Cyclic oligomers of poly(ether ketone) (PEK): synthesis, extraction from polymer, fractionation, and characterisation of the cyclic trimer, tetramer and pentamer
Ben-Haida, Abderrazak; Colquhoun, Howard M.; Hodge, Philip; Williams, David J.; Journal of Materials Chemistry 10 (2000) 2011–; doi:10.1039/b000738m

data_7203965
_publ_section_title
;
 Cyclic oligomers of poly(ether ketone) (PEK): synthesis, extraction
 from polymer, fractionation, and characterisation of the cyclic
 trimer, tetramer and pentamer
;
_journal_issue                   9
_journal_name_full               'Journal of Materials Chemistry'
_journal_page_first              2011
_journal_paper_doi               10.1039/b000738m
_journal_volume                  10
_journal_year                    2000
_chemical_formula_sum            'C42 H34 Cl2 O8'
_chemical_formula_weight         737.59
_space_group_IT_number           14
_symmetry_cell_setting           monoclinic
_symmetry_space_group_name_Hall  '-P 2ybc'
_symmetry_space_group_name_H-M   'P 1 21/c 1'
_atom_sites_solution_hydrogens   geom
_atom_sites_solution_primary     direct
_atom_sites_solution_secondary   difmap
_audit_creation_method           SHELXL
_cell_angle_alpha                90.00
_cell_angle_beta                 96.911(7)
_cell_angle_gamma                90.00
_cell_formula_units_Z            4
_cell_length_a                   11.1071(5)
_cell_length_b                   25.4188(9)
_cell_length_c                   12.5938(5)
_cell_measurement_reflns_used    27
_cell_measurement_temperature    183(2)
_cell_measurement_theta_max      26.45
_cell_measurement_theta_min      11.09
_cell_volume                     3529.8(3)
_computing_cell_refinement       'Siemens XSCANS'
_computing_data_collection       'Siemens XSCANS'
_computing_data_reduction        'Siemens SHELXTL'
_computing_molecular_graphics    'Siemens SHELXTL'
_computing_publication_material  'Siemens SHELXTL'
_computing_structure_refinement  'SHELXL-93 (Sheldrick, 1993)'
_computing_structure_solution    'SHELXS-86 (Sheldrick, 1990)'
_diffrn_ambient_temperature      183(2)
_diffrn_measurement_device       'Siemens P4'
_diffrn_measurement_method       '\w scans'
_diffrn_radiation_monochromator  graphite
_diffrn_radiation_source         'fine-focus sealed tube'
_diffrn_radiation_type           CuK\a
_diffrn_radiation_wavelength     1.54178
_diffrn_reflns_av_R_equivalents  0.0287
_diffrn_reflns_av_sigmaI/netI    0.0321
_diffrn_reflns_limit_h_max       5
_diffrn_reflns_limit_h_min       -12
_diffrn_reflns_limit_k_max       20
_diffrn_reflns_limit_k_min       -29
_diffrn_reflns_limit_l_max       14
_diffrn_reflns_limit_l_min       -11
_diffrn_reflns_number            5870
_diffrn_reflns_theta_max         61.98
_diffrn_reflns_theta_min         3.48
_diffrn_standards_interval_count 97
_diffrn_standards_number         3
_exptl_absorpt_coefficient_mu    2.120
_exptl_absorpt_correction_type   none
_exptl_crystal_density_diffrn    1.388
_exptl_crystal_F_000             1536
_refine_diff_density_max         0.350
_refine_diff_density_min         -0.448
_refine_diff_density_rms         0.066
_refine_ls_extinction_coef       0.0014(2)
_refine_ls_extinction_expression Fc^*^=kFc[1+0.001xFc^2^\l^3^/sin(2\q)]^-1/4^
_refine_ls_extinction_method     SHELXL
_refine_ls_goodness_of_fit_all   1.037
_refine_ls_goodness_of_fit_obs   1.075
_refine_ls_matrix_type           full
_refine_ls_number_parameters     478
_refine_ls_number_reflns         5272
_refine_ls_number_restraints     2
_refine_ls_restrained_S_all      1.060
_refine_ls_restrained_S_obs      1.075
_refine_ls_R_factor_all          0.0647
_refine_ls_R_factor_obs          0.0514
_refine_ls_shift/esd_max         -0.193
_refine_ls_shift/esd_mean        0.003
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'w=1/[\s^2^(Fo^2^)+(0.0840P)^2^+2.2684P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_all         0.1471
_refine_ls_wR_factor_obs         0.1338
_reflns_number_observed          4541
_reflns_number_total             5556
_reflns_observed_criterion       >2sigma(I)
_cod_data_source_file            b000738m.txt
_cod_data_source_block           hmc9815
_cod_depositor_comments
;
The following automatic conversions were performed:
'_symmetry_cell_setting' value 'Monoclinic' changed to 'monoclinic'
according to '/home/saulius/struct/CIF-dictionaries/cif_core.dic'
dictionary named 'cif_core.dic' version 2.4.1 from 2010-06-29.

Automatic conversion script
Id: cif_fix_enum 1527 2010-12-29 10:47:43Z saulius 

The following automatic conversions were performed:

'_refine_ls_weighting_scheme' value 'calc
w=1/[\s^2^(Fo^2^)+(0.0840P)^2^+2.2684P] where P=(Fo^2^+2Fc^2^)/3' was
changed to 'calc'. New tag '_refine_ls_weighting_details' was
created. The value of the new tag was set to
'w=1/[\s^2^(Fo^2^)+(0.0840P)^2^+2.2684P] where P=(Fo^2^+2Fc^2^)/3'.

Automatic conversion script
Id: cif_fix_values 3143 2015-03-26 13:38:13Z robertas 
;
_cod_original_cell_volume        3529.8(2)
_cod_original_sg_symbol_H-M      P2(1)/c
_cod_database_code               7203965