3,3′-Dimethyl-1,1′-methyl­enediimidazolium tetra­bromido­cobaltate(II)

Peppel, T.; Spannenberg, A.

doi:10.1107/S2414314618012129

metal-organic compounds

IUCrDATA

ISSN: 2414-3146

Volume 3| Part 8| August 2018| x181212

https://doi.org/10.1107/S2414314618012129

Open

access

3,3′-Dimethyl-1,1′-methylenediimidazolium tetrabromidocobaltate(II)

Tim Peppel ^a ^* and Anke Spannenberg ^a

^aLeibniz-Institut für Katalyse e. V. an der Universität Rostock, Albert-Einstein-Strasse 29a, 18059 Rostock, Germany
^*Correspondence e-mail: tim.peppel@catalysis.de

Edited by H. Ishida, Okayama University, Japan (Received 17 July 2018; accepted 27 August 2018; online 31 August 2018)

The title compound, (C₉H₁₄N₄)[CoBr₄], was obtained as single crystals directly in very low yield as a side product in the reaction of 1,1′-bis(1-methylimidazolium)acetate bromide and CoBr₂. The title compound consists of an imidazolium-based dication and a tetrabromidocobaltate(II) complex anion, which are connected via C—H⋯Br interactions in the crystal. The dihedral angle between the imidazolium rings in the cation is 72.89 (16)°. The Co^II ion in the anion is coordinated tetrahedrally by four bromide ligands [Co—Br = 2.4025 (5)–2.4091 (5) Å and Br—Co—Br = 106.224 (17)–113.893 (17)°]. The compound exhibits a high melting point (>300°C) and is a light-blue solid under ambient conditions.

Keywords: cobalt; imidazolium; tetrahedral; crystal structure.

CCDC reference: 1863993

Structure description

In recent years, there have been enormous efforts in the field of artificial photosynthesis by converting CO₂ with water and light to hydrocarbons and just recently a review of concept article regarding photocatalytic CO₂ reduction using TiO₂-based materials under controlled reaction conditions has been published (Moustakas & Strunk, 2018 ). Furthermore, homogeneous catalytic CO₂ hydrogenation to formates using Ir-based catalysts is an intensively studied research field because of the demand for formic acid as a key industrial chemical and 1,1′-bis(N-methylimidazolium)acetate bromide, [(MIm)₂CHCOO]Br, has been investigated as a carboxylate-functionalized ligand for Ir^I and Ir^III complexes (Puerta-Oteo & Hölscher et al., 2018 ). The title compound was obtained as individual crystals by decarboxylation of the cation in the reaction of [(MIm)₂CHCOO]Br and CoBr₂ in a boiling mixture of MeNO₂ and MeCN. It can be seen from Fig. 1 that (DMDIm)[CoBr₄] is characterized by an imidazolium-based dication and a tetrabromidocobaltate(II) complex anion. The complex anion consists of a Co^II ion coordinated tetrahedrally by four bromido ligands. In the crystal, C—H⋯Br interactions are observed (Fig. 2 and Table 1). All bond lengths and angles within the cation as well as the complex anion are in expected ranges (Ahrens & Strassner, 2006 ; Kozlova et al., 2009 ; Peppel & Köckerling, 2010 ; Peppel et al., 2017 ).

Table 1
Hydrogen-bond geometry (Å, °)

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
C1—H1⋯Br2	0.95	2.92	3.829 (3)	161
C2—H2⋯Br4ⁱ	0.95	2.84	3.679 (3)	148
C4—H4A⋯Br1ⁱⁱ	0.98	2.90	3.560 (3)	126
C5—H5A⋯Br1	0.99	2.78	3.705 (3)	156
C5—H5B⋯Br3ⁱ	0.99	2.92	3.578 (3)	124
C6—H6⋯Br1ⁱⁱⁱ	0.95	2.88	3.558 (2)	129
C7—H7⋯Br2	0.95	2.87	3.665 (3)	142
C8—H8⋯Br3^iv	0.95	2.83	3.699 (3)	153
Symmetry codes: (i) $[x-{\script{1\over 2}}, y-{\script{1\over 2}}, z]$ ; (ii) x, y+1, z; (iii) $[x-{\script{1\over 2}}, y+{\script{1\over 2}}, z]$ ; (iv) $[-x+{\script{1\over 2}}, -y+{\script{1\over 2}}, -z]$ .

Figure 1
Molecular structure of the title compound with atom labelling and displacement ellipsoids drawn at 30% probability level.

Figure 2
A packing diagram of the title compound viewed along the b axis, showing the C—H⋯Br interactions (dashed lines).

Synthesis and crystallization

The title compound, (DMDIm)[CoBr₄] (DMDIm = C₉H₁₄N₄), was obtained in very low yield as a side product in the reaction of [(MIm)₂CHCOO]Br (Puerta-Oteo & Hölscher et al., 2018; Puerta-Oteo & Jiménez et al., 2018 ) and CoBr₂. In order to obtain the basic characteristics of bulk (DMDIm)[CoBr₄], it was synthesized directly on the gram scale from (DMDIm)Br₂ (Cao et al., 2016 ; Nirmala et al., 2017 ; García-Fernández et al., 2018 ) and CoBr₂ in 1:1 stoichiometry. (DMDIm)Br₂ (1.54 g, 4.57 mmol) was added in one portion to a stirred solution of CoBr₂ (1.00 g, 4.57 mmol) in 100 ml of acetonitrile. The suspension was heated under reflux for 4 h and the light-blue precipitate was filtered off, washed thoroughly with Et₂O and dried in vacuo (T = 80°C, P = 4 mbar, yield: 2.50 g, 98%). Analytical data for (DMDIm)[CoBr₄]: m.p. 310–312°C, EA for C₉H₁₄Br₄CoN₂ % (calc.): C 19.66 (19.41), H 2.37 (2.53), N 9.08 (10.06), Br 57.80 (57.40), Co 10.46 (10.62). UV/Vis (diffuse reflectance, absorbance): λ_max = 726, 702, 671, 645, 604, 590, 579, 563, 484, 472, 465, 435, 426, 398, 344 nm; UV/Vis (MeCN, saturated solution, 25°C, absorbance): λ_max = 699, 634, 618, 305, 278 nm.

Refinement

Crystal data, data collection and structure refinement details are summarized in Table 2.

Table 2
Experimental details

Crystal data
Chemical formula	(C₉H₁₄N₄)[CoBr₄]
M_r	556.81
Crystal system, space group	Monoclinic, C2/c
Temperature (K)	150
a, b, c (Å)	15.7782 (15), 7.4076 (7), 28.567 (3)
β (°)	95.7271 (19)
V (Å³)	3322.2 (5)
Z	8
Radiation type	Mo Kα
μ (mm⁻¹)	10.64
Crystal size (mm)	0.24 × 0.10 × 0.07

Data collection
Diffractometer	Bruker APEXII CCD
Absorption correction	Multi-scan (SADABS; Bruker, 2014 )
T_min, T_max	0.34, 0.52
No. of measured, independent and observed [I > 2σ(I)] reflections	21756, 4017, 3421
R_int	0.030
(sin θ/λ)_max (Å⁻¹)	0.660

Refinement
R[F² > 2σ(F²)], wR(F²), S	0.024, 0.048, 1.05
No. of reflections	4017
No. of parameters	165
H-atom treatment	H-atom parameters constrained
Δρ_max, Δρ_min (e Å⁻³)	0.51, −0.38
Computer programs: APEX2 and SAINT (Bruker, 2013 ), XP in SHELXTL and SHELXS97 (Sheldrick, 2008 ), SHELXL2014 (Sheldrick, 2015 ), DIAMOND (Putz & Brandenburg, 1999 ) and publCIF (Westrip, 2010 ).

Structural data

CCDC reference: 1863993

Crystal structure: contains datablock I. DOI: https://doi.org/10.1107/S2414314618012129/is4029sup1.cif

Structure factors: contains datablock I. DOI: https://doi.org/10.1107/S2414314618012129/is4029Isup2.hkl

checkCIF report

Computing details top

Data collection: APEX2 (Bruker, 2014); cell refinement: SAINT (Bruker, 2013); data reduction: SAINT (Bruker, 2013); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL2014 (Sheldrick, 2015); molecular graphics: XP in SHELXTL (Sheldrick, 2008) and DIAMOND (Putz & Brandenburg, 1999); software used to prepare material for publication: publCIF (Westrip, 2010).

3,3'-Dimethyl-1,1'-methylenediimidazolium tetrabromidocobaltate(II) top

Crystal data top

(C₉H₁₄N₄)[CoBr₄]	F(000) = 2104
M_r = 556.81	D_x = 2.227 Mg m⁻³
Monoclinic, C2/c	Mo Kα radiation, λ = 0.71073 Å
a = 15.7782 (15) Å	Cell parameters from 7863 reflections
b = 7.4076 (7) Å	θ = 2.6–29.7°
c = 28.567 (3) Å	µ = 10.64 mm⁻¹
β = 95.7271 (19)°	T = 150 K
V = 3322.2 (5) Å³	Needle, blue
Z = 8	0.24 × 0.10 × 0.07 mm

Data collection top

Bruker APEXII CCD diffractometer	4017 independent reflections
Radiation source: fine-focus sealed tube	3421 reflections with I > 2σ(I)
Detector resolution: 8.3333 pixels mm^-1	R_int = 0.030
φ and ω scans	θ_max = 28.0°, θ_min = 1.4°
Absorption correction: multi-scan (SADABS; Bruker, 2014)	h = −20→20
T_min = 0.34, T_max = 0.52	k = −9→9
21756 measured reflections	l = −37→37

Refinement top

Refinement on F²	0 restraints
Least-squares matrix: full	Hydrogen site location: inferred from neighbouring sites
R[F² > 2σ(F²)] = 0.024	H-atom parameters constrained
wR(F²) = 0.048	w = 1/[σ²(F_o²) + (0.0174P)² + 5.0295P] where P = (F_o² + 2F_c²)/3
S = 1.05	(Δ/σ)_max = 0.001
4017 reflections	Δρ_max = 0.51 e Å⁻³
165 parameters	Δρ_min = −0.38 e Å⁻³

Special details top

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.

Refinement. All H atoms were placed in idealized positions with C—H = 0.95 Å (CH), 0.98 Å (CH₃) and 0.99 Å (CH₂), and were refined using a riding model with U_iso(H) fixed at 1.2 U_eq(C) for CH and CH₂, and 1.5 U_eq(C) for CH₃.

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å²) top

	x	y	z	U_iso*/U_eq
C1	0.17779 (16)	0.3468 (3)	0.16985 (9)	0.0226 (5)
H1	0.2215	0.3549	0.1494	0.027*
C2	0.06459 (19)	0.2588 (4)	0.20258 (10)	0.0365 (7)
H2	0.0154	0.1927	0.2090	0.044*
C3	0.09624 (18)	0.4055 (4)	0.22558 (10)	0.0345 (7)
H3	0.0736	0.4627	0.2514	0.041*
C4	0.2187 (2)	0.6162 (4)	0.21901 (11)	0.0352 (7)
H4A	0.2699	0.6163	0.2022	0.053*
H4B	0.2352	0.6125	0.2530	0.053*
H4C	0.1856	0.7259	0.2111	0.053*
C5	0.10432 (17)	0.0753 (3)	0.13384 (9)	0.0258 (6)
H5A	0.1605	0.0290	0.1268	0.031*
H5B	0.0734	−0.0247	0.1476	0.031*
C6	−0.02772 (16)	0.1664 (3)	0.08457 (9)	0.0211 (5)
H6	−0.0664	0.1509	0.1077	0.025*
C7	0.09043 (18)	0.1725 (4)	0.04886 (9)	0.0288 (6)
H7	0.1485	0.1624	0.0431	0.035*
C8	0.02555 (18)	0.2265 (4)	0.01830 (9)	0.0289 (6)
H8	0.0291	0.2609	−0.0135	0.035*
C9	−0.13247 (18)	0.2793 (4)	0.02105 (10)	0.0352 (7)
H9A	−0.1756	0.2208	0.0383	0.053*
H9B	−0.1409	0.2439	−0.0121	0.053*
H9C	−0.1378	0.4107	0.0236	0.053*
N1	0.11685 (13)	0.2222 (3)	0.16801 (7)	0.0207 (4)
N2	0.16702 (13)	0.4578 (3)	0.20512 (7)	0.0213 (4)
N3	0.05644 (13)	0.1343 (3)	0.09049 (7)	0.0215 (4)
N4	−0.04719 (14)	0.2232 (3)	0.04118 (7)	0.0244 (5)
Co1	0.40230 (2)	0.18136 (5)	0.12715 (2)	0.02171 (8)
Br1	0.32770 (2)	−0.08576 (4)	0.14779 (2)	0.03035 (7)
Br2	0.31206 (2)	0.32678 (4)	0.06547 (2)	0.02916 (7)
Br3	0.54182 (2)	0.12285 (3)	0.10318 (2)	0.02435 (6)
Br4	0.41673 (2)	0.37353 (4)	0.19523 (2)	0.03257 (7)

Atomic displacement parameters (Å²) top

	U¹¹	U²²	U³³	U¹²	U¹³	U²³
C1	0.0196 (13)	0.0244 (13)	0.0243 (13)	0.0013 (10)	0.0036 (10)	0.0008 (10)
C2	0.0333 (16)	0.0497 (18)	0.0283 (15)	−0.0198 (14)	0.0118 (12)	−0.0084 (13)
C3	0.0315 (16)	0.0500 (18)	0.0245 (14)	−0.0140 (13)	0.0145 (12)	−0.0106 (13)
C4	0.0391 (17)	0.0269 (14)	0.0414 (17)	−0.0133 (13)	0.0127 (14)	−0.0077 (13)
C5	0.0256 (14)	0.0225 (13)	0.0281 (14)	0.0020 (11)	−0.0034 (11)	−0.0035 (11)
C6	0.0201 (13)	0.0210 (12)	0.0225 (12)	0.0014 (10)	0.0034 (10)	−0.0006 (10)
C7	0.0245 (14)	0.0374 (15)	0.0255 (14)	−0.0073 (12)	0.0073 (11)	−0.0086 (12)
C8	0.0315 (15)	0.0342 (15)	0.0216 (13)	−0.0082 (12)	0.0052 (11)	−0.0039 (11)
C9	0.0300 (16)	0.0420 (17)	0.0321 (16)	0.0043 (13)	−0.0054 (13)	0.0039 (13)
N1	0.0174 (10)	0.0245 (11)	0.0199 (10)	−0.0015 (8)	−0.0001 (8)	−0.0016 (8)
N2	0.0203 (11)	0.0242 (11)	0.0197 (10)	−0.0044 (9)	0.0035 (9)	0.0010 (9)
N3	0.0204 (11)	0.0223 (11)	0.0216 (11)	−0.0008 (8)	0.0010 (8)	−0.0053 (9)
N4	0.0221 (11)	0.0277 (12)	0.0228 (11)	−0.0028 (9)	−0.0008 (9)	−0.0027 (9)
Co1	0.02076 (18)	0.02356 (17)	0.02092 (17)	−0.00132 (14)	0.00261 (14)	0.00084 (14)
Br1	0.02704 (14)	0.02493 (13)	0.04071 (16)	−0.00168 (11)	0.01153 (12)	0.00564 (12)
Br2	0.02183 (14)	0.04087 (16)	0.02428 (13)	−0.00203 (11)	−0.00018 (10)	0.00796 (11)
Br3	0.02163 (13)	0.02442 (13)	0.02722 (14)	0.00184 (10)	0.00359 (10)	0.00110 (10)
Br4	0.03414 (16)	0.03955 (16)	0.02469 (14)	−0.01065 (12)	0.00624 (11)	−0.00815 (12)

Geometric parameters (Å, º) top

C1—N2	1.324 (3)	C6—N4	1.316 (3)
C1—N1	1.330 (3)	C6—N3	1.343 (3)
C1—H1	0.9500	C6—H6	0.9500
C2—C3	1.340 (4)	C7—C8	1.339 (4)
C2—N1	1.375 (3)	C7—N3	1.382 (3)
C2—H2	0.9500	C7—H7	0.9500
C3—N2	1.367 (3)	C8—N4	1.376 (3)
C3—H3	0.9500	C8—H8	0.9500
C4—N2	1.461 (3)	C9—N4	1.469 (3)
C4—H4A	0.9800	C9—H9A	0.9800
C4—H4B	0.9800	C9—H9B	0.9800
C4—H4C	0.9800	C9—H9C	0.9800
C5—N3	1.452 (3)	Co1—Br4	2.4025 (5)
C5—N1	1.462 (3)	Co1—Br1	2.4055 (4)
C5—H5A	0.9900	Co1—Br2	2.4067 (5)
C5—H5B	0.9900	Co1—Br3	2.4091 (5)

N2—C1—N1	108.3 (2)	C7—C8—N4	107.7 (2)
N2—C1—H1	125.9	C7—C8—H8	126.1
N1—C1—H1	125.9	N4—C8—H8	126.1
C3—C2—N1	106.9 (2)	N4—C9—H9A	109.5
C3—C2—H2	126.5	N4—C9—H9B	109.5
N1—C2—H2	126.5	H9A—C9—H9B	109.5
C2—C3—N2	107.5 (2)	N4—C9—H9C	109.5
C2—C3—H3	126.3	H9A—C9—H9C	109.5
N2—C3—H3	126.3	H9B—C9—H9C	109.5
N2—C4—H4A	109.5	C1—N1—C2	108.5 (2)
N2—C4—H4B	109.5	C1—N1—C5	126.3 (2)
H4A—C4—H4B	109.5	C2—N1—C5	125.1 (2)
N2—C4—H4C	109.5	C1—N2—C3	108.8 (2)
H4A—C4—H4C	109.5	C1—N2—C4	126.5 (2)
H4B—C4—H4C	109.5	C3—N2—C4	124.7 (2)
N3—C5—N1	111.7 (2)	C6—N3—C7	108.6 (2)
N3—C5—H5A	109.3	C6—N3—C5	125.8 (2)
N1—C5—H5A	109.3	C7—N3—C5	125.6 (2)
N3—C5—H5B	109.3	C6—N4—C8	109.0 (2)
N1—C5—H5B	109.3	C6—N4—C9	125.3 (2)
H5A—C5—H5B	107.9	C8—N4—C9	125.7 (2)
N4—C6—N3	108.1 (2)	Br4—Co1—Br1	107.348 (17)
N4—C6—H6	126.0	Br4—Co1—Br2	109.197 (18)
N3—C6—H6	126.0	Br1—Co1—Br2	106.224 (17)
C8—C7—N3	106.6 (2)	Br4—Co1—Br3	108.743 (17)
C8—C7—H7	126.7	Br1—Co1—Br3	113.893 (17)
N3—C7—H7	126.7	Br2—Co1—Br3	111.280 (16)

N1—C2—C3—N2	0.1 (3)	C2—C3—N2—C4	178.0 (3)
N3—C7—C8—N4	0.6 (3)	N4—C6—N3—C7	−0.2 (3)
N2—C1—N1—C2	1.6 (3)	N4—C6—N3—C5	177.9 (2)
N2—C1—N1—C5	179.0 (2)	C8—C7—N3—C6	−0.3 (3)
C3—C2—N1—C1	−1.0 (3)	C8—C7—N3—C5	−178.3 (2)
C3—C2—N1—C5	−178.4 (2)	N1—C5—N3—C6	−74.8 (3)
N3—C5—N1—C1	−83.8 (3)	N1—C5—N3—C7	102.9 (3)
N3—C5—N1—C2	93.2 (3)	N3—C6—N4—C8	0.6 (3)
N1—C1—N2—C3	−1.5 (3)	N3—C6—N4—C9	−177.7 (2)
N1—C1—N2—C4	−178.6 (2)	C7—C8—N4—C6	−0.8 (3)
C2—C3—N2—C1	0.9 (3)	C7—C8—N4—C9	177.5 (3)

Hydrogen-bond geometry (Å, º) top

D—H···A	D—H	H···A	D···A	D—H···A
C1—H1···Br2	0.95	2.92	3.829 (3)	161
C2—H2···Br4ⁱ	0.95	2.84	3.679 (3)	148
C4—H4A···Br1ⁱⁱ	0.98	2.90	3.560 (3)	126
C5—H5A···Br1	0.99	2.78	3.705 (3)	156
C5—H5B···Br3ⁱ	0.99	2.92	3.578 (3)	124
C6—H6···Br1ⁱⁱⁱ	0.95	2.88	3.558 (2)	129
C7—H7···Br2	0.95	2.87	3.665 (3)	142
C8—H8···Br3^iv	0.95	2.83	3.699 (3)	153

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

Acknowledgements

Professor J. Strunk (LIKAT, Rostock) and A. Wotzka (LIKAT, Rostock) are gratefully acknowledged for their support. The publication of this article was funded by the Open Access Fund of the Leibniz Association.

References

Ahrens, S. & Strassner, T. (2006). Inorg. Chim. Acta, 359, 4789–4796. Web of Science CSD CrossRef CAS Google Scholar
Bruker (2013). SAINT. Bruker AXS Inc., Madison, Wisconsin, USA. Google Scholar
Bruker (2014). APEX2 and SADABS. Bruker AXS Inc., Madison, Wisconsin, USA. Google Scholar
Cao, Q., Hughes, N. L. & Muldoon, M. J. (2016). Chem. Eur. J. 22, 11982–11985. CrossRef Google Scholar
García-Fernández, A., Marcos-Cives, I., Platas-Iglesias, C., Castro-García, S., Vázquez-García, D., Fernández, A. & Sánchez-Andújar, M. (2018). Inorg. Chem. 57, 7655–7664. Google Scholar
Kozlova, S. A., Verevkin, S. P., Heintz, A., Peppel, T. & Köckerling, M. (2009). J. Chem. Eng. Data, 54, 1524–1528. CrossRef Google Scholar
Moustakas, N. G. & Strunk, J. (2018). Chem. Eur. J. 24 doi: 10.1002/chem.201706178. Google Scholar
Nirmala, M., Saranya, G., Viswanathamurthi, P., Bertani, R., Sgarbossa, P. & Malecki, J. G. (2017). J. Organomet. Chem. 831, 1–10. CrossRef Google Scholar
Peppel, T., Hinz, A., Thiele, P., Geppert-Rybczyńska, M., Lehmann, J. K. & Köckerling, M. (2017). Eur. J. Inorg. Chem. pp. 885–893. CrossRef Google Scholar
Peppel, T. & Köckerling, M. (2010). Z. Anorg. Allg. Chem. 636, 2439–2446. CrossRef Google Scholar
Puerta-Oteo, R., Hölscher, M., Jiménez, M. V., Leitner, W., Passarelli, V. & Pérez-Torrente, J. (2018). Organometallics, 37, 684–696. Google Scholar
Puerta-Oteo, R., Jiménez, M. V., Lahoz, F. J., Modrego, F. J., Passarelli, V. & Pérez-Torrente, J. (2018). Inorg. Chem. 57, 5526–5543. Google Scholar
Putz, H. & Brandenburg, K. (1999). DIAMOND. Crystal Impact GbR, Bonn, Germany. Google Scholar
Sheldrick, G. M. (2008). Acta Cryst. A64, 112–122. Web of Science CrossRef CAS IUCr Journals Google Scholar
Sheldrick, G. M. (2015). Acta Cryst. C71, 3–8. Web of Science CrossRef IUCr Journals Google Scholar
Westrip, S. P. (2010). J. Appl. Cryst. 43, 920–925. Web of Science CrossRef CAS IUCr Journals Google Scholar

This is an open-access article distributed under the terms of the Creative Commons Attribution (CC-BY) Licence, which permits unrestricted use, distribution, and reproduction in any medium, provided the original authors and source are cited.