Cyclic alkynes‒electronic behaviour as a function of ring strain
Tykwinski, Rik R.; Chemical Communications  (1999) 905–; doi:10.1039/a900910h

data_7110479
_publ_section_title
;
 Cyclic alkynes--electronic behaviour as a function of ring strain
;
_journal_issue                   10
_journal_name_full               'Chemical Communications'
_journal_page_first              905
_journal_paper_doi               10.1039/a900910h
_journal_year                    1999
_chemical_formula_sum            'C20 H20'
_chemical_formula_weight         260.36
_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           'manual editing of SHELXL template'
_cell_angle_alpha                90.00
_cell_angle_beta                 107.744(7)
_cell_angle_gamma                90.00
_cell_formula_units_Z            4
_cell_length_a                   9.2119(8)
_cell_length_b                   12.5305(12)
_cell_length_c                   14.5747(10)
_cell_measurement_reflns_used    40
_cell_measurement_temperature    213(2)
_cell_measurement_theta_max      12.92
_cell_measurement_theta_min      10.54
_cell_volume                     1602.3(2)
_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      213(2)
_diffrn_measurement_device       'Siemens P4'
_diffrn_measurement_method       '2\q/\w scans'
_diffrn_radiation_monochromator  graphite
_diffrn_radiation_source         'fine-focus rotating anode'
_diffrn_radiation_type           MoKa
_diffrn_radiation_wavelength     0.71073
_diffrn_reflns_av_R_equivalents  0.0455
_diffrn_reflns_av_sigmaI/netI    0.0614
_diffrn_reflns_limit_h_max       10
_diffrn_reflns_limit_h_min       0
_diffrn_reflns_limit_k_max       14
_diffrn_reflns_limit_k_min       0
_diffrn_reflns_limit_l_max       16
_diffrn_reflns_limit_l_min       -17
_diffrn_reflns_number            3000
_diffrn_reflns_theta_max         25.00
_diffrn_reflns_theta_min         2.19
_diffrn_standards_interval_count 297
_diffrn_standards_number         3
_exptl_absorpt_coefficient_mu    0.061
_exptl_absorpt_correction_type   none
_exptl_crystal_colour            colorless
_exptl_crystal_density_diffrn    1.079
_exptl_crystal_description       fragment
_exptl_crystal_F_000             560
_exptl_crystal_size_max          0.60
_exptl_crystal_size_mid          0.30
_exptl_crystal_size_min          0.23
_refine_diff_density_max         .421
_refine_diff_density_min         -.217
_refine_diff_density_rms         .076
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_all   1.024
_refine_ls_goodness_of_fit_obs   1.149
_refine_ls_matrix_type           full
_refine_ls_number_parameters     185
_refine_ls_number_reflns         2814
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      1.024
_refine_ls_restrained_S_obs      1.149
_refine_ls_R_factor_all          0.1618
_refine_ls_R_factor_obs          0.0762
_refine_ls_shift/esd_max         0.004
_refine_ls_shift/esd_mean        0.000
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'w=1/[s^2^(Fo^2^)+( 0.0724P)^2^+0.7846P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_all         0.2012
_refine_ls_wR_factor_obs         0.1549
_reflns_number_observed          1399
_reflns_number_total             2814
_reflns_observed_criterion       >2sigma(I)
_cod_data_source_file            900910hsup1.cif
_cod_data_source_block           rrt9813
_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 2.4.2 from 2011-04-26.

Automatic conversion script
Id: cif_fix_values 1891 2012-01-12 08:04:46Z andrius 

The following automatic conversions were performed:

'_refine_ls_weighting_scheme' value 'calc w=1/[s^2^(Fo^2^)+(
0.0724P)^2^+0.7846P] 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^)+( 0.0724P)^2^+0.7846P] where
P=(Fo^2^+2Fc^2^)/3'.

Automatic conversion script
Id: cif_fix_values 3143 2015-03-26 13:38:13Z robertas 
;
_cod_original_sg_symbol_H-M      P2(1)/c
_cod_database_code               7110479