2,4-Dibromo-6-(2-hydroxy­ethyl­iminiometh­yl)phenolate

The title Schiff base compound, C₉H₉Br₂NO₂, synthesized by the reaction of 3,5-dibromo-2-hydroxy­benzaldehyde and 2-amino­ethanol in ethanol solution, crystallizes in a zwitterionic form. The mol­ecule adopts a trans configuration about the central C=N bond. In the crystal structure, O—H...O inter­molecular hydrogen bonds link the mol­ecules into ribbons along the c axis.

Key indicators

• Single-crystal X-ray study
• T = 295 K
• Mean [sigma](C-C) = 0.005 Å
• R factor = 0.024
• wR factor = 0.055
• Data-to-parameter ratio = 16.2

checkCIF/PLATON results

No syntax errors found



Alert level C
PLAT062_ALERT_4_C Rescale T(min) & T(max) by .....................       0.82
PLAT094_ALERT_2_C Ratio of Maximum / Minimum Residual Density ....       2.14
PLAT431_ALERT_2_C Short Inter HL..A Contact  Br1    ..  Br1     ..       3.55 Ang.
PLAT431_ALERT_2_C Short Inter HL..A Contact  Br1    ..  Br1     ..       3.55 Ang.
PLAT731_ALERT_1_C Bond    Calc     0.90(3), Rep   0.897(10) ......       3.00 su-Ra
              N1   -H1      1.555   1.555
PLAT735_ALERT_1_C D-H     Calc     0.90(3), Rep   0.897(10) ......       3.00 su-Ra
              N1   -H1      1.555   1.555
PLAT737_ALERT_1_C D...A   Calc    2.867(5), Rep    2.867(2) ......       2.50 su-Ra
              O2   -O2      1.555   8.544

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      0.821
            Tmax scaled      0.334 Tmin scaled      0.091
REFLT03_ALERT_4_G Please check that the estimate of the number of Friedel pairs is
            correct. If it is not, please give the correct count in the
            _publ_section_exptl_refinement section of the submitted CIF.
           From the CIF: _diffrn_reflns_theta_max           26.49
           From the CIF: _reflns_number_total               2139
           Count of symmetry unique reflns         1202
           Completeness (_total/calc)            177.95%
           TEST3: Check Friedels for noncentro structure
           Estimate of Friedel pairs measured       937
           Fraction of Friedel pairs measured     0.780
           Are heavy atom types Z>Si present        yes

   0 ALERT level A = In general: serious problem
   0 ALERT level B = Potentially serious problem
   7 ALERT level C = Check and explain
   2 ALERT level G = General alerts; check

   3 ALERT type 1 CIF construction/syntax error, inconsistent or missing data
   3 ALERT type 2 Indicator that the structure model may be wrong or deficient
   1 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

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Computing details

Data collection: SMART (Bruker, 2002); cell refinement: SAINT-Plus (Bruker, 2002); data reduction: SAINT-Plus; program(s) used to solve structure: SHELXS97 (Sheldrick, 1997); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: SHELXTL (Bruker, 2002); software used to prepare material for publication: SHELXL97.

2,4-Dibromo-6-(2-hydroxyethyliminiomethyl)phenolate

Crystal data

C9H9Br2NO2	F(000) = 1248
Mr = 322.99	Dx = 2.079 Mg m^−3
Orthorhombic, Aba2	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: A 2 -2ac	Cell parameters from 5840 reflections
a = 18.7541 (9) Å	θ = 2.2–28.0°
b = 21.9752 (11) Å	µ = 7.83 mm^−1
c = 5.0082 (3) Å	T = 295 K
V = 2064.01 (19) Å^3	Prism, yellow
Z = 8	0.50 × 0.14 × 0.14 mm

Data collection

Bruker APEX area-detector diffractometer	2139 independent reflections
Radiation source: fine-focus sealed tube	2009 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.038
φ and ω scans	θmax = 26.5°, θmin = 1.9°
Absorption correction: multi-scan (SADABS; Sheldrick, 1996)	h = −23→23
Tmin = 0.111, Tmax = 0.407	k = −27→27
10642 measured reflections	l = −6→6

Refinement

Refinement on F^2	Hydrogen site location: inferred from neighbouring sites
Least-squares matrix: full	H atoms treated by a mixture of independent and constrained refinement
R[F^2 > 2σ(F^2)] = 0.024	w = 1/[σ^2(Fo^2) + (0.0326P)^2] where P = (Fo^2 + 2Fc^2)/3
wR(F^2) = 0.055	(Δ/σ)max = 0.001
S = 1.00	Δρmax = 0.92 e Å^−3
2139 reflections	Δρmin = −0.43 e Å^−3
132 parameters	Extinction correction: SHELXL97, Fc^*=kFc[1+0.001xFc^2λ^3/sin(2θ)]^-1/4
2 restraints	Extinction coefficient: 0.0081 (3)
Primary atom site location: structure-invariant direct methods	Absolute structure: Flack (1983), 936 Friedel pairs
Secondary atom site location: difference Fourier map	Absolute structure parameter: 0.027 (12)

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
Br1	−0.182769 (15)	0.613447 (14)	1.30996 (10)	0.03181 (11)
Br2	−0.149288 (18)	0.802597 (14)	0.56070 (10)	0.04049 (12)
O1	−0.04484 (12)	0.56934 (10)	1.0547 (6)	0.0357 (5)
O2	0.21279 (12)	0.58027 (10)	0.8007 (7)	0.0390 (5)
H2	0.2325	0.5910	0.6624	0.058*
N1	0.05429 (15)	0.56737 (14)	0.7025 (6)	0.0306 (6)
H1	0.0301 (17)	0.5503 (14)	0.838 (5)	0.037*
C1	−0.06596 (17)	0.62026 (15)	0.9490 (7)	0.0270 (7)
C2	−0.12788 (15)	0.65041 (14)	1.0364 (7)	0.0253 (6)
C3	−0.15150 (18)	0.70450 (14)	0.9295 (7)	0.0291 (7)
H3	−0.1924	0.7232	0.9955	0.035*
C4	−0.11343 (17)	0.73072 (14)	0.7222 (7)	0.0293 (7)
C5	−0.05276 (18)	0.70377 (14)	0.6237 (7)	0.0299 (8)
H5	−0.0276	0.7220	0.4850	0.036*
C6	−0.02896 (16)	0.64877 (14)	0.7331 (6)	0.0268 (7)
C7	0.03116 (17)	0.61829 (15)	0.6153 (7)	0.0316 (8)
H7	0.0540	0.6363	0.4705	0.038*
C8	0.11121 (16)	0.53393 (15)	0.5721 (9)	0.0367 (8)
H8A	0.1260	0.5557	0.4132	0.044*
H8B	0.0935	0.4944	0.5172	0.044*
C9	0.17480 (17)	0.52545 (15)	0.7544 (8)	0.0352 (10)
H9A	0.1585	0.5093	0.9241	0.042*
H9B	0.2068	0.4958	0.6757	0.042*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
Br1	0.02552 (16)	0.03797 (19)	0.03196 (16)	−0.00023 (13)	0.00313 (17)	0.00580 (16)
Br2	0.0421 (2)	0.02756 (19)	0.0518 (2)	0.00430 (14)	−0.0025 (2)	0.00851 (18)
O1	0.0333 (12)	0.0303 (12)	0.0435 (13)	0.0074 (10)	0.0049 (13)	0.0074 (13)
O2	0.0330 (11)	0.0374 (13)	0.0465 (13)	−0.0038 (10)	0.0026 (15)	−0.0093 (14)
N1	0.0230 (15)	0.0306 (16)	0.0381 (14)	0.0010 (12)	0.0036 (11)	−0.0017 (11)
C1	0.0204 (16)	0.0263 (17)	0.0343 (17)	0.0002 (13)	−0.0060 (13)	−0.0027 (13)
C2	0.0213 (13)	0.0270 (16)	0.0276 (15)	−0.0028 (11)	−0.0026 (14)	0.0022 (14)
C3	0.0257 (18)	0.0269 (18)	0.0347 (17)	0.0020 (14)	−0.0022 (14)	−0.0028 (14)
C4	0.0265 (16)	0.0229 (16)	0.0386 (18)	−0.0027 (14)	−0.0039 (13)	0.0014 (13)
C5	0.0236 (16)	0.0297 (18)	0.037 (2)	−0.0066 (13)	0.0012 (13)	0.0042 (13)
C6	0.0188 (15)	0.0280 (17)	0.0336 (19)	−0.0007 (14)	0.0012 (11)	−0.0012 (12)
C7	0.0221 (16)	0.0397 (19)	0.0328 (19)	−0.0036 (14)	0.0029 (13)	−0.0018 (13)
C8	0.0268 (16)	0.0360 (19)	0.0472 (19)	0.0040 (14)	0.0002 (18)	−0.0148 (19)
C9	0.0260 (16)	0.0318 (18)	0.048 (3)	0.0038 (15)	0.0043 (15)	−0.0035 (15)

Geometric parameters (Å, º)

Br1—C2	1.896 (3)	C3—H3	0.93
Br2—C4	1.898 (3)	C4—C5	1.374 (5)
O1—C1	1.300 (4)	C5—C6	1.400 (4)
O2—C9	1.419 (4)	C5—H5	0.93
O2—H2	0.82	C6—C7	1.438 (5)
N1—C7	1.277 (5)	C7—H7	0.93
N1—C8	1.451 (4)	C8—C9	1.514 (5)
N1—H1	0.897 (10)	C8—H8A	0.97
C1—C2	1.407 (4)	C8—H8B	0.97
C1—C6	1.429 (5)	C9—H9A	0.97
C2—C3	1.377 (4)	C9—H9B	0.97
C3—C4	1.386 (5)
C9—O2—H2	109.5	C5—C6—C1	121.3 (3)
C7—N1—C8	122.7 (3)	C5—C6—C7	119.4 (3)
C7—N1—H1	117 (2)	C1—C6—C7	119.1 (3)
C8—N1—H1	120 (2)	N1—C7—C6	122.3 (3)
O1—C1—C2	122.0 (3)	N1—C7—H7	118.9
O1—C1—C6	122.5 (3)	C6—C7—H7	118.9
C2—C1—C6	115.5 (3)	N1—C8—C9	111.7 (3)
C3—C2—C1	123.4 (3)	N1—C8—H8A	109.3
C3—C2—Br1	118.4 (2)	C9—C8—H8A	109.3
C1—C2—Br1	118.1 (2)	N1—C8—H8B	109.3
C2—C3—C4	119.0 (3)	C9—C8—H8B	109.3
C2—C3—H3	120.5	H8A—C8—H8B	107.9
C4—C3—H3	120.5	O2—C9—C8	112.9 (3)
C5—C4—C3	121.1 (3)	O2—C9—H9A	109.0
C5—C4—Br2	119.9 (3)	C8—C9—H9A	109.0
C3—C4—Br2	118.9 (2)	O2—C9—H9B	109.0
C4—C5—C6	119.7 (3)	C8—C9—H9B	109.0
C4—C5—H5	120.1	H9A—C9—H9B	107.8
C6—C5—H5	120.1
O1—C1—C2—C3	179.7 (3)	C4—C5—C6—C7	175.0 (3)
C6—C1—C2—C3	−1.6 (5)	O1—C1—C6—C5	−179.7 (3)
O1—C1—C2—Br1	−1.9 (4)	C2—C1—C6—C5	1.5 (4)
C6—C1—C2—Br1	176.9 (2)	O1—C1—C6—C7	4.3 (5)
C1—C2—C3—C4	1.0 (5)	C2—C1—C6—C7	−174.4 (3)
Br1—C2—C3—C4	−177.4 (2)	C8—N1—C7—C6	175.0 (3)
C2—C3—C4—C5	−0.3 (5)	C5—C6—C7—N1	−178.4 (3)
C2—C3—C4—Br2	176.2 (2)	C1—C6—C7—N1	−2.4 (5)
C3—C4—C5—C6	0.3 (5)	C7—N1—C8—C9	119.2 (4)
Br2—C4—C5—C6	−176.1 (2)	N1—C8—C9—O2	−71.0 (4)
C4—C5—C6—C1	−1.0 (5)

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
N1—H1···O1	0.90 (1)	1.83 (2)	2.563 (4)	138 (3)
O2—H2···O2^i	0.82	2.10	2.867 (2)	157

Symmetry code: (i) −x+1/2, y, z−1/2.