β-Oligofurans
Fallon, Thomas; Willis, Anthony C.; Rae, A. David; Paddon-Row, Michael N.; Sherburn, Michael S.; Chemical Science 3 (2012) 2133–; doi:10.1039/c2sc20130e

data_1515149
_publ_section_title
;
 \b-Oligofurans
;
_journal_issue                   6
_journal_name_full               'Chemical Science'
_journal_page_first              2133
_journal_paper_doi               10.1039/c2sc20130e
_journal_volume                  3
_journal_year                    2012
_chemical_compound_source        local
_chemical_formula_moiety         'C8 H4 Br2 O2'
_chemical_formula_sum            'C8 H4 Br2 O2'
_chemical_formula_weight         291.93
_space_group_IT_number           15
_symmetry_cell_setting           monoclinic
_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
_audit_creation_date             06-10-16
_audit_creation_method           CRYSTALS_ver_12.18
_audit_update_record
;
2006-10-17 - Report on C8 H4 Br2 O2
by Anthony C. Willis
for Thomas Fallon and Mick Sherburn
2006-10-17 - passes checkcif tests with minor warnings
;
_cell_angle_alpha                90
_cell_angle_beta                 114.947(2)
_cell_angle_gamma                90
_cell_formula_units_Z            4
_cell_length_a                   17.3296(6)
_cell_length_b                   3.8995(1)
_cell_length_c                   13.8867(5)
_cell_measurement_reflns_used    5266
_cell_measurement_temperature    200
_cell_measurement_theta_max      27.5
_cell_measurement_theta_min      3
_cell_volume                     850.86(5)
_computing_cell_refinement       'Denzo/Scalepack (Otwinowski & Minor, 1997)'
_computing_data_collection       'COLLECT (Nonius BV, 1997)'
_computing_data_reduction        'Denzo/Scalepack (Otwinowski & Minor, 1997)'
_computing_molecular_graphics
;
ORTEP-II (Johnson 1976) in teXsan (MSC, 1992-1997)
;
_computing_publication_material  'CRYSTALS (Watkin et al 2003)'
_computing_structure_refinement  'CRYSTALS (Watkin et al 2003)'
_computing_structure_solution    'SIR92 (Altomare et al, 1994)'
_diffrn_ambient_temperature      200
_diffrn_measured_fraction_theta_full 0.996
_diffrn_measured_fraction_theta_max 0.996
_diffrn_measurement_device_type  'Nonius KappaCCD'
_diffrn_measurement_method       ' \f and \w scans with CCD '
_diffrn_radiation_monochromator  graphite
_diffrn_radiation_type           'Mo K\a'
_diffrn_radiation_wavelength     0.71073
_diffrn_reflns_av_R_equivalents  0.037
_diffrn_reflns_limit_h_max       21
_diffrn_reflns_limit_h_min       -22
_diffrn_reflns_limit_k_max       4
_diffrn_reflns_limit_k_min       -5
_diffrn_reflns_limit_l_max       18
_diffrn_reflns_limit_l_min       -18
_diffrn_reflns_number            6439
_diffrn_reflns_theta_full        27.481
_diffrn_reflns_theta_max         27.481
_diffrn_reflns_theta_min         4.821
_diffrn_standards_number         0
_exptl_absorpt_coefficient_mu    9.477
_exptl_absorpt_correction_T_max  0.671
_exptl_absorpt_correction_T_min  0.241
_exptl_absorpt_correction_type   integration
_exptl_absorpt_process_details
;
via Gaussian method (Coppens, 1970) implemented in maXus (2000)
;
_exptl_crystal_colour            colourless
_exptl_crystal_density_diffrn    2.279
_exptl_crystal_density_meas      ?
_exptl_crystal_description       plate
_exptl_crystal_F_000             552
_exptl_crystal_size_max          0.26
_exptl_crystal_size_mid          0.12
_exptl_crystal_size_min          0.04
_refine_diff_density_max         0.66
_refine_diff_density_min         -0.33
_refine_ls_extinction_coef       30(3)
_refine_ls_extinction_method     'Larson (1970), Equation 22'
_refine_ls_goodness_of_fit_ref   1.1356
_refine_ls_hydrogen_treatment    refxyz
_refine_ls_matrix_type           full
_refine_ls_number_parameters     62
_refine_ls_number_reflns         835
_refine_ls_number_restraints     0
_refine_ls_R_factor_all          0.0234
_refine_ls_R_factor_gt           0.0205
_refine_ls_shift/su_max          0.001536
_refine_ls_structure_factor_coef F
_refine_ls_weighting_details
;
Method, part 1, Chebychev polynomial,
(Carruthers & Watkin, 1979, Prince, 1982)
[weight] = 1.0/[A~0~*T~0~(x)+A~1~*T~1~(x) ... +A~n-1~]*T~n-1~(x)]
where A~i~ are the Chebychev coefficients listed below and x= Fcalc/Fmax
Method = Robust Weighting (Prince, 1982)
W = [weight] * [1-(deltaF/6*sigmaF)^2^]^2^
A~i~ are:
-0.522 4.42 -1.13 1.56
;
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_all         0.0244
_refine_ls_wR_factor_gt          0.0225
_refine_ls_wR_factor_ref         0.0225
_reflns_limit_h_max              20
_reflns_limit_h_min              -22
_reflns_limit_k_max              5
_reflns_limit_k_min              0
_reflns_limit_l_max              18
_reflns_limit_l_min              0
_reflns_number_gt                835
_reflns_number_total             968
_reflns_threshold_expression     I>3.0\s(I)
_oxford_diffrn_Wilson_B_factor   2.58
_oxford_diffrn_Wilson_scale      3.63
_oxford_refine_ls_scale          0.7540(19)
_oxford_structure_analysis_title '10161641 she0627'
_cod_data_source_file            c2sc20130e.txt
_cod_data_source_block           she0627
_cod_depositor_comments
;
The following automatic conversions were performed:

'_symmetry_cell_setting' value 'Monoclinic' changed to 'monoclinic'
according to
/usr/data/users/saulius/automatic-downloads/retrospective/RSC/lib/dictionaries/cif_core.dic
dictionary named 'cif_core.dic' version 2.4.2 from 2011-04-26.

Automatic conversion script
Id: cif_fix_values 2281 2013-09-26 08:29:07Z andrius 

The following automatic conversions were performed:

'_exptl_crystal_density_meas' value 'not measured' was changed to '?'
- the value is perceived as not measured.

Automatic conversion script
Id: cif_fix_values 3008 2015-01-20 13:52:24Z robertas 
;
_cod_original_sg_symbol_H-M      'C 1 2/c 1 '
_cod_database_code               1515149