Stress-Responsive Polymers Containing Cyclobutane Core Mechanophores: Reactivity and Mechanistic Insights
Zachary S. Kean; Zhenbin Niu; Gihan B. Hewage; Arnold L. Rheingold; Stephen L. Craig; Journal of the American Chemical Society 135 (2013) 13598–13604; doi:10.1021/ja4075997

data_4120780
_publ_section_title
;
 Stress-Responsive Polymers Containing Cyclobutane Core Mechanophores:
 Reactivity and Mechanistic Insights
;
_journal_name_full               'Journal of the American Chemical Society'
_journal_page_first              13598
_journal_page_last               13604
_journal_paper_doi               10.1021/ja4075997
_journal_volume                  135
_journal_year                    2013
_chemical_formula_sum            'C12 H16 Br2 O4'
_chemical_formula_weight         384.07
_space_group_IT_number           14
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_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           SHELXL-97
_cell_angle_alpha                90.00
_cell_angle_beta                 106.9400(10)
_cell_angle_gamma                90.00
_cell_formula_units_Z            4
_cell_length_a                   8.4288(2)
_cell_length_b                   13.7579(4)
_cell_length_c                   12.3099(3)
_cell_measurement_reflns_used    5442
_cell_measurement_temperature    100(2)
_cell_measurement_theta_max      66.68
_cell_measurement_theta_min      4.94
_cell_volume                     1365.55(6)
_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-97 (Sheldrick, 1997)'
_computing_structure_solution    'SHELXS-97 (Sheldrick, 1990)'
_diffrn_ambient_temperature      100(2)
_diffrn_measured_fraction_theta_full 0.983
_diffrn_measured_fraction_theta_max 0.973
_diffrn_measurement_device_type  'Bruker APEX-II CCD'
_diffrn_measurement_method       '\f and \w scans'
_diffrn_radiation_monochromator  graphite
_diffrn_radiation_source         'fine-focus sealed tube'
_diffrn_radiation_type           CuK\a
_diffrn_radiation_wavelength     1.54178
_diffrn_reflns_av_R_equivalents  0.0519
_diffrn_reflns_av_sigmaI/netI    0.0474
_diffrn_reflns_limit_h_max       9
_diffrn_reflns_limit_h_min       -10
_diffrn_reflns_limit_k_max       16
_diffrn_reflns_limit_k_min       -16
_diffrn_reflns_limit_l_max       14
_diffrn_reflns_limit_l_min       -14
_diffrn_reflns_number            8416
_diffrn_reflns_theta_full        66.50
_diffrn_reflns_theta_max         67.44
_diffrn_reflns_theta_min         4.94
_exptl_absorpt_coefficient_mu    7.588
_exptl_absorpt_correction_T_max  0.5175
_exptl_absorpt_correction_T_min  0.2632
_exptl_absorpt_correction_type   multi-scan
_exptl_absorpt_process_details   SADABS
_exptl_crystal_colour            colorless
_exptl_crystal_density_diffrn    1.868
_exptl_crystal_description       plate
_exptl_crystal_F_000             760
_exptl_crystal_size_max          0.24
_exptl_crystal_size_mid          0.24
_exptl_crystal_size_min          0.10
_refine_diff_density_max         1.090
_refine_diff_density_min         -0.782
_refine_diff_density_rms         0.134
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.074
_refine_ls_hydrogen_treatment    constr
_refine_ls_matrix_type           full
_refine_ls_number_parameters     165
_refine_ls_number_reflns         2391
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      1.074
_refine_ls_R_factor_all          0.0450
_refine_ls_R_factor_gt           0.0409
_refine_ls_shift/su_max          0.003
_refine_ls_shift/su_mean         0.000
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'calc w=1/[\s^2^(Fo^2^)+(0.0380P)^2^+6.0000P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.0988
_refine_ls_wR_factor_ref         0.1017
_reflns_number_gt                2208
_reflns_number_total             2391
_reflns_threshold_expression     >2sigma(I)
_cod_data_source_file            ja4075997_si_001.cif
_cod_data_source_block           niu03
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