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_1576113
_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         'C28 H40 B4 Hf'
_chemical_formula_sum            'C28 H40 B4 Hf'
_chemical_formula_weight         598.33
_space_group_crystal_system      triclinic
_space_group_IT_number           2
_space_group_name_Hall           '-P 1'
_space_group_name_H-M_alt        'P -1'
_atom_sites_solution_hydrogens   geom
_audit_creation_date             2025-06-03
_audit_creation_method
;
Olex2 1.5
(compiled 2024.02.16 svn.r378c4104 for OlexSys, GUI svn.r6928)
;
_audit_update_record
;
2025-06-12 deposited with the CCDC.	2025-10-13 downloaded from the CCDC.
;
_cell_angle_alpha                100.023(2)
_cell_angle_beta                 93.296(2)
_cell_angle_gamma                99.554(2)
_cell_formula_units_Z            2
_cell_length_a                   5.6539(4)
_cell_length_b                   14.0343(9)
_cell_length_c                   17.6063(9)
_cell_measurement_reflns_used    9344
_cell_measurement_temperature    100.00
_cell_measurement_theta_max      27.483
_cell_measurement_theta_min      3.419
_cell_volume                     1351.25(15)
_computing_cell_refinement       'SAINT V8.40B (?, 2016)'
_computing_data_reduction        'SAINT V8.40B (?, 2016)'
_computing_molecular_graphics    'Olex2 1.5 (Dolomanov et al., 2009)'
_computing_publication_material  'Olex2 1.5 (Dolomanov et al., 2009)'
_computing_structure_refinement  'SHELXL 2019/3 (Sheldrick, 2015)'
_computing_structure_solution    'SHELXT 2018/2 (Sheldrick, 2018)'
_diffrn_ambient_temperature      100.00
_diffrn_measured_fraction_theta_full 0.999
_diffrn_measured_fraction_theta_max 0.999
_diffrn_measurement_device_type  'Bruker D8 Venture Duo with Photon 3'
_diffrn_radiation_type           MoK\a
_diffrn_radiation_wavelength     0.71073
_diffrn_reflns_av_R_equivalents  0.0616
_diffrn_reflns_av_unetI/netI     0.0336
_diffrn_reflns_Laue_measured_fraction_full 0.999
_diffrn_reflns_Laue_measured_fraction_max 0.999
_diffrn_reflns_limit_h_max       7
_diffrn_reflns_limit_h_min       -7
_diffrn_reflns_limit_k_max       18
_diffrn_reflns_limit_k_min       -18
_diffrn_reflns_limit_l_max       21
_diffrn_reflns_limit_l_min       -22
_diffrn_reflns_number            49559
_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         27.525
_diffrn_reflns_theta_min         2.359
_exptl_absorpt_coefficient_mu    3.874
_exptl_absorpt_correction_T_max  0.7456
_exptl_absorpt_correction_T_min  0.5907
_exptl_absorpt_correction_type   multi-scan
_exptl_absorpt_process_details
;
SADABS-2016/2 (Bruker,2016/2) was used for absorption correction.
wR2(int) was 0.1280 before and 0.0669 after correction.
The Ratio of minimum to maximum transmission is 0.7922.
The \l/2 correction factor is Not present.
;
_exptl_crystal_colour            'clear colourless'
_exptl_crystal_density_diffrn    1.471
_exptl_crystal_description       plate
_exptl_crystal_F_000             600
_exptl_crystal_size_max          0.24
_exptl_crystal_size_mid          0.168
_exptl_crystal_size_min          0.058
_refine_diff_density_max         0.551
_refine_diff_density_min         -0.763
_refine_diff_density_rms         0.094
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.031
_refine_ls_hydrogen_treatment    constr
_refine_ls_matrix_type           full
_refine_ls_number_parameters     302
_refine_ls_number_reflns         6238
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      1.031
_refine_ls_R_factor_all          0.0211
_refine_ls_R_factor_gt           0.0193
_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^)+(0.0192P)^2^+0.3987P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.0439
_refine_ls_wR_factor_ref         0.0450
_reflns_Friedel_coverage         0.000
_reflns_number_gt                5901
_reflns_number_total             6238
_reflns_threshold_expression     'I > 2\s(I)'
_cod_data_source_file            d5sc06254c3.cif
_cod_data_source_block           dal23_12-copy(2)
_cod_depositor_comments
'Adding full bibliography for 1576111--1576117.cif.'
_cod_database_code               1576113
_shelx_shelxl_version_number     2019/3
_shelx_estimated_absorpt_t_max   0.807
_shelx_estimated_absorpt_t_min   0.457
_olex2_refinement_description
;
1. Fixed Uiso
 At 1.2 times of:
  All C(H) groups, All C(H,H) groups
 At 1.5 times of:
  All B(H,H,H) groups
2.a Secondary CH2 refined with riding coordinates:
 C41(H41A,H41B), C31(H31A,H31B), C11(H11A,H11B), C21(H21A,H21B)
2.b Aromatic/amide H refined with riding coordinates:
 C43(H43), C44(H44), C45(H45), C46(H46), C47(H47), C33(H33), C34(H34),
 C35(H35), C36(H36), C37(H37), C13(H13), C14(H14), C15(H15), C16(H16), C17(H17),
  C23(H23), C24(H24), C25(H25), C26(H26), C27(H27)
2.c Idealised Me refined as rotating group:
 B4(H4A,H4B,H4C), B3(H3A,H3B,H3C), B1(H1A,H1B,H1C), B2(H2A,H2B,H2C)
;
_shelx_res_checksum              4016
_olex2_submission_special_instructions 'No special instructions were received'