A strategy for preparing spirobichroman dianhydride from bisphenol A and its resulting polyimide with low dielectric characteristic
Tang, I-Chun; Wang, Meng Wei; Wu, Chien-Hsin; Dai, Shenghong A.; Jeng, Ru-Jong; Lin, Ching_Husuan; RSC Adv.  (2016) –; doi:10.1039/C6RA25648A

data_7227001
_publ_section_title
;
 A strategy for preparing spirobichroman dianhydride from bisphenol A and
 its resulting polyimide with low dielectric characteristic
;
_journal_name_full               'RSC Adv.'
_journal_paper_doi               10.1039/C6RA25648A
_journal_year                    2016
_chemical_formula_moiety         'C25 H20 O8'
_chemical_formula_sum            'C25 H20 O8'
_chemical_formula_weight         448.41
_chemical_name_common            'siprobichroman dianhydride'
_chemical_name_systematic
4,4,4',4'-tetramethyl-3,3',4,4'-tetrahydro-2,2'-spirobi[furo[3,4-g]chromene]-6,6',8,8'-tetraone
_space_group_IT_number           15
_symmetry_cell_setting           monoclinic
_symmetry_Int_Tables_number      15
_symmetry_space_group_name_Hall  '-C 2yc'
_symmetry_space_group_name_H-M   'C 1 2/c 1'
_atom_sites_solution_hydrogens   geom
_atom_sites_solution_primary     direct
_atom_sites_solution_secondary   difmap
_audit_creation_method           SHELXL-97
_audit_update_record
;
2016-08-10 deposited with the CCDC.
2016-10-31 downloaded from the CCDC.
;
_cell_angle_alpha                90.00
_cell_angle_beta                 127.778(12)
_cell_angle_gamma                90.00
_cell_formula_units_Z            8
_cell_length_a                   26.146(2)
_cell_length_b                   10.3960(5)
_cell_length_c                   20.1104(16)
_cell_measurement_reflns_used    2536
_cell_measurement_temperature    150(2)
_cell_measurement_theta_max      28.8480
_cell_measurement_theta_min      3.1190
_cell_volume                     4320.5(9)
_computing_cell_refinement
; 
CrysAlis RED, Oxford Diffraction Ltd., 
Version 1.171.32.29 (release 10-06-2008 CrysAlis171 .NET) 
(compiled Jun 10 2008,16:49:55) 
;
_computing_data_collection
; 
CrysAlis CCD, Oxford Diffraction Ltd., 
Version 1.171.32.29 (release 10-06-2008 CrysAlis171 .NET) 
(compiled Jun 10 2008,16:49:55) 
;
_computing_data_reduction
; 
CrysAlis RED, Oxford Diffraction Ltd., 
Version 1.171.32.29 (release 10-06-2008 CrysAlis171 .NET) 
(compiled Jun 10 2008,16:49:55) 
;
_computing_molecular_graphics    'Bruker SHELXTL'
_computing_publication_material  'Bruker SHELXTL'
_computing_structure_refinement  'SHELXL-97 (Sheldrick, 2008)'
_computing_structure_solution    'SHELXS-97 (Sheldrick, 2008)'
_diffrn_ambient_temperature      150(2)
_diffrn_measured_fraction_theta_full 0.999
_diffrn_measured_fraction_theta_max 0.843
_diffrn_measurement_device_type  'CCD detector'
_diffrn_measurement_method       '\w scans'
_diffrn_radiation_monochromator  graphite
_diffrn_radiation_probe          x-ray
_diffrn_radiation_type           MoK\a
_diffrn_radiation_wavelength     0.71073
_diffrn_reflns_av_R_equivalents  0.0298
_diffrn_reflns_av_sigmaI/netI    0.0588
_diffrn_reflns_limit_h_max       29
_diffrn_reflns_limit_h_min       -33
_diffrn_reflns_limit_k_max       7
_diffrn_reflns_limit_k_min       -13
_diffrn_reflns_limit_l_max       25
_diffrn_reflns_limit_l_min       -26
_diffrn_reflns_number            9874
_diffrn_reflns_theta_full        26.00
_diffrn_reflns_theta_max         29.30
_diffrn_reflns_theta_min         2.83
_diffrn_source                   'fine-focus sealed tube'
_exptl_absorpt_coefficient_mu    0.104
_exptl_absorpt_correction_T_max  1.00000
_exptl_absorpt_correction_T_min  0.99525
_exptl_absorpt_correction_type   multi-scan
_exptl_absorpt_process_details
; 
CrysAlisPro, Agilent Technologies, 
Version 1.171.37.31 (release 14-01-2014 CrysAlis171 .NET) 
(compiled Jan 14 2014,18:38:05) 
Empirical absorption correction using spherical harmonics, 
 implemented in SCALE3 ABSPACK scaling algorithm. 
;
_exptl_crystal_colour            grey
_exptl_crystal_density_diffrn    1.379
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       parallelepiped
_exptl_crystal_F_000             1872
_exptl_crystal_size_max          0.42
_exptl_crystal_size_mid          0.26
_exptl_crystal_size_min          0.23
_refine_diff_density_max         0.263
_refine_diff_density_min         -0.219
_refine_diff_density_rms         0.047
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.024
_refine_ls_hydrogen_treatment    constr
_refine_ls_matrix_type           full
_refine_ls_number_parameters     298
_refine_ls_number_reflns         4978
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      1.024
_refine_ls_R_factor_all          0.0883
_refine_ls_R_factor_gt           0.0529
_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^)+(0.0421P)^2^+1.6104P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.1014
_refine_ls_wR_factor_ref         0.1176
_reflns_number_gt                3434
_reflns_number_total             4978
_reflns_threshold_expression     >2sigma(I)
_cod_data_source_file            c6ra25648a2.cif
_cod_data_source_block           anhydride
_cod_original_cell_volume        4320.5(5)
_cod_original_sg_symbol_H-M      'C 2/c'
_cod_database_code               7227001