Synthesis of N = 8 Armchair Graphene Nanoribbons from Four Distinct Polydiacetylenes.
Jordan, Robert S.; Li, Yolanda L.; Lin, Cheng-Wei; McCurdy, Ryan D.; Lin, Janice B.; Brosmer, Jonathan L.; Marsh, Kristofer L.; Khan, Saeed I.; Houk, K. N.; Kaner, Richard B.; Rubin, Yves; Journal of the American Chemical Society 139 (2017) 15878–15890; doi:10.1021/jacs.7b08800

data_4131687
_publ_section_title
;
 Synthesis of N = 8 Armchair Graphene Nanoribbons from Four Distinct
 Polydiacetylenes.
;
_journal_issue                   44
_journal_name_full               'Journal of the American Chemical Society'
_journal_page_first              15878
_journal_page_last               15890
_journal_paper_doi               10.1021/jacs.7b08800
_journal_volume                  139
_journal_year                    2017
_chemical_formula_moiety         'C20 H14 O2'
_chemical_formula_sum            'C20 H14 O2'
_chemical_formula_weight         286.31
_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_method           SHELXL-2014/6
_cell_angle_alpha                90
_cell_angle_beta                 90.2187(16)
_cell_angle_gamma                90
_cell_formula_units_Z            2
_cell_length_a                   5.38500(10)
_cell_length_b                   4.94320(10)
_cell_length_c                   27.2148(7)
_cell_measurement_reflns_used    3080
_cell_measurement_temperature    100(2)
_cell_measurement_theta_max      70.45
_cell_measurement_theta_min      3.25
_cell_volume                     724.43(3)
_computing_cell_refinement       'Bruker SAINT'
_computing_data_collection       'Bruker APEX2'
_computing_data_reduction        'Bruker SAINT'
_computing_molecular_graphics    'Bruker SHELXTL'
_computing_publication_material  'Bruker SHELXTL'
_computing_structure_refinement  'SHELXL-2014/6 (Sheldrick, 2014)'
_computing_structure_solution    'SHELXS-97 (Sheldrick 2008)'
_diffrn_ambient_temperature      100(2)
_diffrn_detector_area_resol_mean 8.3333
_diffrn_measured_fraction_theta_full 0.982
_diffrn_measured_fraction_theta_max 0.959
_diffrn_measurement_device_type  'Bruker APEX-II CCD'
_diffrn_measurement_method       '\f and \w scans'
_diffrn_radiation_type           CuK\a
_diffrn_radiation_wavelength     1.54178
_diffrn_reflns_av_R_equivalents  0.0246
_diffrn_reflns_av_unetI/netI     0.0213
_diffrn_reflns_Laue_measured_fraction_full 0.982
_diffrn_reflns_Laue_measured_fraction_max 0.959
_diffrn_reflns_limit_h_max       6
_diffrn_reflns_limit_h_min       -5
_diffrn_reflns_limit_k_max       4
_diffrn_reflns_limit_k_min       -5
_diffrn_reflns_limit_l_max       29
_diffrn_reflns_limit_l_min       -33
_diffrn_reflns_number            6678
_diffrn_reflns_point_group_measured_fraction_full 0.982
_diffrn_reflns_point_group_measured_fraction_max 0.959
_diffrn_reflns_theta_full        67.679
_diffrn_reflns_theta_max         70.977
_diffrn_reflns_theta_min         3.248
_diffrn_source                   'I\mS micro--focus source'
_exptl_absorpt_coefficient_mu    0.667
_exptl_absorpt_correction_T_max  0.75
_exptl_absorpt_correction_T_min  0.66
_exptl_absorpt_correction_type   multi-scan
_exptl_absorpt_process_details   'SADABS V2014/2 (Bruker AXS Inc.)'
_exptl_crystal_colour            colorless
_exptl_crystal_density_diffrn    1.313
_exptl_crystal_description       needle
_exptl_crystal_F_000             300
_exptl_crystal_size_max          0.300
_exptl_crystal_size_mid          0.050
_exptl_crystal_size_min          0.050
_refine_diff_density_max         0.154
_refine_diff_density_min         -0.224
_refine_diff_density_rms         0.037
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.057
_refine_ls_hydrogen_treatment    constr
_refine_ls_matrix_type           full
_refine_ls_number_parameters     101
_refine_ls_number_reflns         1328
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      1.057
_refine_ls_R_factor_all          0.0374
_refine_ls_R_factor_gt           0.0324
_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^)+(0.0488P)^2^+0.1669P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.0867
_refine_ls_wR_factor_ref         0.0891
_reflns_Friedel_coverage         0.000
_reflns_number_gt                1141
_reflns_number_total             1328
_reflns_threshold_expression     'I > 2\s(I)'
_cod_data_source_file            ja7b08800_si_002.cif
_cod_data_source_block           cu_yr1708s
_cod_original_sg_symbol_H-M      'P 21/c'
_cod_database_code               4131687
_shelx_estimated_absorpt_t_min   0.825
_shelx_estimated_absorpt_t_max   0.967
_shelxl_version_number           2014/6
_shelx_res_checksum              6920
_shelx_hkl_checksum              63378