Alkali Metal Cation Effects for Rapid C–H Activation by Iron(0) Complexes
Hidalgo, Nereida; Southwell, Kendal W.; Donnelly, Ryan; Mercado, Brandon Q.; Krajewski, Sebastian M.; Wang, Xiaoping; Holland, Patrick L.; Chemical Science  (2026) –; doi:10.1039/D6SC01470D

data_1576990
_publ_section_title
;
 Alkali metal cation effects for rapid C-H activation by iron(0)
 complexes.
;
_journal_issue                   20
_journal_name_full               'Chemical science'
_journal_page_first              10061
_journal_page_last               10066
_journal_paper_doi               10.1039/d6sc01470d
_journal_volume                  17
_journal_year                    2026
_chemical_formula_moiety
'C11 H17 Cs0.5 O6, C11.5 Cs0.5 O6, C35 H47 Fe N2, 2[C7H8]'
_chemical_formula_sum            'C71.5 H80 Cs Fe N2 O12'
_chemical_formula_weight         1348.13
_space_group_crystal_system      orthorhombic
_space_group_IT_number           62
_space_group_name_Hall           '-P 2ac 2n'
_space_group_name_H-M_alt        'P n m a'
_atom_sites_solution_hydrogens   mixed
_atom_sites_solution_primary     dual
_audit_creation_date             2025-12-09
_audit_creation_method
;
Olex2 1.5
(compiled 2025.07.13 svn.rb7424aed for OlexSys, GUI svn.r7314)
;
_audit_update_record
;
2025-12-16 deposited with the CCDC.	2026-03-31 downloaded from the CCDC.
;
_cell_angle_alpha                90
_cell_angle_beta                 90
_cell_angle_gamma                90
_cell_formula_units_Z            8
_cell_length_a                   23.9088(4)
_cell_length_b                   26.2643(5)
_cell_length_c                   25.6126(5)
_cell_measurement_reflns_used    72566
_cell_measurement_temperature    107.2(6)
_cell_measurement_theta_max      76.8900
_cell_measurement_theta_min      2.4220
_cell_volume                     16083.4(5)
_computing_cell_refinement       'CrysAlisPro 1.171.44.85 (Rigaku OD, 2024)'
_computing_data_collection
'CrysAlisPro system (CCD 43.112a 64-bit (release 01-03-2024))'
_computing_data_reduction        'CrysAlisPro 1.171.44.85 (Rigaku OD, 2024)'
_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_environment      N~2~
_diffrn_ambient_temperature      107.2(6)
_diffrn_detector                 'Hybrid Pixel Array Detector'
_diffrn_detector_area_resol_mean 10.0000
_diffrn_detector_type            'HyPix-Arc 100'
_diffrn_measured_fraction_theta_full 1.000
_diffrn_measured_fraction_theta_max 0.888
_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      6.00  31.00   0.50    3.32    --   46.24 -84.00 -22.00   50
  2  \w    -81.00  21.00   0.50    3.32    --  -47.05  84.00  97.00  204
  3  \w   -115.00 -16.00   0.50   13.29    --  -84.13  84.00  97.00  198
  4  \w   -140.00-115.00   0.50   13.29    --  -84.13 -84.00 -22.00   50
  5  \w     93.00 133.00   0.50   13.29    --  110.65 -84.00 -22.00   80
  6  \w    107.00 133.00   0.50   13.29    --  110.65  84.00  97.00   52
  7  \w    -52.00 -21.00   0.50    3.32    --    8.00 128.00-120.45   62
  8  \w    -44.00 -12.00   0.50    3.32    --   12.00 124.00 -32.01   64
  9  \w    -45.00 -15.00   0.50    3.32    --   16.00 128.00 162.98   60
 10  \w     -2.00  27.00   0.50    3.32    --   36.00  97.00 125.36   58
 11  \w      2.00  28.00   0.50    3.32    --   44.00  96.00 -50.42   52
 12  \w   -124.00 -24.00   0.50    3.32    --  -47.05 -57.00  30.00  200
 13  \w    -80.00   4.00   0.50    3.32    --  -47.05 -19.00 120.00  168
 14  \w   -129.00 -89.00   0.50    3.32    --  -47.05 -19.00 120.00   80
 15  \w      7.00  32.00   0.50    3.32    --   48.00  94.00-139.54   50
 16  \w      9.00  40.00   0.50    3.32    --   48.00  91.00  11.62   62
 17  \w     17.00  42.00   0.50    3.32    --   56.00  90.00 -25.97   50
 18  \w     17.00  42.00   0.50    3.32    --   56.00  90.00  89.75   50
 19  \w     17.00  42.00   0.50    3.32    --   56.00  90.00-131.33   50
 20  \w     17.00  42.00   0.50    3.32    --   56.00  90.00 160.19   50
 21  \w     17.00  42.00   0.50    3.32    --   56.00  90.00  44.84   50
 22  \w     30.00  65.00   0.50    3.32    --   60.00  76.00-137.69   70
 23  \w     30.00  56.00   0.50    3.32    --   60.00  77.00 -49.60   52
 24  \w     78.00 104.00   0.50    3.32    --   60.00  77.00 -49.60   52
 25  \w     98.00 130.00   0.50    3.32    --   60.00  76.00-137.69   64
 26  \w     38.00  64.00   0.50    3.32    --   68.00  76.00 -96.94   52
 27  \w     38.00  64.00   0.50    3.32    --   68.00  76.00  95.65   52
 28  \w     37.00  77.00   0.50    3.32    --   68.00  77.00 -52.79   80
 29  \w     38.00  72.00   0.50    3.32    --   68.00  76.00 -12.07   68
 30  \w   -132.00-106.00   0.50    3.32    --  -76.00 -76.00  76.43   52
 31  \w    -71.00 -46.00   0.50    3.32    --  -76.00 -75.00  15.99   50
 32  \w    -72.00 -46.00   0.50    3.32    --  -76.00 -75.00 171.90   52
 33  \w    -71.00 -45.00   0.50    3.32    --  -76.00 -77.00-155.28   52
 34  \w     46.00  73.00   0.50    3.32    --   76.00  76.00  -1.56   54
 35  \w    -71.00 -45.00   0.50    3.32    --  -76.00 -77.00 115.84   52
 36  \w    -75.00 -45.00   0.50    3.32    --  -76.00 -76.00  76.43   60
 37  \w    -78.00 -51.00   0.50    3.32    --  -80.00 -73.00  43.11   54
 38  \w    -76.00 -50.00   0.50    3.32    --  -80.00 -74.00 -84.24   52
 39  \w    -79.00 -53.00   0.50   13.29    --  -84.00 -77.00 112.92   52
 40  \w    -80.00 -54.00   0.50   13.29    --  -84.00 -74.00 159.68   52
 41  \w    -80.00 -54.00   0.50   13.29    --  -84.00 -74.00-110.79   52
 42  \w    -93.00 -55.00   0.50   13.29    --  -84.00 -73.00   6.61   76
 43  \w   -103.00 -14.00   0.50   13.29    --  -84.13  77.00-120.00  178
 44  \w    -78.00 -53.00   0.50   13.29    --  -84.13 -77.00 150.00   50
 45  \w   -102.00 -15.00   0.50   13.29    --  -84.13  77.00 -30.00  174
 46  \w    -93.00 -57.00   0.50   13.29    --  -88.00 -77.00 -34.14   72
 47  \w   -163.00 -64.00   0.50   13.29    --  -92.25 -77.00  22.72  198
 48  \w    -92.00 -62.00   0.50   13.29    --  -92.25 -75.00 109.38   60
 49  \w    -95.00 -62.00   0.50   13.29    --  -92.25 -77.00-133.94   66
 50  \w   -158.00-112.00   0.50   13.29    --  -92.25 -77.00-133.94   92
 51  \w   -138.00 -63.00   0.50   13.29    --  -92.25 -77.00  93.85  150
 52  \w   -152.00-126.00   0.50   13.29    --  -92.25 -71.00  45.39   52
 53  \w   -100.00 -62.00   0.50   13.29    --  -92.25 -76.00 -82.80   76
 54  \w   -121.00 -65.00   0.50   13.29    --  -92.25 -71.00 168.61  112
 55  \w    -95.00 -64.00   0.50   13.29    --  -92.25 -71.00  -4.23   62
 56  \w   -153.00 -63.00   0.50   13.29    --  -92.25 -74.00 -18.27  180
 57  \w   -100.00 -61.00   0.50   13.29    --  -92.25 -77.00-157.96   78
 58  \w   -163.00 -63.00   0.50   13.29    --  -92.25 -76.00 146.75  200
 59  \w   -162.00 -62.00   0.50   13.29    --  -92.25 -76.00-110.73  200
 60  \w    -97.00 -63.00   0.50   13.29    --  -92.25 -74.00 -49.63   68
 61  \w   -123.00 -65.00   0.50   13.29    --  -92.25 -71.00  45.39  116
 62  \w    -93.00 -63.00   0.50   13.29    --  -92.25 -74.00 -68.28   60
 63  \w   -162.00-100.00   0.50   13.29    --  -92.25 -74.00 -68.28  124
;
_diffrn_measurement_device       'four-circle diffractometer'
_diffrn_measurement_device_type  'XtaLAB Synergy, Dualflex, HyPix-Arc 100'
_diffrn_measurement_method       '\w scans'
_diffrn_orient_matrix_type
'CrysAlisPro convention (1999,Acta A55,543-557)'
_diffrn_orient_matrix_UB_11      -0.0073899000
_diffrn_orient_matrix_UB_12      0.0412716000
_diffrn_orient_matrix_UB_13      0.0421494000
_diffrn_orient_matrix_UB_21      -0.0368416000
_diffrn_orient_matrix_UB_22      0.0311311000
_diffrn_orient_matrix_UB_23      -0.0376513000
_diffrn_orient_matrix_UB_31      -0.0522970000
_diffrn_orient_matrix_UB_32      -0.0277643000
_diffrn_orient_matrix_UB_33      0.0206078000
_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  0.1596
_diffrn_reflns_av_unetI/netI     0.0463
_diffrn_reflns_Laue_measured_fraction_full 1.000
_diffrn_reflns_Laue_measured_fraction_max 0.888
_diffrn_reflns_limit_h_max       28
_diffrn_reflns_limit_h_min       -30
_diffrn_reflns_limit_k_max       31
_diffrn_reflns_limit_k_min       -30
_diffrn_reflns_limit_l_max       29
_diffrn_reflns_limit_l_min       -30
_diffrn_reflns_number            271846
_diffrn_reflns_point_group_measured_fraction_full 1.000
_diffrn_reflns_point_group_measured_fraction_max 0.888
_diffrn_reflns_theta_full        67.684
_diffrn_reflns_theta_max         78.775
_diffrn_reflns_theta_min         2.410
_diffrn_source                   'micro-focus sealed X-ray tube'
_diffrn_source_type              'PhotonJet (Cu) X-ray Source'
_exptl_absorpt_coefficient_mu    5.396
_exptl_absorpt_correction_T_max  1.00000
_exptl_absorpt_correction_T_min  0.20238
_exptl_absorpt_correction_type   multi-scan
_exptl_absorpt_process_details
;
CrysAlisPro 1.171.44.85 (Rigaku Oxford Diffraction, 2024)
Empirical absorption correction using spherical harmonics,
implemented in SCALE3 ABSPACK scaling algorithm.
;
_exptl_crystal_colour            red
_exptl_crystal_colour_primary    red
_exptl_crystal_density_diffrn    1.114
_exptl_crystal_description       block
_exptl_crystal_F_000             5600
_exptl_crystal_size_max          0.22
_exptl_crystal_size_mid          0.13
_exptl_crystal_size_min          0.13
_refine_diff_density_max         2.246
_refine_diff_density_min         -1.458
_refine_diff_density_rms         0.155
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.680
_refine_ls_hydrogen_treatment    mixed
_refine_ls_matrix_type           full
_refine_ls_number_parameters     720
_refine_ls_number_reflns         15758
_refine_ls_number_restraints     883
_refine_ls_restrained_S_all      1.668
_refine_ls_R_factor_all          0.1588
_refine_ls_R_factor_gt           0.1408
_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^)+(0.2000P)^2^] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.4000
_refine_ls_wR_factor_ref         0.4149
_reflns_Friedel_coverage         0.000
_reflns_number_gt                12569
_reflns_number_total             15758
_reflns_threshold_expression     'I > 2\s(I)'
_cod_data_source_file            d6sc01470d2.cif
_cod_data_source_block           syn-24060
_cod_depositor_comments
'Adding full bibliography for 1576987--1576994.cif.'
_cod_original_formula_sum        'C71.50 H80 Cs Fe N2 O12'
_cod_database_code               1576990
_shelx_shelxl_version_number     2019/3
_chemical_oxdiff_formula         C59H46CsFeN2O6
_shelx_estimated_absorpt_t_max   0.541
_shelx_estimated_absorpt_t_min   0.383
_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. Restrained distances
 O13-C58
 2.4 with sigma of 0.02
 C64-C63 \\sim C65-C65_$1 \\sim C64-C63 \\sim C61-C62 \\sim C57-C56 \\sim
C59-C58 \\sim C59-C58 \\sim C57-
 C56 \\sim C55-C54 \\sim C55-C54 \\sim C61-C62
 with sigma of 0.02
 C52-C51 \\sim C49-C50 \\sim C52-C51 \\sim C49-C50
 with sigma of 0.02
 O2-C38 \\sim O2-C39 \\sim O1-C37 \\sim O1-C36 \\sim O6-C47 \\sim O6-C46 \\sim
O5-C45 \\sim O5-C44 \\sim O4-
 C43 \\sim O4-C42 \\sim O3-C41 \\sim O3-C40
 with sigma of 0.02
 C38-C37 \\sim C36-C47 \\sim C46-C45 \\sim C44-C43 \\sim C42-C41 \\sim C40-C39
 with sigma of 0.02
 C37-C36 \\sim C47-C46 \\sim C45-C44 \\sim C43-C42 \\sim C41-C40 \\sim C39-C38
 with sigma of 0.04
 O2-C37 \\sim O1-C47 \\sim O6-C45 \\sim O5-C43 \\sim O4-C41 \\sim O3-C39 \\sim
O1-C38 \\sim O6-C36 \\sim O5-
 C46 \\sim O4-C44 \\sim O3-C42 \\sim O2-C40
 with sigma of 0.04
 O7-C49 \\sim O7-C48
 with sigma of 0.01
 O9-C52 \\sim O9-C53
 with sigma of 0.01
3. Uiso/Uaniso restraints and constraints
O10 \\sim O11 \\sim O12 \\sim O13 \\sim O14 \\sim O15 \\sim O16 \\sim C54 \\sim
C55 \\sim C56 \\sim C57 \\sim C58 \\sim C59 \\sim C60 \\sim C61 \\sim C62 \\sim
C63 \\sim C64 \\sim C65: within 2A with sigma of 0.04 and sigma for terminal
atoms of 0.08 within 2A
O2 \\sim O1 \\sim O3 \\sim O4 \\sim O5 \\sim O6 \\sim C36 \\sim C37 \\sim C38
\\sim C39 \\sim C40 \\sim C41 \\sim C42 \\sim C43 \\sim C44 \\sim C45 \\sim C46
\\sim C47: within 2A with sigma of 0.02 and sigma for terminal atoms of 0.04
within 2A
Uanis(O12) \\sim Ueq, Uanis(O16) \\sim Ueq, Uanis(O16) \\sim Ueq, Uanis(O13)
\\sim Ueq, Uanis(O14) \\sim Ueq, Uanis(O14) \\sim Ueq, Uanis(O15) \\sim Ueq,
Uanis(O15) \\sim Ueq, Uanis(O12) \\sim Ueq, Uanis(O10) \\sim Ueq, Uanis(O11)
\\sim Ueq, Uanis(O11) \\sim Ueq, Uanis(C64) \\sim Ueq, Uanis(C65) \\sim Ueq,
Uanis(C64) \\sim Ueq, Uanis(C65) \\sim Ueq, Uanis(C59) \\sim Ueq, Uanis(C59)
\\sim Ueq, Uanis(C61) \\sim Ueq, Uanis(C60) \\sim Ueq, Uanis(C61) \\sim Ueq,
Uanis(C62) \\sim Ueq, Uanis(C63) \\sim Ueq, Uanis(C62) \\sim Ueq, Uanis(C63)
\\sim Ueq, Uanis(C58) \\sim Ueq, Uanis(C57) \\sim Ueq, Uanis(C58) \\sim Ueq,
Uanis(C57) \\sim Ueq, Uanis(C54) \\sim Ueq, Uanis(C54) \\sim Ueq, Uanis(C56)
\\sim Ueq, Uanis(C55) \\sim Ueq, Uanis(C56) \\sim Ueq, Uanis(C55) \\sim Ueq:
with sigma of 0.1 and sigma for terminal atoms of 0.2
Uanis(C54) \\sim Ueq, Uanis(O16) \\sim Ueq, Uanis(O13) \\sim Ueq, Uanis(O14)
\\sim Ueq, Uanis(O15) \\sim Ueq, Uanis(O12) \\sim Ueq, Uanis(O10) \\sim Ueq,
Uanis(O11) \\sim Ueq, Uanis(C64) \\sim Ueq, Uanis(C65) \\sim Ueq, Uanis(C59)
\\sim Ueq, Uanis(C61) \\sim Ueq, Uanis(C60) \\sim Ueq, Uanis(C62) \\sim Ueq,
Uanis(C63) \\sim Ueq, Uanis(C58) \\sim Ueq, Uanis(C57) \\sim Ueq, Uanis(C56)
\\sim Ueq, Uanis(C55) \\sim Ueq: with sigma of 0.01 and sigma for terminal
atoms of 0.02
Uanis(O8) \\sim Ueq, Uanis(C50) \\sim Ueq, Uanis(C51) \\sim Ueq, Uanis(C49)
\\sim Ueq, Uanis(C52) \\sim Ueq, Uanis(O6) \\sim Ueq, Uanis(O9) \\sim Ueq,
Uanis(O7) \\sim Ueq, Uanis(O4) \\sim Ueq, Uanis(O2) \\sim Ueq, Uanis(C47) \\sim
Ueq, Uanis(C46) \\sim Ueq, Uanis(C53) \\sim Ueq, Uanis(C48) \\sim Ueq,
Uanis(C43) \\sim Ueq, Uanis(C42) \\sim Ueq, Uanis(C38) \\sim Ueq, Uanis(C39)
\\sim Ueq, Uanis(C36) \\sim Ueq, Uanis(C45) \\sim Ueq, Uanis(C44) \\sim Ueq,
Uanis(C41) \\sim Ueq, Uanis(C37) \\sim Ueq, Uanis(C40) \\sim Ueq, Uanis(O1)
\\sim Ueq, Uanis(O5) \\sim Ueq, Uanis(O3) \\sim Ueq: with sigma of 0.015 and
sigma for terminal atoms of 0.03
Uanis(C36) \\sim Ueq: with sigma of 0.005 and sigma for terminal atoms of 0.01
4. Rigid body (RIGU) restrains
 O10, O11, O12, O13, O14, O15, O16, C54, C55, C56, C57, C58, C59, C60, C61,
 C62, C63, C64, C65
 with sigma for 1-2 distances of 0.004 and sigma for 1-3 distances of 0.004
 O2, O1, O3, O4, O5, O6, C36, C37, C38, C39, C40, C41, C42, C43, C44, C45, C46,
  C47
 with sigma for 1-2 distances of 0.004 and sigma for 1-3 distances of 0.004
5. Others
 Fixed Sof: O2(0.5) O1(0.5) O3(0.5) O4(0.5) O5(0.5) O6(0.5) C36(0.5) H36A(0.5)
 H36B(0.5) C37(0.5) H37A(0.5) H37B(0.5) C38(0.5) H38A(0.5) H38B(0.5) C39(0.5)
 H39A(0.5) H39B(0.5) C40(0.5) H40A(0.5) H40B(0.5) C41(0.5) H41A(0.5) H41B(0.5)
 C42(0.5) H42A(0.5) H42B(0.5) C43(0.5) H43A(0.5) H43B(0.5) C44(0.5) H44A(0.5)
 H44B(0.5) C45(0.5) H45A(0.5) H45B(0.5) C46(0.5) H46A(0.5) H46B(0.5) C47(0.5)
 H47A(0.5) H47B(0.5)
6.a Free rotating group:
 O2(O1,O3,O4,O5,O6,C36,C37,C38,C39,C40,C41,C42,C43,C44,C45,C46,C47)
6.b Ternary CH refined with riding coordinates:
 C12(H12), C15(H15), C24(H24), C27(H27)
6.c Secondary CH2 refined with riding coordinates:
 C36(H36A,H36B), C37(H37A,H37B), C38(H38A,H38B), C39(H39A,H39B), C40(H40A,
 H40B), C41(H41A,H41B), C42(H42A,H42B), C43(H43A,H43B), C44(H44A,H44B),
 C45(H45A,H45B), C46(H46A,H46B), C47(H47A,H47B), C51(H51A,H51B), C52(H52A,H52B),
  C53(H53A,H53B)
6.d Aromatic/amide H refined with riding coordinates:
 C3(H3), C8(H8), C9(H9), C10(H10), C20(H20), C21(H21), C22(H22), C31(H31),
 C32(H32), C33(H33), C34(H34), C35(H35)
6.e Idealised Me refined as rotating group:
 C4(H4A,H4B,H4C), C5(H5A,H5B,H5C), C13(H13A,H13B,H13C), C14(H14A,H14B,H14C),
 C16(H16A,H16B,H16C), C17(H17A,H17B,H17C), C25(H25A,H25B,H25C), C26(H26A,H26B,
 H26C), C28(H28A,H28B,H28C), C29(H29A,H29B,H29C)
;
_smtbx_masks_void_probe_radius   1.2
_smtbx_masks_void_truncation_radius 1.2
_shelx_res_checksum              97995
_shelx_fab_checksum              65150
_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 2.672
_oxdiff_exptl_absorpt_empirical_full_min 0.244