Polymerization of acetylene: polyynes, but not carbyne
Prenzel, Dominik; Kirschbaum, Rolf W.; Chalifoux, Wesley A.; McDonald, Robert; Ferguson, Michael J.; Drewello, Thomas; Tykwinski, Rik R.; Organic Chemistry Frontiers 4 (2017) 668–; doi:10.1039/C6QO00648E

data_1553590
_publ_section_title
;
 Polymerization of acetylene: polyynes, but not carbyne
;
_journal_issue                   5
_journal_name_full               'Organic Chemistry Frontiers'
_journal_page_first              668
_journal_paper_doi               10.1039/C6QO00648E
_journal_volume                  4
_journal_year                    2017
_chemical_formula_moiety         'C49 H64'
_chemical_formula_sum            'C49 H64'
_chemical_formula_weight         653.00
_chemical_name_systematic
1,1,1-tris(3,5-di-t-butylphenyl)hepta-2,4,6-triyne
_space_group_crystal_system      trigonal
_space_group_IT_number           159
_space_group_name_Hall           'P 3 -2c'
_space_group_name_H-M_alt        'P 3 1 c'
_atom_sites_solution_hydrogens   geom
_audit_creation_method           SHELXL-2014/7
_audit_update_record
;
2016-11-02 deposited with the CCDC.
2016-11-08 downloaded from the CCDC.
;
_cell_angle_alpha                90
_cell_angle_beta                 90
_cell_angle_gamma                120
_cell_formula_units_Z            2
_cell_length_a                   14.154(3)
_cell_length_b                   14.154(3)
_cell_length_c                   12.123(2)
_cell_measurement_reflns_used    2337
_cell_measurement_temperature    173(2)
_cell_measurement_theta_max      20.58
_cell_measurement_theta_min      2.36
_cell_volume                     2103.3(7)
_computing_cell_refinement       'Bruker SAINT'
_computing_data_collection       'Bruker APEX2'
_computing_data_reduction        'Bruker SAINT'
_computing_molecular_graphics    'Bruker SHELXTL'
_computing_publication_material  'Bruker SHELXTL'
_computing_structure_refinement  'SHELXL-2014/7 (Sheldrick, 2014)'
_computing_structure_solution    'SHELXS-97 (Sheldrick, 2008)'
_diffrn_ambient_temperature      173(2)
_diffrn_measured_fraction_theta_full 1.000
_diffrn_measured_fraction_theta_max 0.999
_diffrn_measurement_device_type  'Bruker APEX-II CCD'
_diffrn_measurement_method       '\w scans'
_diffrn_radiation_type           MoK\a
_diffrn_radiation_wavelength     0.71073
_diffrn_reflns_av_R_equivalents  0.0954
_diffrn_reflns_av_unetI/netI     0.0481
_diffrn_reflns_Laue_measured_fraction_full 1.000
_diffrn_reflns_Laue_measured_fraction_max 0.999
_diffrn_reflns_limit_h_max       17
_diffrn_reflns_limit_h_min       -17
_diffrn_reflns_limit_k_max       17
_diffrn_reflns_limit_k_min       -17
_diffrn_reflns_limit_l_max       14
_diffrn_reflns_limit_l_min       -14
_diffrn_reflns_number            15255
_diffrn_reflns_point_group_measured_fraction_full 1.000
_diffrn_reflns_point_group_measured_fraction_max 0.999
_diffrn_reflns_theta_full        25.242
_diffrn_reflns_theta_max         25.716
_diffrn_reflns_theta_min         1.661
_exptl_absorpt_coefficient_mu    0.057
_exptl_absorpt_correction_T_max  1.0000
_exptl_absorpt_correction_T_min  0.9173
_exptl_absorpt_correction_type   numerical
_exptl_absorpt_process_details   'SADABS 2014/5'
_exptl_crystal_colour            colourless
_exptl_crystal_density_diffrn    1.031
_exptl_crystal_description       rod
_exptl_crystal_F_000             716
_exptl_crystal_recrystallization_method
'Re-crystallisation from solvent: xylenes'
_exptl_crystal_size_max          0.460
_exptl_crystal_size_mid          0.068
_exptl_crystal_size_min          0.046
_refine_diff_density_max         0.130
_refine_diff_density_min         -0.164
_refine_diff_density_rms         0.033
_refine_ls_abs_structure_details
; 
 Flack x determined using 836 quotients [(I+)-(I-)]/[(I+)+(I-)] 
 (Parsons, Flack and Wagner, Acta Cryst. B69 (2013) 249-259). 
;
_refine_ls_abs_structure_Flack   0.0(10)
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.035
_refine_ls_hydrogen_treatment    constr
_refine_ls_matrix_type           full
_refine_ls_number_parameters     148
_refine_ls_number_reflns         2685
_refine_ls_number_restraints     1
_refine_ls_restrained_S_all      1.034
_refine_ls_R_factor_all          0.0720
_refine_ls_R_factor_gt           0.0411
_refine_ls_shift/su_max          0.000
_refine_ls_shift/su_mean         0.000
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'w=1/[\s^2^(Fo^2^)+(0.0327P)^2^+0.3159P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.0776
_refine_ls_wR_factor_ref         0.0882
_reflns_Friedel_coverage         0.989
_reflns_Friedel_fraction_full    1.000
_reflns_Friedel_fraction_max     0.999
_reflns_number_gt                1988
_reflns_number_total             2685
_reflns_threshold_expression     'I > 2\s(I)'
_cod_data_source_file            c6qo00648e2.cif
_cod_data_source_block           Tr-H3
_cod_original_cell_volume        2103.4(9)
_cod_database_code               1553590
_shelx_shelxl_version_number     2014/7
_shelx_estimated_absorpt_t_min   0.974
_shelx_estimated_absorpt_t_max   0.997
_shelx_res_checksum              71670
_shelx_hkl_checksum              79775