Bis{4-bromo-2-[(2-hy­droxy­eth­yl)imino­meth­yl]phenolato-κ³O,N,O′}cadmium

The centrosymmetric title compound, [Cd(C₉H₉BrNO₂)₂], was obtained by the reaction of 5-bromo­salicyl­aldehyde, 2-amino­ethanol and cadmium nitrate in ethanol. The Cd atom, located on an inversion centre, is hexa­coordinated by two Schiff base ligands in an octa­hedral coordination through the phenolate O atom, the imine N atom and the hy­droxy O atoms. In the crystal, mol­ecules are linked through inter­molecular O—H...O hydrogen bonds, forming chains along the b axis.

Key indicators

• Single-crystal X-ray study
• T = 298 K
• Mean [sigma](C-C) = 0.011 Å
• R factor = 0.055
• wR factor = 0.126
• Data-to-parameter ratio = 17.2

checkCIF/PLATON results

No syntax errors found



Alert level C
PLAT234_ALERT_4_C Large Hirshfeld Difference C8     --  C9      ..       0.22 Ang.
PLAT241_ALERT_2_C Check High      Ueq as Compared to Neighbors for         C8
PLAT241_ALERT_2_C Check High      Ueq as Compared to Neighbors for         C9
PLAT242_ALERT_2_C Check Low       Ueq as Compared to Neighbors for        Cd1
PLAT242_ALERT_2_C Check Low       Ueq as Compared to Neighbors for         C5
PLAT250_ALERT_2_C Large U3/U1 Ratio for Average U(i,j) Tensor ....        2.8
PLAT342_ALERT_3_C Low Bond Precision on  C-C Bonds ...............     0.0112 Ang
PLAT360_ALERT_2_C Short  C(sp3)-C(sp3) Bond  C8     -   C9     ...       1.36 Ang.
PLAT911_ALERT_3_C Missing # FCF Refl Between THmin & STh/L=  0.600          9
PLAT912_ALERT_4_C Missing # of FCF Reflections Above STh/L=  0.600          8

Alert level G
PLAT002_ALERT_2_G Number of Distance or Angle Restraints on AtSite          2
PLAT005_ALERT_5_G No _iucr_refine_instructions_details in CIF ....          ?
PLAT083_ALERT_2_G SHELXL Second Parameter in WGHT Unusually Large.       5.85
PLAT128_ALERT_4_G Alternate Setting of Space-group P2/c    .......      P2/n
PLAT860_ALERT_3_G Note: Number of Least-Squares Restraints .......          1

   0 ALERT level A = Most likely a serious problem - resolve or explain
   0 ALERT level B = A potentially serious problem, consider carefully
  10 ALERT level C = Check. Ensure it is not caused by an omission or oversight
   5 ALERT level G = General information/check it is not something unexpected

   0 ALERT type 1 CIF construction/syntax error, inconsistent or missing data
   8 ALERT type 2 Indicator that the structure model may be wrong or deficient
   3 ALERT type 3 Indicator that the structure quality may be low
   3 ALERT type 4 Improvement, methodology, query or suggestion
   1 ALERT type 5 Informative message, check

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S1. Comment

Schiff base cadmium(II) complexes have been received much attention due to their interesting structures and luminescent properties (Sarkar et al., 2011; Das et al., 2010; Fang & Nie, 2010; Niu et al., 2010; Keypour et al., 2009).

The molecule of the title complex, (I) (Fig. 1), is centrosymmetric, with the inversion center located at the Cd atom. The Cd atom is hexa-coordinated by two Schiff base ligands, forming an octahedral coordination. The Schiff base coordinates to the Co atom through the phenolate O atom, the imine N atom, and the hydroxy O atom. The bond lengths are within normal values. In the crystal, molecules are linked through intermolecular O—H···O hydrogen bonds (Table 1), to form chains along the b axis, Fig. 2.

Related literature

For the structures and properties of Schiff base–cadmium(II) complexes, see: Sarkar et al. (2011); Das et al. (2010); Fang & Nie (2010); Niu et al. (2010); Keypour et al. (2009).

S2. Experimental

To a solution of 5-bromosalicylaldehyde (0.181 g, 1.0 mmol), 2-aminoethanol (0.061 g, 1.0 mmol) in 20 ml absolute ethanol was added slowly a solution of cadmium nitrate (0.154 g, 0.5 mmol) in ethanol. The mixture was stirred for 2 h at room temperature to give a colorless solution, which was filtered and the filtrate was left to stand at room temperature. Colorless block crystals suitable for X-ray diffraction were obtained by slow evaporation.

S3. Refinement

H2 atom bonded to O2 atom was located in a difference map and refined with distance restraint of O—H = 0.85 (1) Å. Other H atoms were positioned geometrically and refined using a riding model, with C—H = 0.93–0.97 Å.

Computing details

Data collection: SMART (Bruker, 2001); cell refinement: SAINT (Bruker, 2001); data reduction: SAINT (Bruker, 2001); program(s) used to solve structure: SHELXTL (Sheldrick, 2008); program(s) used to refine structure: SHELXTL (Sheldrick, 2008); molecular graphics: SHELXTL (Sheldrick, 2008); software used to prepare material for publication: SHELXTL (Sheldrick, 2008) and local programs.

Figures

	Fig. 1. The molecular structure of (I), with atom labels and 30% probability displacement ellipsoids for non-H atoms. Unlabelled atoms are at the symmetry position 1/2 - x, y, 1/2 - z.
	Fig. 2. The packing of (I), viewed down the c axis. Hydrogen bonds are drawn as dashed lines. H atoms not involved in hydrogen bonding have been omitted.

Bis{4-bromo-2-[(2-hydroxyethyl)iminomethyl]phenolato- κ³O,N,O'}cadmium

Crystal data

[Cd(C9H9BrNO2)2]	F(000) = 580
Mr = 598.56	Dx = 1.985 Mg m^−3
Monoclinic, P2/n	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2yac	Cell parameters from 1609 reflections
a = 10.207 (4) Å	θ = 2.5–24.4°
b = 5.3275 (19) Å	µ = 5.11 mm^−1
c = 18.656 (7) Å	T = 298 K
β = 99.156 (4)°	Block, colorless
V = 1001.5 (6) Å^3	0.23 × 0.20 × 0.20 mm
Z = 2

Data collection

Bruker SMART 1K CCD area-detector diffractometer	2172 independent reflections
Radiation source: fine-focus sealed tube	1524 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.039
ω scans	θmax = 27.0°, θmin = 2.1°
Absorption correction: multi-scan (SADABS; Sheldrick, 2004)	h = −13→12
Tmin = 0.386, Tmax = 0.428	k = −6→6
7794 measured reflections	l = −23→23

Refinement

Refinement on F^2	Primary atom site location: structure-invariant direct methods
Least-squares matrix: full	Secondary atom site location: difference Fourier map
R[F^2 > 2σ(F^2)] = 0.055	Hydrogen site location: inferred from neighbouring sites
wR(F^2) = 0.126	H atoms treated by a mixture of independent and constrained refinement
S = 1.02	w = 1/[σ^2(Fo^2) + (0.034P)^2 + 5.8476P] where P = (Fo^2 + 2Fc^2)/3
2172 reflections	(Δ/σ)max < 0.001
126 parameters	Δρmax = 1.41 e Å^−3
1 restraint	Δρmin = −1.55 e Å^−3

Special details

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 (Ų)

	x	y	z	Uiso*/Ueq
Cd1	0.2500	0.38621 (12)	0.2500	0.0491 (2)
Br1	0.21431 (12)	0.4350 (3)	0.64964 (5)	0.1157 (5)
N1	0.4104 (7)	0.2594 (14)	0.3415 (3)	0.0705 (19)
O1	0.2194 (5)	0.6681 (8)	0.3344 (2)	0.0577 (13)
O2	0.3921 (6)	0.0979 (9)	0.2021 (3)	0.0676 (14)
C1	0.3083 (7)	0.4314 (13)	0.4410 (3)	0.0529 (17)
C2	0.2245 (7)	0.6144 (12)	0.4037 (3)	0.0476 (15)
C3	0.1433 (9)	0.7475 (15)	0.4453 (4)	0.073 (2)
H3	0.0893	0.8751	0.4231	0.087*
C4	0.1407 (9)	0.6964 (18)	0.5174 (4)	0.081 (3)
H4	0.0842	0.7849	0.5428	0.097*
C5	0.2219 (9)	0.5144 (17)	0.5511 (4)	0.069 (2)
C6	0.3057 (8)	0.3868 (16)	0.5151 (4)	0.067 (2)
H6	0.3625	0.2677	0.5397	0.080*
C7	0.4004 (8)	0.2792 (17)	0.4087 (4)	0.073 (2)
H7	0.4597	0.1840	0.4407	0.088*
C8	0.5021 (11)	0.066 (2)	0.3211 (5)	0.112 (4)
H8A	0.5895	0.0913	0.3493	0.134*
H8B	0.4712	−0.0987	0.3329	0.134*
C9	0.5113 (10)	0.075 (2)	0.2490 (6)	0.113 (4)
H9A	0.5551	−0.0772	0.2366	0.136*
H9B	0.5676	0.2151	0.2409	0.136*
H2	0.358 (8)	−0.047 (7)	0.194 (5)	0.080*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
Cd1	0.0826 (6)	0.0363 (3)	0.0287 (3)	0.000	0.0101 (3)	0.000
Br1	0.1431 (11)	0.1725 (13)	0.0387 (5)	0.0486 (9)	0.0363 (6)	0.0257 (6)
N1	0.082 (5)	0.092 (5)	0.038 (3)	0.029 (4)	0.011 (3)	−0.004 (3)
O1	0.107 (4)	0.038 (2)	0.030 (2)	0.007 (2)	0.018 (2)	0.0017 (18)
O2	0.084 (4)	0.056 (3)	0.064 (3)	−0.005 (3)	0.016 (3)	−0.026 (3)
C1	0.067 (5)	0.060 (4)	0.032 (3)	0.008 (3)	0.008 (3)	0.000 (3)
C2	0.074 (5)	0.037 (3)	0.033 (3)	−0.004 (3)	0.013 (3)	−0.002 (3)
C3	0.114 (7)	0.062 (5)	0.044 (4)	0.024 (5)	0.021 (4)	0.003 (4)
C4	0.111 (7)	0.095 (6)	0.042 (4)	0.033 (6)	0.030 (4)	0.000 (4)
C5	0.089 (6)	0.086 (5)	0.032 (4)	0.017 (5)	0.014 (4)	0.004 (4)
C6	0.083 (6)	0.081 (5)	0.036 (4)	0.021 (5)	0.006 (4)	0.004 (4)
C7	0.088 (6)	0.095 (6)	0.037 (4)	0.035 (5)	0.011 (4)	0.007 (4)
C8	0.112 (8)	0.166 (11)	0.059 (5)	0.078 (8)	0.020 (5)	0.005 (6)
C9	0.084 (7)	0.157 (11)	0.094 (7)	0.031 (7)	0.002 (6)	−0.069 (7)

Geometric parameters (Å, º)

Cd1—O1	2.233 (4)	C1—C7	1.443 (10)
Cd1—O1^i	2.233 (4)	C2—C3	1.413 (10)
Cd1—N1	2.272 (6)	C3—C4	1.376 (10)
Cd1—N1^i	2.272 (6)	C3—H3	0.9300
Cd1—O2^i	2.382 (5)	C4—C5	1.363 (11)
Cd1—O2	2.382 (5)	C4—H4	0.9300
Br1—C5	1.900 (7)	C5—C6	1.352 (11)
N1—C7	1.278 (8)	C6—H6	0.9300
N1—C8	1.482 (10)	C7—H7	0.9300
O1—C2	1.318 (7)	C8—C9	1.364 (13)
O2—C9	1.387 (11)	C8—H8A	0.9700
O2—H2	0.850 (10)	C8—H8B	0.9700
C1—C2	1.405 (9)	C9—H9A	0.9700
C1—C6	1.407 (9)	C9—H9B	0.9700
O1—Cd1—O1^i	95.5 (2)	C4—C3—C2	122.8 (7)
O1—Cd1—N1	80.5 (2)	C4—C3—H3	118.6
O1^i—Cd1—N1	124.4 (2)	C2—C3—H3	118.6
O1—Cd1—N1^i	124.4 (2)	C5—C4—C3	119.1 (7)
O1^i—Cd1—N1^i	80.5 (2)	C5—C4—H4	120.4
N1—Cd1—N1^i	145.4 (4)	C3—C4—H4	120.4
O1—Cd1—O2^i	90.41 (19)	C6—C5—C4	121.0 (7)
O1^i—Cd1—O2^i	149.32 (19)	C6—C5—Br1	119.7 (6)
N1—Cd1—O2^i	86.3 (2)	C4—C5—Br1	119.3 (6)
N1^i—Cd1—O2^i	71.4 (2)	C5—C6—C1	121.1 (7)
O1—Cd1—O2	149.32 (19)	C5—C6—H6	119.5
O1^i—Cd1—O2	90.41 (19)	C1—C6—H6	119.5
N1—Cd1—O2	71.4 (2)	N1—C7—C1	127.9 (7)
N1^i—Cd1—O2	86.3 (2)	N1—C7—H7	116.1
O2^i—Cd1—O2	99.7 (3)	C1—C7—H7	116.1
C7—N1—C8	117.5 (7)	C9—C8—N1	112.1 (8)
C7—N1—Cd1	123.5 (5)	C9—C8—H8A	109.2
C8—N1—Cd1	115.0 (5)	N1—C8—H8A	109.2
C2—O1—Cd1	123.9 (4)	C9—C8—H8B	109.2
C9—O2—Cd1	110.2 (5)	N1—C8—H8B	109.2
C9—O2—H2	109 (6)	H8A—C8—H8B	107.9
Cd1—O2—H2	113 (6)	C8—C9—O2	115.7 (9)
C2—C1—C6	119.8 (6)	C8—C9—H9A	108.3
C2—C1—C7	124.7 (6)	O2—C9—H9A	108.3
C6—C1—C7	115.5 (6)	C8—C9—H9B	108.3
O1—C2—C1	124.2 (6)	O2—C9—H9B	108.3
O1—C2—C3	119.7 (6)	H9A—C9—H9B	107.4
C1—C2—C3	116.2 (6)

Symmetry code: (i) −x+1/2, y, −z+1/2.

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
O2—H2···O1^ii	0.85 (1)	1.75 (2)	2.599 (7)	173 (9)

Symmetry code: (ii) −x+1/2, y−1, −z+1/2.