Amidines: a deeper look at the archetypal pro-ligand.
de Vere-Tucker, Matthew; Squire, Imogen; Tritto, Michelangelo; Anandkar, Rohil; Syeda, Tayyibah; Uthayan, Divia; Aguila, Gabrielle; Silva de Moraes, Lygia; Bakewell, Clare; Dalton transactions (Cambridge, England : 2003) 55 (2026) 4977–4987; doi:10.1039/d6dt00276e

data_7720576
_publ_section_title
;
 Amidines: a deeper look at the archetypal pro-ligand.
;
_journal_issue                   12
_journal_name_full
'Dalton transactions (Cambridge, England : 2003)'
_journal_page_first              4977
_journal_page_last               4987
_journal_paper_doi               10.1039/d6dt00276e
_journal_volume                  55
_journal_year                    2026
_chemical_formula_moiety         'C35 H50 N2'
_chemical_formula_sum            'C35 H50 N2'
_chemical_formula_weight         498.77
_space_group_crystal_system      monoclinic
_space_group_IT_number           14
_space_group_name_Hall           '-P 2yn'
_space_group_name_H-M_alt        'P 1 21/n 1'
_atom_sites_solution_hydrogens   geom
_atom_sites_solution_primary     dual
_audit_creation_date             2026-01-29
_audit_creation_method
;
Olex2 1.5
(compiled 2025.07.13 svn.rb7424aed for OlexSys, GUI svn.r7314)
;
_audit_update_record
;
2026-01-30 deposited with the CCDC.	2026-03-03 downloaded from the CCDC.
;
_cell_angle_alpha                90
_cell_angle_beta                 102.313(3)
_cell_angle_gamma                90
_cell_formula_units_Z            4
_cell_length_a                   10.0630(3)
_cell_length_b                   17.1840(5)
_cell_length_c                   18.5068(5)
_cell_measurement_reflns_used    8198
_cell_measurement_temperature    293.15(10)
_cell_measurement_theta_max      75.4880
_cell_measurement_theta_min      3.5560
_cell_volume                     3126.63(16)
_computing_cell_refinement       'CrysAlisPro 1.171.44.118a (Rigaku OD, 2025)'
_computing_data_collection
'CrysAlisPro system (CCD 44.122a 64-bit (release 14-09-2025))'
_computing_data_reduction        'CrysAlisPro 1.171.44.118a (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)'
_computing_structure_solution    'SHELXT 2018/2 (Sheldrick, 2018)'
_diffrn_ambient_environment      air
_diffrn_ambient_temperature      293.15(10)
_diffrn_detector                 'Hybrid Pixel Array Detector'
_diffrn_detector_area_resol_mean 10.0000
_diffrn_detector_type            'HyPix-Arc 100'
_diffrn_measured_fraction_theta_full 0.998
_diffrn_measured_fraction_theta_max 0.988
_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     59.00 111.00   0.50    0.24    --   95.64-125.00 -60.00  104
  2  \w     23.00  48.00   0.50    0.24    --   95.64-125.00 -60.00   50
  3  \w     34.00  88.00   0.50    0.24    --  101.75 -88.00 -37.66  108
  4  \w     28.00 103.00   0.50    0.24    --   95.64 -95.00  30.00  150
  5  \w     33.00 107.00   0.50    0.24    --  101.75 -88.00  48.15  148
  6  \w     61.00  95.00   0.50    0.24    --  101.75 -86.00  80.43   68
  7  \w     55.00  81.00   0.50    0.24    --  101.75 -85.00  58.19   52
  8  \w     37.00  86.00   0.50    0.24    --  101.75 -84.00 157.19   98
  9  \w     38.00  76.00   0.50    0.24    --  101.75 -87.00 -60.91   76
 10  \w     59.00 109.00   0.50    0.24    --  101.75 -85.00 -99.63  100
 11  \w     37.00  67.00   0.50    0.24    --  101.75 -83.00-143.32   60
 12  \w     37.00  62.00   0.50    0.24    --  101.75 -85.00-167.22   50
 13  \w    -25.00  27.00   0.50    0.24    --   49.58 -19.00-120.00  104
 14  \w    -31.00  -4.00   0.50    0.24    --   24.00 129.00-109.36   54
 15  \w     54.00  99.00   0.50    0.24    --  101.75 -79.00 -31.47   90
 16  \w     33.00  66.00   0.50    0.24    --  101.75 -75.00-129.59   66
 17  \w     34.00 103.00   0.50    0.24    --  101.75 -76.00  89.39  138
 18  \w     40.00  66.00   0.50    0.24    --  101.75 -79.00 123.05   52
 19  \w     37.00 100.00   0.50    0.24    --  101.75 -75.00 167.83  126
 20  \w     22.00  74.00   0.50    0.24    --   95.64 -61.00  90.00  104
 21  \w     18.00  44.00   0.50    0.24    --   95.64 -45.00-150.00   52
 22  \w     26.00  51.00   0.50    0.24    --   56.00  78.00-141.35   50
 23  \w     42.00 127.00   0.50    0.24    --   49.58  32.00-174.00  170
 24  \w    107.00 165.00   0.50    0.24    --  101.75  12.00-124.28  116
 25  \w     89.00 172.00   0.50    0.24    --   95.64  32.00-174.00  166
 26  \w     47.00  73.00   0.50    0.24    --  101.75  12.00-124.28   52
 27  \w    120.00 157.00   0.50    0.24    --  101.75   8.00 109.48   74
 28  \w     37.00  76.00   0.50    0.24    --  101.75   8.00 109.48   78
 29  \w   -129.00 -41.00   0.50    0.24    --  -51.33 -32.00  26.00  176
 30  \w   -165.00 -77.00   0.50    0.24    --  -87.86 -32.00  26.00  176
 31  \w    -34.00  26.00   0.50    0.24    --  -51.33  32.00-174.00  120
;
_diffrn_measurement_device       'four-circle diffractometer'
_diffrn_measurement_device_type  'XtaLAB Synergy R, DW system, HyPix-Arc 100'
_diffrn_measurement_method       '\w scans'
_diffrn_orient_matrix_type
'CrysAlisPro convention (1999,Acta A55,543-557)'
_diffrn_orient_matrix_UB_11      -0.1111154000
_diffrn_orient_matrix_UB_12      0.0576841000
_diffrn_orient_matrix_UB_13      0.0111066000
_diffrn_orient_matrix_UB_21      -0.1104132000
_diffrn_orient_matrix_UB_22      -0.0596359000
_diffrn_orient_matrix_UB_23      -0.0334306000
_diffrn_orient_matrix_UB_31      0.0052003000
_diffrn_orient_matrix_UB_32      -0.0339481000
_diffrn_orient_matrix_UB_33      0.0775818000
_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  0.0257
_diffrn_reflns_av_unetI/netI     0.0167
_diffrn_reflns_Laue_measured_fraction_full 0.998
_diffrn_reflns_Laue_measured_fraction_max 0.988
_diffrn_reflns_limit_h_max       12
_diffrn_reflns_limit_h_min       -12
_diffrn_reflns_limit_k_max       21
_diffrn_reflns_limit_k_min       -21
_diffrn_reflns_limit_l_max       23
_diffrn_reflns_limit_l_min       -16
_diffrn_reflns_number            32652
_diffrn_reflns_point_group_measured_fraction_full 0.998
_diffrn_reflns_point_group_measured_fraction_max 0.988
_diffrn_reflns_theta_full        67.684
_diffrn_reflns_theta_max         76.196
_diffrn_reflns_theta_min         3.548
_diffrn_source                   'Rotating-anode X-ray tube'
_diffrn_source_type              'Rigaku (Cu) X-ray Source'
_exptl_absorpt_coefficient_mu    0.451
_exptl_absorpt_correction_T_max  1.000
_exptl_absorpt_correction_T_min  0.314
_exptl_absorpt_correction_type   gaussian
_exptl_absorpt_process_details
;
CrysAlisPro 1.171.44.118a (Rigaku Oxford Diffraction, 2025)
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            'clear colourless'
_exptl_crystal_colour_lustre     clear
_exptl_crystal_colour_primary    colourless
_exptl_crystal_density_diffrn    1.060
_exptl_crystal_description       cube
_exptl_crystal_F_000             1096
_exptl_crystal_recrystallization_method
'Re-crystallisation from solvent: ethanol'
_exptl_crystal_size_max          0.43
_exptl_crystal_size_mid          0.33
_exptl_crystal_size_min          0.18
_refine_diff_density_max         0.324
_refine_diff_density_min         -0.248
_refine_diff_density_rms         0.038
_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     425
_refine_ls_number_reflns         6467
_refine_ls_number_restraints     33
_refine_ls_restrained_S_all      1.029
_refine_ls_R_factor_all          0.0737
_refine_ls_R_factor_gt           0.0609
_refine_ls_shift/su_max          0.000
_refine_ls_shift/su_mean         0.000
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'w=1/[\s^2^(Fo^2^)+(0.0735P)^2^+0.8131P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.1604
_refine_ls_wR_factor_ref         0.1671
_reflns_Friedel_coverage         0.000
_reflns_number_gt                5416
_reflns_number_total             6467
_reflns_threshold_expression     'I > 2\s(I)'
_cod_data_source_file            d6dt00276e3.cif
_cod_data_source_block           dippAmAdH_14
_cod_depositor_comments
'Adding full bibliography for 7720566--7720581.cif.'
_cod_database_code               7720576
_shelx_shelxl_version_number     2019/3
_chemical_oxdiff_formula         'C35 H50 N2'
_chemical_oxdiff_usercomment     'Room Temperature'
_cell_oxdiff_angle_alpha         90.008(3)
_cell_oxdiff_angle_beta          102.370(3)
_cell_oxdiff_angle_gamma         89.994(3)
_cell_oxdiff_length_a            10.0631(4)
_cell_oxdiff_length_b            17.1846(7)
_cell_oxdiff_length_c            18.5100(5)
_cell_oxdiff_measurement_reflns_used 8198
_cell_oxdiff_volume              3126.61(19)
_shelx_estimated_absorpt_t_max   0.923
_shelx_estimated_absorpt_t_min   0.830
_diffrn_oxdiff_digest_od_ed
;

;
_diffrn_oxdiff_measurement_exp_name exp_5_DVT405_fullexp.par
_olex2_refinement_description
;
1. Fixed Uiso
 At 1.2 times of:
  All C(H) groups, All C(H,H) groups, All N(H) groups
 At 1.5 times of:
  All C(H,H,H) groups
2. Restrained distances
 C2-C5 \\sim C2-C37
 with sigma of 0.02
 C2-C3 \\sim C2-C3A
 with sigma of 0.02
 C2-C4 \\sim C2-C36
 with sigma of 0.02
 C8-C7 \\sim C38-C42
 with sigma of 0.02
 C8-C5 \\sim C38-C37
 with sigma of 0.02
 C8-C9 \\sim C38-C39
 with sigma of 0.02
 C7-C6 \\sim C42-C6A
 with sigma of 0.02
 C11-C6 \\sim C41-C6A
 with sigma of 0.02
 C11-C10 \\sim C41-C40
 with sigma of 0.02
 C6-C3 \\sim C6A-C3A
 with sigma of 0.02
 C9-C10 \\sim C39-C40
 with sigma of 0.02
 C10-C4 \\sim C40-C36
 with sigma of 0.02
 C1-C5 \\sim C1-C37
 with sigma of 0.04
 C1-C3 \\sim C1-C3A
 with sigma of 0.04
 C1-C4 \\sim C1-C36
 with sigma of 0.04
 C2-C8 \\sim C2-C38
 with sigma of 0.04
 C2-C6 \\sim C2-C6A
 with sigma of 0.04
 C2-C10 \\sim C2-C40
 with sigma of 0.04
 C8-C6 \\sim C38-C6A
 with sigma of 0.04
 C8-C10 \\sim C38-C40
 with sigma of 0.04
 C7-C11 \\sim C42-C41
 with sigma of 0.04
 C7-C5 \\sim C42-C37
 with sigma of 0.04
 C7-C3 \\sim C42-C3A
 with sigma of 0.04
 C7-C9 \\sim C42-C39
 with sigma of 0.04
 C11-C3 \\sim C41-C3A
 with sigma of 0.04
 C11-C9 \\sim C41-C39
 with sigma of 0.04
 C11-C4 \\sim C41-C36
 with sigma of 0.04
 C5-C3 \\sim C37-C3A
 with sigma of 0.04
 C5-C9 \\sim C37-C39
 with sigma of 0.04
 C5-C4 \\sim C37-C36
 with sigma of 0.04
 C6-C10 \\sim C6A-C40
 with sigma of 0.04
 C3-C4 \\sim C3A-C36
 with sigma of 0.04
 C9-C4 \\sim C39-C36
 with sigma of 0.04
3. Others
 Sof(C3A)=Sof(H3AA)=Sof(H3AB)=Sof(C36)=Sof(H36A)=Sof(H36B)=Sof(C37)=Sof(H37A)=
 Sof(H37B)=Sof(C38)=Sof(H38)=Sof(C39)=Sof(H39A)=Sof(H39B)=Sof(C40)=Sof(H40)=
 Sof(C6A)=Sof(H6A)=Sof(C41)=Sof(H41A)=Sof(H41B)=Sof(C42)=Sof(H42A)=Sof(H42B)=1-
 FVAR(1)
 Sof(C8)=Sof(H8)=Sof(C7)=Sof(H7A)=Sof(H7B)=Sof(C11)=Sof(H11A)=Sof(H11B)=
 Sof(C5)=Sof(H5A)=Sof(H5B)=Sof(C6)=Sof(H6)=Sof(C3)=Sof(H3A)=Sof(H3B)=Sof(C9)=
 Sof(H9A)=Sof(H9B)=Sof(C10)=Sof(H10)=Sof(C4)=Sof(H4A)=Sof(H4B)=FVAR(1)
 Sof(H2)=1-FVAR(2)
 Sof(H1)=FVAR(2)
4.a Ternary CH refined with riding coordinates:
 C18(H18), C21(H21), C33(H33), C30(H30), C8(H8), C6(H6), C10(H10), C38(H38),
 C40(H40), C6A(H6A)
4.b Secondary CH2 refined with riding coordinates:
 C7(H7A,H7B), C11(H11A,H11B), C5(H5A,H5B), C3(H3A,H3B), C9(H9A,H9B), C4(H4A,
 H4B), C3A(H3AA,H3AB), C36(H36A,H36B), C37(H37A,H37B), C39(H39A,H39B), C41(H41A,
 H41B), C42(H42A,H42B)
4.c Aromatic/amide H refined with riding coordinates:
 N1(H1), N2(H2), C14(H14), C16(H16), C26(H26), C28(H28), C15(H15), C27(H27)
4.d Idealised Me refined as rotating group:
 C20(H20A,H20B,H20C), C32(H32A,H32B,H32C), C23(H23A,H23B,H23C), C35(H35A,H35B,
 H35C), C22(H22A,H22B,H22C), C19(H19A,H19B,H19C), C31(H31A,H31B,H31C), C34(H34A,
 H34B,H34C)
;
_shelx_res_checksum              83747
_shelx_hkl_checksum              11979
_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 2.051
_oxdiff_exptl_absorpt_empirical_full_min 0.431