Thermal Generation of Pentacenes from Soluble 6,13-Dihydro-6,13-ethenopentacene Precursors by a Diels-Alder-retro-Diels-Alder Sequence with 3,6-Disubstituted Tetrazines
Rafael P. Bula; Iris M. Oppel; Holger F. Bettinger; Journal of Organic Chemistry 77 (2012) 3538–3542; doi:10.1021/jo202450u

data_4027096
_publ_section_title
;
 Thermal Generation of Pentacenes from Soluble
 6,13-Dihydro-6,13-ethenopentacene Precursors by a
 Diels-Alder-retro-Diels-Alder Sequence with 3,6-Disubstituted Tetrazines
;
_journal_name_full               'Journal of Organic Chemistry'
_journal_page_first              3538
_journal_page_last               3542
_journal_paper_doi               10.1021/jo202450u
_journal_volume                  77
_journal_year                    2012
_chemical_formula_sum            'C20 H28 O8'
_chemical_formula_weight         396.42
_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                 99.6000(10)
_cell_angle_gamma                90.00
_cell_formula_units_Z            4
_cell_length_a                   14.21380(10)
_cell_length_b                   10.06440(10)
_cell_length_c                   14.48310(10)
_cell_measurement_reflns_used    6881
_cell_measurement_temperature    113(2)
_cell_measurement_theta_max      65.3
_cell_measurement_theta_min      3.1
_cell_volume                     2042.84(3)
_computing_cell_refinement       'CrysAlis RED Oxford diffraction'
_computing_data_collection       'CrysAlis CCD Oxford diffraction'
_computing_data_reduction        'CrysAlis RED Oxford diffraction'
_computing_molecular_graphics    SHELXL-97
_computing_publication_material  SHELXL-97
_computing_structure_refinement  'SHELXL-97 (Sheldrick, 1997)'
_computing_structure_solution    'SHELXS-97 (Sheldrick, 1990)'
_diffrn_ambient_temperature      113(2)
_diffrn_measured_fraction_theta_full 0.963
_diffrn_measured_fraction_theta_max 0.963
_diffrn_measurement_device_type  '1532 frames in \w and 5 to 15 sec'
_diffrn_radiation_monochromator  graphite
_diffrn_radiation_source         'Enhance (Cu) x-ray Source'
_diffrn_radiation_type           CuK\a
_diffrn_radiation_wavelength     1.54178
_diffrn_reflns_av_R_equivalents  0.0323
_diffrn_reflns_av_sigmaI/netI    0.0284
_diffrn_reflns_limit_h_max       16
_diffrn_reflns_limit_h_min       -16
_diffrn_reflns_limit_k_max       11
_diffrn_reflns_limit_k_min       -8
_diffrn_reflns_limit_l_max       16
_diffrn_reflns_limit_l_min       -16
_diffrn_reflns_number            11842
_diffrn_reflns_theta_full        65.44
_diffrn_reflns_theta_max         65.44
_diffrn_reflns_theta_min         4.03
_exptl_absorpt_coefficient_mu    0.832
_exptl_absorpt_correction_type   none
_exptl_crystal_colour            colourless
_exptl_crystal_density_diffrn    1.289
_exptl_crystal_description       needle
_exptl_crystal_F_000             848
_exptl_crystal_size_max          0.576
_exptl_crystal_size_mid          0.265
_exptl_crystal_size_min          0.222
_refine_diff_density_max         0.185
_refine_diff_density_min         -0.235
_refine_diff_density_rms         0.049
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.086
_refine_ls_hydrogen_treatment    constr
_refine_ls_matrix_type           full
_refine_ls_number_parameters     257
_refine_ls_number_reflns         3382
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      1.086
_refine_ls_R_factor_all          0.0412
_refine_ls_R_factor_gt           0.0347
_refine_ls_shift/su_max          0.001
_refine_ls_shift/su_mean         0.000
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'calc w=1/[\s^2^(Fo^2^)+(0.0621P)^2^+0.0000P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.0919
_refine_ls_wR_factor_ref         0.0941
_reflns_number_gt                2865
_reflns_number_total             3382
_reflns_threshold_expression     >2sigma(I)
_cod_data_source_file            jo202450u_si_002.cif
_cod_data_source_block           p21n
_cod_database_code               4027096