4-Bromo­thio­phene-2-carbox­aldehyde

The title compound, C₄H₃BrOS, (I), was recrystallized from ethanol at 273 K. The crystal structure of (I) has been determined at 100 K.

Key indicators

• Single-crystal X-ray study
• T = 100 K
• Mean [sigma](C-C) = 0.002 Å
• R factor = 0.019
• wR factor = 0.047
• Data-to-parameter ratio = 20.5

checkCIF/PLATON results

No syntax errors found



Alert level B
PLAT431_ALERT_2_B Short Inter HL..A Contact  Br1    ..  O1       =       3.02 Ang.

Alert level C
PLAT061_ALERT_3_C Tmax/Tmin Range Test RR' too Large .............       0.77

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

   0 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
   1 ALERT type 3 Indicator that the structure quality may be low
   0 ALERT type 4 Improvement, methodology, query or suggestion

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Computing details

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

4-bromothiophene-2-carboxaldehyde

Crystal data

C5H3BrOS	F(000) = 368
Mr = 191.04	Dx = 2.115 Mg m^−3
Monoclinic, P21/c	Melting point: 318 K
Hall symbol: -P 2ybc	Mo Kα radiation, λ = 0.71073 Å
a = 4.1169 (4) Å	Cell parameters from 5955 reflections
b = 8.4929 (8) Å	θ = 2.4–28.3°
c = 17.1626 (16) Å	µ = 7.08 mm^−1
β = 90.788 (2)°	T = 100 K
V = 600.02 (10) Å^3	Needle, colorless
Z = 4	0.26 × 0.26 × 0.26 mm

Data collection

Bruker SMART CCD area-detector diffractometer	1499 independent reflections
Radiation source: fine-focus sealed tube	1408 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.034
ω scans	θmax = 28.3°, θmin = 2.4°
Absorption correction: multi-scan (Blessing, 1995)	h = −5→5
Tmin = 0.141, Tmax = 0.159	k = −11→11
5955 measured reflections	l = −22→22

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)] = 0.019	Hydrogen site location: inferred from neighbouring sites
wR(F^2) = 0.047	H-atom parameters constrained
S = 1.05	w = 1/[σ^2(Fo^2) + (0.0039P)^2 + 0.449P] where P = (Fo^2 + 2Fc^2)/3
1499 reflections	(Δ/σ)max = 0.004
73 parameters	Δρmax = 0.50 e Å^−3
0 restraints	Δρmin = −0.32 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
Br1	0.56152 (4)	0.61751 (2)	0.386801 (10)	0.01665 (7)
C5	0.7032 (4)	0.3447 (2)	0.29427 (10)	0.0158 (3)
H5A	0.5908	0.3882	0.2506	0.019*
C4	0.7335 (4)	0.4173 (2)	0.36537 (10)	0.0143 (3)
C3	0.9122 (4)	0.3287 (2)	0.42095 (10)	0.0153 (3)
H3A	0.9551	0.3617	0.4730	0.018*
C2	1.0159 (4)	0.1885 (2)	0.39000 (10)	0.0147 (3)
S1	0.89385 (11)	0.16559 (5)	0.29431 (2)	0.01622 (10)
O1	1.3051 (3)	−0.05117 (17)	0.40139 (8)	0.0245 (3)
C1	1.2162 (4)	0.0717 (2)	0.43016 (11)	0.0182 (4)
H1A	1.2817	0.0932	0.4824	0.022*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
Br1	0.01927 (10)	0.01518 (11)	0.01542 (11)	0.00351 (6)	−0.00299 (7)	−0.00154 (6)
C5	0.0173 (8)	0.0155 (8)	0.0146 (8)	0.0009 (6)	−0.0031 (6)	0.0004 (7)
C4	0.0136 (7)	0.0134 (7)	0.0160 (8)	0.0001 (6)	−0.0003 (6)	−0.0001 (6)
C3	0.0161 (8)	0.0170 (8)	0.0126 (8)	−0.0014 (6)	−0.0016 (6)	0.0004 (6)
C2	0.0146 (8)	0.0162 (8)	0.0134 (8)	−0.0012 (6)	−0.0014 (6)	0.0003 (6)
S1	0.0191 (2)	0.0160 (2)	0.0135 (2)	0.00151 (16)	−0.00205 (16)	−0.00237 (16)
O1	0.0281 (7)	0.0200 (7)	0.0254 (7)	0.0068 (6)	−0.0027 (6)	−0.0005 (6)
C1	0.0179 (8)	0.0192 (8)	0.0173 (9)	0.0004 (7)	−0.0025 (7)	0.0023 (7)

Geometric parameters (Å, º)

Br1—C4	1.8804 (18)	C3—H3A	0.9500
C5—C4	1.371 (2)	C2—C1	1.457 (2)
C5—S1	1.7118 (19)	C2—S1	1.7218 (17)
C5—H5A	0.9500	O1—C1	1.213 (2)
C4—C3	1.414 (2)	C1—H1A	0.9500
C3—C2	1.374 (2)
C4—C5—S1	111.27 (14)	C4—C3—H3A	124.4
C4—C5—H5A	124.4	C3—C2—C1	125.71 (16)
S1—C5—H5A	124.4	C3—C2—S1	112.23 (13)
C5—C4—C3	113.67 (16)	C1—C2—S1	122.03 (14)
C5—C4—Br1	123.40 (14)	C5—S1—C2	91.61 (9)
C3—C4—Br1	122.92 (13)	O1—C1—C2	124.39 (18)
C2—C3—C4	111.23 (16)	O1—C1—H1A	117.8
C2—C3—H3A	124.4	C2—C1—H1A	117.8