A stable enol in small ring systems: clear differentiation between penta- and tri-valency of phosphorus atoms.
Ionkin, Alex S; Marshall, William J; Fish, Brian M; Schiffhauer, Matthew F; McEwen, Charles N; Chemical communications (Cambridge, England)  (2008) 5432–5434; doi:10.1039/b809877h

data_7103467
_publ_section_title
;
 A stable enol in small ring systems: clear differentiation between
 penta- and tri-valency of phosphorus atoms.
;
_journal_issue                   42
_journal_name_full
'Chemical communications (Cambridge, England)'
_journal_page_first              5432
_journal_page_last               5434
_journal_paper_doi               10.1039/b809877h
_journal_year                    2008
_chemical_formula_sum            'C28 H56 O2 P2 Si2'
_chemical_formula_weight         542.85
_chemical_name_systematic
;
?
;
_space_group_IT_number           167
_symmetry_cell_setting           rhombohedral
_symmetry_space_group_name_Hall  '-R 3 2"c'
_symmetry_space_group_name_H-M   'R -3 c :H'
_atom_sites_solution_hydrogens   geom
_atom_sites_solution_primary     direct
_atom_sites_solution_secondary   difmap
_audit_creation_method           SHELXL-97
_cell_angle_alpha                90.00
_cell_angle_beta                 90.00
_cell_angle_gamma                120.00
_cell_formula_units_Z            18
_cell_length_a                   17.1720(18)
_cell_length_b                   17.1720(18)
_cell_length_c                   60.643(7)
_cell_measurement_temperature    293(2)
_cell_volume                     15486(3)
_computing_cell_refinement       'Bruker XSCANS'
_computing_data_collection       'Bruker XSCANS'
_computing_data_reduction        'Bruker SHELXTL'
_computing_molecular_graphics    'Bruker SHELXTL'
_computing_publication_material  'Bruker SHELXTL'
_computing_structure_refinement  'SHELXL-97 (Sheldrick, 1997)'
_computing_structure_solution    'SHELXS-97 (Sheldrick, 1990)'
_diffrn_ambient_temperature      293(2)
_diffrn_measured_fraction_theta_full 0.998
_diffrn_measured_fraction_theta_max 0.998
_diffrn_measurement_device_type  'Bruker P4'
_diffrn_measurement_method       '\w scans'
_diffrn_radiation_monochromator  graphite
_diffrn_radiation_source         'fine-focus sealed tube'
_diffrn_radiation_type           MoK\a
_diffrn_radiation_wavelength     0.71073
_diffrn_reflns_av_R_equivalents  0.0477
_diffrn_reflns_av_sigmaI/netI    0.0191
_diffrn_reflns_limit_h_max       21
_diffrn_reflns_limit_h_min       -22
_diffrn_reflns_limit_k_max       22
_diffrn_reflns_limit_k_min       -20
_diffrn_reflns_limit_l_max       78
_diffrn_reflns_limit_l_min       -77
_diffrn_reflns_number            55549
_diffrn_reflns_theta_full        27.25
_diffrn_reflns_theta_max         27.25
_diffrn_reflns_theta_min         1.53
_exptl_absorpt_coefficient_mu    0.216
_exptl_absorpt_correction_type   none
_exptl_crystal_colour            colourless
_exptl_crystal_density_diffrn    1.048
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       ireg.blok
_exptl_crystal_F_000             5364
_exptl_crystal_size_max          0.500
_exptl_crystal_size_mid          0.480
_exptl_crystal_size_min          0.480
_refine_diff_density_max         0.534
_refine_diff_density_min         -0.346
_refine_diff_density_rms         0.054
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.091
_refine_ls_hydrogen_treatment    riding
_refine_ls_matrix_type           full
_refine_ls_number_parameters     167
_refine_ls_number_reflns         3863
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      1.091
_refine_ls_R_factor_all          0.0624
_refine_ls_R_factor_gt           0.0480
_refine_ls_shift/su_max          0.001
_refine_ls_shift/su_mean         0.000
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'calc w=1/[\s^2^(Fo^2^)+(0.0656P)^2^+28.5907P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.1232
_refine_ls_wR_factor_ref         0.1418
_reflns_number_gt                3183
_reflns_number_total             3863
_reflns_threshold_expression     >2sigma(I)
_cod_data_source_file            b809877h.txt
_cod_data_source_block           06210
_cod_depositor_comments
;
The following automatic conversions were performed:
'_symmetry_cell_setting' value 'Rhombohedral' changed to 'rhombohedral'
according to '/home/saulius/struct/CIF-dictionaries/cif_core.dic'
dictionary named 'cif_core.dic' version 2.4.1 from 2010-06-29.

Automatic conversion script
Id: cif_fix_enum 1527 2010-12-29 10:47:43Z saulius 
;
_cod_original_sg_symbol_H-M      R-3c
_cod_database_code               7103467