The first structural and spectroscopic characterisation of a ring-opened form of a 2H-naphtho[1,2-b]pyran: a novel photomerocyanine
Stuart Aiken; Kathryn Booth; Christopher D. Gabbutt; B. Mark Heron; Craig R. Rice; Azzam Charaf-Eddin; Denis Jacquemin; Chem.Commun. 50 (2014) 7900–; doi:10.1039/C4CC03435J

data_7115275
_publ_section_title
;
 The first structural and spectroscopic characterisation of a ring-opened
 form of a 2H-naphtho[1,2-b]pyran: a novel photomerocyanine
;
_journal_name_full               Chem.Commun.
_journal_page_first              7900
_journal_paper_doi               10.1039/C4CC03435J
_journal_volume                  50
_journal_year                    2014
_chemical_formula_sum            'C28 H24 O4'
_chemical_formula_weight         424.47
_space_group_crystal_system      monoclinic
_space_group_IT_number           15
_space_group_name_Hall           '-C 2yc'
_space_group_name_H-M_alt        'C 1 2/c 1'
_symmetry_space_group_name_Hall  '-C 2yc'
_symmetry_space_group_name_H-M   'C 1 2/c 1'
_atom_sites_solution_hydrogens   geom
_audit_creation_method           SHELXL-2013
_cell_angle_alpha                90
_cell_angle_beta                 94.4847(19)
_cell_angle_gamma                90
_cell_formula_units_Z            8
_cell_length_a                   17.9087(7)
_cell_length_b                   13.6467(6)
_cell_length_c                   17.9157(7)
_cell_measurement_reflns_used    8251
_cell_measurement_temperature    150(2)
_cell_measurement_theta_max      70.17
_cell_measurement_theta_min      4.08
_cell_volume                     4365.1(3)
_computing_structure_refinement  'SHELXL-2013 (Sheldrick, 2013)'
_diffrn_ambient_temperature      150(2)
_diffrn_measured_fraction_theta_full 0.993
_diffrn_measured_fraction_theta_max 0.992
_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  0.0555
_diffrn_reflns_av_unetI/netI     0.0460
_diffrn_reflns_Laue_measured_fraction_full 0.993
_diffrn_reflns_Laue_measured_fraction_max 0.992
_diffrn_reflns_limit_h_max       21
_diffrn_reflns_limit_h_min       -21
_diffrn_reflns_limit_k_max       16
_diffrn_reflns_limit_k_min       -16
_diffrn_reflns_limit_l_max       21
_diffrn_reflns_limit_l_min       -21
_diffrn_reflns_number            17375
_diffrn_reflns_point_group_measured_fraction_full 0.993
_diffrn_reflns_point_group_measured_fraction_max 0.992
_diffrn_reflns_theta_full        67.679
_diffrn_reflns_theta_max         70.163
_diffrn_reflns_theta_min         4.077
_exptl_absorpt_coefficient_mu    0.687
_exptl_absorpt_correction_T_max  0.88
_exptl_absorpt_correction_T_min  0.77
_exptl_absorpt_correction_type   multi-scan
_exptl_absorpt_process_details   sadabs
_exptl_crystal_colour            orange
_exptl_crystal_density_diffrn    1.292
_exptl_crystal_description       block
_exptl_crystal_F_000             1792
_exptl_crystal_size_max          0.300
_exptl_crystal_size_mid          0.200
_exptl_crystal_size_min          0.200
_refine_diff_density_max         0.267
_refine_diff_density_min         -0.291
_refine_diff_density_rms         0.063
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.062
_refine_ls_hydrogen_treatment    constr
_refine_ls_matrix_type           full
_refine_ls_number_parameters     292
_refine_ls_number_reflns         4119
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      1.062
_refine_ls_R_factor_all          0.0657
_refine_ls_R_factor_gt           0.0532
_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^)+(0.1020P)^2^+2.4276P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.1554
_refine_ls_wR_factor_ref         0.1668
_reflns_Friedel_coverage         0.000
_reflns_number_gt                3333
_reflns_number_total             4119
_reflns_threshold_expression     'I > 2\s(I)'
_cod_data_source_file            c4cc03435j2.cif
_cod_data_source_block           cu_MarkCC_orange_0m
_cod_database_code               7115275
_shelx_estimated_absorpt_t_min   0.820
_shelx_estimated_absorpt_t_max   0.875
_shelxl_version_number           2013-4
_shelx_res_checksum              11252