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In the title compound, [Zn(C7H3Br2O2)2(H2O)2], the ZnII atom is six-coordinated in a slightly distorted octa­hedral coordination geometry by four O atoms of two 3,5-dibromo-2-hydroxy­benzaldehyde ligands and by two water mol­ecules. The Zn—O bond lengths lie in the range 2.040 (4)–2.121 (4) Å, and the angles subtended at the ZnII atom range from 84.10 (18) to 96.64 (17)°. The mol­ecules are linked into a chain along the a axis by O—H...O and O—H...Br hydrogen bonds.

Supporting information

cif

Crystallographic Information File (CIF) https://doi.org/10.1107/S1600536807018259/ci2359sup1.cif
Contains datablocks global, I

hkl

Structure factor file (CIF format) https://doi.org/10.1107/S1600536807018259/ci2359Isup2.hkl
Contains datablock I

CCDC reference: 646605

Key indicators

  • Single-crystal X-ray study
  • T = 293 K
  • Mean [sigma](C-C) = 0.009 Å
  • R factor = 0.041
  • wR factor = 0.127
  • Data-to-parameter ratio = 18.5

checkCIF/PLATON results

No syntax errors found



Alert level C PLAT062_ALERT_4_C Rescale T(min) & T(max) by ..................... 0.73 PLAT152_ALERT_1_C Supplied and Calc Volume s.u. Inconsistent ..... ? PLAT341_ALERT_3_C Low Bond Precision on C-C bonds (x 1000) Ang ... 9 PLAT431_ALERT_2_C Short Inter HL..A Contact Br2 .. O3 .. 3.29 Ang. PLAT720_ALERT_4_C Number of Unusual/Non-Standard Label(s) ........ 4
Alert level G ABSTM02_ALERT_3_G When printed, the submitted absorption T values will be replaced by the scaled T values. Since the ratio of scaled T's is identical to the ratio of reported T values, the scaling does not imply a change to the absorption corrections used in the study. Ratio of Tmax expected/reported 0.731 Tmax scaled 0.243 Tmin scaled 0.078 PLAT199_ALERT_1_G Check the Reported _cell_measurement_temperature 293 K PLAT200_ALERT_1_G Check the Reported _diffrn_ambient_temperature . 293 K
0 ALERT level A = In general: serious problem 0 ALERT level B = Potentially serious problem 5 ALERT level C = Check and explain 3 ALERT level G = General alerts; check 3 ALERT type 1 CIF construction/syntax error, inconsistent or missing data 1 ALERT type 2 Indicator that the structure model may be wrong or deficient 2 ALERT type 3 Indicator that the structure quality may be low 2 ALERT type 4 Improvement, methodology, query or suggestion 0 ALERT type 5 Informative message, check

Comment top

Interest in packing arrangements of halogenated compounds goes back many years to what Schmidt (1964) called the "chloro effect",

wherein the presence of chloro substituents on aromatic compounds frequently results in stacking arrangements with a short (ca 4 Å) crystallographic axis (Cohen et al., 1964; Zordan et al., 2005; Desiraju, 1989). We report here the crystal structure of the title mononuclear zinc(II) complex, Zn(L)2(H2O)2 (I), where LH is 3,5-dibromo-2-hydroxy-benzaldehyde, a dibrominated ligand with two Br atoms accessible at the periphery of each ligand.

The asymmetric unit of (I) contains one unique ZnII centre, two independent L- ligands and two coordinated water molecules (Fig. 1). The ZnII atom is coordinated by four O atoms from two L- ligands and two O atoms from two water molecules, forming slightly distorted octahedral geometry (Table 1). The L- ligand is present in the chelating bidentate mode.

The molecules are linked into a chain along the a axis by O—H···O and O—H···Br hydrogen bonds (Table 2).

Related literature top

A similar cobalt(II) complex also forms a distorted octahedral geometry (Xiao et al., 2002). For related literature, see: Cohen et al. (1964); Desiraju (1989); Schmidt (1964); Zordan et al. (2005).

Experimental top

A solution of taurine (2 mmol, 0.253 g) and caustic potash (2 mmol, 0.112 g) in distilled water (10 ml) was slowly added to a solution of 3,5-dibromo- 2-hydroxy-benzaldehyde (2 mmol, 0.560 g) in ethanol (10 ml). The mixture was stirred for 30 min at room temperature, then the solution was slowly added to a solution of zinc nitrate (1 mmol, 0.297 g) in distilled water (10 ml). The mixture was stirred and refluxed for 4 h at room temperature. Colourless needle-shaped single-crystal of (I) were obtained by slow evaporation at room temperature (yield 68%, based on zinc).

Refinement top

H atoms of the water molecule were located in a difference Fourier map. The O—H distances were normalized to 0.85 Å and the H atoms were allowed to ride during subsequent refinement, with Uiso(H) = 1.5 Ueq(O).

All other H atoms were positioned geometrically and were treated as riding atoms, with C–H = 0.93 Å and Uiso(H) = 1.2 Ueq(C).

Structure description top

Interest in packing arrangements of halogenated compounds goes back many years to what Schmidt (1964) called the "chloro effect",

wherein the presence of chloro substituents on aromatic compounds frequently results in stacking arrangements with a short (ca 4 Å) crystallographic axis (Cohen et al., 1964; Zordan et al., 2005; Desiraju, 1989). We report here the crystal structure of the title mononuclear zinc(II) complex, Zn(L)2(H2O)2 (I), where LH is 3,5-dibromo-2-hydroxy-benzaldehyde, a dibrominated ligand with two Br atoms accessible at the periphery of each ligand.

The asymmetric unit of (I) contains one unique ZnII centre, two independent L- ligands and two coordinated water molecules (Fig. 1). The ZnII atom is coordinated by four O atoms from two L- ligands and two O atoms from two water molecules, forming slightly distorted octahedral geometry (Table 1). The L- ligand is present in the chelating bidentate mode.

The molecules are linked into a chain along the a axis by O—H···O and O—H···Br hydrogen bonds (Table 2).

A similar cobalt(II) complex also forms a distorted octahedral geometry (Xiao et al., 2002). For related literature, see: Cohen et al. (1964); Desiraju (1989); Schmidt (1964); Zordan et al. (2005).

Computing details top

Data collection: SMART (Bruker, 2001); cell refinement: SAINT (Bruker, 2001); data reduction: SAINT; program(s) used to solve structure: SHELXS97 (Sheldrick, 1997); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: ORTEPII (Johnson, 1976); software used to prepare material for publication: SHELXTL.

Figures top
[Figure 1] Fig. 1. The molecular structure of (I), showing 30% probability displacement ellipsoids. For clarity, all but water H atoms have been omitted.
[Figure 2] Fig. 2. The crystal packing of (I). Dashed lines indicate hydrogen bonds. C-bound H atoms have been omitted for clarity.
Diaquabis(2,4-dibromo-6-formylphenolato-κ2N,N')zinc(II) top
Crystal data top
[Zn(C7H3Br2O2)2(H2O)2]F(000) = 1248
Mr = 659.23Dx = 2.396 Mg m3
Monoclinic, P21/cMo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2ybcCell parameters from 5376 reflections
a = 7.6486 (15) Åθ = 1–27.5°
b = 28.095 (6) ŵ = 10.12 mm1
c = 8.6716 (17) ÅT = 293 K
β = 101.25 (3)°Needle, colourless
V = 1827.6 (6) Å30.40 × 0.16 × 0.14 mm
Z = 4
Data collection top
Bruker SMART CCD area-detector
diffractometer
4189 independent reflections
Radiation source: fine-focus sealed tube2577 reflections with I > 2σ(I)
Graphite monochromatorRint = 0.066
φ and ω scansθmax = 27.6°, θmin = 1.5°
Absorption correction: multi-scan
(SADABS; Sheldrick, 1996)
h = 99
Tmin = 0.107, Tmax = 0.332k = 3633
12164 measured reflectionsl = 1011
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)] = 0.041Hydrogen site location: inferred from neighbouring sites
wR(F2) = 0.127H-atom parameters constrained
S = 1.03 w = 1/[σ2(Fo2) + (0.0561P)2]
where P = (Fo2 + 2Fc2)/3
4189 reflections(Δ/σ)max = 0.001
226 parametersΔρmax = 0.76 e Å3
0 restraintsΔρmin = 0.77 e Å3
Crystal data top
[Zn(C7H3Br2O2)2(H2O)2]V = 1827.6 (6) Å3
Mr = 659.23Z = 4
Monoclinic, P21/cMo Kα radiation
a = 7.6486 (15) ŵ = 10.12 mm1
b = 28.095 (6) ÅT = 293 K
c = 8.6716 (17) Å0.40 × 0.16 × 0.14 mm
β = 101.25 (3)°
Data collection top
Bruker SMART CCD area-detector
diffractometer
4189 independent reflections
Absorption correction: multi-scan
(SADABS; Sheldrick, 1996)
2577 reflections with I > 2σ(I)
Tmin = 0.107, Tmax = 0.332Rint = 0.066
12164 measured reflections
Refinement top
R[F2 > 2σ(F2)] = 0.0410 restraints
wR(F2) = 0.127H-atom parameters constrained
S = 1.03Δρmax = 0.76 e Å3
4189 reflectionsΔρmin = 0.77 e Å3
226 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
Br10.55634 (12)0.25086 (3)0.72223 (10)0.0510 (2)
Br20.38278 (11)0.43461 (3)0.91144 (8)0.0425 (2)
Br30.07491 (13)0.72472 (3)0.08867 (13)0.0708 (3)
Br40.23829 (11)0.63158 (3)0.65207 (8)0.0425 (2)
C10.3092 (8)0.3676 (2)0.4757 (7)0.0254 (14)
C20.3114 (8)0.4041 (2)0.5911 (7)0.0223 (13)
C30.3828 (8)0.3896 (2)0.7481 (7)0.0279 (15)
C40.4534 (9)0.3450 (2)0.7876 (8)0.0338 (16)
H40.50170.33770.89180.041*
C50.4518 (10)0.3107 (2)0.6699 (9)0.0357 (17)
C60.3789 (9)0.3217 (2)0.5193 (8)0.0327 (16)
H60.37440.29850.44210.039*
C70.2336 (9)0.3744 (3)0.3118 (8)0.0352 (17)
H70.22890.34740.24890.042*
C80.1252 (9)0.5882 (2)0.1838 (8)0.0304 (15)
C90.1785 (8)0.5864 (2)0.3508 (7)0.0247 (14)
C100.1614 (9)0.6300 (2)0.4297 (8)0.0300 (15)
C110.0909 (9)0.6704 (3)0.3535 (9)0.0399 (18)
H110.08020.69790.41030.048*
C120.0361 (10)0.6701 (3)0.1931 (9)0.0393 (18)
C130.0548 (9)0.6299 (3)0.1089 (8)0.0385 (18)
H130.01990.63030.00000.046*
C140.1414 (9)0.5481 (3)0.0829 (8)0.0318 (16)
H140.11590.55440.02440.038*
O10.1748 (6)0.41087 (16)0.2442 (5)0.0305 (10)
O20.2526 (6)0.44684 (15)0.5594 (5)0.0303 (10)
O30.1838 (6)0.50740 (17)0.1193 (5)0.0325 (11)
O40.2395 (6)0.54800 (15)0.4281 (5)0.0291 (10)
O1W0.4842 (6)0.47247 (17)0.3266 (5)0.0328 (11)
H1WB0.55310.45410.38880.049*
H1WA0.54340.49770.31900.049*
O2W0.0665 (6)0.48299 (16)0.3156 (5)0.0291 (10)
H2WA0.14640.50330.27930.044*
H2WB0.11360.46390.37190.044*
Zn10.21512 (10)0.47942 (3)0.34528 (8)0.02439 (19)
Atomic displacement parameters (Å2) top
U11U22U33U12U13U23
Br10.0589 (5)0.0313 (4)0.0632 (5)0.0112 (4)0.0130 (4)0.0182 (4)
Br20.0587 (5)0.0441 (5)0.0252 (4)0.0025 (4)0.0089 (3)0.0051 (3)
Br30.0697 (7)0.0406 (5)0.0988 (8)0.0178 (5)0.0080 (6)0.0331 (5)
Br40.0599 (5)0.0325 (4)0.0371 (4)0.0081 (4)0.0142 (4)0.0102 (3)
C10.025 (3)0.024 (3)0.029 (3)0.002 (3)0.009 (3)0.002 (3)
C20.023 (3)0.018 (3)0.029 (3)0.002 (2)0.012 (3)0.001 (3)
C30.025 (4)0.032 (4)0.027 (3)0.003 (3)0.006 (3)0.002 (3)
C40.035 (4)0.037 (4)0.028 (4)0.002 (3)0.004 (3)0.008 (3)
C50.041 (4)0.021 (4)0.045 (4)0.005 (3)0.008 (3)0.012 (3)
C60.040 (4)0.021 (4)0.037 (4)0.004 (3)0.008 (3)0.001 (3)
C70.042 (4)0.029 (4)0.033 (4)0.003 (3)0.005 (3)0.010 (3)
C80.029 (4)0.028 (4)0.031 (4)0.005 (3)0.002 (3)0.003 (3)
C90.019 (3)0.023 (3)0.032 (4)0.002 (3)0.003 (3)0.004 (3)
C100.029 (4)0.028 (4)0.035 (4)0.001 (3)0.011 (3)0.002 (3)
C110.035 (4)0.029 (4)0.058 (5)0.000 (3)0.016 (4)0.000 (4)
C120.037 (4)0.027 (4)0.057 (5)0.007 (3)0.014 (4)0.016 (4)
C130.033 (4)0.041 (5)0.036 (4)0.003 (3)0.006 (3)0.014 (3)
C140.034 (4)0.038 (4)0.020 (3)0.000 (3)0.002 (3)0.001 (3)
O10.033 (3)0.029 (3)0.025 (2)0.001 (2)0.004 (2)0.002 (2)
O20.044 (3)0.023 (2)0.024 (2)0.005 (2)0.007 (2)0.0003 (18)
O30.038 (3)0.035 (3)0.023 (2)0.003 (2)0.005 (2)0.001 (2)
O40.033 (3)0.022 (2)0.029 (2)0.0020 (19)0.003 (2)0.0015 (19)
O1W0.025 (2)0.036 (3)0.035 (3)0.000 (2)0.000 (2)0.001 (2)
O2W0.023 (2)0.032 (3)0.032 (2)0.000 (2)0.0040 (19)0.000 (2)
Zn10.0266 (4)0.0229 (4)0.0223 (4)0.0022 (3)0.0015 (3)0.0017 (3)
Geometric parameters (Å, º) top
Br1—C51.880 (6)C9—O41.308 (7)
Br2—C31.899 (6)C9—C101.420 (9)
Br3—C121.896 (7)C10—C111.370 (10)
Br4—C101.904 (7)C11—C121.372 (10)
C1—C61.418 (9)C11—H110.93
C1—C21.431 (8)C12—C131.369 (11)
C1—C71.439 (9)C13—H130.93
C2—O21.292 (7)C14—O31.214 (8)
C2—C31.424 (8)C14—H140.93
C3—C41.383 (9)O1—Zn12.114 (4)
C4—C51.401 (10)O2—Zn12.040 (4)
C4—H40.93O3—Zn12.081 (4)
C5—C61.353 (9)O4—Zn12.052 (4)
C6—H60.93O1W—Zn12.105 (4)
C7—O11.223 (8)O1W—H1WB0.85
C7—H70.93O1W—H1WA0.85
C8—C131.394 (9)O2W—Zn12.121 (4)
C8—C91.426 (9)O2W—H2WA0.85
C8—C141.447 (9)O2W—H2WB0.85
C6—C1—C2120.9 (6)C13—C12—Br3119.8 (6)
C6—C1—C7116.2 (6)C11—C12—Br3120.0 (6)
C2—C1—C7122.9 (6)C12—C13—C8121.0 (7)
O2—C2—C3121.4 (5)C12—C13—H13119.5
O2—C2—C1124.2 (6)C8—C13—H13119.5
C3—C2—C1114.4 (6)O3—C14—C8128.8 (6)
C4—C3—C2123.7 (6)O3—C14—H14115.6
C4—C3—Br2118.4 (5)C8—C14—H14115.6
C2—C3—Br2117.9 (5)C7—O1—Zn1123.7 (4)
C3—C4—C5119.7 (6)C2—O2—Zn1126.3 (4)
C3—C4—H4120.2C14—O3—Zn1125.2 (4)
C5—C4—H4120.2C9—O4—Zn1126.6 (4)
C6—C5—C4119.4 (6)Zn1—O1W—H1WB120.1
C6—C5—Br1120.9 (5)Zn1—O1W—H1WA118.3
C4—C5—Br1119.7 (5)H1WB—O1W—H1WA106.3
C5—C6—C1121.9 (6)Zn1—O2W—H2WA135.8
C5—C6—H6119.1Zn1—O2W—H2WB115.8
C1—C6—H6119.1H2WA—O2W—H2WB106.3
O1—C7—C1128.6 (6)O2—Zn1—O496.64 (17)
O1—C7—H7115.7O2—Zn1—O3175.22 (18)
C1—C7—H7115.7O4—Zn1—O387.75 (18)
C13—C8—C9120.8 (6)O2—Zn1—O1W93.58 (19)
C13—C8—C14116.3 (6)O4—Zn1—O1W95.20 (18)
C9—C8—C14123.0 (6)O3—Zn1—O1W84.10 (18)
O4—C9—C10121.4 (6)O2—Zn1—O187.25 (17)
O4—C9—C8123.6 (6)O4—Zn1—O1175.34 (17)
C10—C9—C8115.0 (6)O3—Zn1—O188.45 (18)
C11—C10—C9123.1 (6)O1W—Zn1—O187.10 (17)
C11—C10—Br4118.9 (5)O2—Zn1—O2W95.20 (18)
C9—C10—Br4118.0 (5)O4—Zn1—O2W91.08 (17)
C10—C11—C12119.9 (7)O3—Zn1—O2W86.59 (18)
C10—C11—H11120.0O1W—Zn1—O2W168.55 (17)
C12—C11—H11120.0O1—Zn1—O2W85.99 (17)
C13—C12—C11120.1 (7)
Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
O1W—H1WB···O4i0.852.012.751 (6)144
O1W—H1WA···O2i0.852.313.065 (6)148
O2W—H2WA···O2ii0.852.242.773 (6)121
O2W—H2WB···O4ii0.852.172.932 (6)149
O1W—H1WA···Br2i0.852.893.596 (5)141
O2W—H2WA···Br2ii0.852.813.637 (5)166
O2W—H2WB···Br4ii0.852.843.509 (5)137
Symmetry codes: (i) x+1, y+1, z+1; (ii) x, y+1, z+1.

Experimental details

Crystal data
Chemical formula[Zn(C7H3Br2O2)2(H2O)2]
Mr659.23
Crystal system, space groupMonoclinic, P21/c
Temperature (K)293
a, b, c (Å)7.6486 (15), 28.095 (6), 8.6716 (17)
β (°) 101.25 (3)
V3)1827.6 (6)
Z4
Radiation typeMo Kα
µ (mm1)10.12
Crystal size (mm)0.40 × 0.16 × 0.14
Data collection
DiffractometerBruker SMART CCD area-detector
Absorption correctionMulti-scan
(SADABS; Sheldrick, 1996)
Tmin, Tmax0.107, 0.332
No. of measured, independent and
observed [I > 2σ(I)] reflections
12164, 4189, 2577
Rint0.066
(sin θ/λ)max1)0.651
Refinement
R[F2 > 2σ(F2)], wR(F2), S 0.041, 0.127, 1.03
No. of reflections4189
No. of parameters226
H-atom treatmentH-atom parameters constrained
Δρmax, Δρmin (e Å3)0.76, 0.77

Computer programs: SMART (Bruker, 2001), SAINT (Bruker, 2001), SAINT, SHELXS97 (Sheldrick, 1997), SHELXL97 (Sheldrick, 1997), ORTEPII (Johnson, 1976), SHELXTL.

Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
O1W—H1WB···O4i0.852.012.751 (6)144
O1W—H1WA···O2i0.852.313.065 (6)148
O2W—H2WA···O2ii0.852.242.773 (6)121
O2W—H2WB···O4ii0.852.172.932 (6)149
O1W—H1WA···Br2i0.852.893.596 (5)141
O2W—H2WA···Br2ii0.852.813.637 (5)166
O2W—H2WB···Br4ii0.852.843.509 (5)137
Symmetry codes: (i) x+1, y+1, z+1; (ii) x, y+1, z+1.
 

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