[μ-N,N,N',N'-Tetra-kis(2-pyridyl-meth-yl)butane-1,4-diamine]-bis-[dibromidocopper(II)].

The title dinuclear copper complex, [Cu(2)Br(4)(C(28)H(32)N(6))], is located on an inversion center. The unique Cu(II) ion is in a slightly distorted square-pyramidal environment in which the N atoms of a dipicolyl-amine group and a bromide ligand form the basal plane. The apical site is occupied by a second Br atom. While the Cu-N distances involving the pyridine N atoms are the same within experimental error, the Cu-N distance involving the tertiary N atom is slightly elongated. Due to the typical Jahn-Teller distortion of copper(II) complexes, the apical Cu-Br distance is elongated.

Related literature

For crystallographic data of tetra­kis­(pyridin-2-yl-meth­yl)alkyl-diamine compounds, see: Fujihara et al. (2004 ▶); Mam­banda et al. (2007 ▶). For the superoxide dismutase activity of iron complexes, see: Tamura et al. (2000 ▶). For dinuclear Pt complexes of similar ligands, see: Ertürk et al. (2007 ▶). For the use of the dipicolyl­amine moiety for binding of the M(CO)3 core (M = Re,99Tc), see: Bartholomä et al. (2009 ▶). For crystal structures closely related to the title compound, see: Bartholomä et al. (2010a ▶,b ▶,c ▶,d ▶).

Experimental

Crystal data

[Cu2Br4(C28H32N6)]

M = 899.32

Monoclinic,

a = 8.8613 (6) Å

b = 14.249 (1) Å

c = 11.9488 (9) Å

β = 98.588 (2)°

V = 1491.80 (18) Å3

Z = 2

Mo Kα radiation

μ = 6.81 mm−1

T = 90 K

0.18 × 0.12 × 0.08 mm

Data collection

Bruker APEX CCD diffractometer

Absorption correction: multi-scan (SADABS; Bruker, 1998 ▶) T min = 0.374, T max = 0.612

14513 measured reflections

3623 independent reflections

3171 reflections with I > 2σ(I)

R int = 0.052

Refinement

R[F 2 > 2σ(F 2)] = 0.074

wR(F 2) = 0.147

S = 1.38

3623 reflections

181 parameters

H-atom parameters constrained

Δρmax = 1.38 e Å−3

Δρmin = −0.85 e Å−3

Data collection: SMART (Bruker, 1998 ▶); cell refinement: SAINT (Bruker, 1998 ▶); data reduction: SAINT; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008 ▶); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008 ▶); molecular graphics: DIAMOND (Brandenburg & Putz, 1999 ▶); software used to prepare material for publication: SHELXTL (Sheldrick, 2008 ▶).

Crystal structure: contains datablocks I, global. DOI: 10.1107/S1600536810034537/lh5106sup1.cif

Structure factors: contains datablocks I. DOI: 10.1107/S1600536810034537/lh5106Isup2.hkl

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

[Cu2Br4(C28H32N6)]	F(000) = 880
Mr = 899.32	Dx = 2.002 Mg m−3
Monoclinic, P21/n	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2yn	Cell parameters from 2666 reflections
a = 8.8613 (6) Å	θ = 2.7–27.2°
b = 14.249 (1) Å	µ = 6.81 mm−1
c = 11.9488 (9) Å	T = 90 K
β = 98.588 (2)°	Plates, green
V = 1491.80 (18) Å3	0.18 × 0.12 × 0.08 mm
Z = 2

Bruker APEX CCD diffractometer	3623 independent reflections
Radiation source: fine-focus sealed tube	3171 reflections with I > 2σ(I)
graphite	Rint = 0.052
Detector resolution: 512 pixels mm-1	θmax = 28.1°, θmin = 2.2°
φ and ω scans	h = −10→11
Absorption correction: multi-scan (SADABS; Bruker, 1998)	k = −18→18
Tmin = 0.374, Tmax = 0.612	l = −15→15
14513 measured reflections

Refinement on F2	Primary atom site location: structure-invariant direct methods
Least-squares matrix: full	Secondary atom site location: difference Fourier map
R[F2 > 2σ(F2)] = 0.074	Hydrogen site location: inferred from neighbouring sites
wR(F2) = 0.147	H-atom parameters constrained
S = 1.38	w = 1/[σ2(Fo2) + (0.042P)2 + 10.8322P] where P = (Fo2 + 2Fc2)/3
3623 reflections	(Δ/σ)max = 0.001
181 parameters	Δρmax = 1.38 e Å−3
0 restraints	Δρmin = −0.85 e Å−3

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.

	x	y	z	Uiso*/Ueq
Cu1	0.35669 (10)	0.75522 (6)	0.35899 (7)	0.0111 (2)
Br1	0.21437 (9)	0.82045 (5)	0.15805 (6)	0.01711 (19)
Br2	0.29274 (9)	0.87831 (5)	0.48204 (6)	0.01847 (19)
N1	0.4360 (6)	0.6374 (4)	0.2878 (5)	0.0087 (11)
N2	0.1789 (7)	0.6693 (4)	0.3702 (5)	0.0101 (11)
N3	0.5695 (6)	0.8000 (4)	0.3456 (5)	0.0099 (11)
C1	0.2983 (8)	0.5899 (5)	0.2279 (6)	0.0138 (14)
H1A	0.3214	0.5230	0.2157	0.017*
H1B	0.2676	0.6195	0.1530	0.017*
C2	0.1707 (8)	0.5972 (5)	0.2964 (6)	0.0118 (13)
C3	0.0522 (8)	0.5333 (5)	0.2869 (6)	0.0161 (15)
H3	0.0470	0.4837	0.2334	0.019*
C4	−0.0587 (9)	0.5423 (5)	0.3564 (7)	0.0208 (16)
H4	−0.1415	0.4994	0.3507	0.025*
C5	−0.0474 (9)	0.6153 (6)	0.4350 (7)	0.0214 (16)
H5	−0.1201	0.6219	0.4854	0.026*
C6	0.0718 (8)	0.6775 (5)	0.4377 (6)	0.0159 (14)
H6	0.0784	0.7284	0.4896	0.019*
C7	0.5359 (8)	0.6749 (5)	0.2094 (6)	0.0136 (14)
H7A	0.4729	0.7002	0.1406	0.016*
H7B	0.6010	0.6242	0.1863	0.016*
C8	0.6340 (8)	0.7514 (5)	0.2682 (6)	0.0132 (14)
C9	0.7788 (9)	0.7733 (5)	0.2435 (6)	0.0169 (15)
H9	0.8206	0.7398	0.1866	0.020*
C10	0.8606 (8)	0.8445 (5)	0.3033 (6)	0.0167 (15)
H10	0.9603	0.8600	0.2890	0.020*
C11	0.7950 (9)	0.8930 (5)	0.3845 (6)	0.0186 (15)
H11	0.8492	0.9421	0.4267	0.022*
C12	0.6489 (9)	0.8689 (5)	0.4032 (6)	0.0147 (14)
H12	0.6041	0.9024	0.4587	0.018*
C13	0.5282 (8)	0.5732 (5)	0.3704 (6)	0.0111 (13)
H13A	0.6209	0.6073	0.4052	0.013*
H13B	0.5620	0.5193	0.3281	0.013*
C14	0.4471 (7)	0.5353 (4)	0.4650 (5)	0.0096 (13)
H14A	0.3506	0.5042	0.4323	0.011*
H14B	0.4224	0.5875	0.5139	0.011*

	U11	U22	U33	U12	U13	U23
Cu1	0.0124 (4)	0.0090 (4)	0.0126 (4)	0.0003 (3)	0.0041 (3)	−0.0005 (3)
Br1	0.0196 (4)	0.0162 (4)	0.0155 (3)	0.0032 (3)	0.0024 (3)	0.0062 (3)
Br2	0.0249 (4)	0.0131 (3)	0.0198 (4)	−0.0001 (3)	0.0110 (3)	−0.0037 (3)
N1	0.009 (3)	0.008 (3)	0.011 (3)	−0.002 (2)	0.004 (2)	0.000 (2)
N2	0.014 (3)	0.009 (3)	0.008 (2)	−0.002 (2)	0.003 (2)	0.003 (2)
N3	0.010 (3)	0.009 (3)	0.011 (3)	0.002 (2)	0.003 (2)	0.004 (2)
C1	0.018 (4)	0.012 (3)	0.012 (3)	−0.003 (3)	0.003 (3)	−0.006 (3)
C2	0.013 (3)	0.010 (3)	0.011 (3)	0.003 (3)	−0.003 (3)	0.005 (2)
C3	0.017 (4)	0.010 (3)	0.018 (3)	−0.002 (3)	−0.006 (3)	−0.002 (3)
C4	0.013 (4)	0.019 (4)	0.032 (4)	−0.002 (3)	0.005 (3)	0.005 (3)
C5	0.014 (4)	0.027 (4)	0.025 (4)	0.001 (3)	0.007 (3)	0.009 (3)
C6	0.014 (4)	0.018 (4)	0.015 (3)	0.003 (3)	0.003 (3)	0.001 (3)
C7	0.014 (4)	0.016 (3)	0.013 (3)	0.001 (3)	0.009 (3)	−0.004 (3)
C8	0.019 (4)	0.011 (3)	0.010 (3)	−0.001 (3)	0.003 (3)	0.005 (3)
C9	0.018 (4)	0.019 (4)	0.016 (3)	0.003 (3)	0.007 (3)	0.005 (3)
C10	0.011 (3)	0.015 (3)	0.024 (4)	−0.004 (3)	0.002 (3)	0.009 (3)
C11	0.019 (4)	0.015 (3)	0.020 (4)	−0.001 (3)	−0.002 (3)	0.001 (3)
C12	0.021 (4)	0.008 (3)	0.016 (3)	0.002 (3)	0.003 (3)	0.007 (3)
C13	0.010 (3)	0.010 (3)	0.015 (3)	0.002 (3)	0.005 (3)	0.004 (2)
C14	0.007 (3)	0.008 (3)	0.013 (3)	0.000 (2)	0.001 (2)	0.005 (2)

Cu1—N2	2.015 (6)	C5—C6	1.375 (11)
Cu1—N3	2.019 (6)	C5—H5	0.9500
Cu1—N1	2.053 (5)	C6—H6	0.9500
Cu1—Br2	2.4099 (11)	C7—C8	1.502 (10)
Cu1—Br1	2.7045 (11)	C7—H7A	0.9900
N1—C7	1.482 (8)	C7—H7B	0.9900
N1—C1	1.482 (9)	C8—C9	1.394 (10)
N1—C13	1.495 (8)	C9—C10	1.382 (11)
N2—C6	1.340 (9)	C9—H9	0.9500
N2—C2	1.349 (9)	C10—C11	1.388 (11)
N3—C12	1.337 (9)	C10—H10	0.9500
N3—C8	1.349 (9)	C11—C12	1.389 (11)
C1—C2	1.496 (10)	C11—H11	0.9500
C1—H1A	0.9900	C12—H12	0.9500
C1—H1B	0.9900	C13—C14	1.526 (9)
C2—C3	1.381 (10)	C13—H13A	0.9900
C3—C4	1.384 (11)	C13—H13B	0.9900
C3—H3	0.9500	C14—C14i	1.536 (12)
C4—C5	1.395 (12)	C14—H14A	0.9900
C4—H4	0.9500	C14—H14B	0.9900
N2—Cu1—N3	161.0 (2)	C6—C5—H5	120.8
N2—Cu1—N1	81.4 (2)	C4—C5—H5	120.8
N3—Cu1—N1	81.0 (2)	N2—C6—C5	122.7 (7)
N2—Cu1—Br2	98.29 (16)	N2—C6—H6	118.7
N3—Cu1—Br2	97.22 (16)	C5—C6—H6	118.7
N1—Cu1—Br2	166.96 (16)	N1—C7—C8	109.0 (5)
N2—Cu1—Br1	90.12 (16)	N1—C7—H7A	109.9
N3—Cu1—Br1	97.95 (15)	C8—C7—H7A	109.9
N1—Cu1—Br1	93.22 (16)	N1—C7—H7B	109.9
Br2—Cu1—Br1	99.82 (4)	C8—C7—H7B	109.9
C7—N1—C1	112.7 (5)	H7A—C7—H7B	108.3
C7—N1—C13	108.6 (5)	N3—C8—C9	121.9 (7)
C1—N1—C13	111.7 (5)	N3—C8—C7	114.7 (6)
C7—N1—Cu1	103.9 (4)	C9—C8—C7	123.4 (6)
C1—N1—Cu1	105.4 (4)	C10—C9—C8	118.9 (7)
C13—N1—Cu1	114.4 (4)	C10—C9—H9	120.6
C6—N2—C2	119.0 (6)	C8—C9—H9	120.6
C6—N2—Cu1	128.2 (5)	C9—C10—C11	119.0 (7)
C2—N2—Cu1	112.7 (4)	C9—C10—H10	120.5
C12—N3—C8	119.0 (6)	C11—C10—H10	120.5
C12—N3—Cu1	128.1 (5)	C10—C11—C12	119.2 (7)
C8—N3—Cu1	112.9 (5)	C10—C11—H11	120.4
N1—C1—C2	109.8 (5)	C12—C11—H11	120.4
N1—C1—H1A	109.7	N3—C12—C11	122.0 (7)
C2—C1—H1A	109.7	N3—C12—H12	119.0
N1—C1—H1B	109.7	C11—C12—H12	119.0
C2—C1—H1B	109.7	N1—C13—C14	115.7 (5)
H1A—C1—H1B	108.2	N1—C13—H13A	108.4
N2—C2—C3	121.5 (7)	C14—C13—H13A	108.4
N2—C2—C1	116.0 (6)	N1—C13—H13B	108.4
C3—C2—C1	122.5 (6)	C14—C13—H13B	108.4
C2—C3—C4	119.2 (7)	H13A—C13—H13B	107.4
C2—C3—H3	120.4	C13—C14—C14i	108.6 (7)
C4—C3—H3	120.4	C13—C14—H14A	110.0
C3—C4—C5	119.2 (7)	C14i—C14—H14A	110.0
C3—C4—H4	120.4	C13—C14—H14B	110.0
C5—C4—H4	120.4	C14i—C14—H14B	110.0
C6—C5—C4	118.3 (7)	H14A—C14—H14B	108.3
N2—Cu1—N1—C7	151.6 (4)	Cu1—N2—C2—C3	−176.6 (5)
N3—Cu1—N1—C7	−35.6 (4)	C6—N2—C2—C1	−177.1 (6)
Br2—Cu1—N1—C7	−118.9 (7)	Cu1—N2—C2—C1	4.5 (7)
Br1—Cu1—N1—C7	62.0 (4)	N1—C1—C2—N2	24.0 (8)
N2—Cu1—N1—C1	32.9 (4)	N1—C1—C2—C3	−154.9 (6)
N3—Cu1—N1—C1	−154.3 (4)	N2—C2—C3—C4	−1.4 (10)
Br2—Cu1—N1—C1	122.4 (7)	C1—C2—C3—C4	177.4 (7)
Br1—Cu1—N1—C1	−56.7 (4)	C2—C3—C4—C5	−0.5 (11)
N2—Cu1—N1—C13	−90.2 (4)	C3—C4—C5—C6	2.1 (11)
N3—Cu1—N1—C13	82.6 (4)	C2—N2—C6—C5	−0.2 (10)
Br2—Cu1—N1—C13	−0.7 (10)	Cu1—N2—C6—C5	178.0 (5)
Br1—Cu1—N1—C13	−179.8 (4)	C4—C5—C6—N2	−1.7 (11)
N3—Cu1—N2—C6	137.8 (7)	C1—N1—C7—C8	158.0 (6)
N1—Cu1—N2—C6	160.1 (6)	C13—N1—C7—C8	−77.8 (7)
Br2—Cu1—N2—C6	−6.7 (6)	Cu1—N1—C7—C8	44.4 (6)
Br1—Cu1—N2—C6	−106.7 (6)	C12—N3—C8—C9	−2.4 (10)
N3—Cu1—N2—C2	−44.0 (9)	Cu1—N3—C8—C9	177.9 (5)
N1—Cu1—N2—C2	−21.7 (4)	C12—N3—C8—C7	179.3 (6)
Br2—Cu1—N2—C2	171.5 (4)	Cu1—N3—C8—C7	−0.3 (7)
Br1—Cu1—N2—C2	71.6 (4)	N1—C7—C8—N3	−30.7 (8)
N2—Cu1—N3—C12	−136.2 (7)	N1—C7—C8—C9	151.1 (6)
N1—Cu1—N3—C12	−158.5 (6)	N3—C8—C9—C10	2.5 (10)
Br2—Cu1—N3—C12	8.4 (6)	C7—C8—C9—C10	−179.4 (7)
Br1—Cu1—N3—C12	109.4 (5)	C8—C9—C10—C11	−1.1 (10)
N2—Cu1—N3—C8	43.4 (9)	C9—C10—C11—C12	−0.2 (10)
N1—Cu1—N3—C8	21.0 (4)	C8—N3—C12—C11	1.1 (10)
Br2—Cu1—N3—C8	−172.0 (4)	Cu1—N3—C12—C11	−179.4 (5)
Br1—Cu1—N3—C8	−71.0 (4)	C10—C11—C12—N3	0.2 (10)
C7—N1—C1—C2	−151.4 (6)	C7—N1—C13—C14	174.3 (6)
C13—N1—C1—C2	86.1 (7)	C1—N1—C13—C14	−60.8 (7)
Cu1—N1—C1—C2	−38.8 (6)	Cu1—N1—C13—C14	58.8 (7)
C6—N2—C2—C3	1.8 (10)	N1—C13—C14—C14i	175.1 (6)

Table 1

Selected bond lengths (Å)

Cu1—N2	2.015 (6)
Cu1—N3	2.019 (6)
Cu1—N1	2.053 (5)
Cu1—Br2	2.4099 (11)
Cu1—Br1	2.7045 (11)