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_7042151
_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         'C12 H24 B2 O4'
_chemical_formula_sum            'C12 H24 B2 O4'
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_space_group_crystal_system      monoclinic
_space_group_IT_number           9
_space_group_name_Hall           'I -2ya'
_space_group_name_H-M_alt        'I 1 a 1'
_symmetry_space_group_name_Hall  'I -2ya'
_symmetry_space_group_name_H-M   'I 1 a 1'
_atom_sites_solution_hydrogens   geom
_atom_sites_solution_primary     iterative
_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                 98.798(6)
_cell_angle_gamma                90
_cell_formula_units_Z            8
_cell_length_a                   10.1407(7)
_cell_length_b                   14.8953(9)
_cell_length_c                   19.4745(10)
_cell_measurement_reflns_used    4884
_cell_measurement_temperature    100(2)
_cell_measurement_theta_max      28.70
_cell_measurement_theta_min      3.46
_cell_volume                     2907.0(3)
_computing_cell_refinement
;
 CrysAlisPro, Rigaku Oxford Diffraction, 2015,
 Version 1.171.38.43, 2015
;
_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, Rigaku Oxford Diffraction, 2015,
 Version 1.171.38.43, 2015
;
_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., 2015, A71, 3--8)
;
_computing_structure_solution
;
 SHELXT (Ver. 2014/4) (G. M. Sheldrick, Acta Cryst., 2015, A71, 3--8)
;
_diffrn_ambient_environment      N~2~
_diffrn_ambient_temperature      100(2)
_diffrn_detector_area_resol_mean 16.1419
_diffrn_measured_fraction_theta_full 0.999
_diffrn_measured_fraction_theta_max 0.997
_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  0.0593
_diffrn_reflns_av_unetI/netI     0.0622
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_diffrn_reflns_point_group_measured_fraction_max 0.980
_diffrn_reflns_theta_full        25.242
_diffrn_reflns_theta_max         27.996
_diffrn_reflns_theta_min         2.450
_exptl_absorpt_coefficient_mu    0.082
_exptl_absorpt_correction_T_max  0.990
_exptl_absorpt_correction_T_min  0.981
_exptl_absorpt_correction_type   analytical
_exptl_absorpt_process_details
;
 CrysAlisPro 1.171.38.43 (Rigaku Oxford Diffraction, 2015)
 Analytical numeric absorption correction using a multifaceted crystal
 model based on expressions derived by R.C. Clark & J.S. Reid.
 (Clark, R. C. & Reid, J. S. (1995). Acta Cryst. A51, 887-897)
 Empirical absorption correction using spherical harmonics,
 implemented in SCALE3 ABSPACK scaling algorithm.
;
_exptl_crystal_colour            'clear colourless'
_exptl_crystal_density_diffrn    1.160
_exptl_crystal_description       'fragment of prism'
_exptl_crystal_F_000             1104
_exptl_crystal_recrystallization_method
;
 From solution in n-pentane at -40 deg C.
;
_exptl_crystal_size_max          0.31
_exptl_crystal_size_mid          0.19
_exptl_crystal_size_min          0.14
_refine_diff_density_max         0.323
_refine_diff_density_min         -0.349
_refine_diff_density_rms         0.055
_refine_ls_abs_structure_details
;
 Flack x determined using 1860 quotients [(I+)-(I-)]/[(I+)+(I-)]
 (Parsons, Flack and Wagner, Acta Cryst. B69 (2013) 249-259).
;
_refine_ls_abs_structure_Flack   -1.0(10)
_refine_ls_extinction_coef       0.0026(5)
_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   1.037
_refine_ls_hydrogen_treatment    constr
_refine_ls_matrix_type           full
_refine_ls_number_parameters     412
_refine_ls_number_reflns         6886
_refine_ls_number_restraints     26
_refine_ls_restrained_S_all      1.037
_refine_ls_R_factor_all          0.0890
_refine_ls_R_factor_gt           0.0558
_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^)+(0.0704P)^2^+0.2888P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.1259
_refine_ls_wR_factor_ref         0.1492
_reflns_Friedel_coverage         0.964
_reflns_Friedel_fraction_full    0.998
_reflns_Friedel_fraction_max     0.964
_reflns_number_gt                4871
_reflns_number_total             6886
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_cod_data_source_file            c7dt00334j2.cif
_cod_data_source_block           ck57ck
_cod_depositor_comments
'Adding full bibliography for 7042146--7042160.cif.'
_cod_database_code               7042151
_shelx_shelxl_version_number     2014/7
_shelx_res_checksum              82435