) = 0.068
S = 0.87
2202 reflections
170 parameters
20 restraints
H-atom parameters constrained
Δρ_max = 0.83 e Å⁻³
Δρ_min = −0.62 e Å⁻³

Data collection: APEX2 (Bruker, 2006 ▸); cell refinement: SAINT (Bruker, 2006 ▸); data reduction: SAINT; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008 ▸); program(s) used to refine structure: CRYSTALS (Betteridge et al., 2003 ▸); molecular graphics: ATOMS (Dowty, 2000 ▸); software used to prepare material for publication: CRYSTALS.

Supplementary Material

Crystal structure: contains datablock(s) I. DOI: 10.1107/S2056989015009548/wm5160sup1.cif

e-71-0m135-sup1.cif^{(20.3KB, cif)}

Structure factors: contains datablock(s) I. DOI: 10.1107/S2056989015009548/wm5160Isup2.hkl

e-71-0m135-Isup2.hkl^{(157.1KB, hkl)}

Click here for additional data file.^{(1.7MB, tif)}

4 − . DOI: 10.1107/S2056989015009548/wm5160fig1.tif

The cationic chain structure of the title compound with displacement ellipsoids drawn at the 50% probability level. The BF₄ ⁻ anion is shown only with the major part of the disorder.

Click here for additional data file.^{(1.6MB, tif)}

4 − . DOI: 10.1107/S2056989015009548/wm5160fig2.tif

The crystal packing of the title compound with displacement ellipsoids drawn at the 50% probability level. The BF₄ ⁻ anion is shown only with the major part of the disorder. (Colour code: dark blue: Co, purple: N, blue: C, red: O, cyan: B, green: F, grey: H).

CCDC reference: 1401602

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

Table 1. Hydrogen-bond geometry (, ).

DHA	DH	HA	D A	DHA
C2H22O1ⁱ	0.97	2.52	3.348(3)	143(1)
O1H12F1ⁱⁱ	0.83	1.89	2.72(2)	175(1)
O1H11F2ⁱ	0.82	1.87	2.669(13)	163(1)

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Symmetry codes: (i) Inline graphic ; (ii) .

Acknowledgments

This work was supported by the DGIST R&D Program of Ministry of Science, ICT and Future Planning of Korea (grant No. 15-HRLA-01).

supplementary crystallographic information

S1. Experimental

A solvent was prepared first by mixing ethylene carbonate (EC) and ethyl methyl carbonate (EMC) in an 1:2 volume ratio (3.3 ml and 6.6 ml, respectively). 0.934 g of lithium tetrafluoridoborate (LiBF₄) were added to the solvent, and it was stirred for about 5 hours to dissolve the salt completely to form an 1M solution. 0.60 g (5 wt.%) of cobalt(II) tetrafluoridoborate hexahydrate and 0.24 g (2 wt.%) hex-3-enedinitrile were added and dissolved in the solution. The solution was kept for 48 hours in an argon-atmosphere glove-box at room temperature, resulting in the growth of red crystals. The crystals were washed with pure EMC solvent three times in the argon-atmosphere glove-box.

S2. Refinement

H atoms attached to C atoms of the title compound were placed in geometrically idealized positions and treated as rigid bodies with C—H distances constrained to 0.92–0.97 Å. Water H atoms were located from a difference map and refined with a distance of 0.82 Å. The BF₄^- counter anion was refined with a positional disorder model where F2, F3 and F4 atoms are split into two positions while B1 and F1 atoms are not. Such a disorder model resulted in a slightly better refinement, reducing the R1 factor values from 0.041 to 0.033.