Ureas are identified as the first neutral O-donors broadly effective in stabilizing ionic liquids and other salts of boron-centred cations: synthesis and detailed characterization
Crowley, Margaret E.; Merchant, Gabriel A.; Davis, James H.; Stachurski, Christopher D.; Zeller, Matthias; Salter, E. A.; Wierzbicki, A.; Trulove, Paul C.; Durkin, David P.; Kingrey, Grace L.; Escalante, Edgar E.; O'Brien, Richard A.; Whillock, Novita M.; RSC Advances 15 (2025) 40519–40527; doi:10.1039/D5RA05311K

data_7251142
_publ_section_title
;
 Ureas are identified as the first neutral O-donors broadly effective in
 stabilizing ionic liquids and other salts of boron-centred cations:
 synthesis and detailed characterization
;
_journal_issue                   48
_journal_name_full               'RSC Advances'
_journal_page_first              40519
_journal_page_last               40527
_journal_paper_doi               10.1039/D5RA05311K
_journal_volume                  15
_journal_year                    2025
_chemical_formula_moiety         'C24 H20 B, C9 H23 B N3 O'
_chemical_formula_sum            'C33 H43 B2 N3 O'
_chemical_formula_weight         519.32
_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'
_atom_sites_solution_hydrogens   geom
_atom_sites_solution_primary     dual
_atom_sites_solution_secondary   difmap
_audit_creation_method           SHELXL-2019/3
_audit_update_record
;
2025-07-15 deposited with the CCDC.	2025-10-09 downloaded from the CCDC.
;
_cell_angle_alpha                90
_cell_angle_beta                 90
_cell_angle_gamma                90
_cell_formula_units_Z            8
_cell_length_a                   19.249(12)
_cell_length_b                   16.089(3)
_cell_length_c                   19.492(6)
_cell_measurement_reflns_used    9917
_cell_measurement_temperature    150(2)
_cell_measurement_theta_max      28.1763
_cell_measurement_theta_min      2.3424
_cell_volume                     6037(4)
_computing_cell_refinement       'SAINT V8.40B (Bruker, 2020)'
_computing_data_collection       'Apex4 v2022.10-1 (Bruker, 2022)'
_computing_data_reduction        'SAINT V8.40B (Bruker, 2020)'
_computing_structure_refinement
;  
SHELXL-2019/2 (Sheldrick, 2015a, 2019), 
SHELXLE Rev1573 (H\"ubschle et al., 2011)
;
_computing_structure_solution    'SHELXT (Sheldrick, 2015b)'
_diffrn_ambient_temperature      150(2)
_diffrn_detector_area_resol_mean 7.4074
_diffrn_detector_type
'PhotonII charge-integrating pixel array (CPAD)'
_diffrn_measured_fraction_theta_full 0.999
_diffrn_measured_fraction_theta_max 0.999
_diffrn_measurement_device       'three circle diffractometer'
_diffrn_measurement_device_type  'Bruker AXS D8 Quest'
_diffrn_measurement_method       'omega and phi scans'
_diffrn_radiation_monochromator  'Triumph curved graphite crystal'
_diffrn_radiation_type           MoK\a
_diffrn_radiation_wavelength     0.71073
_diffrn_reflns_av_R_equivalents  0.0436
_diffrn_reflns_av_unetI/netI     0.0219
_diffrn_reflns_Laue_measured_fraction_full 0.999
_diffrn_reflns_Laue_measured_fraction_max 0.999
_diffrn_reflns_limit_h_max       25
_diffrn_reflns_limit_h_min       -25
_diffrn_reflns_limit_k_max       21
_diffrn_reflns_limit_k_min       -20
_diffrn_reflns_limit_l_max       25
_diffrn_reflns_limit_l_min       -25
_diffrn_reflns_number            71792
_diffrn_reflns_point_group_measured_fraction_full 0.999
_diffrn_reflns_point_group_measured_fraction_max 0.999
_diffrn_reflns_theta_full        25.242
_diffrn_reflns_theta_max         28.278
_diffrn_reflns_theta_min         2.342
_diffrn_source                   'fine focus sealed tube X-ray source'
_diffrn_source_current           '30 mA'
_diffrn_source_voltage           '50 kV'
_exptl_absorpt_coefficient_mu    0.068
_exptl_absorpt_correction_T_max  0.7457
_exptl_absorpt_correction_T_min  0.6710
_exptl_absorpt_correction_type   multi-scan
_exptl_absorpt_process_details
;
 SADABS 2016/2: Krause, L., Herbst-Irmer, R., Sheldrick G.M. & Stalke D.,
 J. Appl. Cryst. 48 (2015) 3-10
;
_exptl_crystal_colour            colourless
_exptl_crystal_density_diffrn    1.143
_exptl_crystal_description       plate
_exptl_crystal_F_000             2240
_exptl_crystal_size_max          0.320
_exptl_crystal_size_mid          0.290
_exptl_crystal_size_min          0.150
_refine_diff_density_max         0.301
_refine_diff_density_min         -0.217
_refine_diff_density_rms         0.038
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.038
_refine_ls_hydrogen_treatment    mixed
_refine_ls_matrix_type           full
_refine_ls_number_parameters     390
_refine_ls_number_reflns         7484
_refine_ls_number_restraints     114
_refine_ls_restrained_S_all      1.040
_refine_ls_R_factor_all          0.0597
_refine_ls_R_factor_gt           0.0434
_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^)+(0.0528P)^2^+1.8086P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.1074
_refine_ls_wR_factor_ref         0.1203
_reflns_Friedel_coverage         0.000
_reflns_number_gt                5831
_reflns_number_total             7484
_reflns_threshold_expression     'I > 2\s(I)'
_cod_data_source_file            d5ra05311k2.cif
_cod_data_source_block           12-BPh4
_cod_original_cell_volume        6036(4)
_cod_database_code               7251142
_shelx_shelxl_version_number     2019/3
_shelx_estimated_absorpt_t_min   0.979
_shelx_estimated_absorpt_t_max   0.990
_shelx_res_checksum              38742