Exciton delocalization drives rapid singlet fission in nanoparticles of acene derivatives.
Pensack, Ryan D.; Tilley, Andrew J.; Parkin, Sean R.; Lee, Tia S.; Payne, Marcia M.; Gao, Dong; Jahnke, Ashlee A.; Oblinsky, Daniel G.; Li, Peng-Fei; Anthony, John E.; Seferos, Dwight S.; Scholes, Gregory D.; Journal of the American Chemical Society 137 (2015) 6790–6803; doi:10.1021/ja512668r

data_4123698
_publ_section_title
;
 Exciton delocalization drives rapid singlet fission in nanoparticles of
 acene derivatives.
;
_journal_issue                   21
_journal_name_full               'Journal of the American Chemical Society'
_journal_page_first              6790
_journal_page_last               6803
_journal_paper_doi               10.1021/ja512668r
_journal_volume                  137
_journal_year                    2015
_chemical_formula_moiety         'C50 H66 Si2'
_chemical_formula_sum            'C50 H66 Si2'
_chemical_formula_weight         723.21
_space_group_IT_number           14
_symmetry_cell_setting           monoclinic
_symmetry_space_group_name_Hall  '-P 2yn'
_symmetry_space_group_name_H-M   'P 1 21/n 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                 105.977(1)
_cell_angle_gamma                90.00
_cell_formula_units_Z            2
_cell_length_a                   11.7476(2)
_cell_length_b                   12.5710(2)
_cell_length_c                   15.1412(3)
_cell_measurement_reflns_used    9916
_cell_measurement_temperature    90.0(2)
_cell_measurement_theta_max      67.97
_cell_measurement_theta_min      4.24
_cell_volume                     2149.67(7)
_computing_cell_refinement       APEX2
_computing_data_collection       'APEX2 (Bruker-AXS, 2006)'
_computing_data_reduction        APEX2
_computing_molecular_graphics    'XP in SHELXTL (Sheldrick, 2008)'
_computing_publication_material
; 
SHELX-97 (Sheldrick, 2008) and local procedures 
;
_computing_structure_refinement  'SHELXL-97 (Sheldrick, 2008)'
_computing_structure_solution    'SHELXS-97 (Sheldrick, 2008)'
_diffrn_ambient_temperature      90.0(2)
_diffrn_detector_area_resol_mean 5.6
_diffrn_measured_fraction_theta_full 0.996
_diffrn_measured_fraction_theta_max 0.996
_diffrn_measurement_device_type  'Bruker X8 Proteum diffractometer'
_diffrn_measurement_method       '\f and \w scans'
_diffrn_radiation_monochromator  'graded multilayer optics'
_diffrn_radiation_source         'fine-focus rotating anode'
_diffrn_radiation_type           CuK\a
_diffrn_radiation_wavelength     1.54178
_diffrn_reflns_av_R_equivalents  0.0568
_diffrn_reflns_av_sigmaI/netI    0.0294
_diffrn_reflns_limit_h_max       14
_diffrn_reflns_limit_h_min       -14
_diffrn_reflns_limit_k_max       15
_diffrn_reflns_limit_k_min       -15
_diffrn_reflns_limit_l_max       18
_diffrn_reflns_limit_l_min       -17
_diffrn_reflns_number            29298
_diffrn_reflns_theta_full        68.21
_diffrn_reflns_theta_max         68.21
_diffrn_reflns_theta_min         4.24
_diffrn_standards_number         0
_exptl_absorpt_coefficient_mu    0.975
_exptl_absorpt_correction_T_max  0.981
_exptl_absorpt_correction_T_min  0.801
_exptl_absorpt_correction_type   multi-scan
_exptl_absorpt_process_details   'Sadabs in APEX2 (BrukerAXS, 2006)'
_exptl_crystal_colour            blue
_exptl_crystal_density_diffrn    1.117
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       flake
_exptl_crystal_F_000             788
_exptl_crystal_size_max          0.18
_exptl_crystal_size_mid          0.15
_exptl_crystal_size_min          0.02
_refine_diff_density_max         0.739
_refine_diff_density_min         -0.430
_refine_diff_density_rms         0.066
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.040
_refine_ls_hydrogen_treatment    constr
_refine_ls_matrix_type           full
_refine_ls_number_parameters     268
_refine_ls_number_reflns         3912
_refine_ls_number_restraints     30
_refine_ls_restrained_S_all      1.039
_refine_ls_R_factor_all          0.1170
_refine_ls_R_factor_gt           0.0809
_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^)+(0.0852P)^2^+4.4894P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.1916
_refine_ls_wR_factor_ref         0.2340
_reflns_number_gt                2805
_reflns_number_total             3912
_reflns_threshold_expression     >2\s(I)
_cod_data_source_file            ja512668r_si_002.cif
_cod_data_source_block           x09086
_cod_depositor_comments
'Adding full bibliography for 4123696--4123698.cif.'
_cod_original_sg_symbol_H-M      'P 21/n'
_cod_database_code               4123698