X-ray crystallography - Royal Society of Chemistry

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© The Royal Society of Chemistry 2000
Supplementary data
Hydroxy-substituted triarylcarbenium bromides. Synthesis, structure, derivatization and
facile conversion to highly substituted xanthenes.
Maarten B. Dinger and Michael J. Scott*
Department of Chemistry, University of Florida, P.O. Box 117200 Gainesville, FL 32611-7200.
Fax: 352-392-3255; E-mail: [email protected]
1
© The Royal Society of Chemistry 2000
X-ray crystallography
Unit cell dimensions and intensity data for all the structures were obtained on a Siemens
CCD SMART diffractometer at –100ºC, with monochromatic Mo-K X-rays ( = 0.71073 Å).
The data collections nominally covered over a hemisphere of reciprocal space, by a combination
of three sets of exposures; each set had a different  angle for the crystal and each exposure
covered 0.3 in . The crystal to detector distance was 5.0 cm. The data sets were corrected
empirically for absorption using SADABS (R. H. Blessing, Acta Cryst., Sect. A , 1995, 51, 33).
All the structures were solved using the Bruker SHELXTL software package for the PC, using
the direct methods option of SHELXS. The space groups for all of the structures were
determined from an examination of the systematic absences in the data, and the successful
solution and refinement of the structures confirmed these assignments. Except for the hydrogen
atoms involved in hydrogen-bonding interactions, all hydrogen atoms were assigned idealized
locations and were given a thermal parameter equivalent to 1.2 or 1.5 times the thermal
parameter of the carbon atom to which it was attached. For the methyl groups, where the location
of the hydrogen atoms was uncertain, the AFIX 137 card was used to allow the hydrogen atoms
to rotate to the maximum area of residual density, while fixing their geometry.
41
7
33
6
32
5
O1
40
8
39
42
38
4
31
34
3
9
26
24
2
10
30
29
7
6
5
O1
30
8
25
12
1
11
29
28
31
43
3
9
32
30
2
10
13
33
31
23
14
21
15
17
22
20
15
1
19
16
O3
29
17
24
18
15
20
14
24
34
12
21
23
1
14
2
22
25
23
11
19
27
22
O1
12
3
10
4
6
9
5
21
26
1a, 2a, 4a and 8a
32
33
11
O2
28
16
18
O2
25
19
13
34
O2
16
17
12
35
O3
28
26
4
37
36
27
27
18
20
7b lithium salt
Complete numbering scheme for X-ray structures.
2
7
8
3a and 5a
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