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_1548601
_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 S4, 3 (C4 H8 O)'
_chemical_formula_sum            'C54 H86 B2 N4 O3 S4'
_chemical_formula_weight         989.12
_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                   16.39(3)
_cell_length_b                   17.61(3)
_cell_length_c                   38.28(7)
_cell_measurement_reflns_used    241
_cell_measurement_temperature    100(2)
_cell_measurement_theta_max      14.64
_cell_measurement_theta_min      2.55
_cell_volume                     11049(3)
_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_measured_fraction_theta_full 0.996
_diffrn_measured_fraction_theta_max 0.996
_diffrn_measurement_device_type  'Bruker X8-APEX II'
_diffrn_measurement_method       '\f and \w scans'
_diffrn_radiation_type           MoK\a
_diffrn_radiation_wavelength     0.71073
_diffrn_reflns_av_R_equivalents  0.9489
_diffrn_reflns_av_unetI/netI     0.8518
_diffrn_reflns_Laue_measured_fraction_full 0.996
_diffrn_reflns_Laue_measured_fraction_max 0.996
_diffrn_reflns_limit_h_max       18
_diffrn_reflns_limit_h_min       -18
_diffrn_reflns_limit_k_max       20
_diffrn_reflns_limit_k_min       -19
_diffrn_reflns_limit_l_max       44
_diffrn_reflns_limit_l_min       -45
_diffrn_reflns_number            52737
_diffrn_reflns_point_group_measured_fraction_full 0.996
_diffrn_reflns_point_group_measured_fraction_max 0.996
_diffrn_reflns_theta_full        24.713
_diffrn_reflns_theta_max         24.713
_diffrn_reflns_theta_min         1.636
_diffrn_source
'rotating-anode X-ray tube or sealed X-ray tube'
_exptl_absorpt_coefficient_mu    0.217
_exptl_absorpt_correction_T_max  0.958
_exptl_absorpt_correction_T_min  0.561
_exptl_absorpt_correction_type   multi-scan
_exptl_absorpt_process_details   'twinabs 2014/4 (Bruker 2014)'
_exptl_crystal_colour            yellow
_exptl_crystal_density_diffrn    1.189
_exptl_crystal_description       needle
_exptl_crystal_F_000             4288
_exptl_crystal_size_max          0.320
_exptl_crystal_size_mid          0.041
_exptl_crystal_size_min          0.023
_refine_diff_density_max         0.860
_refine_diff_density_min         -0.533
_refine_diff_density_rms         0.135
_refine_ls_extinction_coef       0.0135(15)
_refine_ls_extinction_expression Fc^*^=kFc[1+0.001xFc^2^\l^3^/sin(2\q)]^-1/4^
_refine_ls_extinction_method     'SHELXL-2014/7 (Sheldrick 2014'
_refine_ls_goodness_of_fit_ref   1.036
_refine_ls_hydrogen_treatment    constr
_refine_ls_matrix_type           full
_refine_ls_number_parameters     621
_refine_ls_number_reflns         9390
_refine_ls_number_restraints     444
_refine_ls_restrained_S_all      1.016
_refine_ls_R_factor_all          0.4879
_refine_ls_R_factor_gt           0.2150
_refine_ls_shift/su_max          0.000
_refine_ls_shift/su_mean         0.000
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'w=1/[\s^2^(Fo^2^)+(0.2000P)^2^] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.4095
_refine_ls_wR_factor_ref         0.5370
_reflns_Friedel_coverage         0.000
_reflns_number_gt                2177
_reflns_number_total             9390
_reflns_threshold_expression     'I > 2\s(I)'
_cod_data_source_file            c7sc04789d2.cif
_cod_data_source_block           OrthoP_a
_cod_depositor_comments
'Adding full bibliography for 1548594--1548603.cif.'
_cod_original_cell_volume        11049(34)
_cod_database_code               1548601
_shelx_shelxl_version_number     2014/7
_shelx_estimated_absorpt_t_min   0.934
_shelx_estimated_absorpt_t_max   0.995
_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              57073