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Di-μ-bromido-bis­­({2-[(4,6-di­methyl­pyrimidin-2-yl)disulfan­yl]-4,6-di­methyl­pyrimidine-κ2N1,S2}copper(I))

aDepartment of Chemistry and Center for Innovation in Chemistry, Faculty of Science, Prince of Songkla University, Hat Yai, Songkhla 90112, Thailand, and bDepartment of Chemistry, Faculty of Science, Prince of Songkla University, Hat Yai 90112, Thailand
*Correspondence e-mail: chaveng.p@psu.ac.th

(Received 30 March 2012; accepted 15 April 2012; online 21 April 2012)

The title dinuclear complex, [Cu2Br2(C12H14N4S2)2], is located about an inversion center. The CuI ion is coordinated in a distorted tetra­hedral geometry by two bridging Br atoms in addition to an N and an S atom from the 2-[(4,6-dimethyl­pyrimidin-2-yl)disulfan­yl]-4,6-dimethyl­pyrimidine ligand. In the crystal, ππ stacking inter­actions are observed with a centroid–centroid distance of 3.590 (2) Å.

Related literature

For potential applications of heterocyclic thio­amides and their metal complexes, see: Battistuzzi & Peyronel (1981[Battistuzzi, R. & Peyronel, G. (1981). Can. J. Chem. 59, 591-596.]); Holm & Solomon (1996[Holm, R. H. & Solomon, E. J. (1996). Chem. Rev. 96, 2239-2341.]); Cox et al. (2006[Cox, P. J., Kaltzoglou, A. & Aslanidis, P. (2006). Inorg. Chim. Acta, 359, 3183-3190.]); Falcomer et al. (2006[Falcomer, V. A. S., Lemos, S. S., Batista, A. A., Ellena, A. & Castellano, E. E. (2006). Inorg. Chim. Acta, 359, 1064-1070.]); Sevier & Kaiser (2006[Sevier, C. S. & Kaiser, C. A. (2006). Antioxid. Redox Signal. 8, 797-811.]); Saxena et al. (2009[Saxena, A., Dugan, E. C., Liaw, J., Dembo, M. D. & Pike, R. D. (2009). Polyhedron, 28, 4017-4031.]). For related structures, see: Lemos et al. (2001[Lemos, S. S., Camargo, M. A., Cadoso, Z. Z., Deflon, V. M., Försterling, F. H. & Hagenbach, A. (2001). Polyhedron, 20, 849-854.]); Aslanidis et al. (2004[Aslanidis, P., Cox, P. J., Divanidis, S. & Karagiannidis, P. (2004). Inorg. Chim. Acta, 357, 4231-4239.]); Freeman et al. (2008[Freeman, F., Po, H. N., Ho, T. S. & Wang, X. (2008). J. Phys. Chem. A, 112, 1643-1655.]).

[Scheme 1]

Experimental

Crystal data
  • [Cu2Br2(C12H14N4S2)2]

  • Mr = 843.68

  • Monoclinic, C 2/c

  • a = 15.3351 (7) Å

  • b = 15.3898 (7) Å

  • c = 14.3398 (7) Å

  • β = 109.178 (1)°

  • V = 3196.4 (3) Å3

  • Z = 4

  • Mo Kα radiation

  • μ = 4.12 mm−1

  • T = 293 K

  • 0.21 × 0.18 × 0.10 mm

Data collection
  • Bruker SMART CCD diffractometer

  • Absorption correction: integration (SADABS; Bruker, 2003[Bruker (2003). SAINT and SADABS. Bruker AXS Inc., Madison, Wisconsin, USA.]) Tmin = 0.425, Tmax = 0.662

  • 12339 measured reflections

  • 2732 independent reflections

  • 2344 reflections with I > 2σ(I)

  • Rint = 0.024

Refinement
  • R[F2 > 2σ(F2)] = 0.028

  • wR(F2) = 0.077

  • S = 1.04

  • 2732 reflections

  • 181 parameters

  • 55 restraints

  • H-atom parameters constrained

  • Δρmax = 0.37 e Å−3

  • Δρmin = −0.31 e Å−3

Data collection: SMART (Bruker, 1998[Bruker (1998). SMART. Bruker AXS Inc., Madison, Wisconsin, USA.]); cell refinement: SAINT (Bruker, 2003[Bruker (2003). SAINT and SADABS. Bruker AXS Inc., Madison, Wisconsin, USA.]); data reduction: SAINT; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008[Sheldrick, G. M. (2008). Acta Cryst. A64, 112-122.]); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008[Sheldrick, G. M. (2008). Acta Cryst. A64, 112-122.]); molecular graphics: SHELXTL (Sheldrick, 2008[Sheldrick, G. M. (2008). Acta Cryst. A64, 112-122.]); software used to prepare material for publication: SHELXL97 and publCIF (Westrip, 2010[Westrip, S. P. (2010). J. Appl. Cryst. 43, 920-925.]).

Supporting information


Comment top

The studies of cooordination multidentate ligands such as heterocyclic thioamides, in complexes of closed-shell d10 metal ions, have been shown attention from a number of researchers (Saxena et al., 2009; Cox et al., 2006; Falcomer et al., 2006) because of their interesting biochemical properties and presence in active sites of many metalloproteins (Holm & Solomon, 1996; Battistuzzi & Peyronel, 1981). Particularly, the formation of disulfide bonds is an essential step in the folding and assembly of the extracellular domains of many membrane and secreted proteins which are important features of the structure of many proteins (Sevier & Kaiser, 2006).

The molecular structure of the title compound is shown in Fig. 1. The complex is dinuclear in which the CuI ions adopt distorted tetrahedral geometries. There is a binuclear µ,µ'-dibromobridged CuBr2Cu core. The Cu—S and Cu—N distances are similar to those reported for other thioamide containing complexes (Aslanidis et al., 2004; Lemos et al., 2001) and the disulfide bond distances is shorter than that reported in a related compound with a disulfide bond (Freeman et al., 2008). The 'bite' angle S—Cu—N angle is 90.77 (7)°. The molecule lies on a crystallographic inversion center which is at the center of the CuBr2Cu core with a Cu···Cu separation of 2.7802 (7) Å. This value is close the sum of the van der Waals radii for two Cu atoms (2.8 Å). In the crystal ππ stacking interactions with a centroid to centroid distance of 3.590 (2) Å are observed (Fig. 2). In addition, fairly short C(sp3)—H···N intermolecular distances (H···N = 2.67 Å, C(sp3)—N = 3.41 Å and C(sp3)—H···N = 134.2°) are observed (Fig. 3).

Related literature top

For potential applications of heterocyclic thioamides and their metal complexes, see: Battistuzzi & Peyronel (1981); Holm & Solomon (1996); Cox et al. (2006); Falcomer et al. (2006); Sevier & Kaiser (2006); Saxena et al. (2009). For related structures, see: Lemos et al. (2001); Aslanidis et al. (2004); Freeman et al. (2008).

Experimental top

4,6-Dimethyl-2-pyrimidinethiol, dmpymtH, (0.07 g, 0.50 mmol) was dissolved in 30 cm3 of methanol at 343-348K. CuBr (0.1 g, 0.70 mmol) was added and the mixture was stirred for 5 h. The resulting clear solution was filtered off and left to evaporate at room temperature. The crystalline complex, which was deposited upon standing for several days, was filtered off and dried in vacuo (yield 75%).

Refinement top

The H atoms bonded to C atoms were constrained with a riding model of C—H = 0.93–0.96 Å and with Uiso(H) = 1.2Ueq(C). The DELU instruction in SHELXL (Sheldrick, 2008) was used without any further parameters. This sets up 'rigid bond' restraints for all non-hydrogen atom. The dafault standard deviation values are 0.01 and 0.01. This appears to have little effect but it does affect the no of restraints (55) listed in the CIF.

Computing details top

Data collection: SMART (Bruker, 1998); cell refinement: SAINT (Bruker, 2003); data reduction: SAINT (Bruker, 2003); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: SHELXTL (Sheldrick, 2008); software used to prepare material for publication: SHELXL97 (Sheldrick, 2008) and publCIF (Westrip, 2010).

Figures top
[Figure 1] Fig. 1. The molecular structure with displacement ellipsoids drawn at the 50% probability level. Unlabeled atoms are related by (-x+1/2, -y+1/2, -z+1).
[Figure 2] Fig. 2. Part of the crystal structure with ππ stacking interactions shown as dashed lines.
[Figure 3] Fig. 3. Part of the crystal structure with weak C—H···N hydrogen bonds shown as dashed lines.
Di-µ-bromido-bis({2-[(4,6-dimethylpyrimidin-2-yl)disulfanyl]-4,6- dimethylpyrimidine-κ2N1,S2}copper(I)) top
Crystal data top
[Cu2Br2(C12H14N4S2)2]F(000) = 1680
Mr = 843.68Dx = 1.753 Mg m3
Monoclinic, C2/cMo Kα radiation, λ = 0.71073 Å
Hall symbol: -C 2ycCell parameters from 16645 reflections
a = 15.3351 (7) Åθ = 1.9–24.7°
b = 15.3898 (7) ŵ = 4.12 mm1
c = 14.3398 (7) ÅT = 293 K
β = 109.178 (1)°Plate, colorless
V = 3196.4 (3) Å30.21 × 0.18 × 0.10 mm
Z = 4
Data collection top
Bruker SMART CCD
diffractometer
2732 independent reflections
Radiation source: fine-focus sealed tube2344 reflections with I > 2σ(I)
Graphite monochromatorRint = 0.024
ϕ and ω scansθmax = 24.7°, θmin = 1.9°
Absorption correction: integration
(SADABS; Bruker, 2003)
h = 1818
Tmin = 0.425, Tmax = 0.662k = 1817
12339 measured reflectionsl = 1616
Refinement top
Refinement on F2Primary atom site location: structure-invariant direct methods
Least-squares matrix: fullSecondary atom site location: difference Fourier map
R[F2 > 2σ(F2)] = 0.028Hydrogen site location: inferred from neighbouring sites
wR(F2) = 0.077H-atom parameters constrained
S = 1.04 w = 1/[σ2(Fo2) + (0.0412P)2 + 3.1838P]
where P = (Fo2 + 2Fc2)/3
2732 reflections(Δ/σ)max = 0.001
181 parametersΔρmax = 0.37 e Å3
55 restraintsΔρmin = 0.31 e Å3
Crystal data top
[Cu2Br2(C12H14N4S2)2]V = 3196.4 (3) Å3
Mr = 843.68Z = 4
Monoclinic, C2/cMo Kα radiation
a = 15.3351 (7) ŵ = 4.12 mm1
b = 15.3898 (7) ÅT = 293 K
c = 14.3398 (7) Å0.21 × 0.18 × 0.10 mm
β = 109.178 (1)°
Data collection top
Bruker SMART CCD
diffractometer
2732 independent reflections
Absorption correction: integration
(SADABS; Bruker, 2003)
2344 reflections with I > 2σ(I)
Tmin = 0.425, Tmax = 0.662Rint = 0.024
12339 measured reflections
Refinement top
R[F2 > 2σ(F2)] = 0.02855 restraints
wR(F2) = 0.077H-atom parameters constrained
S = 1.04Δρmax = 0.37 e Å3
2732 reflectionsΔρmin = 0.31 e Å3
181 parameters
Special details top

Geometry. All e.s.d.'s (except the e.s.d. in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell e.s.d.'s are taken into account individually in the estimation of e.s.d.'s in distances, angles and torsion angles; correlations between e.s.d.'s in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell e.s.d.'s is used for estimating e.s.d.'s involving l.s. planes.

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 (Å2) top
xyzUiso*/Ueq
C1A0.12116 (19)0.06625 (19)0.6388 (2)0.0437 (7)
C2A0.0939 (2)0.0746 (2)0.5935 (3)0.0541 (8)
C3A0.1153 (2)0.0561 (2)0.5100 (3)0.0559 (8)
H1A0.11180.09940.46370.067*
C4A0.1417 (2)0.0265 (2)0.4949 (2)0.0491 (7)
C5A0.0690 (3)0.1640 (2)0.6172 (4)0.0806 (12)
H2A0.05310.16220.67660.097*
H4A0.12060.20220.62640.097*
H3A0.01720.18490.56370.097*
C6A0.1667 (3)0.0518 (3)0.4062 (3)0.0738 (11)
H7A0.18350.11210.41070.089*
H5A0.11470.04230.34770.089*
H6A0.21780.01730.40330.089*
C1B0.0927 (2)0.3281 (2)0.6662 (2)0.0444 (7)
C2B0.0657 (2)0.4721 (2)0.6545 (2)0.0535 (8)
C3B0.0270 (2)0.4533 (2)0.6114 (2)0.0572 (8)
H1B0.07000.49790.59100.069*
C4B0.0549 (2)0.3680 (2)0.5989 (2)0.0534 (8)
C5B0.1020 (3)0.5630 (2)0.6741 (3)0.0741 (11)
H2B0.16790.56140.70440.089*
H4B0.07490.59140.71740.089*
H3B0.08660.59430.61290.089*
C6B0.1546 (2)0.3429 (3)0.5541 (3)0.0743 (11)
H5B0.15990.28070.55160.089*
H6B0.17870.36610.48850.089*
H7B0.18900.36580.59370.089*
Cu10.20241 (3)0.20852 (2)0.55473 (3)0.05128 (14)
N1A0.09541 (17)0.01146 (17)0.65843 (19)0.0522 (6)
N2A0.14596 (16)0.09016 (15)0.56177 (17)0.0420 (5)
N1B0.12747 (18)0.40741 (17)0.68337 (19)0.0515 (6)
N2B0.00657 (18)0.30262 (16)0.62617 (19)0.0491 (6)
S1A0.12183 (7)0.14055 (6)0.73360 (6)0.0591 (2)
S1B0.18435 (6)0.24973 (5)0.70698 (6)0.0506 (2)
Br10.13259 (2)0.31106 (2)0.42440 (3)0.05795 (13)
Atomic displacement parameters (Å2) top
U11U22U33U12U13U23
C1A0.0383 (15)0.0440 (16)0.0466 (16)0.0048 (12)0.0110 (13)0.0077 (13)
C2A0.0375 (17)0.0438 (17)0.072 (2)0.0002 (13)0.0056 (15)0.0108 (16)
C3A0.0514 (19)0.0434 (17)0.066 (2)0.0011 (14)0.0099 (16)0.0083 (15)
C4A0.0506 (18)0.0460 (17)0.0482 (17)0.0027 (14)0.0127 (14)0.0042 (14)
C5A0.070 (3)0.049 (2)0.113 (3)0.0075 (18)0.017 (2)0.017 (2)
C6A0.107 (3)0.062 (2)0.063 (2)0.011 (2)0.042 (2)0.0166 (18)
C1B0.0487 (17)0.0486 (17)0.0411 (16)0.0076 (13)0.0216 (13)0.0017 (13)
C2B0.070 (2)0.0468 (18)0.0517 (18)0.0055 (15)0.0303 (16)0.0021 (14)
C3B0.060 (2)0.0566 (19)0.059 (2)0.0166 (15)0.0256 (16)0.0068 (16)
C4B0.0501 (18)0.063 (2)0.0504 (18)0.0081 (15)0.0211 (14)0.0066 (15)
C5B0.092 (3)0.051 (2)0.083 (3)0.0023 (19)0.034 (2)0.0080 (19)
C6B0.051 (2)0.090 (3)0.082 (3)0.0056 (19)0.0231 (18)0.018 (2)
Cu10.0570 (3)0.0424 (2)0.0616 (3)0.00037 (16)0.0292 (2)0.00422 (17)
N1A0.0473 (14)0.0483 (15)0.0595 (16)0.0005 (12)0.0157 (12)0.0126 (13)
N2A0.0429 (13)0.0409 (13)0.0426 (13)0.0011 (10)0.0146 (10)0.0018 (10)
N1B0.0565 (16)0.0476 (15)0.0552 (15)0.0014 (12)0.0249 (12)0.0074 (12)
N2B0.0477 (15)0.0521 (15)0.0501 (15)0.0017 (12)0.0197 (12)0.0034 (12)
S1A0.0828 (6)0.0531 (5)0.0510 (5)0.0106 (4)0.0351 (4)0.0078 (4)
S1B0.0495 (4)0.0485 (5)0.0521 (4)0.0070 (3)0.0142 (3)0.0062 (4)
Br10.0467 (2)0.0548 (2)0.0746 (3)0.01020 (14)0.02299 (17)0.02122 (16)
Geometric parameters (Å, º) top
C1A—N1A1.319 (4)C2B—C3B1.381 (5)
C1A—N2A1.332 (4)C2B—C5B1.498 (5)
C1A—S1A1.774 (3)C3B—C4B1.375 (5)
C2A—N1A1.341 (4)C3B—H1B0.9300
C2A—C3A1.371 (5)C4B—N2B1.346 (4)
C2A—C5A1.496 (4)C4B—C6B1.501 (5)
C3A—C4A1.372 (4)C5B—H2B0.9600
C3A—H1A0.9300C5B—H4B0.9600
C4A—N2A1.358 (4)C5B—H3B0.9600
C4A—C6A1.495 (5)C6B—H5B0.9600
C5A—H2A0.9600C6B—H6B0.9600
C5A—H4A0.9600C6B—H7B0.9600
C5A—H3A0.9600Cu1—N2A2.033 (2)
C6A—H7A0.9600Cu1—S1B2.3754 (9)
C6A—H5A0.9600Cu1—Br12.4114 (5)
C6A—H6A0.9600Cu1—Br1i2.4669 (5)
C1B—N2B1.315 (4)Cu1—Cu1i2.7801 (7)
C1B—N1B1.323 (4)S1A—S1B2.0318 (13)
C1B—S1B1.798 (3)Br1—Cu1i2.4668 (5)
C2B—N1B1.342 (4)
N1A—C1A—N2A127.9 (3)C3B—C4B—C6B122.1 (3)
N1A—C1A—S1A110.3 (2)C2B—C5B—H2B109.5
N2A—C1A—S1A121.7 (2)C2B—C5B—H4B109.5
N1A—C2A—C3A120.0 (3)H2B—C5B—H4B109.5
N1A—C2A—C5A117.2 (3)C2B—C5B—H3B109.5
C3A—C2A—C5A122.8 (3)H2B—C5B—H3B109.5
C2A—C3A—C4A119.9 (3)H4B—C5B—H3B109.5
C2A—C3A—H1A120.0C4B—C6B—H5B109.5
C4A—C3A—H1A120.0C4B—C6B—H6B109.5
N2A—C4A—C3A120.3 (3)H5B—C6B—H6B109.5
N2A—C4A—C6A116.5 (3)C4B—C6B—H7B109.5
C3A—C4A—C6A123.2 (3)H5B—C6B—H7B109.5
C2A—C5A—H2A109.5H6B—C6B—H7B109.5
C2A—C5A—H4A109.5N2A—Cu1—S1B90.77 (7)
H2A—C5A—H4A109.5N2A—Cu1—Br1122.47 (7)
C2A—C5A—H3A109.5S1B—Cu1—Br1112.43 (3)
H2A—C5A—H3A109.5N2A—Cu1—Br1i108.72 (7)
H4A—C5A—H3A109.5S1B—Cu1—Br1i110.22 (3)
C4A—C6A—H7A109.5Br1—Cu1—Br1i110.523 (16)
C4A—C6A—H5A109.5N2A—Cu1—Cu1i138.63 (7)
H7A—C6A—H5A109.5S1B—Cu1—Cu1i129.62 (3)
C4A—C6A—H6A109.5Br1—Cu1—Cu1i56.200 (16)
H7A—C6A—H6A109.5Br1i—Cu1—Cu1i54.323 (15)
H5A—C6A—H6A109.5C1A—N1A—C2A116.6 (3)
N2B—C1B—N1B129.9 (3)C1A—N2A—C4A115.2 (3)
N2B—C1B—S1B120.5 (2)C1A—N2A—Cu1122.05 (19)
N1B—C1B—S1B109.5 (2)C4A—N2A—Cu1122.3 (2)
N1B—C2B—C3B120.1 (3)C1B—N1B—C2B115.2 (3)
N1B—C2B—C5B116.9 (3)C1B—N2B—C4B114.3 (3)
C3B—C2B—C5B123.0 (3)C1A—S1A—S1B105.86 (11)
C4B—C3B—C2B119.3 (3)C1B—S1B—S1A104.42 (11)
C4B—C3B—H1B120.4C1B—S1B—Cu1101.24 (10)
C2B—C3B—H1B120.4S1A—S1B—Cu199.01 (4)
N2B—C4B—C3B121.2 (3)Cu1—Br1—Cu1i69.476 (16)
N2B—C4B—C6B116.7 (3)
Symmetry code: (i) x+1/2, y+1/2, z+1.

Experimental details

Crystal data
Chemical formula[Cu2Br2(C12H14N4S2)2]
Mr843.68
Crystal system, space groupMonoclinic, C2/c
Temperature (K)293
a, b, c (Å)15.3351 (7), 15.3898 (7), 14.3398 (7)
β (°) 109.178 (1)
V3)3196.4 (3)
Z4
Radiation typeMo Kα
µ (mm1)4.12
Crystal size (mm)0.21 × 0.18 × 0.10
Data collection
DiffractometerBruker SMART CCD
diffractometer
Absorption correctionIntegration
(SADABS; Bruker, 2003)
Tmin, Tmax0.425, 0.662
No. of measured, independent and
observed [I > 2σ(I)] reflections
12339, 2732, 2344
Rint0.024
(sin θ/λ)max1)0.588
Refinement
R[F2 > 2σ(F2)], wR(F2), S 0.028, 0.077, 1.04
No. of reflections2732
No. of parameters181
No. of restraints55
H-atom treatmentH-atom parameters constrained
Δρmax, Δρmin (e Å3)0.37, 0.31

Computer programs: SMART (Bruker, 1998), SAINT (Bruker, 2003), SHELXS97 (Sheldrick, 2008), SHELXTL (Sheldrick, 2008), SHELXL97 (Sheldrick, 2008) and publCIF (Westrip, 2010).

 

Acknowledgements

We gratefully acknowledge financial support from the Center for Innovation in Chemistry (PERCH–CIC), the Commission on Higher Education, Ministry of Education, the Department of Chemistry and the Graduate School, Prince of Songkla University.

References

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