A new tricyclic ring and a nitrogen???sulfur analogue of the tri-pentagon bowl: cycloaddition reactions of the unstablised 1,3,4-thiadiazolium-3-methanide 1,3-dipole: steric influences on the endo-effect: substituted pyrrolo[2,1-b]-1,3,4-thiadiazole systems: azolium 1,3-dipoles
Butler, Richard N.; Smyth, Georgina M.; McArdle, Patrick; Cunningham, Desmond; Journal of the Chemical Society, Perkin Transactions 1  (2002) 2851–; doi:10.1039/b208544p

data_7204524
_publ_section_title
;
 A new tricyclic ring and a nitrogen???sulfur analogue of the
 tri-pentagon bowl: cycloaddition reactions of the unstablised
 1,3,4-thiadiazolium-3-methanide 1,3-dipole: steric influences on the
 endo-effect: substituted pyrrolo[2,1-b]-1,3,4-thiadiazole systems:
 azolium 1,3-dipoles
;
_journal_issue                   24
_journal_name_full
'Journal of the Chemical Society, Perkin Transactions 1'
_journal_page_first              2851
_journal_paper_doi               10.1039/b208544p
_journal_year                    2002
_chemical_formula_sum            'C20 H17 N3 O2 S'
_chemical_formula_weight         363.43
_chemical_name_systematic
;
?
;
_space_group_IT_number           14
_symmetry_cell_setting           monoclinic
_symmetry_space_group_name_Hall  '-P 2yab'
_symmetry_space_group_name_H-M   'P 1 21/a 1'
_atom_sites_solution_hydrogens   geom
_atom_sites_solution_primary     direct
_atom_sites_solution_secondary   difmap
_audit_creation_method           SHELXL-97
_cell_angle_alpha                90.00
_cell_angle_beta                 99.75(2)
_cell_angle_gamma                90.00
_cell_formula_units_Z            4
_cell_length_a                   12.524(2)
_cell_length_b                   11.088(3)
_cell_length_c                   12.935(2)
_cell_measurement_reflns_used    25
_cell_measurement_temperature    293(2)
_cell_measurement_theta_max      18
_cell_measurement_theta_min      12
_cell_volume                     1770.3(6)
_computing_cell_refinement       'Nonius CAD4 software'
_computing_data_collection       'Nonius CAD4 software'
_computing_data_reduction        'XCAD (P.McArdle, 2000)'
_computing_molecular_graphics    'ORTEX (P.McArdle, 1995)'
_computing_publication_material  'SHELXL-97/2 (Sheldrick,1997)'
_computing_structure_refinement  'SHELXL-97 (Sheldrick, 1997)'
_computing_structure_solution    'SHELXS-97 (Sheldrick, 1990)'
_diffrn_ambient_temperature      293(2)
_diffrn_measured_fraction_theta_full 0.999
_diffrn_measured_fraction_theta_max 0.999
_diffrn_measurement_device_type  '4-circle diffractometer'
_diffrn_measurement_method       'scintillation counter'
_diffrn_radiation_monochromator  graphite
_diffrn_radiation_source         'fine-focus sealed tube'
_diffrn_radiation_type           MoK\a
_diffrn_radiation_wavelength     0.71069
_diffrn_reflns_av_R_equivalents  0.0228
_diffrn_reflns_av_sigmaI/netI    0.1239
_diffrn_reflns_limit_h_max       13
_diffrn_reflns_limit_h_min       -5
_diffrn_reflns_limit_k_max       11
_diffrn_reflns_limit_k_min       -3
_diffrn_reflns_limit_l_max       13
_diffrn_reflns_limit_l_min       -13
_diffrn_reflns_number            2370
_diffrn_reflns_theta_full        21.98
_diffrn_reflns_theta_max         21.98
_diffrn_reflns_theta_min         2.43
_exptl_absorpt_coefficient_mu    0.203
_exptl_crystal_colour            Colourless
_exptl_crystal_density_diffrn    1.364
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       Parallelepiped
_exptl_crystal_F_000             760
_exptl_crystal_size_max          0.50
_exptl_crystal_size_mid          0.40
_exptl_crystal_size_min          0.20
_refine_diff_density_max         0.193
_refine_diff_density_min         -0.226
_refine_diff_density_rms         0.050
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   0.877
_refine_ls_hydrogen_treatment    mixed
_refine_ls_matrix_type           full
_refine_ls_number_parameters     236
_refine_ls_number_reflns         2164
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      0.877
_refine_ls_R_factor_all          0.1254
_refine_ls_R_factor_gt           0.0422
_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=3D1/[\s^2^(Fo^2^)+(0.0429P)^2^+0.0000P] where P=3D(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.0859
_refine_ls_wR_factor_ref         0.1022
_reflns_number_gt                1072
_reflns_number_total             2164
_reflns_threshold_expression     >2sigma(I)
_cod_data_source_file            b208544p.txt
_cod_data_source_block           gs1
_cod_depositor_comments
;
The following automatic conversions were performed:
'_atom_site_symetry_multiplicity' tag replaced with
'_atom_site_symmetry_multiplicity'.

Automatic conversion script
Id: cif_correct_tags 1440 2010-10-19 06:21:57Z saulius 

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 
;
_cod_original_sg_symbol_H-M      P21/a
_cod_database_code               7204524