Influence of (2,3,4,5,6-Pentamethyl/phenyl)phenyl Scaffold: Stereoelectronic Control of the Persistence of o-Quinonoid Reactive Intermediates of Photochromic Chromenes
Susovan Mandal; Keshaba Nanda Parida; Subhas Samanta; Jarugu Narasimha Moorthy; Journal of Organic Chemistry 76 (2011) 7406–7414; doi:10.1021/jo201144t

data_4026574
_publ_contact_author_address
;Departmet of chemistry
Indian Institute of Technology - Kanpur
Kanpur - 208 016
INDIA
;
_publ_contact_author_email       moorthy@iitk.ac.in
_publ_contact_author_fax         +915122597436
_publ_contact_author_name        'Prof. J. N. Moorthy'
_publ_contact_author_phone       +915122597438
_publ_section_title
;
 Influence of (2,3,4,5,6-Pentamethyl/phenyl)phenyl Scaffold:
 Stereoelectronic Control of the Persistence of o-Quinonoid Reactive
 Intermediates of Photochromic Chromenes
;
_journal_name_full               'Journal of Organic Chemistry'
_journal_page_first              7406
_journal_page_last               7414
_journal_paper_doi               10.1021/jo201144t
_journal_volume                  76
_journal_year                    2011
_chemical_formula_moiety         'C32 H30 O'
_chemical_formula_sum            'C32 H30 O'
_chemical_formula_weight         430.56
_chemical_melting_point          343(1)
_chemical_name_common            'Pentamethylphenylchromene 5Ch'
_chemical_name_systematic
;
 Pentamethylphenylchromene 5Ch
;
_space_group_IT_number           2
_symmetry_cell_setting           triclinic
_symmetry_Int_Tables_number      2
_symmetry_space_group_name_Hall  '-P 1'
_symmetry_space_group_name_H-M   'P -1'
_atom_sites_solution_hydrogens   geom
_atom_sites_solution_primary     direct
_atom_sites_solution_secondary   difmap
_audit_creation_method           SHELXL-97
_cell_angle_alpha                92.095(5)
_cell_angle_beta                 95.857(5)
_cell_angle_gamma                93.976(5)
_cell_formula_units_Z            2
_cell_length_a                   8.850(2)
_cell_length_b                   8.977(2)
_cell_length_c                   14.964(4)
_cell_measurement_temperature    293(2)
_cell_volume                     1178.6(5)
_computing_cell_refinement       'Bruker SAINT'
_computing_data_collection       'Bruker APEX'
_computing_data_reduction        'Bruker SAINT'
_computing_molecular_graphics    'SHELXL 5.1, XP (Sheldrick, 1994)'
_computing_publication_material  SHELXS-97
_computing_structure_refinement  'SHELXL-97 (Sheldrick, 2008)'
_computing_structure_solution    'SHELXS-97 (Sheldrick, 2008)'
_diffrn_ambient_temperature      293(2)
_diffrn_measured_fraction_theta_full 0.944
_diffrn_measured_fraction_theta_max 0.944
_diffrn_measurement_device_type  'Bruker SMART APEX'
_diffrn_measurement_method       'phi and omega scans'
_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  0.0252
_diffrn_reflns_av_sigmaI/netI    0.0666
_diffrn_reflns_limit_h_max       11
_diffrn_reflns_limit_h_min       -11
_diffrn_reflns_limit_k_max       11
_diffrn_reflns_limit_k_min       -7
_diffrn_reflns_limit_l_max       19
_diffrn_reflns_limit_l_min       -19
_diffrn_reflns_number            7772
_diffrn_reflns_theta_full        28.32
_diffrn_reflns_theta_max         28.32
_diffrn_reflns_theta_min         2.28
_exptl_absorpt_coefficient_mu    0.071
_exptl_absorpt_correction_type   none
_exptl_crystal_colour            colorless
_exptl_crystal_density_diffrn    1.213
_exptl_crystal_description       cuboidal
_exptl_crystal_F_000             460
_exptl_crystal_size_max          0.23
_exptl_crystal_size_mid          0.17
_exptl_crystal_size_min          0.12
_refine_diff_density_max         0.580
_refine_diff_density_min         -0.466
_refine_diff_density_rms         0.085
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.442
_refine_ls_hydrogen_treatment    constr
_refine_ls_matrix_type           full
_refine_ls_number_parameters     298
_refine_ls_number_reflns         5538
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      1.442
_refine_ls_R_factor_all          0.1323
_refine_ls_R_factor_gt           0.0875
_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^)+(0.1000P)^2^+0.0000P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.2187
_refine_ls_wR_factor_ref         0.2739
_reflns_number_gt                3584
_reflns_number_total             5538
_reflns_threshold_expression     >2sigma(I)
_cod_data_source_file            jo201144t_si_002.cif
_cod_data_source_block           27aprbm
_cod_original_cell_volume        1178.7(5)
_cod_database_code               4026574