A small change in molecular structure, a big difference in the AIEE mechanism.
Cai, Minmin; Gao, Zhiqiang; Zhou, Xinhui; Wang, Xupeng; Chen, Shufen; Zhao, Yuezhi; Qian, Yan; Shi, Naien; Mi, Baoxiu; Xie, Linghai; Huang, Wei; Physical chemistry chemical physics : PCCP 14 (2012) 5289–5296; doi:10.1039/c2cp23040b

data_7207676
_publ_section_title
;
 A small change in molecular structure, a big difference in the AIEE
 mechanism.
;
_journal_issue                   15
_journal_name_full               'Physical chemistry chemical physics : PCCP'
_journal_page_first              5289
_journal_page_last               5296
_journal_paper_doi               10.1039/c2cp23040b
_journal_volume                  14
_journal_year                    2012
_chemical_formula_sum            'C32 H26 N2 O4 S'
_chemical_formula_weight         534.61
_space_group_IT_number           2
_symmetry_space_group_name_Hall  '-P 1'
_symmetry_space_group_name_H-M   'P -1'
_atom_sites_solution_hydrogens   geom
_atom_sites_solution_primary     direct
_atom_sites_solution_secondary   difmap
_audit_creation_method           SHELXL-97
_cell_angle_alpha                105.468(9)
_cell_angle_beta                 95.318(9)
_cell_angle_gamma                100.648(10)
_cell_formula_units_Z            2
_cell_length_a                   9.119(7)
_cell_length_b                   10.382(8)
_cell_length_c                   15.374(11)
_cell_measurement_temperature    296(2)
_cell_volume                     1363.1(18)
_computing_structure_refinement  'SHELXL-97 (Sheldrick, 1997)'
_computing_structure_solution    'SHELXS-97 (Sheldrick, 1990)'
_diffrn_ambient_temperature      296(2)
_diffrn_measured_fraction_theta_full 0.981
_diffrn_measured_fraction_theta_max 0.981
_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  0.0590
_diffrn_reflns_av_sigmaI/netI    0.0390
_diffrn_reflns_limit_h_max       10
_diffrn_reflns_limit_h_min       -10
_diffrn_reflns_limit_k_max       5
_diffrn_reflns_limit_k_min       -12
_diffrn_reflns_limit_l_max       17
_diffrn_reflns_limit_l_min       -18
_diffrn_reflns_number            6778
_diffrn_reflns_theta_full        25.00
_diffrn_reflns_theta_max         25.00
_diffrn_reflns_theta_min         2.09
_exptl_absorpt_coefficient_mu    0.159
_exptl_absorpt_correction_T_max  0.9811
_exptl_absorpt_correction_T_min  0.9765
_exptl_crystal_density_diffrn    1.303
_exptl_crystal_density_method    'not measured'
_exptl_crystal_F_000             560
_exptl_crystal_size_max          0.15
_exptl_crystal_size_mid          0.14
_exptl_crystal_size_min          0.12
_refine_diff_density_max         0.298
_refine_diff_density_min         -0.249
_refine_diff_density_rms         0.041
_refine_ls_extinction_coef       0.0125(19)
_refine_ls_extinction_expression Fc^*^=kFc[1+0.001xFc^2^\l^3^/sin(2\q)]^-1/4^
_refine_ls_extinction_method     SHELXL
_refine_ls_goodness_of_fit_ref   1.063
_refine_ls_hydrogen_treatment    mixed
_refine_ls_matrix_type           full
_refine_ls_number_parameters     356
_refine_ls_number_reflns         4703
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      1.063
_refine_ls_R_factor_all          0.0513
_refine_ls_R_factor_gt           0.0414
_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^)+(0.0662P)^2^+0.0877P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.1150
_refine_ls_wR_factor_ref         0.1219
_reflns_number_gt                3793
_reflns_number_total             4703
_reflns_threshold_expression     >2sigma(I)
_cod_data_source_file            c2cp23040b.txt
_cod_data_source_block           T4AC
_cod_original_cell_volume        1363.1(17)
_cod_database_code               7207676