Fluorenyl-Tethered N-Heterocyclic Carbene Complexes of the Heavy Alkali Metals
Burnett, Stuart; Kennedy, Alan; Mansell, Stephen M.; Weetman, Catherine Ellen; Chemical Communications  (2026) –; doi:10.1039/D5CC06477E

data_7135308
_publ_section_title
;
 Fluorenyl-Tethered N-Heterocyclic Carbene Complexes of the Heavy Alkali
 Metals
;
_journal_name_full               'Chemical Communications'
_journal_paper_doi               10.1039/D5CC06477E
_journal_year                    2026
_chemical_formula_moiety         'C27 H25 N2 Rb1'
_chemical_formula_sum            'C27 H25 N2 Rb'
_chemical_formula_weight         462.96
_chemical_properties_physical
Air-sensitive,Moisture-sensitive,Oxygen-sensitive
_space_group_crystal_system      monoclinic
_space_group_IT_number           14
_space_group_name_Hall           '-P 2ybc'
_space_group_name_H-M_alt        'P 1 21/c 1'
_atom_sites_solution_hydrogens   geom
_audit_creation_date             2025-07-07
_audit_creation_method
;
Olex2 1.5
(compiled 2025.05.31 svn.r86d253d1 for OlexSys, GUI svn.r7254)
;
_audit_update_record
;
2025-11-10 deposited with the CCDC.	2025-12-04 downloaded from the CCDC.
;
_cell_angle_alpha                90
_cell_angle_beta                 101.790(1)
_cell_angle_gamma                90
_cell_formula_units_Z            8
_cell_length_a                   14.3566(1)
_cell_length_b                   11.8396(1)
_cell_length_c                   26.4983(3)
_cell_measurement_reflns_used    25445
_cell_measurement_temperature    100(2)
_cell_measurement_theta_max      72.6930
_cell_measurement_theta_min      3.1290
_cell_volume                     4409.06(7)
_computing_cell_refinement       'CrysAlisPro 1.171.44.94a (Rigaku OD, 2025)'
_computing_data_collection
'CrysAlisPro system (CCD 44.94a 64-bit (release 17-02-2025))'
_computing_data_reduction        'CrysAlisPro 1.171.44.94a (Rigaku OD, 2025)'
_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)'
_diffrn_ambient_environment      N~2~
_diffrn_ambient_temperature      100(2)
_diffrn_detector                 'Hybrid Pixel Array Detector'
_diffrn_detector_area_resol_mean 10.0000
_diffrn_detector_type            HyPix3000
_diffrn_measured_fraction_theta_full 0.997
_diffrn_measured_fraction_theta_max 0.991
_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   -106.00 -75.00   0.50    5.00    --  -40.33 156.00 -17.00   62
  2  \w    -72.00 -26.00   0.50    5.00    --  -40.33 120.00-173.00   92
  3  \w    -96.00 -53.00   0.50    5.00    --  -40.33-156.00 -54.00   86
  4  \w     55.00 103.00   0.50    5.00    --   40.33 156.00 -17.00   96
  5  \w     76.00 102.00   0.50    5.00    --   40.33-156.00 -54.00   52
  6  \w     36.00  61.00   0.50    5.00    --   40.33-156.00 -54.00   50
  7  \w     21.00  47.00   0.50    5.00    --   40.33-120.00 102.00   52
  8  \w   -110.00 -84.00   0.50   10.00    -- -104.00 156.00 -17.00   52
  9  \w   -131.00-106.00   0.50   10.00    -- -104.00-156.00 -54.00   50
 10  \w   -132.00-106.00   0.50   10.00    -- -104.00-120.00 102.00   52
 11  \w    -99.00 -74.00   0.50   10.00    -- -104.00 120.00-173.00   50
 12  \w     60.00  85.00   0.50   10.00    --  104.00-156.00 -54.00   50
 13  \w     51.00  76.00   0.50   10.00    --  104.00-120.00 102.00   50
 14  \w     83.00 108.00   0.50   10.00    --  104.00 156.00 -17.00   50
 15  \w   -108.00 -17.00   0.50    5.00    --  -40.33 -64.00 -30.00  182
 16  \w   -109.00 -13.00   0.50    5.00    --  -40.33 -77.00 -60.00  192
 17  \w    -20.00  28.00   0.50    5.00    --  -40.33  25.00 150.00   96
 18  \w   -106.00 -26.00   0.50    5.00    --  -40.33 -38.00 150.00  160
 19  \w    -31.00  30.00   0.50    5.00    --  -40.33  25.00 -60.00  122
 20  \w    -28.00  -3.00   0.50    5.00    --  -40.33  64.00 150.00   50
 21  \w   -115.00 -41.00   0.50    5.00    --  -40.33-178.00 -90.00  148
 22  \w    -63.00 -30.00   0.50    5.00    --  -40.33  64.00 150.00   66
 23  \w    -51.00 -26.00   0.50    5.00    --  -40.33  50.00 -30.00   50
 24  \w     33.00  58.00   0.50    5.00    --   40.33  64.00  30.00   50
 25  \w    -29.00  18.00   0.50    5.00    --   40.33 -25.00   0.00   94
 26  \w     62.00  87.00   0.50    5.00    --   40.33-178.00  30.00   50
 27  \w     63.00 108.00   0.50    5.00    --   40.33 178.00-120.00   90
 28  \w     91.00 117.00   0.50    5.00    --   40.33-178.00  30.00   52
 29  \w     14.00  39.00   0.50    5.00    --   40.33 -64.00 -60.00   50
 30  \w     26.00  52.00   0.50    5.00    --   40.33  38.00 150.00   52
 31  \w     77.00 103.00   0.50    5.00    --   40.33  25.00-120.00   52
 32  \w     32.00  64.00   0.50    5.00    --   40.33  25.00-120.00   64
 33  \w     30.00  65.00   0.50    5.00    --   40.33-112.00-180.00   70
 34  \w     81.00 106.00   0.50    5.00    --   40.33  64.00  30.00   50
 35  \w    -25.00   8.00   0.50    5.00    --   40.33 -12.00 -30.00   66
 36  \w   -168.00 -77.00   0.50   10.00    -- -104.00 -77.00 -60.00  182
 37  \w   -104.00 -60.00   0.50   10.00    -- -104.00  77.00 120.00   88
 38  \w   -115.00 -90.00   0.50   10.00    -- -104.00 -25.00-180.00   50
 39  \w   -158.00-122.00   0.50   10.00    -- -104.00 -25.00-180.00   72
 40  \w    -68.00 -36.00   0.50   10.00    -- -104.00  59.00   0.00   64
 41  \w   -106.00 -81.00   0.50   10.00    -- -104.00  96.00-120.00   50
 42  \w   -105.00 -76.00   0.50   10.00    -- -104.00  96.00 -90.00   58
 43  \w    -56.00 -30.00   0.50   10.00    -- -104.00  96.00 -90.00   52
 44  \w    -63.00 -36.00   0.50   10.00    -- -104.00 136.00  56.13   54
 45  \w    -78.00 -30.00   0.50   10.00    -- -104.00  96.00-150.00   96
 46  \w   -174.00 -98.00   0.50   10.00    -- -104.00 -25.00  90.00  152
 47  \w   -121.00 -96.00   0.50   10.00    -- -104.00 136.00  56.13   50
 48  \w   -105.00 -35.00   0.50   10.00    -- -104.00  77.00-150.00  140
 49  \w    -76.00 -50.00   0.50   10.00    -- -104.00 145.00  90.00   52
 50  \w   -127.00-101.00   0.50   10.00    -- -104.00 145.00  90.00   52
 51  \w   -171.00 -82.00   0.50   10.00    -- -104.00 -59.00   0.00  178
 52  \w   -108.00 -80.00   0.50   10.00    -- -104.00 -68.00-150.00   56
 53  \w   -103.00 -35.00   0.50   10.00    -- -104.00  77.00 -90.00  136
 54  \w   -157.00-131.00   0.50   10.00    -- -104.00 -68.00-150.00   52
 55  \w    -78.00 -40.00   0.50   10.00    -- -104.00 117.00 120.00   76
 56  \w    -75.00 -49.00   0.50   10.00    -- -104.00  68.00  90.00   52
 57  \w   -169.00-143.00   0.50   10.00    -- -104.00 -25.00-120.00   52
 58  \w   -104.00 -79.00   0.50   10.00    -- -104.00-117.00 -30.00   50
 59  \w    -68.00 -39.00   0.50   10.00    -- -104.00  59.00  60.00   58
 60  \w   -172.00-137.00   0.50   10.00    -- -104.00 -96.00 120.00   70
 61  \w   -109.00 -83.00   0.50   10.00    -- -104.00 117.00 120.00   52
 62  \w    -79.00 -54.00   0.50   10.00    -- -104.00  68.00-150.00   50
 63  \w    -71.00 -35.00   0.50   10.00    -- -104.00 145.00-120.00   72
 64  \w   -152.00-127.00   0.50   10.00    -- -104.00 -72.00-121.21   50
 65  \w   -127.00 -86.00   0.50   10.00    -- -104.00 145.00-120.00   82
 66  \w   -162.00-114.00   0.50   10.00    -- -104.00 -77.00 -90.00   96
 67  \w    -91.00 -38.00   0.50   10.00    -- -104.00  77.00   0.00  106
 68  \w   -109.00 -42.00   0.50   10.00    -- -104.00 117.00 -30.00  134
 69  \w   -148.00-102.00   0.50   10.00    -- -104.00 -42.00-120.00   92
 70  \w    -68.00 -39.00   0.50   10.00    -- -104.00  59.00 150.00   58
 71  \w    -55.00 -30.00   0.50   10.00    -- -104.00  96.00-120.00   50
 72  \w    -95.00 -69.00   0.50   10.00    -- -104.00  96.00 150.00   52
 73  \w    -87.00 -36.00   0.50   10.00    -- -104.00  70.00 -44.58  102
 74  \w   -131.00 -90.00   0.50   10.00    -- -104.00 -33.00  90.00   82
 75  \w   -133.00-106.00   0.50   10.00    -- -104.00 -25.00 120.00   54
 76  \w   -147.00-122.00   0.50   10.00    -- -104.00 -33.00 -30.00   50
 77  \w   -126.00-100.00   0.50   10.00    -- -104.00 -33.00-120.00   52
 78  \w   -128.00 -80.00   0.50   10.00    -- -104.00 -68.00-180.00   96
 79  \w   -104.00 -78.00   0.50   10.00    -- -104.00  89.00  90.13   52
 80  \w    -86.00 -36.00   0.50   10.00    -- -104.00  77.00  90.00  100
 81  \w   -171.00-135.00   0.50   10.00    -- -104.00 -68.00-180.00   72
 82  \w    -65.00 -40.00   0.50   10.00    -- -104.00 117.00 -90.00   50
 83  \w    -69.00 -34.00   0.50   10.00    -- -104.00  89.00  90.13   70
 84  \w   -112.00 -43.00   0.50   10.00    -- -104.00 128.00 -13.57  138
 85  \w   -110.00 -84.00   0.50   10.00    -- -104.00 117.00 -90.00   52
 86  \w   -115.00 -90.00   0.50   10.00    -- -104.00 -25.00  30.00   50
 87  \w   -149.00-100.00   0.50   10.00    -- -104.00 -87.00-150.00   98
 88  \w   -172.00 -82.00   0.50   10.00    -- -104.00 -59.00 -30.00  180
 89  \w   -103.00 -42.00   0.50   10.00    -- -104.00  96.00 120.00  122
 90  \w   -168.00-118.00   0.50   10.00    -- -104.00 -77.00  60.00  100
 91  \w   -102.00 -77.00   0.50   10.00    -- -104.00 -77.00  60.00   50
 92  \w   -105.00 -60.00   0.50   10.00    -- -104.00 117.00-120.00   90
 93  \w   -109.00 -40.00   0.50   10.00    -- -104.00 117.00 -60.00  138
 94  \w   -105.00 -63.00   0.50   10.00    -- -104.00  86.00-128.49   84
 95  \w    -90.00 -64.00   0.50   10.00    -- -104.00  77.00  30.00   52
 96  \w    -99.00 -73.00   0.50   10.00    -- -104.00 102.00  75.45   52
 97  \w    -99.00 -73.00   0.50   10.00    -- -104.00  96.00 -30.00   52
 98  \w    -56.00 -31.00   0.50   10.00    -- -104.00  96.00  60.00   50
 99  \w   -146.00 -94.00   0.50   10.00    -- -104.00 -33.00  30.00  104
100  \w   -155.00-130.00   0.50   10.00    -- -104.00 -33.00 150.00   50
101  \w   -168.00-114.00   0.50   10.00    -- -104.00-123.00-102.39  108
102  \w   -159.00-126.00   0.50   10.00    -- -104.00 -42.00-150.00   66
103  \w   -150.00-125.00   0.50   10.00    -- -104.00 -42.00 -30.00   50
104  \w   -122.00 -96.00   0.50   10.00    -- -104.00 -42.00   0.00   52
105  \w   -149.00-117.00   0.50   10.00    -- -104.00-121.00 126.08   64
106  \w   -151.00-125.00   0.50   10.00    -- -104.00 -97.00  36.01   52
107  \w     42.00  67.00   0.50   10.00    --  104.00 -59.00  90.00   50
108  \w    131.00 156.00   0.50   10.00    --  104.00  59.00 -30.00   50
109  \w    107.00 135.00   0.50   10.00    --  104.00 117.00  30.00   56
110  \w    116.00 141.00   0.50   10.00    --  104.00  25.00 -60.00   50
111  \w     98.00 123.00   0.50   10.00    --  104.00 120.00-173.00   50
;
_diffrn_measurement_device       'four-circle diffractometer'
_diffrn_measurement_device_type
'XtaLAB Synergy, Single source at home/near, HyPix3000'
_diffrn_measurement_method       '\w scans'
_diffrn_orient_matrix_type
'CrysAlisPro convention (1999,Acta A55,543-557)'
_diffrn_orient_matrix_UB_11      0.0283894000
_diffrn_orient_matrix_UB_12      0.0765279000
_diffrn_orient_matrix_UB_13      0.0476917000
_diffrn_orient_matrix_UB_21      -0.0204495000
_diffrn_orient_matrix_UB_22      0.1052425000
_diffrn_orient_matrix_UB_23      -0.0346835000
_diffrn_orient_matrix_UB_31      -0.1039002000
_diffrn_orient_matrix_UB_32      0.0001526000
_diffrn_orient_matrix_UB_33      0.0070250000
_diffrn_radiation_monochromator  mirror
_diffrn_radiation_probe          x-ray
_diffrn_radiation_type           'Cu K\a'
_diffrn_radiation_wavelength     1.54184
_diffrn_reflns_av_R_equivalents  0.0686
_diffrn_reflns_av_unetI/netI     0.0342
_diffrn_reflns_Laue_measured_fraction_full 0.997
_diffrn_reflns_Laue_measured_fraction_max 0.991
_diffrn_reflns_limit_h_max       13
_diffrn_reflns_limit_h_min       -17
_diffrn_reflns_limit_k_max       14
_diffrn_reflns_limit_k_min       -14
_diffrn_reflns_limit_l_max       32
_diffrn_reflns_limit_l_min       -32
_diffrn_reflns_number            67895
_diffrn_reflns_point_group_measured_fraction_full 0.997
_diffrn_reflns_point_group_measured_fraction_max 0.991
_diffrn_reflns_theta_full        70.000
_diffrn_reflns_theta_max         73.674
_diffrn_reflns_theta_min         6.339
_diffrn_source                   'micro-focus sealed X-ray tube'
_diffrn_source_type              'PhotonJet (Cu) X-ray Source'
_exptl_absorpt_coefficient_mu    3.192
_exptl_absorpt_correction_T_max  1.00000
_exptl_absorpt_correction_T_min  0.81487
_exptl_absorpt_correction_type   multi-scan
_exptl_absorpt_process_details
;
CrysAlisPro 1.171.44.94a (Rigaku Oxford Diffraction, 2025)
Empirical absorption correction using spherical harmonics,
implemented in SCALE3 ABSPACK scaling algorithm.
;
_exptl_crystal_colour            red
_exptl_crystal_density_diffrn    1.395
_exptl_crystal_description       prism
_exptl_crystal_F_000             1904
_exptl_crystal_size_max          0.14
_exptl_crystal_size_mid          0.07
_exptl_crystal_size_min          0.05
_refine_diff_density_max         2.476
_refine_diff_density_min         -0.663
_refine_diff_density_rms         0.107
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.027
_refine_ls_hydrogen_treatment    constr
_refine_ls_matrix_type           full
_refine_ls_number_parameters     547
_refine_ls_number_reflns         8826
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      1.027
_refine_ls_R_factor_all          0.0638
_refine_ls_R_factor_gt           0.0561
_refine_ls_shift/su_max          0.002
_refine_ls_shift/su_mean         0.000
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'w=1/[\s^2^(Fo^2^)+(0.0914P)^2^+5.1553P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.1452
_refine_ls_wR_factor_ref         0.1512
_reflns_Friedel_coverage         0.000
_reflns_number_gt                7577
_reflns_number_total             8826
_reflns_threshold_expression     'I > 2\s(I)'
_cod_data_source_file            d5cc06477e2.cif
_cod_data_source_block           sb060_auto_smart_abs
_cod_original_formula_sum        'C27 H25 N2 Rb1'
_cod_database_code               7135308
_shelx_shelxl_version_number     2019/3
_shelx_estimated_absorpt_t_max   0.857
_shelx_estimated_absorpt_t_min   0.664
_diffrn_oxdiff_digest_hkl
;
433accf712b20bdf206ff08c2448da5e7fcf54
;
_diffrn_oxdiff_digest_od_ed
;

;
_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.a Secondary CH2 refined with riding coordinates:
 C4(H4A,H4B), C5(H5A,H5B), C31(H31A,H31B), C32(H32A,H32B)
2.b Aromatic/amide H refined with riding coordinates:
 C2(H2), C3(H3), C8(H8), C9(H9), C10(H10), C11(H11), C14(H14), C15(H15),
 C16(H16), C17(H17), C21(H21), C23(H23), C29(H29), C30(H30), C35(H35), C36(H36),
  C37(H37), C38(H38), C41(H41), C42(H42), C43(H43), C44(H44), C48(H48), C50(H50)
2.c Idealised Me refined as rotating group:
 C25(H25A,H25B,H25C), C26(H26A,H26B,H26C), C27(H27A,H27B,H27C), C52(H52A,H52B,
 H52C), C53(H53A,H53B,H53C), C54(H54A,H54B,H54C)
;
_shelx_res_checksum              12037
_shelx_hkl_checksum              58599
_olex2_submission_special_instructions 'No special instructions were received'
_oxdiff_exptl_absorpt_empirical_details
;
Empirical correction (ABSPACK) includes:
- Absorption correction using spherical harmonics
- Frame scaling
;
_oxdiff_exptl_absorpt_empirical_full_max 1.416
_oxdiff_exptl_absorpt_empirical_full_min 0.793