B-B bond activation and NHC ring-expansion reactions of diboron(4) compounds, and accurate molecular structures of B2(NMe2)4, B2eg2, B2neop2 and B2pin2.
Eck, Martin; Würtemberger-Pietsch, Sabrina; Eichhorn, Antonius; Berthel, Johannes H. J.; Bertermann, Rüdiger; Paul, Ursula S. D.; Schneider, Heidi; Friedrich, Alexandra; Kleeberg, Christian; Radius, Udo; Marder, Todd B.; Dalton transactions (Cambridge, England : 2003) 46 (2017) 3661–3680; doi:10.1039/c7dt00334j

data_7042148
_publ_section_title
;
 B-B bond activation and NHC ring-expansion reactions of diboron(4)
 compounds, and accurate molecular structures of B2(NMe2)4, B2eg2, B2neop2
 and B2pin2.
;
_journal_issue                   11
_journal_name_full
'Dalton transactions (Cambridge, England : 2003)'
_journal_page_first              3661
_journal_page_last               3680
_journal_paper_doi               10.1039/c7dt00334j
_journal_volume                  46
_journal_year                    2017
_chemical_formula_moiety         'C10 H20 B2 O4'
_chemical_formula_sum            'C10 H20 B2 O4'
_chemical_formula_weight         225.89
_space_group_crystal_system      trigonal
_space_group_IT_number           167
_space_group_name_Hall           '-R 3 2"c'
_space_group_name_H-M_alt        'R -3 c :H'
_symmetry_space_group_name_Hall  '-R 3 2"c'
_symmetry_space_group_name_H-M   'R -3 c :H'
_atom_sites_solution_hydrogens   geom
_atom_sites_solution_primary     direct
_atom_sites_solution_secondary   difmap
_audit_creation_method           SHELXL-2014/7
_audit_update_record
;
2017-01-27 deposited with the CCDC.
2017-02-21 downloaded from the CCDC.
;
_cell_angle_alpha                90
_cell_angle_beta                 90
_cell_angle_gamma                120
_cell_formula_units_Z            6
_cell_length_a                   8.8311(5)
_cell_length_b                   8.8311(5)
_cell_length_c                   27.5396(16)
_cell_measurement_reflns_used    2781
_cell_measurement_temperature    115(2)
_cell_measurement_theta_max      26.87
_cell_measurement_theta_min      3.038
_cell_volume                     1860.02(18)
_computing_cell_refinement
;
 CrysAlisPro, Agilent Technologies,
 Version 1.171.37.35 (release 13-08-2014 CrysAlis171 .NET)
 (compiled Aug 13 2014,18:06:01)
;
_computing_data_collection
;
 CrysAlisPro, Agilent Technologies,
 Version 1.171.37.35 (release 13-08-2014 CrysAlis171 .NET)
 (compiled Aug 13 2014,18:06:01)
;
_computing_data_reduction
;
 CrysAlisPro, Agilent Technologies,
 Version 1.171.37.35 (release 13-08-2014 CrysAlis171 .NET)
 (compiled Aug 13 2014,18:06:01)
;
_computing_molecular_graphics
;
 K. Brandenburg, 1999, Diamond 3.2i, Crystal Impact GbR, Bonn, Germany.
;
_computing_publication_material
;
 WinGX v2014.1 (L. J. Farrugia, J. Appl. Cryst., 2012, 45, 849-854.)
;
_computing_structure_refinement
;
 SHELXL-2014/7 (G. M. Sheldrick, Acta Cryst. (2008), A64, 112-122)'
;
_computing_structure_solution
;
 SHELXS (G. M. Sheldrick, Acta Cryst., 2008, A64, 112--122)
;
_diffrn_ambient_temperature      115(2)
_diffrn_detector_area_resol_mean 16.1419
_diffrn_measured_fraction_theta_full 1.000
_diffrn_measured_fraction_theta_max 0.998
_diffrn_measurement_device_type  'Oxford Diffraction, Xcalibur, EOS'
_diffrn_measurement_method       \w-scan
_diffrn_radiation_monochromator  graphite
_diffrn_radiation_source         'Enhance (Mo) X-ray Source'
_diffrn_radiation_type           MoK\a
_diffrn_radiation_wavelength     0.71073
_diffrn_reflns_av_R_equivalents  0.0327
_diffrn_reflns_av_unetI/netI     0.0105
_diffrn_reflns_Laue_measured_fraction_full 1.000
_diffrn_reflns_Laue_measured_fraction_max 0.998
_diffrn_reflns_limit_h_max       11
_diffrn_reflns_limit_h_min       -11
_diffrn_reflns_limit_k_max       12
_diffrn_reflns_limit_k_min       -11
_diffrn_reflns_limit_l_max       37
_diffrn_reflns_limit_l_min       -36
_diffrn_reflns_number            14504
_diffrn_reflns_point_group_measured_fraction_full 1.000
_diffrn_reflns_point_group_measured_fraction_max 0.998
_diffrn_reflns_theta_full        25.242
_diffrn_reflns_theta_max         28.975
_diffrn_reflns_theta_min         3.047
_exptl_absorpt_coefficient_mu    0.087
_exptl_absorpt_correction_T_max  1.000
_exptl_absorpt_correction_T_min  0.922
_exptl_absorpt_correction_type   multi-scan
_exptl_absorpt_process_details
;
 CrysAlisPro, Agilent Technologies,
 Version 1.171.37.35 (release 13-08-2014 CrysAlis171 .NET)
 (compiled Aug 13 2014,18:06:01)
 Empirical absorption correction using spherical harmonics,
 implemented in SCALE3 ABSPACK scaling algorithm.
;
_exptl_crystal_colour            'clear colourless'
_exptl_crystal_density_diffrn    1.210
_exptl_crystal_description       prism
_exptl_crystal_F_000             732
_exptl_crystal_recrystallization_method
;
 Gas phase diffusion of n-hexane into a solution in C6H6 at rt.
;
_exptl_crystal_size_max          0.49
_exptl_crystal_size_mid          0.45
_exptl_crystal_size_min          0.34
_refine_diff_density_max         0.273
_refine_diff_density_min         -0.187
_refine_diff_density_rms         0.040
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.055
_refine_ls_hydrogen_treatment    constr
_refine_ls_matrix_type           full
_refine_ls_number_parameters     37
_refine_ls_number_reflns         552
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      1.055
_refine_ls_R_factor_all          0.0591
_refine_ls_R_factor_gt           0.0510
_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^)+(0.0527P)^2^+2.2065P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.1239
_refine_ls_wR_factor_ref         0.1312
_reflns_number_gt                490
_reflns_number_total             552
_reflns_threshold_expression     'I > 2\s(I)'
_cod_data_source_file            c7dt00334j2.cif
_cod_data_source_block           ck41ck_115K
_cod_depositor_comments
'Adding full bibliography for 7042146--7042160.cif.'
_cod_original_cell_volume        1860.0(2)
_cod_database_code               7042148
_shelx_shelxl_version_number     2014/7
_shelx_res_checksum              47095