Santonic acid: catemeric hydrogen bonding in a γ,ε-diketo carboxylic acid
Brunskill, Andrew P. J.; Thompson, Hugh W.; Lalancette, Roger A.; Acta Crystallographica Section C 55 (1999) 566–568; doi:10.1107/S0108270198014231

data_2008344
_publ_section_title
;
 Santonic acid: catemeric hydrogen bonding in a \g,\e-diketo carboxylic
 acid
;
_journal_issue                   4
_journal_name_full               'Acta Crystallographica Section C'
_journal_page_first              566
_journal_page_last               568
_journal_paper_doi               10.1107/S0108270198014231
_journal_volume                  55
_journal_year                    1999
_chemical_formula_analytical     'C15 H20 O4'
_chemical_formula_moiety         'C15 H20 O4'
_chemical_formula_structural     'C15 H20 O4'
_chemical_formula_sum            'C15 H20 O4'
_chemical_formula_weight         264.31
_chemical_melting_point          446
_chemical_name_common
;
Santonic Acid
;
_chemical_name_systematic
;
(-)-octahydro-\a,3a,5-trimethyl-6,8-dioxo-1,4-methano-
1H-indene-1-acetic acid
;
_space_group_IT_number           19
_symmetry_cell_setting           orthorhombic
_symmetry_space_group_name_Hall  'P 2ac 2ab'
_symmetry_space_group_name_H-M   'P 21 21 21'
_audit_creation_method           SHELXTL\PC
_cell_angle_alpha                90.00
_cell_angle_beta                 90.00
_cell_angle_gamma                90.00
_cell_formula_units_Z            4
_cell_length_a                   7.7910(10)
_cell_length_b                   11.1980(10)
_cell_length_c                   16.986(2)
_cell_measurement_reflns_used    26
_cell_measurement_temperature    293(2)
_cell_measurement_theta_max      14.66
_cell_measurement_theta_min      10.06
_cell_volume                     1481.9(3)
_computing_cell_refinement       'XSCANS (Siemens,  1996)'
_computing_data_collection       'XSCANS (Fait, 1991)'
_computing_data_reduction        XSCANS
_computing_molecular_graphics    SHELXTL/PC
_computing_publication_material  SHELXTL/PC
_computing_structure_refinement  SHELXTL/PC
_computing_structure_solution    'SHELXTL/PC (Sheldrick, 1994)'
_diffrn_ambient_temperature      293(2)
_diffrn_measurement_device       'Siemens P4'
_diffrn_measurement_method       '2\q/\q scans'
_diffrn_radiation_monochromator  graphite
_diffrn_radiation_source         'normal-focus sealed tube'
_diffrn_radiation_type           MoK\a
_diffrn_radiation_wavelength     0.71073
_diffrn_reflns_av_R_equivalents  0.017
_diffrn_reflns_av_sigmaI/netI    0.040
_diffrn_reflns_limit_h_max       9
_diffrn_reflns_limit_h_min       -9
_diffrn_reflns_limit_k_max       13
_diffrn_reflns_limit_k_min       0
_diffrn_reflns_limit_l_max       20
_diffrn_reflns_limit_l_min       0
_diffrn_reflns_number            3373
_diffrn_reflns_theta_max         26.00
_diffrn_reflns_theta_min         2.18
_diffrn_standards_decay_%        'No decay. Variation < 1'
_diffrn_standards_interval_count 97
_diffrn_standards_number         3
_exptl_absorpt_coefficient_mu    0.085
_exptl_absorpt_correction_T_max  0.974
_exptl_absorpt_correction_T_min  0.951
_exptl_absorpt_correction_type   'Face-indexed numerical (Sheldrick, 1994)'
_exptl_crystal_colour            colorless
_exptl_crystal_density_diffrn    1.185
_exptl_crystal_density_meas      1.184(2)
_exptl_crystal_density_method    'flotation in p-xylene/CCl~4~'
_exptl_crystal_description       trapezoid
_exptl_crystal_F_000             568
_exptl_crystal_size_max          0.75
_exptl_crystal_size_mid          0.55
_exptl_crystal_size_min          0.40
_refine_diff_density_max         0.21
_refine_diff_density_min         -0.19
_refine_ls_abs_structure_details '(Flack, 1983)'
_refine_ls_abs_structure_Flack   '2(2), using 1220 Friedel pairs'
_refine_ls_extinction_coef       0.015(2)
_refine_ls_extinction_method     'SHELXTL/PC (Sheldrick, 1994)'
_refine_ls_goodness_of_fit_all   1.08
_refine_ls_goodness_of_fit_obs   1.12
_refine_ls_hydrogen_treatment    'For hydrogen treatment, see text'
_refine_ls_matrix_type           full
_refine_ls_number_parameters     179
_refine_ls_number_reflns         2907
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      1.08
_refine_ls_restrained_S_obs      1.12
_refine_ls_R_factor_all          0.077
_refine_ls_R_factor_obs          0.053
_refine_ls_shift/esd_max         0.001
_refine_ls_shift/esd_mean        0.000
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'w = 1/[\s^2^(Fo^2^)+(0.0519P)^2^+0.3413P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_all         0.135
_refine_ls_wR_factor_obs         0.120
_reflns_number_observed          2174
_reflns_number_total             2908
_reflns_observed_criterion       >2sigma(I)
_cod_data_source_file            fg1516.cif
_cod_data_source_block           I
_cod_depositor_comments
;
The following automatic conversions were performed:
'_symmetry_cell_setting' value 'Orthorhombic' changed to 'orthorhombic'
according to '/home/saulius/struct/CIF-dictionaries/cif_core.dic'
dictionary named 'cif_core.dic' version 2.4.1 from
2010-06-29.

'_geom_bond_publ_flag' value 'Y' changed to 'y' according to
'/home/saulius/struct/CIF-dictionaries/cif_core.dic' dictionary named
'cif_core.dic' version 2.4.1 from 2010-06-29 (4 times).

Automatic conversion script
Id: cif_fix_enum 1527 2010-12-29 10:47:43Z saulius 

The following automatic conversions were performed:

'_chemical_melting_point' value '446K' was changed to '446' - the
value should be numeric and without a unit designator.

Automatic conversion script
Id: cif_fix_values 1646 2011-03-28 12:23:43Z adriana 

The following automatic conversions were performed:

'_chemical_melting_point' value '446K' was changed to '446' - the
value should be numeric and without a unit
designator.

'_symmetry_cell_setting' value 'Orthorhombic' changed to
'orthorhombic' according to
/home/saulius/struct/CIF-dictionaries/cif_core.dic dictionary named
'cif_core.dic' version 2.4.1 from 2010-06-29.

'_geom_bond_publ_flag'
value 'Y' changed to 'y' according to
/home/saulius/struct/CIF-dictionaries/cif_core.dic dictionary named
'cif_core.dic' version 2.4.1 from 2010-06-29 (4
times).

'_geom_angle_publ_flag' value 'Y' changed to 'y' according
to /home/saulius/struct/CIF-dictionaries/cif_core.dic dictionary
named 'cif_core.dic' version 2.4.1 from 2010-06-29 (2 times).

Automatic conversion script
Id: cif_fix_values 1715 2011-07-08 13:25:40Z adriana 

The following automatic conversions were performed:

'_refine_ls_weighting_scheme' value 'calc w =
1/[\s^2^(Fo^2^)+(0.0519P)^2^+0.3413P] where P=(Fo^2^+2Fc^2^)/3' was
changed to 'calc'. New tag '_refine_ls_weighting_details' was
created. The value of the new tag was set to 'w =
1/[\s^2^(Fo^2^)+(0.0519P)^2^+0.3413P] where P=(Fo^2^+2Fc^2^)/3'.

Automatic conversion script
Id: cif_fix_values 3143 2015-03-26 13:38:13Z robertas 
;
_cod_original_sg_symbol_H-M      'P 2~1~ 2~1~ 2~1~'
_cod_database_code               2008344