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_1548596
_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 Se3, 2 (C4 H8 O)'
_chemical_formula_sum            'C50 H78 B2 N4 O2 Se3'
_chemical_formula_weight         1025.66
_chemical_properties_physical    Air-sensitive,Moisture-sensitive,Heat-sensitive
_space_group_crystal_system      monoclinic
_space_group_IT_number           15
_space_group_name_Hall           '-C 2yc'
_space_group_name_H-M_alt        'C 1 2/c 1'
_symmetry_space_group_name_Hall  '-C 2yc'
_symmetry_space_group_name_H-M   'C 1 2/c 1'
_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                 103.042(5)
_cell_angle_gamma                90
_cell_formula_units_Z            4
_cell_length_a                   16.059(3)
_cell_length_b                   17.563(3)
_cell_length_c                   17.928(3)
_cell_measurement_reflns_used    3311
_cell_measurement_temperature    100(2)
_cell_measurement_theta_max      23.98
_cell_measurement_theta_min      2.25
_cell_volume                     4926.1(15)
_computing_cell_refinement       'Saint+ ver. 7.68A (Bruker AXS)'
_computing_data_collection       'APEX2 ver. 2014.9 (Bruker AXS)'
_computing_data_reduction        'Saint+ ver. 7.68A (Bruker AXS)'
_computing_molecular_graphics    'ShelXLe (Huebschle et all, 2011)'
_computing_publication_material  'SHELXL-2014/6 (Sheldrick, 2014) '
_computing_structure_refinement  'SHELXL-2014/7 (Sheldrick, 2014)'
_computing_structure_solution    'SHELXT 2014/4 (Sheldrick, 2014)'
_diffrn_ambient_temperature      100(2)
_diffrn_detector_area_resol_mean 3888
_diffrn_measured_fraction_theta_full 1.000
_diffrn_measured_fraction_theta_max 1.000
_diffrn_measurement_device_type  'Bruker Apex II'
_diffrn_measurement_method       '\f and \w scans'
_diffrn_radiation_type           MoK\a
_diffrn_radiation_wavelength     0.71073
_diffrn_reflns_av_R_equivalents  0.1333
_diffrn_reflns_av_unetI/netI     0.0973
_diffrn_reflns_Laue_measured_fraction_full 1.000
_diffrn_reflns_Laue_measured_fraction_max 1.000
_diffrn_reflns_limit_h_max       20
_diffrn_reflns_limit_h_min       -20
_diffrn_reflns_limit_k_max       22
_diffrn_reflns_limit_k_min       -19
_diffrn_reflns_limit_l_max       22
_diffrn_reflns_limit_l_min       -14
_diffrn_reflns_number            37199
_diffrn_reflns_point_group_measured_fraction_full 1.000
_diffrn_reflns_point_group_measured_fraction_max 1.000
_diffrn_reflns_theta_full        26.000
_diffrn_reflns_theta_max         27.100
_diffrn_reflns_theta_min         1.743
_diffrn_source
'rotating-anode X-ray tube or sealed X-ray tube'
_exptl_absorpt_coefficient_mu    2.282
_exptl_absorpt_correction_T_max  0.7455
_exptl_absorpt_correction_T_min  0.5834
_exptl_absorpt_correction_type   multi-scan
_exptl_absorpt_process_details   'Sadabs 2014/4 (Bruker 2014)'
_exptl_crystal_colour            yellow
_exptl_crystal_density_diffrn    1.383
_exptl_crystal_description       plate
_exptl_crystal_F_000             2136
_exptl_crystal_size_max          0.078
_exptl_crystal_size_mid          0.043
_exptl_crystal_size_min          0.035
_refine_diff_density_max         1.575
_refine_diff_density_min         -1.112
_refine_diff_density_rms         0.133
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.073
_refine_ls_hydrogen_treatment    constr
_refine_ls_matrix_type           full
_refine_ls_number_parameters     284
_refine_ls_number_reflns         5443
_refine_ls_number_restraints     18
_refine_ls_restrained_S_all      1.074
_refine_ls_R_factor_all          0.1018
_refine_ls_R_factor_gt           0.0574
_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^)+(0.0231P)^2^+17.1985P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.0891
_refine_ls_wR_factor_ref         0.1007
_reflns_Friedel_coverage         0.000
_reflns_number_gt                3822
_reflns_number_total             5443
_reflns_threshold_expression     'I > 2\s(I)'
_cod_data_source_file            c7sc04789d2.cif
_cod_data_source_block           final_a
_cod_depositor_comments
'Adding full bibliography for 1548594--1548603.cif.'
_cod_original_cell_volume        4926.3(15)
_cod_database_code               1548596
_shelx_shelxl_version_number     2014/7
_shelx_estimated_absorpt_t_min   0.842
_shelx_estimated_absorpt_t_max   0.924
_exptl_absorpt_special_details
;The crystal was immersed in a film of perfluoropolyether oil, 
mounted on a a glass fiber and transferred to stream of cold nitrogen.
;
_shelx_res_checksum              66513