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_4027095
_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            'C12 H20 O4'
_chemical_formula_weight         228.28
_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                 106.497(4)
_cell_angle_gamma                90.00
_cell_formula_units_Z            4
_cell_length_a                   7.3934(2)
_cell_length_b                   15.6929(4)
_cell_length_c                   10.0693(3)
_cell_measurement_reflns_used    5035
_cell_measurement_temperature    113(2)
_cell_measurement_theta_max      27.5
_cell_measurement_theta_min      2.87
_cell_volume                     1120.19(6)
_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 0.998
_diffrn_measured_fraction_theta_max 0.998
_diffrn_measurement_device_type  '562 frames in \w and 10 sec'
_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  0.0302
_diffrn_reflns_av_sigmaI/netI    0.0304
_diffrn_reflns_limit_h_max       9
_diffrn_reflns_limit_h_min       -9
_diffrn_reflns_limit_k_max       13
_diffrn_reflns_limit_k_min       -19
_diffrn_reflns_limit_l_max       12
_diffrn_reflns_limit_l_min       -12
_diffrn_reflns_number            9940
_diffrn_reflns_theta_full        26.00
_diffrn_reflns_theta_max         26.00
_diffrn_reflns_theta_min         3.35
_exptl_absorpt_coefficient_mu    0.100
_exptl_absorpt_correction_type   none
_exptl_crystal_colour            colourless
_exptl_crystal_density_diffrn    1.354
_exptl_crystal_description       prism
_exptl_crystal_F_000             496
_exptl_crystal_size_max          0.428
_exptl_crystal_size_mid          0.394
_exptl_crystal_size_min          0.227
_refine_diff_density_max         0.309
_refine_diff_density_min         -0.397
_refine_diff_density_rms         0.053
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.050
_refine_ls_hydrogen_treatment    constr
_refine_ls_matrix_type           full
_refine_ls_number_parameters     145
_refine_ls_number_reflns         2194
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      1.050
_refine_ls_R_factor_all          0.0469
_refine_ls_R_factor_gt           0.0361
_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^)+(0.0558P)^2^+0.1096P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.0925
_refine_ls_wR_factor_ref         0.0951
_reflns_number_gt                1733
_reflns_number_total             2194
_reflns_threshold_expression     >2sigma(I)
_cod_data_source_file            jo202450u_si_001.cif
_cod_data_source_block           p21n
_cod_original_cell_volume        1120.19(5)
_cod_database_code               4027095