Unravelling the chemical basis of the bathochromic shift in the lobster carapace; new crystal structures of unbound astaxanthin, canthaxanthin and zeaxanthin
Bartalucci, Giuditta; Coppin, Jennifer; Fisher, Stuart; Hall, Gillian; Helliwell, John R.; Helliwell, Madeleine; Liaaen-Jensen, Synnøve; Acta Crystallographica Section B 63 (2007) 328–337; doi:10.1107/S0108768106052633

data_2102772
_publ_section_title
;
 Unravelling the chemical basis of the bathochromic shift in the
 lobster carapace; new crystal structures of unbound astaxanthin,
 canthaxanthin and zeaxanthin
;
_journal_coeditor_code           BM5041
_journal_issue                   2
_journal_name_full               'Acta Crystallographica Section B'
_journal_page_first              328
_journal_page_last               337
_journal_paper_doi               10.1107/S0108768106052633
_journal_volume                  63
_journal_year                    2007
_chemical_formula_moiety         'C40 H52 O4, 2(C5 H5 N)'
_chemical_formula_sum            'C50 H62 N2 O4'
_chemical_formula_weight         755.02
_chemical_name_systematic
;
 ?
;
_space_group_IT_number           14
_symmetry_cell_setting           monoclinic
_symmetry_space_group_name_Hall  '-P 2yn'
_symmetry_space_group_name_H-M   'P 1 21/n 1'
_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                 107.746(4)
_cell_angle_gamma                90.00
_cell_formula_units_Z            2
_cell_length_a                   18.568(4)
_cell_length_b                   6.1926(13)
_cell_length_c                   19.803(4)
_cell_measurement_reflns_used    1008
_cell_measurement_temperature    100(2)
_cell_measurement_theta_max      19.57
_cell_measurement_theta_min      2.16
_cell_volume                     2168.7(8)
_computing_cell_refinement       'Bruker SMART'
_computing_data_collection       'Bruker SMART'
_computing_data_reduction        'Bruker SAINT'
_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      100(2)
_diffrn_measured_fraction_theta_full 0.999
_diffrn_measured_fraction_theta_max 0.999
_diffrn_measurement_device_type  'CCD area detector'
_diffrn_measurement_method       'phi and omega 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  0.1477
_diffrn_reflns_av_sigmaI/netI    0.1531
_diffrn_reflns_limit_h_max       20
_diffrn_reflns_limit_h_min       -20
_diffrn_reflns_limit_k_max       6
_diffrn_reflns_limit_k_min       -6
_diffrn_reflns_limit_l_max       22
_diffrn_reflns_limit_l_min       -22
_diffrn_reflns_number            12345
_diffrn_reflns_theta_full        23.26
_diffrn_reflns_theta_max         23.26
_diffrn_reflns_theta_min         1.32
_exptl_absorpt_coefficient_mu    0.072
_exptl_absorpt_correction_type   none
_exptl_crystal_colour            red
_exptl_crystal_density_diffrn    1.156
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       plate
_exptl_crystal_F_000             816
_exptl_crystal_size_max          0.60
_exptl_crystal_size_mid          0.15
_exptl_crystal_size_min          0.05
_refine_diff_density_max         0.26
_refine_diff_density_min         -0.173
_refine_ls_extinction_coef       0.0040(9)
_refine_ls_extinction_expression Fc^*^=kFc[1+0.001xFc^2^\l^3^/sin(2\q)]^-1/4^
_refine_ls_extinction_method     SHELXL
_refine_ls_goodness_of_fit_ref   0.768
_refine_ls_hydrogen_treatment    mixed
_refine_ls_matrix_type           full
_refine_ls_number_parameters     292
_refine_ls_number_reflns         3103
_refine_ls_number_restraints     7
_refine_ls_restrained_S_all      0.775
_refine_ls_R_factor_all          0.1204
_refine_ls_R_factor_gt           0.0485
_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^)+(0.0351P)^2^+0.0000P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.0994
_refine_ls_wR_factor_ref         0.1160
_reflns_number_gt                1400
_reflns_number_total             3104
_reflns_threshold_expression     >2sigma(I)
_cod_data_source_file            bm5041.cif
_cod_data_source_block           axt-PY
_cod_depositor_comments
;
The following automatic conversions were performed:
'_symmetry_cell_setting' value 'Monoclinic' changed to 'monoclinic'
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 

The following automatic conversions were performed:

'_symmetry_cell_setting' value 'Monoclinic' changed to 'monoclinic'
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_values 1715 2011-07-08 13:25:40Z adriana 
;
_cod_original_sg_symbol_Hall     -P2yn
_cod_original_sg_symbol_H-M      P21/n
_cod_database_code               2102772
_cod_database_fobs_code          2102772