Tris­(μ4-azepane-1-carbodi­thio­ato)bis­(μ3-azepane-1-carbodi­thio­ato)-μ9-bromido-tetra-μ2-bromido-octa­copper(I)­copper(II)

Takashi Okubo; Haruho Anma; Masahiko Maekawa; Takayoshi Kuroda-Sowa

doi:10.1107/S1600536813009938

. 2013 Apr 20;69(Pt 5):m275–m276. doi: 10.1107/S1600536813009938

Tris(μ₄-azepane-1-carbodithioato)bis(μ₃-azepane-1-carbodithioato)-μ₉-bromido-tetra-μ₂-bromido-octacopper(I)copper(II)

Takashi Okubo ^a,^b,^*, Haruho Anma ^a, Masahiko Maekawa ^a, Takayoshi Kuroda-Sowa ^a

PMCID: PMC3647813 PMID: 23723779

Abstract

The reaction of Cu(Hm-dtc)₂ (H₂m-dtc is azepane-1-carbodithioic acid), CuBr₂ and methyl isothiocyanate yielded the title mixed-valence nonanuclear Cu^I/Cu^II compound, [Cu₉Br₅(C₇H₁₂NS₂)₅] or [Cu^I ₈Cu^IIBr₅(Hm-dtc)₅], encapsulating a bromide anion in the center of the Cu₉Br₄S₁₀ cluster cage. The cage consists of a mononuclear Cu^II unit [Cu(Hm-dtc)₂], three μ₄-bridging Hm-dtc⁻ ligands, eight Cu^I ions with distorted tetrahedral or trigonal pyramidal coordination geometries and four μ₂-bridging bromide anions. The incorporated central bromide anion interacts with nine Cu ions with shorter Cu—Br separations than the sum of the van der Waals radii for Cu and Br.

Related literature

For copper clusters with dithiocarbamate ligands, see: Cardell et al. (2006 ▶); Okubo, Kuwamoto et al. (2011 ▶); Liao et al. (2012 ▶). For coordination polymers with dithiocarbamate ligands, see: Golding et al. (1974 ▶); Hendrickson et al. (1975 ▶); Okubo et al. (2010 ▶); Okubo, Tanaka et al. (2011 ▶). For pmononuclear copper complexes with dithiocarbamate ligands, see: Jian et al. (1999 ▶); Ngo et al. (2003 ▶). graphic file with name e-69-0m275-scheme1.jpg

Experimental

Crystal data

[Cu₉Br₅(C₇H₁₂NS₂)₅]
M _r = 1842.93
Monoclinic,
a = 12.5728 (6) Å
b = 19.5997 (7) Å
c = 22.9708 (8) Å
β = 107.0411 (12)°
V = 5412.0 (4) Å³
Z = 4
Mo Kα radiation
μ = 7.59 mm⁻¹
T = 296 K
0.90 × 0.60 × 0.10 mm

Data collection

Rigaku R-AXIS RAPID diffractometer
Absorption correction: multi-scan (ABSCOR; Rigaku, 1995 ▶) T _min = 0.241, T _max = 0.468
50620 measured reflections
12284 independent reflections
10468 reflections with I > 2σ(I)
R _int = 0.078

Refinement

R[F ² > 2σ(F ²)] = 0.050
wR(F ²) = 0.122
S = 1.03
12284 reflections
577 parameters
H-atom parameters constrained
Δρ_max = 2.35 e Å⁻³
Δρ_min = −1.54 e Å⁻³

Data collection: RAPID-AUTO (Rigaku, 2006 ▶); cell refinement: RAPID-AUTO; data reduction: RAPID-AUTO; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008 ▶); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008 ▶); molecular graphics: CrystalStructure (Rigaku, 2010 ▶); software used to prepare material for publication: CrystalStructure.

Supplementary Material

Click here for additional data file.^{(58.8KB, cif)}

Crystal structure: contains datablock(s) global, I. DOI: 10.1107/S1600536813009938/is5263sup1.cif

e-69-0m275-sup1.cif^{(58.8KB, cif)}

Click here for additional data file.^{(600.6KB, hkl)}

Structure factors: contains datablock(s) I. DOI: 10.1107/S1600536813009938/is5263Isup2.hkl

e-69-0m275-Isup2.hkl^{(600.6KB, hkl)}

Click here for additional data file.^{(9.5KB, cdx)}

Supplementary material file. DOI: 10.1107/S1600536813009938/is5263Isup4.cdx

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

Table 1. Selected bond lengths (Å).

Br1—Cu3	2.6912 (8)
Br2—Cu2	2.3748 (7)
Br2—Cu6	2.4201 (6)
Br3—Cu3	2.4149 (6)
Br3—Cu7	2.3993 (7)
Br4—Cu5	2.3748 (7)
Br4—Cu9	2.4414 (7)
Br5—Cu4	2.3705 (7)
Br5—Cu8	2.3962 (6)
Cu1—S1	2.3087 (10)
Cu1—S2	2.3208 (13)
Cu1—S3	2.3122 (10)
Cu1—S4	2.3322 (13)
Cu2—S1	2.2805 (12)
Cu2—S5	2.2623 (14)
Cu3—S2	2.3216 (11)
Cu3—S7	2.2711 (10)
Cu4—S3	2.2645 (11)
Cu4—S7	2.2619 (14)
Cu5—S4	2.3110 (12)
Cu5—S5	2.2447 (10)
Cu6—S6	2.2805 (15)
Cu6—S9	2.2537 (12)
Cu7—S8	2.2480 (11)
Cu7—S9	2.2788 (13)
Cu8—S8	2.3043 (15)
Cu8—S10	2.2647 (13)
Cu9—S6	2.2771 (11)
Cu9—S10	2.2705 (12)

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Acknowledgments

This work was partly supported by a Grant-in-Aid for Science Research from the Ministry of Education, Culture, Sports, Science and Technology of Japan.

supplementary crystallographic information

Comment

Dithiocarbamate (dtc) derivatives are good candidates for ligands in polynuclear metal complexes. This is because ligands that contain dithiocarboxyl groups have the ability not only to bridge metal ions by sulfur atoms, which have large atomic orbitals, in the ligands but also to stabilize Cu complexes in a wide range of oxidation states such as Cu(I), Cu(II), and Cu(III). To date, several metal clusters (Cardell et al., 2006; Okubo, Kuwamoto et al., 2011; Liao et al., 2012) and coordination polymers (Golding et al., 1974; Hendrickson et al., 1975; Okubo et al., 2010; Okubo, Tanaka et al., 2011) have been synthesized from dithiocarbamate derivatives.

Single-crystal X-ray analysis reveals the formation of a new mixed -valence Cu(I)/Cu(II) cluster of formula [Cu^I₈Cu^IIBr₅(Hm-dtc)₅]. This complex has a cage structure consisting of a mononuclear Cu(Hm-dtc)₂ unit, eight Cu ions, four Br anions and bridging µ-Hm-dtc^- ligands, and the Br1 is incorporated in the center of the cage through bonding to the Cu3 ion. The Cu1 ion of the mononuclear units has distorted square-planar coordination geometries in which the Hm-dtc^- ligands coordinate with the Cu1 ion in four-membered chelate rings. The Cu3 ion forms a tetrahedral S₂Br₂ coordination geometry. The other Cu ions, Cu2, Cu4, Cu5, Cu6, Cu7 and Cu8, have trigonal pyramidal S₂Br₁ coordination geometries, where the Br1 ion is located close to the Cu ions, thereby forming a pseudo tetrahedral geometry for the Cu ions; the Cu2—Br1, Cu4—Br1, Cu5—Br1, Cu6—Br1, Cu7—Br1, Cu8—Br1 and Cu9—Br1 separations are 2.9054 (6), 2.8672 (6), 2.7825 (8), 2.9319 (6), 2.9262 (8), 2.9563 (7) and 2.9013 (7) Å, respectively; these separations are slightly larger than the Cu3—Br1 distance [2.6912 (8) Å] and smaller than that of the sum of the van der Waals radii for Cu and Br (3.25 Å). In addition, the incorporated Br1 ion is also located close to the Cu1 ion of the mononuclear Cu(Hm-dtc)₂ unit with the separation of 2.9650 (6) Å. Usually, the oxidation states of Cu complexes with dithiocarbamate ligands can be determined by the Cu—S distances. In the mononuclear Cu(Hm-dtc)₂ unit, the average Cu—S distance is 2.3185 (13) Å, which is similar to the typical Cu(II)—S distances for Cu(II) -dithiocarbamate complexes such as Cu^II(Et₂dtc)₂ [av. 2.312 (1) Å], Cu^II(i-Pr₂dtc)₂ [av. 2.2884 (7) Å] and Cu^II(n-Bu₂dtc)₂ [av. 2.308 (1) Å] (Jian et al., 1999; Ngo et al., 2003). Based on its charge neutrality, it is concluded that this complex is in the mixed-valence state with formula [Cu^I₈Cu^IIBr₅(Hm-dtc)₅], in which the square-planar Cu1 is divalent and the other Cu ions of Cu2—Cu9 with distorted tetrahedral or trigonal pyramidal coordination geometries are monovalent.

Experimental

A CHCl₃ solution (20 ml) of Cu(Hm-dtc)₂ (0.1 mmol) was placed in a 50 ml glass vessel with a screw type cap, and a mixed-solvent (10 ml) of CHCl₃ and MeOH was slowly added on the solution. Then, a MeOH solution (20 ml) of CuBr₂ (0.2 mmol) and methylisothiocyanate (1.0 mmol) was slowly added on the solution making the layers of the solutions. By the slow diffusion of the solutions, black plate-shaped single crystals were obtained after a few days standing at room temperature.