Crystal structure of a cyclotetramer from a strained cyclic allene.
Mahlokozera, Tatenda; Goods, John B.; Childs, Adam M.; Thamattoor, Dasan M.; Organic letters 11 (2009) 5095–5097; doi:10.1021/ol902177b

data_1504262
_publ_section_title
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 Crystal structure of a cyclotetramer from a strained cyclic allene.
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_journal_issue                   22
_journal_name_full               'Organic letters'
_journal_page_first              5095
_journal_page_last               5097
_journal_paper_doi               10.1021/ol902177b
_journal_volume                  11
_journal_year                    2009
_chemical_formula_moiety         'C60 H40'
_chemical_formula_sum            'C60 H40'
_chemical_formula_weight         760.92
_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
_atom_sites_solution_secondary   difmap
_audit_creation_method           SHELXL-97
_cell_angle_alpha                90.00
_cell_angle_beta                 112.458(7)
_cell_angle_gamma                90.00
_cell_formula_units_Z            4
_cell_length_a                   25.789(11)
_cell_length_b                   10.154(4)
_cell_length_c                   15.750(7)
_cell_measurement_reflns_used    4007
_cell_measurement_temperature    173(2)
_cell_measurement_theta_max      27.57
_cell_measurement_theta_min      2.18
_cell_volume                     3812(3)
_computing_cell_refinement       'Bruker SMART'
_computing_data_collection       'Bruker SMART'
_computing_data_reduction        'Bruker SAINT'
_computing_molecular_graphics    'Bruker SHELXTL'
_computing_publication_material  'Bruker SHELXTL'
_computing_structure_refinement  'SHELXL-97 (Sheldrick, 1997)'
_computing_structure_solution    'SHELXS-97 (Sheldrick, 1990)'
_diffrn_ambient_temperature      173(2)
_diffrn_measured_fraction_theta_full 0.981
_diffrn_measured_fraction_theta_max 0.981
_diffrn_measurement_device_type  'CCD area detector'
_diffrn_measurement_method       'phi and omega scans'
_diffrn_radiation_monochromator  graphite
_diffrn_radiation_source         'fine-focus sealed tube'
_diffrn_radiation_type           MoK\a
_diffrn_radiation_wavelength     0.71073
_diffrn_reflns_av_R_equivalents  0.1042
_diffrn_reflns_av_sigmaI/netI    0.0756
_diffrn_reflns_limit_h_max       34
_diffrn_reflns_limit_h_min       -34
_diffrn_reflns_limit_k_max       13
_diffrn_reflns_limit_k_min       -13
_diffrn_reflns_limit_l_max       21
_diffrn_reflns_limit_l_min       -20
_diffrn_reflns_number            17782
_diffrn_reflns_theta_full        28.46
_diffrn_reflns_theta_max         28.46
_diffrn_reflns_theta_min         1.71
_exptl_absorpt_coefficient_mu    0.075
_exptl_absorpt_correction_type   none
_exptl_crystal_colour            colourless
_exptl_crystal_density_diffrn    1.326
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       'rectangular prism'
_exptl_crystal_F_000             1600
_exptl_crystal_size_max          0.32
_exptl_crystal_size_mid          0.21
_exptl_crystal_size_min          0.11
_refine_diff_density_max         0.466
_refine_diff_density_min         -0.227
_refine_diff_density_rms         0.059
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.045
_refine_ls_hydrogen_treatment    constr
_refine_ls_matrix_type           full
_refine_ls_number_parameters     271
_refine_ls_number_reflns         4729
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      1.045
_refine_ls_R_factor_all          0.0832
_refine_ls_R_factor_gt           0.0575
_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^)+(0.0722P)^2^+0.0000P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.1401
_refine_ls_wR_factor_ref         0.1533
_reflns_number_gt                3241
_reflns_number_total             4729
_reflns_threshold_expression     >2sigma(I)
_cod_data_source_file            ol902177b_si_002.cif
_cod_data_source_block           das0912m
_cod_original_sg_symbol_H-M      C2/c
_cod_database_code               1504262