Direct measurement of covalent three-center, two-electron M-H-B bonding in Zr and Hf borohydrides using B K-edge XAS.
Hansen, Hannah M.; Zgrabik, Joshua C.; Zacher, 3rd, Peter A; Schuely, Jacob J.; Amano, Emily M.; Yang, Mai Yer; Unruh, Daniel K.; Zuin, Lucia; Keith, Jason M.; Daly, Scott R.; Chemical science 16 (2025) 22333–22347; doi:10.1039/d5sc06254c

data_1576115
_publ_section_title
;
 Direct measurement of covalent three-center, two-electron M-H-B bonding
 in Zr and Hf borohydrides using B K-edge XAS.
;
_journal_issue                   47
_journal_name_full               'Chemical science'
_journal_page_first              22333
_journal_page_last               22347
_journal_paper_doi               10.1039/d5sc06254c
_journal_volume                  16
_journal_year                    2025
_chemical_formula_moiety         'C24 H32 B4 Zr'
_chemical_formula_sum            'C24 H32 B4 Zr'
_chemical_formula_weight         454.95
_space_group_crystal_system      triclinic
_space_group_IT_number           1
_space_group_name_Hall           'P 1'
_space_group_name_H-M_alt        'P 1'
_atom_sites_solution_hydrogens   geom
_audit_creation_date             2025-06-04
_audit_creation_method
;
Olex2 1.5
(compiled 2025.04.05 svn.rf049d14d for OlexSys, GUI svn.r7224)
;
_audit_update_record
;
2025-06-12 deposited with the CCDC.	2025-10-13 downloaded from the CCDC.
;
_cell_angle_alpha                97.458(5)
_cell_angle_beta                 105.662(5)
_cell_angle_gamma                97.063(5)
_cell_formula_units_Z            3
_cell_length_a                   10.1671(10)
_cell_length_b                   13.3719(13)
_cell_length_c                   14.4875(13)
_cell_measurement_reflns_used    9815
_cell_measurement_temperature    150.15
_cell_measurement_theta_max      26.345
_cell_measurement_theta_min      2.1975
_cell_volume                     1854.5(3)
_computing_molecular_graphics    'Olex2 1.5 (Dolomanov et al., 2009)'
_computing_publication_material  'Olex2 1.5 (Dolomanov et al., 2009)'
_computing_structure_refinement  'SHELXL 2016/4 (Sheldrick, 2015)'
_computing_structure_solution    'SHELXT 2018/2 (Sheldrick, 2018)'
_diffrn_ambient_temperature      150.15
_diffrn_measured_fraction_theta_full 0.999
_diffrn_measured_fraction_theta_max 0.997
_diffrn_measurement_device_type  'Bruker Nonius Kappa Apex'
_diffrn_measurement_method       'CCD Phi and Omega Scans'
_diffrn_radiation_type           MoK\a
_diffrn_radiation_wavelength     0.71073
_diffrn_reflns_av_R_equivalents  0.0347
_diffrn_reflns_av_unetI/netI     0.0369
_diffrn_reflns_Laue_measured_fraction_full 0.999
_diffrn_reflns_Laue_measured_fraction_max 0.997
_diffrn_reflns_limit_h_max       12
_diffrn_reflns_limit_h_min       -12
_diffrn_reflns_limit_k_max       16
_diffrn_reflns_limit_k_min       -16
_diffrn_reflns_limit_l_max       18
_diffrn_reflns_limit_l_min       -18
_diffrn_reflns_number            40767
_diffrn_reflns_point_group_measured_fraction_full 0.967
_diffrn_reflns_point_group_measured_fraction_max 0.957
_diffrn_reflns_theta_full        25.242
_diffrn_reflns_theta_max         26.390
_diffrn_reflns_theta_min         1.958
_exptl_absorpt_coefficient_mu    0.452
_exptl_absorpt_correction_T_max  1.0000
_exptl_absorpt_correction_T_min  0.9683
_exptl_absorpt_correction_type   multi-scan
_exptl_absorpt_process_details
;
SADABS-2016/2 (Bruker,2016/2) was used for absorption correction.
wR2(int) was 0.1093 before and 0.0503 after correction.
The Ratio of minimum to maximum transmission is 0.9683.
The \l/2 correction factor is Not present.
;
_exptl_crystal_colour            colorless
_exptl_crystal_density_diffrn    1.222
_exptl_crystal_description       prism-like
_exptl_crystal_F_000             708
_exptl_crystal_size_max          0.195
_exptl_crystal_size_mid          0.165
_exptl_crystal_size_min          0.155
_refine_diff_density_max         0.256
_refine_diff_density_min         -0.342
_refine_diff_density_rms         0.043
_refine_ls_abs_structure_details
;
 Flack x determined using 6400 quotients [(I+)-(I-)]/[(I+)+(I-)]
 (Parsons, Flack and Wagner, Acta Cryst. B69 (2013) 249-259).
;
_refine_ls_abs_structure_Flack   -0.022(11)
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.035
_refine_ls_hydrogen_treatment    constr
_refine_ls_matrix_type           full
_refine_ls_number_parameters     796
_refine_ls_number_reflns         14530
_refine_ls_number_restraints     3
_refine_ls_restrained_S_all      1.035
_refine_ls_R_factor_all          0.0269
_refine_ls_R_factor_gt           0.0251
_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^)+(0.0297P)^2^+0.2267P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.0581
_refine_ls_wR_factor_ref         0.0599
_reflns_Friedel_coverage         0.920
_reflns_Friedel_fraction_full    0.934
_reflns_Friedel_fraction_max     0.917
_reflns_number_gt                13988
_reflns_number_total             14530
_reflns_threshold_expression     'I > 2\s(I)'
_cod_data_source_file            d5sc06254c3.cif
_cod_data_source_block           dal2213
_cod_depositor_comments
'Adding full bibliography for 1576111--1576117.cif.'
_cod_database_code               1576115
_shelx_shelxl_version_number     2016/4
_shelx_estimated_absorpt_t_max   0.933
_shelx_estimated_absorpt_t_min   0.917
_olex2_refinement_description
;
1. Fixed Uiso
 At 1.2 times of:
  All C(H) groups
 At 1.5 times of:
  All B(H,H,H) groups
2.a Aromatic/amide H refined with riding coordinates:
 C8(H8), C9(H9), C45(H45), C10(H10), C20(H20), C57(H57), C58(H58), C14(H14),
 C46(H46), C56(H56), C17(H17), C38(H38), C62(H62), C30(H30), C72(H72), C4(H4),
 C12(H12), C32(H32), C44(H44), C68(H68), C54(H54), C48(H48), C18(H18), C3(H3),
 C11(H11), C50(H50), C24(H24), C47(H47), C2(H2), C69(H69), C66(H66), C6(H6),
 C26(H26), C53(H53), C33(H33), C60(H60), C21(H21), C65(H65), C29(H29), C64(H64),
  C40(H40), C70(H70), C28(H28), C42(H42), C59(H59), C52(H52), C5(H5), C16(H16),
 C22(H22), C15(H15), C71(H71), C51(H51), C23(H23), C39(H39), C27(H27), C34(H34),
  C41(H41), C36(H36), C63(H63), C35(H35)
2.b Idealised Me refined as rotating group:
 B1(H1A,H1B,H1C), B4(H4A,H4B,H4C), B2(H2A,H2B,H2C), B10(H10A,H10B,H10C),
 B11(H11A,H11B,H11C), B8(H8A,H8B,H8C), B5(H5A,H5B,H5C), B6(H6A,H6B,H6C), B9(H9A,
 H9B,H9C), B7(H7A,H7B,H7C), B3(H3A,H3B,H3C), B12(H12A,H12B,H12C)
;
_shelx_res_checksum              90034
_olex2_submission_special_instructions 'No special instructions were received'