© 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: mjscott@chem.ufl.edu 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