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_1576688
_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         'C20 H35 Cl N3 Ru, Cl'
_chemical_formula_sum            'C20 H35 Cl2 N3 Ru'
_chemical_formula_weight         489.48
_space_group_IT_number           14
_space_group_name_Hall           '-P 2yn'
_space_group_name_H-M_alt        'P 1 21/n 1'
_symmetry_cell_setting           monoclinic
_symmetry_Int_Tables_number      14
_symmetry_space_group_name_Hall  '-P 2yn'
_symmetry_space_group_name_H-M   'P 1 21/n 1'
_atom_sites_solution_hydrogens   mixed
_atom_sites_solution_primary     dual
_audit_creation_date             2025-03-13T10:07:14-00:00
_audit_update_record
;
2025-09-11 deposited with the CCDC.	2025-12-29 downloaded from the CCDC.
;
_cell_angle_alpha                90
_cell_angle_beta                 92.6898(11)
_cell_angle_gamma                90
_cell_formula_units_Z            4
_cell_length_a                   10.69797(14)
_cell_length_b                   9.17128(11)
_cell_length_c                   22.3384(3)
_cell_measurement_reflns_used    52232
_cell_measurement_temperature    173.00(10)
_cell_measurement_theta_max      33.604
_cell_measurement_theta_min      2.08
_cell_volume                     2189.30(5)
_computing_cell_refinement       'CrysAlisPro 1.171.43.143a (Rigaku OD, 2024)'
_computing_data_collection
'CrysAlisPro system (CCD 43.105a 64-bit (release 11-01-2024))'
_computing_data_reduction        'CrysAlisPro 1.171.43.143a (Rigaku OD, 2024)'
_computing_molecular_graphics    'Olex2 1.3 (Dolomanov et al., 2009)'
_computing_publication_material  'Olex2 1.3 (Dolomanov et al., 2009)'
_computing_structure_refinement  'SHELXL 2019/3 (Sheldrick, 2015)'
_computing_structure_solution    'SHELXT 2018/2 (Sheldrick, 2018)'
_diffrn_ambient_environment      N~2~
_diffrn_ambient_temperature      173.00(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    -93.00 -34.00   0.50    0.60    --  -13.56 163.00-170.00  118
  2  \w    -65.00  -8.00   0.50    0.60    --  -13.56 117.00  40.00  114
  3  \w     -8.00  90.00   0.50    0.60    --   13.17  57.00 150.00  196
  4  \w     -8.00  90.00   0.50    0.60    --   13.17  57.00 150.00  196
  5  \w     -7.00  94.00   0.50    0.60    --   13.17  38.00-180.00  202
  6  \w    -87.00 -42.00   0.50    0.60    --  -13.56-178.00  90.00   90
  7  \w    -90.00   8.00   0.50    0.60    --  -13.56 -57.00-180.00  196
  8  \w    -33.00  -7.00   0.50    0.60    --  -13.56 -57.00-180.00   52
  9  \w    -94.00   7.00   0.50    0.60    --  -13.56 -38.00 -90.00  202
 10  \w    -73.00 -48.00   0.50    0.60    --  -13.56-178.00 -30.00   50
 11  \w    -82.00 -44.00   0.50    0.60    --  -13.56-178.00  60.00   76
 12  \w    -78.00 -52.00   0.50    0.60    --  -13.56-178.00   0.00   52
 13  \w    -87.00 -62.00   0.50    0.60    --  -13.56-178.00 120.00   50
 14  \w    -84.00 -58.00   0.50    0.60    --  -13.56-178.00 150.00   52
 15  \w    -18.00  29.00   0.50    0.60    --  -13.56 -99.00 150.00   94
;
_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      0.0096699
_diffrn_orient_matrix_UB_12      -0.076344
_diffrn_orient_matrix_UB_13      -0.0016204
_diffrn_orient_matrix_UB_21      -0.0025336
_diffrn_orient_matrix_UB_22      0.0040808
_diffrn_orient_matrix_UB_23      -0.0317567
_diffrn_orient_matrix_UB_31      0.0656142
_diffrn_orient_matrix_UB_32      0.0114458
_diffrn_orient_matrix_UB_33      0.0005055
_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  0.0243
_diffrn_reflns_av_unetI/netI     0.0124
_diffrn_reflns_Laue_measured_fraction_full 1
_diffrn_reflns_Laue_measured_fraction_max 1
_diffrn_reflns_limit_h_max       14
_diffrn_reflns_limit_h_min       -15
_diffrn_reflns_limit_k_max       13
_diffrn_reflns_limit_k_min       -13
_diffrn_reflns_limit_l_max       31
_diffrn_reflns_limit_l_min       -31
_diffrn_reflns_number            65779
_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         2.074
_diffrn_source                   'micro-focus sealed X-ray tube'
_diffrn_source_type              'Mova (Mo) X-ray Source'
_exptl_absorpt_coefficient_mu    0.97
_exptl_absorpt_correction_T_max  1
_exptl_absorpt_correction_T_min  0.795
_exptl_absorpt_correction_type   gaussian
_exptl_absorpt_process_details
;
        CrysAlisPro 1.171.43.143a (Rigaku Oxford Diffraction, 2024)
        Numerical absorption correction based on gaussian integration over
        a multifaceted crystal model
        Empirical absorption correction using spherical harmonics,
        implemented in SCALE3 ABSPACK scaling algorithm.
;
_exptl_crystal_colour            orange
_exptl_crystal_density_diffrn    1.485
_exptl_crystal_description       irregular
_exptl_crystal_F_000             1016
_exptl_crystal_size_max          0.268
_exptl_crystal_size_mid          0.193
_exptl_crystal_size_min          0.086
_refine_diff_density_max         0.388
_refine_diff_density_min         -0.403
_refine_diff_density_rms         0.052
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.05
_refine_ls_hydrogen_treatment    mixed
_refine_ls_matrix_type           full
_refine_ls_number_parameters     268
_refine_ls_number_reflns         6679
_refine_ls_number_restraints     26
_refine_ls_restrained_S_all      1.074
_refine_ls_R_factor_all          0.0202
_refine_ls_R_factor_gt           0.0183
_refine_ls_shift/su_max          0.003
_refine_ls_shift/su_mean         0
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'w=1/[\s^2^(Fo^2^)+(0.0227P)^2^+0.8950P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.047
_refine_ls_wR_factor_ref         0.0477
_reflns_Friedel_coverage         0
_reflns_number_gt                6222
_reflns_number_total             6679
_reflns_threshold_expression     'I > 2\s(I)'
_cod_data_source_file            d5sc08206d2.cif
_cod_data_source_block           Ru-2a
_cod_depositor_comments
'Adding full bibliography for 1576683--1576688.cif.'
_cod_database_code               1576688
_shelx_estimated_absorpt_t_min   0.78
_shelx_estimated_absorpt_t_max   0.918
_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 1.123
_oxdiff_exptl_absorpt_empirical_full_min 0.898
_shelx_shelxl_version_number     2019/3
_olex2_refinement_description
;
        1. Fixed Uiso
 At 1.2 times of:
  All C(H) groups, All C(H,H) groups, All C(H,H,H,H) groups
 At 1.5 times of:
  All C(H,H,H) groups
        2. Restrained distances
 C19-C18 \\sim C19A-C18
 with sigma of 0.002
        3. Rigid bond restraints
 C19, C18, C19A
 with sigma for 1-2 distances of 0.001 and sigma for 1-3 distances of 0.001
 C5A, C4, C3
 with sigma for 1-2 distances of 0.001 and sigma for 1-3 distances of 0.001
 C5, C4, C3
 with sigma for 1-2 distances of 0.001 and sigma for 1-3 distances of 0.001
        4. Uiso/Uaniso restraints and constraints
        C19 \\sim C19A: within 2A with sigma of 0.004 and sigma for terminal atoms of
        0.004 within 2A
        Uanis(C19) \\sim Ueq: with sigma of 0.01 and sigma for terminal atoms of 0.004
        Uanis(C19A) \\sim Ueq: with sigma of 0.01 and sigma for terminal atoms of 0.005
        5. Others
 Sof(H6BC)=Sof(H6BD)=Sof(H4BC)=Sof(H4BD)=Sof(C5A)=Sof(H5AA)=Sof(H5AB)=1-FVAR(1)
 Sof(H6AA)=Sof(H6AB)=Sof(H4AA)=Sof(H4AB)=Sof(C5)=Sof(H5A)=Sof(H5B)=FVAR(1)
 Sof(H18A)=Sof(C19A)=Sof(H19D)=Sof(H19E)=Sof(H19F)=1-FVAR(2)
 Sof(H18)=Sof(C19)=Sof(H19A)=Sof(H19B)=Sof(H19C)=FVAR(2)
        6.a Ternary CH refined with riding coordinates:
 C18(H18), C18(H18A)
        6.b Secondary CH2 refined with riding coordinates:
 C10(H10A,H10B), C6(H6AA,H6AB), C6(H6BC,H6BD), C7(H7A,H7B), C3(H3A,H3B),
 C9(H9A,H9B), C8(H8A,H8B), C4(H4AA,H4AB), C4(H4BC,H4BD), C5(H5A,H5B), C5A(H5AA,
 H5AB)
        6.c Aromatic/amide H refined with riding coordinates:
 C12(H12), C13(H13), C16(H16), C15(H15)
        6.d Idealised Me refined as rotating group:
 C17(H17A,H17B,H17C), C20(H20A,H20B,H20C), C2(H2A,H2B,H2C), C19(H19A,H19B,
 H19C), C19A(H19D,H19E,H19F)
;
_shelx_res_checksum              2241