Structural disorder as a key to photoprotection in eumelanin multimers.
Vinod, Kavya; Thomas, Diana; Hariharan, Mahesh; Chemical science 16 (2025) 14304–14313; doi:10.1039/d5sc00920k

data_1574997
_publ_section_title
;
 Structural disorder as a key to photoprotection in eumelanin multimers.
;
_journal_issue                   31
_journal_name_full               'Chemical science'
_journal_page_first              14304
_journal_page_last               14313
_journal_paper_doi               10.1039/d5sc00920k
_journal_volume                  16
_journal_year                    2025
_chemical_formula_moiety         'C21 H20 N2 O5'
_chemical_formula_sum            'C21 H20 N2 O5'
_chemical_formula_weight         380.39
_space_group_crystal_system      monoclinic
_space_group_IT_number           14
_space_group_name_Hall           '-P 2ybc'
_space_group_name_H-M_alt        'P 1 21/c 1'
_atom_sites_solution_hydrogens   geom
_audit_creation_date             2024-10-02
_audit_creation_method
;
Olex2 1.5
(compiled 2022.04.07 svn.rca3783a0 for OlexSys, GUI svn.r6498)
;
_audit_update_record
;
2024-10-10 deposited with the CCDC.	2025-07-01 downloaded from the CCDC.
;
_cell_angle_alpha                90
_cell_angle_beta                 104.941(5)
_cell_angle_gamma                90
_cell_formula_units_Z            4
_cell_length_a                   14.018(3)
_cell_length_b                   17.554(3)
_cell_length_c                   7.8113(15)
_cell_measurement_reflns_used    2136
_cell_measurement_temperature    296(2)
_cell_measurement_theta_max      18.39
_cell_measurement_theta_min      2.77
_cell_volume                     1857.2(6)
_computing_cell_refinement       'APEX3/SAINT (Br uker, 2016)'
_computing_data_collection       'APEX3 (Bruker, 2016)'
_computing_data_reduction        'SAINT/XPREP (Bruker, 2016)'
_computing_molecular_graphics    'Olex2 1.5 (Dolomanov et al., 2009)'
_computing_publication_material  'Olex2 1.5 (Dolomanov et al., 2009)'
_computing_structure_refinement  'SHELXL-2018/3 (Sheldrick, 2018)'
_computing_structure_solution    'SHELXT 2018/2 (Sheldrick, 2018)'
_diffrn_ambient_temperature      296(2)
_diffrn_detector_area_resol_mean 0
_diffrn_measured_fraction_theta_full 0.999
_diffrn_measured_fraction_theta_max 0.986
_diffrn_measurement_device_type  'Bruker KAPPA APEX-II CCD'
_diffrn_measurement_method       '\f and \w scans'
_diffrn_radiation_type           MoK\a
_diffrn_radiation_wavelength     0.71073
_diffrn_reflns_av_R_equivalents  0.1062
_diffrn_reflns_av_unetI/netI     0.0890
_diffrn_reflns_Laue_measured_fraction_full 0.999
_diffrn_reflns_Laue_measured_fraction_max 0.986
_diffrn_reflns_limit_h_max       18
_diffrn_reflns_limit_h_min       -18
_diffrn_reflns_limit_k_max       23
_diffrn_reflns_limit_k_min       -23
_diffrn_reflns_limit_l_max       10
_diffrn_reflns_limit_l_min       -10
_diffrn_reflns_number            31352
_diffrn_reflns_point_group_measured_fraction_full 0.999
_diffrn_reflns_point_group_measured_fraction_max 0.986
_diffrn_reflns_theta_full        25.242
_diffrn_reflns_theta_max         28.471
_diffrn_reflns_theta_min         2.765
_diffrn_source                   'sealed tube'
_exptl_absorpt_coefficient_mu    0.098
_exptl_absorpt_correction_T_max  0.997
_exptl_absorpt_correction_T_min  0.994
_exptl_absorpt_correction_type   multi-scan
_exptl_absorpt_process_details   'SADABS (Bruker, 2016)'
_exptl_crystal_colour            colourless
_exptl_crystal_colour_primary    colourless
_exptl_crystal_density_diffrn    1.360
_exptl_crystal_density_meas      1.361
_exptl_crystal_density_method    none
_exptl_crystal_description       block
_exptl_crystal_F_000             800
_exptl_crystal_size_max          0.5
_exptl_crystal_size_mid          0.085
_exptl_crystal_size_min          0.03
_refine_diff_density_max         0.323
_refine_diff_density_min         -0.233
_refine_diff_density_rms         0.052
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.025
_refine_ls_hydrogen_treatment    constr
_refine_ls_matrix_type           full
_refine_ls_number_parameters     253
_refine_ls_number_reflns         4644
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      1.025
_refine_ls_R_factor_all          0.1613
_refine_ls_R_factor_gt           0.0664
_refine_ls_shift/su_max          0.000
_refine_ls_shift/su_mean         0.000
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'w=1/[\s^2^(Fo^2^)+(0.0751P)^2^+0.0301P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.1446
_refine_ls_wR_factor_ref         0.1789
_reflns_Friedel_coverage         0.000
_reflns_number_gt                2239
_reflns_number_total             4644
_reflns_threshold_expression     'I > 2\s(I)'
_cod_data_source_file            d5sc00920k2.cif
_cod_data_source_block           shelx
_cod_depositor_comments          'Adding full bibliography for 1574997.cif.'
_cod_original_cell_volume        1857.1(6)
_cod_database_code               1574997
_shelx_shelxl_version_number     2018/3
_shelx_estimated_absorpt_t_max   0.997
_shelx_estimated_absorpt_t_min   0.953
_olex2_refinement_description
;
1.a Secondary CH2 refined with riding coordinates:
 C12(H12A,H12B)
1.b Me refined with riding coordinates:
 C13(H13A,H13B,H13C), C18(H18A,H18B,H18C), C21(H21A,H21B,H21C)
1.c Aromatic/amide H refined with riding coordinates:
 C1(H1), C2(H2), C6(H6), C7(H7), C8(H8), C16(H16), C20(H20), N1(H1A), N2(H2A)
;
_shelx_res_checksum              77121
_olex2_submission_special_instructions 'No special instructions were received'