Structure determination of taurine with the Bruker SMART X2S benchtop crystallographic system
A crystal of taurine
with the dimensions of 0.40 mm x 0.40 mm x 0.60 mm mounted on a
Mitegen Micromount was automatically centered on a Bruker SMART X2S benchtop
crystallographic system. Intensity measurements were performed using a
monochromated (Doubly Curved Silicon Crystal) Mo-Kα-radiation
(0.71073 Å) from a sealed MicroFocus tube. Generator settings were 50 kV, 1 mA.
Data collection temperature was 23°C.
Data were acquired using three sets of Omega
scans at different Phi settings. The frame width was 0.5°.
The detailed data collection strategy was as follows:
Detector distance: 40 mm
Detector swing angle (fixed 2 Theta): -20°.
|
Run |
Omega (start) |
Omega (end) |
Phi |
Frames |
|
1 |
-20.0 |
-200.0 |
0.0 |
360 |
|
2 |
-20.0 |
-140.0 |
120.0 |
240 |
|
3 |
-20.0 |
-80.0 |
240.0 |
120 |
APEX2 software was used for preliminary determination of the unit cell. Determination
of integral intensities and unit cell refinement were performed using SAINT.
The integration of the data yielded a total of 4600
reflections to a maximum θ angle of 25.01° (0.84 Å resolution).
The constants for the monoclinic unit cell are a = 5.2939(5) Å, b = 11.6458(15) Å,
c = 7.9361(11) Å, β = 94.099(4)°,
V = 488.02(11) Å3.
Data were corrected for absorption
effects with SADABS using the multiscan technique. The ratio of minimum to
maximum apparent transmission is 89.6:100. The
average residual for symmetry equivalent reflections is Rint = 4.35% and Rσ = 2.71%.
XPREP determined the space group to be P
1 21/c 1, with Z = 4 for the formula unit, C2H7NO3S.
The structure was solved with XS and
subsequent structure refinements were performed with XL. The final anisotropic
full-matrix least-squares refinement on Fo2 with 65 variables converged at R1 = 2.81% for the observed data and wR2 = 7.23% for all data. The goodness-of-fit was 1.091. The largest peak on the final difference electron
density synthesis was 0.38 e-/Å3
and the deepest hole was -0.33 e-/Å3
with an RMS deviation of 0.05 e-/Å3.
On the basis of the final model, the calculated density is 1.703
g/cm3 and F(000) = 264.
APEX2 Version 2.2 (Bruker AXS
Inc., 2007)
SAINT Version 7.34a (Bruker AXS Inc., 2007)
SADABS Version 2007/2 (Sheldrick, Bruker AXS Inc.)
XPREP Version 2005/2 (Sheldrick, Bruker AXS Inc.)
XS Version 2008/1 (George M. Sheldrick, Acta Cryst. (2008). A64,
112-122)
XL Version 2008/1 (George M. Sheldrick, Acta Cryst. (2008). A64, 112-122)
|
|
|
|
Table 1. Crystal data and structure refinement for taurine. |
|
Identification
code |
taurine |
|
|
Empirical
formula |
C2 H7 N O3 S |
|
|
Formula weight |
125.15 |
|
|
Temperature |
296(2) K |
|
|
Wavelength |
0.71073 Å |
|
|
Crystal system |
Monoclinic |
|
|
Space group |
P 1 21/c 1 |
|
|
Unit cell
dimensions |
a = 5.2939(5) Å |
α = 90° |
|
|
b = 11.6458(15) Å |
β = 94.099(4)° |
|
|
c = 7.9361(11) Å |
γ = 90° |
|
Volume |
488.02(11) Å3 |
|
|
Z |
4 |
|
|
Density
(calculated) |
1.703 Mg/cm3 |
|
|
Absorption
coefficient |
0.554 mm-1 |
|
|
F(000) |
264 |
|
|
Crystal size |
0.40 x 0.40 x 0.60 mm3 |
|
|
Index ranges |
-6<=h<=6, -13<=k<=13, -9<=l<=9 |
|
|
Reflections
collected |
4600 |
|
|
Independent
reflections |
859 [R(int) = 0.0435] |
|
|
Absorption
correction |
Multiscan |
|
|
Max. and min.
transmission |
0.8087 and 0.7320 |
|
|
Refinement
method |
Full-matrix least-squares on F2 |
|
|
Data /
restraints / parameters |
859 / 0 / 65 |
|
|
Goodness-of-fit
on F2 |
1.091 |
|
|
Final R indices
[I>2sigma(I)] |
R1 = 0.0281, wR2 = 0.0712 |
|
|
R indices (all
data) |
R1 = 0.0303, wR2 = 0.0723 |
|
|
Largest diff.
peak and hole |
0.383 and -0.326 |
|
Rint = Σ|Fo2 - Fo2(mean)|
/ Σ[Fo2]
R1 = Σ||Fo| - |Fc|| / Σ|Fo|
GOOF = S = {Σ[w(Fo2 - Fc2)2]
/ (n - p)}1/2
wR2 = {Σ[w(Fo2 - Fc2)2]
/ Σ[w(Fo2)2]}1/2
w = 1 / [σ(Fo2) + (aP)2 +
bP] where P is [2Fc2 + Max(Fo2,
0)] / 3
|
Table 2. Atomic coordinates (x104) and equivalent isotropic displacement parameters (Å2x103) for taurine. |
|
U(eq) is defined as one third of the trace of the orthogonalized Uij tensor. |
|
|
|
|
x |
y |
z |
U(eq) |
|
S1 |
7966(1) |
8486(1) |
1490(1) |
24(1) |
|
O1 |
6581(3) |
7416(1) |
1459(2) |
39(1) |
|
O3 |
10633(3) |
8371(1) |
2070(2) |
38(1) |
|
O2 |
7679(3) |
9105(1) |
-110(2) |
31(1) |
|
N1 |
7364(3) |
11289(1) |
1687(2) |
26(1) |
|
C1 |
7895(4) |
10546(2) |
3184(3) |
29(1) |
|
C2 |
6609(4) |
9386(2) |
2995(3) |
27(1) |
|
Table 3. Bond lengths (Å) and angles (°) for taurine. |
|
S1-O1 |
1.4458(14) |
|
S1-O2 |
1.4584(14) |
|
S1-O3 |
1.4597(15) |
|
S1-C2 |
1.779(2) |
|
N1-C1 |
1.480(2) |
|
C1-C2 |
1.516(3) |
|
|
|
|
O1-S1-O2 |
112.96(9) |
|
O1-S1-O3 |
113.80(9) |
|
O2-S1-O3 |
110.99(9) |
|
O1-S1-C2 |
106.92(9) |
|
O2-S1-C2 |
105.79(9) |
|
O3-S1-C2 |
105.70(9) |
|
N1-C1-C2 |
112.53(16) |
|
C1-C2-S1 |
113.05(14) |
|
Table 4. Anisotropic displacement parameters (Å2x103) for taurine. |
|
The anisotropic displacement factor exponent takes the form: -2π2[ h2 a*2 U11 + ... + 2 h k a* b* U12 ] |
|
|
U11 |
U22 |
U33 |
U23 |
U13 |
U12 |
|
S1 |
21(1) |
15(1) |
35(1) |
1(1) |
3(1) |
-1(1) |
|
O1 |
42(1) |
22(1) |
53(1) |
-5(1) |
11(1) |
-13(1) |
|
O3 |
23(1) |
28(1) |
62(1) |
4(1) |
-3(1) |
5(1) |
|
O2 |
33(1) |
27(1) |
33(1) |
1(1) |
5(1) |
0(1) |
|
N1 |
26(1) |
19(1) |
34(1) |
-2(1) |
4(1) |
-2(1) |
|
C1 |
31(1) |
23(1) |
32(1) |
-4(1) |
-3(1) |
2(1) |
|
C2 |
27(1) |
24(1) |
29(1) |
2(1) |
4(1) |
0(1) |
|
Table 5. Hydrogen coordinates (x104) and isotropic displacement parameters (Å2x103) for taurine. |
|
|
x |
y |
z |
U(eq) |
|
H1A |
8162 |
11013 |
824 |
40 |
|
H1B |
7908 |
11998 |
1923 |
40 |
|
H1C |
5705 |
11302 |
1414 |
40 |
|
H1D |
7323 |
10930 |
4172 |
35 |
|
H1E |
9710 |
10433 |
3365 |
35 |
|
H2A |
4830 |
9501 |
2656 |
32 |
|
H2B |
6718 |
9002 |
4083 |
32 |