New polymorphs of curcumin
Palash Sanphui; N. Rajesh Goud; U. B. Rao Khandavilli; Sreenu Bhanoth; Ashwini Nangia; Chem.Commun. 47 (2011) 5013–; doi:10.1039/c1cc10204d

data_7106288
_publ_section_title
;
 New polymorphs of curcumin
;
_journal_name_full               Chem.Commun.
_journal_page_first              5013
_journal_paper_doi               10.1039/c1cc10204d
_journal_volume                  47
_journal_year                    2011
_chemical_formula_sum            'C21 H20 O6'
_chemical_formula_weight         368.37
_chemical_name_systematic
;
?
;
_space_group_IT_number           61
_symmetry_cell_setting           orthorhombic
_symmetry_space_group_name_Hall  '-P 2ac 2ab'
_symmetry_space_group_name_H-M   'P b c a'
_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                90.00
_cell_formula_units_Z            8
_cell_length_a                   12.536(3)
_cell_length_b                   7.9916(17)
_cell_length_c                   34.462(7)
_cell_measurement_reflns_used    869
_cell_measurement_temperature    100(2)
_cell_measurement_theta_max      26.3135
_cell_measurement_theta_min      2.8033
_cell_volume                     3452.5(13)
_computing_structure_refinement  'SHELXL-97 (Sheldrick, 1997)'
_computing_structure_solution    'SHELXS-97 (Sheldrick, 1990)'
_diffrn_ambient_temperature      100(2)
_diffrn_measured_fraction_theta_full 0.999
_diffrn_measured_fraction_theta_max 0.999
_diffrn_measurement_device_type  'Xcalibur, Eos, Gemini'
_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  0.1808
_diffrn_reflns_av_sigmaI/netI    0.2958
_diffrn_reflns_limit_h_max       9
_diffrn_reflns_limit_h_min       -15
_diffrn_reflns_limit_k_max       9
_diffrn_reflns_limit_k_min       -6
_diffrn_reflns_limit_l_max       43
_diffrn_reflns_limit_l_min       -40
_diffrn_reflns_number            8888
_diffrn_reflns_theta_full        26.36
_diffrn_reflns_theta_max         26.36
_diffrn_reflns_theta_min         2.87
_exptl_absorpt_coefficient_mu    0.104
_exptl_absorpt_correction_T_max  0.9897
_exptl_absorpt_correction_T_min  0.9795
_exptl_absorpt_correction_type   multi-scan
_exptl_absorpt_process_details   SADABS
_exptl_crystal_colour            red
_exptl_crystal_density_diffrn    1.417
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       needle
_exptl_crystal_F_000             1552
_exptl_crystal_size_max          0.20
_exptl_crystal_size_mid          0.12
_exptl_crystal_size_min          0.10
_refine_diff_density_max         0.279
_refine_diff_density_min         -0.296
_refine_diff_density_rms         0.074
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   0.930
_refine_ls_hydrogen_treatment    mixed
_refine_ls_matrix_type           full
_refine_ls_number_parameters     258
_refine_ls_number_reflns         3510
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      0.930
_refine_ls_R_factor_all          0.2681
_refine_ls_R_factor_gt           0.0893
_refine_ls_shift/su_max          0.000
_refine_ls_shift/su_mean         0.000
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'calc w=1/[\s^2^(Fo^2^)+(0.0000P)^2^+0.0000P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.1125
_refine_ls_wR_factor_ref         0.1681
_reflns_number_gt                1127
_reflns_number_total             3510
_reflns_threshold_expression     >2sigma(I)
_cod_data_source_file            c1cc10204d.txt
_cod_data_source_block           Form3_Pbca
_cod_original_cell_volume        3452.3(13)
_cod_original_sg_symbol_H-M      Pbca
_cod_database_code               7106288