Ligand flexibility as a concept to unlock catalytic activity: acyclic carbenes for base-free transfer ruthenium hydrogenation catalysis.
Righetti, Gianluca; Koidan, Georgyi; Filimonchuk, Sergiy L.; Shishkina, Svitlana; Kostyuk, Aleksandr; Albrecht, Martin; Chemical science 17 (2026) 4325–4331; doi:10.1039/d5sc08206d

data_1576685
_publ_section_title
;
 Ligand flexibility as a concept to unlock catalytic activity: acyclic
 carbenes for base-free transfer ruthenium hydrogenation catalysis.
;
_journal_issue                   8
_journal_name_full               'Chemical science'
_journal_page_first              4325
_journal_page_last               4331
_journal_paper_doi               10.1039/d5sc08206d
_journal_volume                  17
_journal_year                    2026
_chemical_formula_moiety         'C17 H26 N2 O3 Ru'
_chemical_formula_sum            'C17 H26 N2 O3 Ru'
_chemical_formula_weight         407.47
_space_group_IT_number           14
_space_group_name_Hall           '-P 2ybc'
_space_group_name_H-M_alt        'P 1 21/c 1'
_symmetry_cell_setting           monoclinic
_symmetry_Int_Tables_number      14
_symmetry_space_group_name_Hall  '-P 2ybc'
_symmetry_space_group_name_H-M   'P 1 21/c 1'
_atom_sites_solution_hydrogens   mixed
_atom_sites_solution_primary     dual
_audit_creation_date             2024-12-18T13:55:16-00:00
_audit_update_record
;
2025-09-11 deposited with the CCDC.	2025-12-29 downloaded from the CCDC.
;
_cell_angle_alpha                90
_cell_angle_beta                 101.8491(14)
_cell_angle_gamma                90
_cell_formula_units_Z            4
_cell_length_a                   8.13073(13)
_cell_length_b                   11.29004(18)
_cell_length_c                   19.3239(3)
_cell_measurement_reflns_used    25498
_cell_measurement_temperature    300.26(10)
_cell_measurement_theta_max      33.589
_cell_measurement_theta_min      2.548
_cell_volume                     1736.06(5)
_computing_cell_refinement       'CrysAlisPro 1.171.43.95a (Rigaku OD, 2023)'
_computing_data_collection
'CrysAlisPro system (CCD 43.105a 64-bit (release 11-01-2024))'
_computing_data_reduction        'CrysAlisPro 1.171.43.95a (Rigaku OD, 2023)'
_computing_molecular_graphics    'Olex2 1.3 (Dolomanov et al., 2009)'
_computing_publication_material  'Olex2 1.3 (Dolomanov et al., 2009)'
_computing_structure_refinement  'SHELXL 2018/3 (Sheldrick, 2015)'
_computing_structure_solution    'SHELXT 2018/2 (Sheldrick, 2018)'
_diffrn_ambient_environment      air
_diffrn_ambient_temperature      300.26(10)
_diffrn_detector                 'Hybrid Pixel Array Detector'
_diffrn_detector_area_resol_mean 10
_diffrn_detector_type            'HyPix-Arc 100'
_diffrn_measured_fraction_theta_full 1
_diffrn_measured_fraction_theta_max 1
_diffrn_measurement_details
;
        List of Runs (angles in degrees, time in seconds):
  # Type    Start    End  Width  t~exp~   \w     \q     \k     \f   Frames
        --------------------------------------------------------------------------
  1  \w     -5.00  93.00   0.50    4.00    --   13.17  46.00 124.00  196
  2  \w    -66.00  32.00   0.50    4.00    --   13.17 -46.00 -24.00  196
  3  \w    -68.00  28.00   0.50    4.00    --   13.17 -19.00   0.00  192
  4  \w    -18.00  54.00   0.50    4.00    --   13.17 -99.00  60.00  144
  5  \w    -68.00  28.00   0.50    4.00    --   13.17 -19.00   0.00  192
  6  \w    -19.00  29.00   0.50    4.00    --  -13.56 -99.00 120.00   96
  7  \w    -87.00 -42.00   0.50    4.00    --  -13.56-178.00-180.00   90
  8  \w    -89.00 -40.00   0.50    4.00    --  -13.56 178.00 150.00   98
  9  \w    -19.00  29.00   0.50    4.00    --  -13.56 -99.00  60.00   96
 10  \w    -19.00  29.00   0.50    4.00    --  -13.56 -99.00 -90.00   96
 11  \w    -19.00  29.00   0.50    4.00    --  -13.56 -99.00-150.00   96
 12  \w    -87.00 -42.00   0.50    4.00    --  -13.56-178.00 120.00   90
 13  \w    -42.00  40.00   0.50    4.00    --  -13.56  77.00 120.00  164
;
_diffrn_measurement_device       'four-circle diffractometer'
_diffrn_measurement_device_type  'XtaLAB Synergy R, HyPix-Arc 100'
_diffrn_measurement_method       '\w scans'
_diffrn_orient_matrix_type
'CrysAlisPro convention (1999,Acta A55,543-557)'
_diffrn_orient_matrix_UB_11      -0.0483562
_diffrn_orient_matrix_UB_12      -0.0503264
_diffrn_orient_matrix_UB_13      -0.0134944
_diffrn_orient_matrix_UB_21      0.0656399
_diffrn_orient_matrix_UB_22      -0.0193107
_diffrn_orient_matrix_UB_23      -0.0164486
_diffrn_orient_matrix_UB_31      0.0360619
_diffrn_orient_matrix_UB_32      -0.0322721
_diffrn_orient_matrix_UB_33      0.030877
_diffrn_radiation_monochromator  mirror
_diffrn_radiation_probe          x-ray
_diffrn_radiation_type           'Mo K\a'
_diffrn_radiation_wavelength     0.71073
_diffrn_reflns_av_R_equivalents  0.0274
_diffrn_reflns_av_unetI/netI     0.0353
_diffrn_reflns_Laue_measured_fraction_full 1
_diffrn_reflns_Laue_measured_fraction_max 1
_diffrn_reflns_limit_h_max       11
_diffrn_reflns_limit_h_min       -11
_diffrn_reflns_limit_k_max       16
_diffrn_reflns_limit_k_min       -16
_diffrn_reflns_limit_l_max       27
_diffrn_reflns_limit_l_min       -27
_diffrn_reflns_number            52124
_diffrn_reflns_point_group_measured_fraction_full 1
_diffrn_reflns_point_group_measured_fraction_max 1
_diffrn_reflns_theta_full        25.242
_diffrn_reflns_theta_max         30.507
_diffrn_reflns_theta_min         2.101
_diffrn_source                   'micro-focus sealed X-ray tube'
_diffrn_source_type              'Mova (Mo) X-ray Source'
_exptl_absorpt_coefficient_mu    0.919
_exptl_absorpt_correction_T_max  0.954
_exptl_absorpt_correction_T_min  0.917
_exptl_absorpt_correction_type   analytical
_exptl_absorpt_process_details
;
        CrysAlisPro 1.171.43.95a (Rigaku Oxford Diffraction, 2023)
        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            orange
_exptl_crystal_density_diffrn    1.559
_exptl_crystal_description       block
_exptl_crystal_F_000             840
_exptl_crystal_size_max          0.142
_exptl_crystal_size_mid          0.124
_exptl_crystal_size_min          0.065
_refine_diff_density_max         0.784
_refine_diff_density_min         -0.724
_refine_diff_density_rms         0.07
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.058
_refine_ls_hydrogen_treatment    mixed
_refine_ls_matrix_type           full
_refine_ls_number_parameters     244
_refine_ls_number_reflns         5296
_refine_ls_number_restraints     73
_refine_ls_restrained_S_all      1.089
_refine_ls_R_factor_all          0.0395
_refine_ls_R_factor_gt           0.0324
_refine_ls_shift/su_max          0.001
_refine_ls_shift/su_mean         0
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'w=1/[\s^2^(Fo^2^)+(0.0472P)^2^+1.1321P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.0922
_refine_ls_wR_factor_ref         0.0957
_reflns_Friedel_coverage         0
_reflns_number_gt                4514
_reflns_number_total             5296
_reflns_threshold_expression     'I > 2\s(I)'
_cod_data_source_file            d5sc08206d2.cif
_cod_data_source_block           Ru-2b
_cod_depositor_comments
'Adding full bibliography for 1576683--1576688.cif.'
_cod_original_cell_volume        1736.07(5)
_cod_database_code               1576685
_shelx_estimated_absorpt_t_min   0.882
_shelx_estimated_absorpt_t_max   0.938
_oxdiff_exptl_absorpt_empirical_details
;
        Empirical correction (ABSPACK) includes:
        - Absorption correction using spherical harmonics
        - Frame scaling
        - Detector area scaling
;
_oxdiff_exptl_absorpt_empirical_full_max 1.294
_oxdiff_exptl_absorpt_empirical_full_min 0.818
_shelx_shelxl_version_number     2018/3
_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 C(H,H,H) groups
        2. Restrained distances
 C16-C15 \\sim C16A-C15A \\sim C17-C15 \\sim C17A-C15A
 with sigma of 0.002
 C9-C15 \\sim C9-C15A
 with sigma of 0.002
        3. Rigid bond restraints
 C9, C15A, C17A, C16A
 with sigma for 1-2 distances of 0.001 and sigma for 1-3 distances of 0.001
 C15, C9, C16, C17
 with sigma for 1-2 distances of 0.001 and sigma for 1-3 distances of 0.001
        4. Uiso/Uaniso restraints and constraints
        C17 \\sim C17A: within 2A with sigma of 0.004 and sigma for terminal atoms of
        0.004 within 2A
        C15 \\sim C15A: within 2A with sigma of 0.004 and sigma for terminal atoms of
        0.004 within 2A
        C16A \\sim C16: within 2A with sigma of 0.004 and sigma for terminal atoms of
        0.004 within 2A
        Uanis(C16) \\sim Ueq, Uanis(C16A) \\sim Ueq, Uanis(C15) \\sim Ueq, Uanis(C15A)
        \\sim Ueq, Uanis(C17) \\sim Ueq, Uanis(C17A) \\sim Ueq: with sigma of 0.005 and
        sigma for terminal atoms of 0.005
        5. Others
 Sof(C17A)=Sof(H17A)=Sof(H17B)=Sof(H17C)=Sof(C15A)=Sof(H15A)=Sof(C16A)=
 Sof(H16D)=Sof(H16E)=Sof(H16F)=1-FVAR(1)
 Sof(C15)=Sof(H15)=Sof(C16)=Sof(H16A)=Sof(H16B)=Sof(H16C)=Sof(C17)=Sof(H17D)=
 Sof(H17E)=Sof(H17F)=FVAR(1)
        6.a Ternary CH refined with riding coordinates:
 C15(H15), C15A(H15A)
        6.b Secondary CH2 refined with riding coordinates:
 C6(H6A,H6B), C3(H3A,H3B), C4(H4A,H4B), C5(H5A,H5B)
        6.c Me refined with riding coordinates:
 C16(H16A,H16B,H16C), C16A(H16D,H16E,H16F)
        6.d Aromatic/amide H refined with riding coordinates:
 C13(H13), C8(H8), C11(H11), C10(H10)
        6.e Idealised Me refined as rotating group:
 C1(H1A,H1B,H1C), C14(H14A,H14B,H14C), C17A(H17A,H17B,H17C), C17(H17D,H17E,H17F)
;
_shelx_res_checksum              12700