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The title complex, [Cu(C11H14BrN2O)(N3)]n, is an inter­esting azide-bridged polynuclear copper(II) compound. The CuII atom is five-coordinated in a square-pyramidal configuration, with one O and two N atoms of one Schiff base and one terminal N atom of a bridging azide ligand defining the basal plane, and another terminal N atom of another bridging azide ligand occupying the axial position. The {4-bromo-2-[2-(dimethyl­amino)ethyl­imino­meth­yl]phenolato}copper(II) moieties are linked by the bridging azide ligands, forming polymeric chains running along the b axis. Adjacent chains are further linked by weak Br...Br inter­actions into a sheet.

Supporting information

cif

Crystallographic Information File (CIF) https://doi.org/10.1107/S0108270105016240/sk1843sup1.cif
Contains datablocks global, I

hkl

Structure factor file (CIF format) https://doi.org/10.1107/S0108270105016240/sk1843Isup2.hkl
Contains datablock I

CCDC reference: 278541

Comment top

The magnetic properties of extended coordination compounds featuring exchange-coupled magnetic centres have become a fascinating subject in recent years (Kahn, 1993; Dalai et al., 2002; Bhaduri et al., 2003). The prime strategy for designing these molecular materials is to use a suitable bridging ligand that determines the nature of the magnetic interactions (Koner et al., 2003). Due to the versatile coordination modes of the flexidentate azido ligand and the wide range of magnetic coupling mediated by azide bridges, this pseudohalide ligand has become one of the most extensively studied building blocks in the field (Thompson & Tandon, 1996; Meyer & Pritzkow, 2001). Azido complexes of various dimensionalities have been obtained (Mukherjee et al., 2001; Goher et al., 2002). These also include some examples of the so-called alternating one-dimensional magnetic systems, which have two or more different structural bridges and which are of considerable interest in terms of their magnetic behaviour (Vicente et al., 1992; Escuer et al., 1994; Ribas et al., 1995; Vicente & Escuer, 1995). A major obstacle to a more comprehensive study of such azido-based polymeric coordination compounds is the lack of rational synthetic procedures, since with the present state of knowledge it is hardly possible to determine which coordination mode will be adopted by the azide ligand and whether the sought-after alternating chain structure will finally be formed (Ribas et al., 1999).

Our work is aimed at obtaining multidimensional polymetallic complexes. Based on the above considerations, we designed and synthesized a flexible tridentate ligand, 4-bromo-2-[(2-dimethylaminoethylimino)methyl]phenol (BDMP). The reason we do not use a rigid ligand is that the flexible BDMP ligand can adopt a different coordination mode according to the geometric need of the transition metal ions and the coordination environment (Mondal et al., 2001). The second ligand, azide, is a well known bridging group. It readily bridges different metal ions through the terminal donor atoms, forming polynuclear complexes (Monfort et al., 2001). Copper(II) is a good candidate for octahedral coordination geometry. Here, we report the novel one-dimensional infinite chains in the structure of the title compound, (I), formed by the reaction of BDMP, azide and copper(II) acetate.

Complex (I) is an azido-bridged polynuclear copper(II) compound (Fig. 1). The smallest repeat unit contains one BDMP–CuII cation and one bridging azide ligand. The CuII atom is in a square-pyramidal coordination environment and is coordinated by the NNO donor set of one Schiff base, and by one terminal N atom of a bridging azide ligand defining the basal plane, and by a different but symmetry-related terminal N atom occupying the axial position. The Schiff base acts as a tridentate ligand and ligates to the metal atom via the three O and N donor atoms. It is very interesting that the azide anion acts as a bridging ligand and ligates to two different but symmetry-related copper(II) atoms via the terminal N atom. Atom N3 acts as a basal donor of the Cu1 moiety, while for the Cu1ii moiety, it acts as the axial donor atom. The Cu1ii—N3 bond [2.655 (2) Å] is much longer than the Cu1—N3 bond [1.981 (2) Å] [symmetry code: (ii) 3/2 − x, y − 1/2, 3/2 − z], which is probably due to the hindrance effects of the copper(II) moieties. The basal least-squares planes of the adjacent two CuII centres are not parallel and form a dihedral angle of 43.5 (2)°. The deviation of atom Cu1 from the best-fit square plane towards atom N3 is 0.054 (2) Å.

The bond lengths (Table 1) subtended at atom Cu1 in the basal plane are comparable with those observed in other Schiff base copper(II) complexes (Zhang et al., 2001; Elmali et al., 2000) and, as expected, the bond involving the amino atom N2 [2.070 (2) Å] is longer than that involving the imino atom N1 [1.950 (2) Å] (Mondal et al., 2001). The bridging NNN group is nearly linear and shows bent coordination modes with the metal atoms [angles N3—N4—N5, Cu1—N3—N4 and Cu1i—N3—N4 are 177.7 (3), 117.8 (2) and 113.1 (2)°, respectively; symmetry code: (i) 3/2 − x, 1/2 + y, 3/2 − z]. The N1—Cu1—N2 bond angle [84.90 (8)°] of the five-membered chelate ring is much smaller than 90°, which is due to the strain created by the five-membered chelate ring Cu1/N2/C9/C8/N1.

In the crystal structure, the 4-bromo-2-[(2-dimethylaminoethylimino)methyl]phenolatocopper(II) moieties are linked by the bridging azide ligands, forming polymeric chains running along the b axis. Adjacent chains are further linked by weak Br···Br interactions into a sheet (Fig. 2).

Experimental top

5-Bromosalicylaldehyde (0.1 mmol, 20.1 mg) and N,N-dimethylethane-1,2-diamine (0.1 mmol, 8.8 mg) were dissolved in MeOH (10 ml). The mixture was stirred at room temperature for 10 min to give a yellow solution. To this solution was added an aqueous solution (2 ml) of NaN3 (0.1 mmol, 6.5 mg) and an MeOH solution (3 ml) of Cu(CH3COO)2·H2O (0.1 mmol, 19.9 mg), with stirring. The mixture was stirred for another 10 min at room temperature. After keeping the filtrate in air for 7 d, blue block-shaped crystals of (I) were formed.

Refinement top

All H atoms were placed in geometrically idealized positions and allowed to ride on their parent atoms, with C—H distances in the range 0.93–0.97 Å and with Uiso(H) = 1.2 or 1.5Ueq(C).

Computing details top

Data collection: SMART (Bruker, 1998); cell refinement: SMART; data reduction: SAINT (Bruker, 1998); program(s) used to solve structure: SHELXS97 (Sheldrick, 1997a); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997a); molecular graphics: SHELXTL (Sheldrick, 1997b); software used to prepare material for publication: SHELXTL.

Figures top
[Figure 1] Fig. 1. The structure of (I), showing the atom-numbering scheme. Displacement ellipsoids are drawn at the 30% probability level. [Symmetry codes: (i) 3/2 − x, 1/2 + y, 3/2 − z; (ii) 3/2 − x, y − 1/2, 3/2 − z.]
[Figure 2] Fig. 2. The crystal packing of (I), viewed along the b axis. Dashed lines show the Br···Br interactions.
catena-Poly[[{4-bromo-2-[2- (dimethylamino)ethyliminomethyl]phenolato}copper(II)]-µ-azido] top
Crystal data top
[Cu(C11H14BrN2O)(N3)]F(000) = 748
Mr = 375.72Dx = 1.748 Mg m3
Monoclinic, P21/nMo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2ynCell parameters from 5698 reflections
a = 12.076 (2) Åθ = 2.3–27.0°
b = 6.757 (2) ŵ = 4.33 mm1
c = 17.875 (2) ÅT = 298 K
β = 101.88 (1)°Block, blue
V = 1427.3 (5) Å30.18 × 0.14 × 0.12 mm
Z = 4
Data collection top
Bruker SMART CCD area-detector
diffractometer
3258 independent reflections
Radiation source: fine-focus sealed tube2631 reflections with I > 2σ(I)
Graphite monochromatorRint = 0.033
ω scansθmax = 27.5°, θmin = 2.3°
Absorption correction: multi-scan
(SADABS; Sheldrick, 1996)
h = 1515
Tmin = 0.510, Tmax = 0.625k = 88
15608 measured reflectionsl = 2222
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)] = 0.029Hydrogen site location: inferred from neighbouring sites
wR(F2) = 0.077H-atom parameters constrained
S = 1.05 w = 1/[σ2(Fo2) + (0.0336P)2 + 0.7176P]
where P = (Fo2 + 2Fc2)/3
3258 reflections(Δ/σ)max < 0.001
174 parametersΔρmax = 0.88 e Å3
0 restraintsΔρmin = 0.50 e Å3
Crystal data top
[Cu(C11H14BrN2O)(N3)]V = 1427.3 (5) Å3
Mr = 375.72Z = 4
Monoclinic, P21/nMo Kα radiation
a = 12.076 (2) ŵ = 4.33 mm1
b = 6.757 (2) ÅT = 298 K
c = 17.875 (2) Å0.18 × 0.14 × 0.12 mm
β = 101.88 (1)°
Data collection top
Bruker SMART CCD area-detector
diffractometer
3258 independent reflections
Absorption correction: multi-scan
(SADABS; Sheldrick, 1996)
2631 reflections with I > 2σ(I)
Tmin = 0.510, Tmax = 0.625Rint = 0.033
15608 measured reflections
Refinement top
R[F2 > 2σ(F2)] = 0.0290 restraints
wR(F2) = 0.077H-atom parameters constrained
S = 1.05Δρmax = 0.88 e Å3
3258 reflectionsΔρmin = 0.50 e Å3
174 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
Cu10.79396 (2)0.04323 (4)0.819384 (15)0.03328 (10)
Br11.36883 (2)0.45925 (5)0.928613 (16)0.05307 (11)
O10.93630 (14)0.0421 (3)0.78870 (10)0.0397 (4)
N10.86110 (15)0.1375 (3)0.92178 (10)0.0300 (4)
N20.64354 (17)0.0441 (3)0.85784 (11)0.0335 (4)
N30.72361 (18)0.0774 (3)0.71995 (11)0.0387 (5)
N40.68144 (18)0.0313 (3)0.66898 (12)0.0374 (5)
N50.6395 (2)0.1303 (4)0.61845 (14)0.0591 (7)
C11.02788 (19)0.1317 (3)0.82277 (13)0.0323 (5)
C21.1189 (2)0.1445 (4)0.78440 (14)0.0437 (6)
H21.11140.08490.73670.052*
C31.2175 (2)0.2408 (4)0.81447 (14)0.0440 (6)
H31.27530.24810.78730.053*
C41.23024 (19)0.3282 (4)0.88650 (14)0.0372 (5)
C51.14586 (19)0.3188 (4)0.92653 (13)0.0344 (5)
H51.15580.37800.97440.041*
C61.04384 (18)0.2204 (3)0.89620 (12)0.0300 (5)
C70.95973 (19)0.2130 (3)0.94272 (12)0.0316 (5)
H70.97850.26710.99150.038*
C80.7812 (2)0.1421 (4)0.97296 (13)0.0376 (5)
H8A0.80140.24621.01070.045*
H8B0.78190.01680.99950.045*
C90.6653 (2)0.1806 (4)0.92434 (14)0.0392 (6)
H9A0.60820.16130.95470.047*
H9B0.66070.31650.90650.047*
C100.6163 (2)0.1569 (4)0.88077 (17)0.0487 (7)
H10A0.54960.15230.90200.073*
H10B0.67840.20710.91840.073*
H10C0.60330.24210.83680.073*
C110.5461 (2)0.1180 (4)0.80069 (16)0.0461 (6)
H11A0.53000.02760.75840.069*
H11B0.56390.24580.78280.069*
H11C0.48120.12870.82370.069*
Atomic displacement parameters (Å2) top
U11U22U33U12U13U23
Cu10.02836 (16)0.04217 (18)0.02858 (15)0.00228 (12)0.00416 (11)0.00644 (12)
Br10.03709 (16)0.0734 (2)0.04961 (18)0.01609 (13)0.01101 (12)0.01344 (14)
O10.0320 (9)0.0493 (10)0.0378 (9)0.0014 (8)0.0068 (7)0.0158 (8)
N10.0313 (10)0.0324 (10)0.0263 (9)0.0039 (8)0.0061 (8)0.0004 (8)
N20.0312 (10)0.0356 (11)0.0338 (10)0.0009 (8)0.0068 (8)0.0007 (8)
N30.0396 (12)0.0409 (12)0.0327 (11)0.0042 (9)0.0005 (9)0.0052 (9)
N40.0419 (12)0.0377 (11)0.0326 (11)0.0098 (9)0.0077 (9)0.0078 (10)
N50.0797 (18)0.0527 (15)0.0415 (13)0.0035 (14)0.0043 (13)0.0069 (12)
C10.0300 (12)0.0332 (12)0.0323 (11)0.0049 (9)0.0029 (9)0.0044 (10)
C20.0375 (13)0.0599 (17)0.0350 (13)0.0033 (12)0.0105 (11)0.0138 (12)
C30.0322 (13)0.0613 (17)0.0405 (13)0.0021 (12)0.0121 (11)0.0078 (12)
C40.0292 (12)0.0443 (14)0.0366 (12)0.0022 (10)0.0031 (10)0.0016 (11)
C50.0341 (12)0.0387 (13)0.0291 (11)0.0006 (10)0.0035 (9)0.0032 (10)
C60.0278 (11)0.0327 (12)0.0289 (11)0.0038 (9)0.0045 (9)0.0010 (9)
C70.0343 (12)0.0338 (12)0.0245 (10)0.0028 (10)0.0010 (9)0.0014 (9)
C80.0368 (13)0.0458 (14)0.0317 (12)0.0027 (11)0.0103 (10)0.0009 (11)
C90.0367 (13)0.0413 (14)0.0423 (13)0.0011 (11)0.0143 (11)0.0036 (11)
C100.0531 (16)0.0389 (15)0.0561 (17)0.0062 (12)0.0157 (13)0.0044 (12)
C110.0322 (13)0.0540 (16)0.0505 (16)0.0021 (12)0.0050 (12)0.0048 (13)
Geometric parameters (Å, º) top
Cu1—O11.909 (2)C3—H30.9300
Cu1—N11.950 (2)C4—C51.362 (3)
Cu1—N31.981 (2)C5—C61.407 (3)
Cu1—N22.070 (2)C5—H50.9300
Br1—C41.906 (2)C6—C71.440 (3)
O1—C11.297 (3)C7—H70.9300
N1—C71.279 (3)C8—C91.510 (3)
N1—C81.461 (3)C8—H8A0.9700
N2—C101.475 (3)C8—H8B0.9700
N2—C111.477 (3)C9—H9A0.9700
N2—C91.484 (3)C9—H9B0.9700
N3—N41.199 (3)C10—H10A0.9600
N4—N51.154 (3)C10—H10B0.9600
C1—C21.413 (3)C10—H10C0.9600
C1—C61.420 (3)C11—H11A0.9600
C2—C31.366 (4)C11—H11B0.9600
C2—H20.9300C11—H11C0.9600
C3—C41.396 (3)
O1—Cu1—N192.63 (7)C6—C5—H5119.7
O1—Cu1—N389.18 (8)C5—C6—C1119.8 (2)
N1—Cu1—N3174.47 (9)C5—C6—C7117.4 (2)
O1—Cu1—N2177.37 (8)C1—C6—C7122.8 (2)
N1—Cu1—N284.90 (8)N1—C7—C6124.7 (2)
N3—Cu1—N293.19 (9)N1—C7—H7117.6
C1—O1—Cu1126.47 (15)C6—C7—H7117.6
C7—N1—C8120.26 (19)N1—C8—C9107.27 (19)
C7—N1—Cu1125.97 (16)N1—C8—H8A110.3
C8—N1—Cu1113.21 (14)C9—C8—H8A110.3
C10—N2—C11108.2 (2)N1—C8—H8B110.3
C10—N2—C9111.2 (2)C9—C8—H8B110.3
C11—N2—C9109.2 (2)H8A—C8—H8B108.5
C10—N2—Cu1110.51 (16)N2—C9—C8110.1 (2)
C11—N2—Cu1113.55 (15)N2—C9—H9A109.6
C9—N2—Cu1104.18 (14)C8—C9—H9A109.6
N4—N3—Cu1117.78 (17)N2—C9—H9B109.6
N5—N4—N3177.7 (3)C8—C9—H9B109.6
O1—C1—C2118.3 (2)H9A—C9—H9B108.1
O1—C1—C6124.8 (2)N2—C10—H10A109.5
C2—C1—C6116.9 (2)N2—C10—H10B109.5
C3—C2—C1122.7 (2)H10A—C10—H10B109.5
C3—C2—H2118.6N2—C10—H10C109.5
C1—C2—H2118.6H10A—C10—H10C109.5
C2—C3—C4119.1 (2)H10B—C10—H10C109.5
C2—C3—H3120.5N2—C11—H11A109.5
C4—C3—H3120.5N2—C11—H11B109.5
C5—C4—C3120.8 (2)H11A—C11—H11B109.5
C5—C4—Br1120.36 (18)N2—C11—H11C109.5
C3—C4—Br1118.81 (18)H11A—C11—H11C109.5
C4—C5—C6120.7 (2)H11B—C11—H11C109.5
C4—C5—H5119.7
N1—Cu1—O1—C116.6 (2)C2—C3—C4—Br1179.2 (2)
N3—Cu1—O1—C1168.6 (2)C3—C4—C5—C60.1 (4)
O1—Cu1—N1—C715.0 (2)Br1—C4—C5—C6179.25 (18)
N2—Cu1—N1—C7165.9 (2)C4—C5—C6—C10.7 (3)
O1—Cu1—N1—C8173.58 (16)C4—C5—C6—C7178.7 (2)
N2—Cu1—N1—C85.51 (16)O1—C1—C6—C5178.1 (2)
N1—Cu1—N2—C1098.92 (17)C2—C1—C6—C51.4 (3)
N3—Cu1—N2—C1075.88 (17)O1—C1—C6—C72.6 (4)
N1—Cu1—N2—C11139.30 (18)C2—C1—C6—C7177.9 (2)
N3—Cu1—N2—C1145.90 (18)C8—N1—C7—C6178.5 (2)
N1—Cu1—N2—C920.65 (15)Cu1—N1—C7—C67.7 (3)
N3—Cu1—N2—C9164.55 (15)C5—C6—C7—N1176.5 (2)
O1—Cu1—N3—N493.7 (2)C1—C6—C7—N14.1 (4)
N2—Cu1—N3—N487.4 (2)C7—N1—C8—C9141.7 (2)
Cu1—O1—C1—C2168.57 (18)Cu1—N1—C8—C930.3 (2)
Cu1—O1—C1—C610.9 (3)C10—N2—C9—C876.1 (3)
O1—C1—C2—C3178.0 (3)C11—N2—C9—C8164.6 (2)
C6—C1—C2—C31.5 (4)Cu1—N2—C9—C843.0 (2)
C1—C2—C3—C40.9 (4)N1—C8—C9—N249.2 (3)
C2—C3—C4—C50.2 (4)

Experimental details

Crystal data
Chemical formula[Cu(C11H14BrN2O)(N3)]
Mr375.72
Crystal system, space groupMonoclinic, P21/n
Temperature (K)298
a, b, c (Å)12.076 (2), 6.757 (2), 17.875 (2)
β (°) 101.88 (1)
V3)1427.3 (5)
Z4
Radiation typeMo Kα
µ (mm1)4.33
Crystal size (mm)0.18 × 0.14 × 0.12
Data collection
DiffractometerBruker SMART CCD area-detector
diffractometer
Absorption correctionMulti-scan
(SADABS; Sheldrick, 1996)
Tmin, Tmax0.510, 0.625
No. of measured, independent and
observed [I > 2σ(I)] reflections
15608, 3258, 2631
Rint0.033
(sin θ/λ)max1)0.650
Refinement
R[F2 > 2σ(F2)], wR(F2), S 0.029, 0.077, 1.05
No. of reflections3258
No. of parameters174
H-atom treatmentH-atom parameters constrained
Δρmax, Δρmin (e Å3)0.88, 0.50

Computer programs: SMART (Bruker, 1998), SMART, SAINT (Bruker, 1998), SHELXS97 (Sheldrick, 1997a), SHELXL97 (Sheldrick, 1997a), SHELXTL (Sheldrick, 1997b), SHELXTL.

Selected geometric parameters (Å, º) top
Cu1—O11.909 (2)Cu1—N31.981 (2)
Cu1—N11.950 (2)Cu1—N22.070 (2)
O1—Cu1—N192.63 (7)O1—Cu1—N2177.37 (8)
O1—Cu1—N389.18 (8)N1—Cu1—N284.90 (8)
N1—Cu1—N3174.47 (9)N3—Cu1—N293.19 (9)
 

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