Closely related yet different: a borylene and its dimer are non-interconvertible but connected through reactivity.
Auerhammer, Dominic; Arrowsmith, Merle; Dewhurst, Rian D.; Kupfer, Thomas; Böhnke, Julian; Braunschweig, Holger; Chemical science 9 (2018) 2252–2260; doi:10.1039/c7sc04789d

data_1548600
_publ_section_title
;
 Closely related yet different: a borylene and its dimer are
 non-interconvertible but connected through reactivity.
;
_journal_issue                   8
_journal_name_full               'Chemical science'
_journal_page_first              2252
_journal_page_last               2260
_journal_paper_doi               10.1039/c7sc04789d
_journal_volume                  9
_journal_year                    2018
_chemical_formula_moiety         'C42 H62 B2 N4 Se'
_chemical_formula_sum            'C42 H62 B2 N4 Se'
_chemical_formula_weight         723.53
_chemical_properties_physical    Air-sensitive,Moisture-sensitive
_space_group_crystal_system      orthorhombic
_space_group_IT_number           61
_space_group_name_Hall           '-P 2ac 2ab'
_space_group_name_H-M_alt        'P b c a'
_symmetry_space_group_name_Hall  '-P 2ac 2ab'
_symmetry_space_group_name_H-M   'P b c a'
_atom_sites_solution_hydrogens   geom
_audit_creation_method           SHELXL-2014/7
_audit_update_record
;
2017-10-27 deposited with the CCDC.
2018-01-04 downloaded from the CCDC.
;
_cell_angle_alpha                90
_cell_angle_beta                 90
_cell_angle_gamma                90
_cell_formula_units_Z            8
_cell_length_a                   17.8352(15)
_cell_length_b                   16.7797(16)
_cell_length_c                   28.365(3)
_cell_measurement_reflns_used    9883
_cell_measurement_temperature    100(2)
_cell_measurement_theta_max      27.09
_cell_measurement_theta_min      2.20
_cell_volume                     8488.8(14)
_computing_data_collection       'Smart NT ver. 5.63 (Bruker AXS)'
_computing_molecular_graphics    'ShelXLe (Huebschle et all, 2011)'
_computing_publication_material  'SHELXL-2014/6 (Sheldrick, 2014)'
_computing_structure_refinement  'SHELXL-2014/6 (Sheldrick, 2014)'
_computing_structure_solution    'SHELXT (Sheldrick, 2012)'
_diffrn_ambient_temperature      100(2)
_diffrn_detector                 'CCD area detector (Apex1)'
_diffrn_detector_area_resol_mean 8.333
_diffrn_measured_fraction_theta_full 0.999
_diffrn_measured_fraction_theta_max 0.996
_diffrn_measurement_device_type  'Bruker SMART-APEX'
_diffrn_measurement_method       '\f and \w scans'
_diffrn_radiation_type           MoK\a
_diffrn_radiation_wavelength     0.71073
_diffrn_reflns_av_R_equivalents  0.1082
_diffrn_reflns_av_unetI/netI     0.0424
_diffrn_reflns_Laue_measured_fraction_full 0.999
_diffrn_reflns_Laue_measured_fraction_max 0.996
_diffrn_reflns_limit_h_max       22
_diffrn_reflns_limit_h_min       -22
_diffrn_reflns_limit_k_max       21
_diffrn_reflns_limit_k_min       -21
_diffrn_reflns_limit_l_max       36
_diffrn_reflns_limit_l_min       -32
_diffrn_reflns_number            148765
_diffrn_reflns_point_group_measured_fraction_full 0.999
_diffrn_reflns_point_group_measured_fraction_max 0.996
_diffrn_reflns_theta_full        26.000
_diffrn_reflns_theta_max         27.165
_diffrn_reflns_theta_min         1.436
_diffrn_source                   'sealed tube'
_exptl_absorpt_coefficient_mu    0.916
_exptl_absorpt_correction_T_max  0.7455
_exptl_absorpt_correction_T_min  0.6427
_exptl_absorpt_correction_type   multi-scan
_exptl_absorpt_process_details   'SadAbs 2014/4 (Bruker AXS)'
_exptl_crystal_colour            yellow
_exptl_crystal_density_diffrn    1.132
_exptl_crystal_description       block
_exptl_crystal_F_000             3088
_exptl_crystal_size_max          0.391
_exptl_crystal_size_mid          0.351
_exptl_crystal_size_min          0.202
_refine_diff_density_max         0.453
_refine_diff_density_min         -0.433
_refine_diff_density_rms         0.067
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.097
_refine_ls_hydrogen_treatment    constr
_refine_ls_matrix_type           full
_refine_ls_number_parameters     750
_refine_ls_number_reflns         9396
_refine_ls_number_restraints     1084
_refine_ls_restrained_S_all      1.097
_refine_ls_R_factor_all          0.0869
_refine_ls_R_factor_gt           0.0508
_refine_ls_shift/su_max          0.001
_refine_ls_shift/su_mean         0.000
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'w=1/[\s^2^(Fo^2^)+(0.0292P)^2^+16.3051P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.1029
_refine_ls_wR_factor_ref         0.1182
_reflns_Friedel_coverage         0.000
_reflns_number_gt                6493
_reflns_number_total             9396
_reflns_threshold_expression     'I > 2\s(I)'
_cod_data_source_file            c7sc04789d2.cif
_cod_data_source_block           final_a_CCDC2
_cod_depositor_comments
'Adding full bibliography for 1548594--1548603.cif.'
_cod_original_cell_volume        8488.9(13)
_cod_database_code               1548600
_shelx_shelxl_version_number     2014/7
_shelx_estimated_absorpt_t_min   0.716
_shelx_estimated_absorpt_t_max   0.837
_shelx_res_checksum              79493