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_7720577
_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         '1.5(C68 H94 Al2 N4)'
_chemical_formula_sum            'C102 H141 Al3 N6'
_chemical_formula_weight         1532.14
_chemical_properties_physical    Air-sensitive,Moisture-sensitive
_space_group_crystal_system      monoclinic
_space_group_IT_number           15
_space_group_name_Hall           '-I 2ya'
_space_group_name_H-M_alt        'I 1 2/a 1'
_atom_sites_solution_hydrogens   mixed
_atom_sites_solution_primary     dual
_audit_creation_date             2026-01-28
_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                 93.0560(10)
_cell_angle_gamma                90
_cell_formula_units_Z            4
_cell_length_a                   15.5008(2)
_cell_length_b                   23.4406(3)
_cell_length_c                   25.4848(3)
_cell_measurement_reflns_used    38127
_cell_measurement_temperature    100.00(10)
_cell_measurement_theta_max      30.2660
_cell_measurement_theta_min      2.8360
_cell_volume                     9246.7(2)
_computing_cell_refinement       'CrysAlisPro 1.171.43.90 (Rigaku OD, 2023)'
_computing_data_collection
'CrysAlisPro system (CCD 43.122a 64-bit (release 15-05-2024))'
_computing_data_reduction        'CrysAlisPro 1.171.43.90 (Rigaku OD, 2023)'
_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      100.00(10)
_diffrn_detector                 'Hybrid Pixel Array Detector'
_diffrn_detector_area_resol_mean 13.3333
_diffrn_detector_type            'Eiger2 1M'
_diffrn_measured_fraction_theta_full 0.999
_diffrn_measured_fraction_theta_max 0.874
_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    -60.00 -12.00   0.50   10.86    --   -7.69 130.00  71.00   96
  2  \w    -67.00 -17.00   0.50   10.86    --   -7.69 140.00-114.00  100
  3  \w    -32.00  64.00   0.50   10.86    --   -7.69   0.00 -60.00  192
  4  \w    -42.00  15.00   0.50   10.86    --   -7.69   0.00 -60.00  114
  5  \w    -73.00   8.00   0.50   10.86    --   -7.69 -57.00  30.00  162
  6  \w    -21.00  58.00   0.50   10.86    --   -7.69  57.00-180.00  158
  7  \w    -64.00 -38.00   0.50   10.86    --   -7.69 -77.00   0.00   52
  8  \w    -31.00   8.00   0.50   10.86    --   -7.69 -77.00   0.00   78
  9  \w    -71.00   7.00   0.50   10.86    --   -7.69 -57.00 -60.00  156
 10  \w      6.00  71.00   0.50   10.86    --    8.47  57.00 -90.00  130
 11  \w     48.00  73.00   0.50   10.86    --    8.47  57.00 -60.00   50
 12  \w    -19.00  18.00   0.50   10.86    --    8.47 -57.00  90.00   74
 13  \w    -17.00  38.50   0.50   10.86    --    8.47  77.00-180.00  111
;
_diffrn_measurement_device       'four-circle diffractometer'
_diffrn_measurement_device_type  'XtaLAB Synergy, Dualflex, Eiger2 1M'
_diffrn_measurement_method       '\w scans'
_diffrn_orient_matrix_type
'CrysAlisPro convention (1999,Acta A55,543-557)'
_diffrn_orient_matrix_UB_11      -0.0030019000
_diffrn_orient_matrix_UB_12      0.0177991000
_diffrn_orient_matrix_UB_13      -0.0225205000
_diffrn_orient_matrix_UB_21      -0.0027279000
_diffrn_orient_matrix_UB_22      -0.0244762000
_diffrn_orient_matrix_UB_23      -0.0164018000
_diffrn_orient_matrix_UB_31      -0.0456290000
_diffrn_orient_matrix_UB_32      0.0003012000
_diffrn_orient_matrix_UB_33      0.0009574000
_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  0.0470
_diffrn_reflns_av_unetI/netI     0.0341
_diffrn_reflns_Laue_measured_fraction_full 0.999
_diffrn_reflns_Laue_measured_fraction_max 0.874
_diffrn_reflns_limit_h_max       21
_diffrn_reflns_limit_h_min       -19
_diffrn_reflns_limit_k_max       33
_diffrn_reflns_limit_k_min       -32
_diffrn_reflns_limit_l_max       36
_diffrn_reflns_limit_l_min       -36
_diffrn_reflns_number            102333
_diffrn_reflns_point_group_measured_fraction_full 0.999
_diffrn_reflns_point_group_measured_fraction_max 0.874
_diffrn_reflns_theta_full        25.242
_diffrn_reflns_theta_max         30.954
_diffrn_reflns_theta_min         2.727
_diffrn_source                   'micro-focus sealed X-ray tube'
_diffrn_source_type              'PhotonJet (Mo) X-ray Source'
_exptl_absorpt_coefficient_mu    0.089
_exptl_absorpt_correction_T_max  1.11
_exptl_absorpt_correction_T_min  0.82
_exptl_absorpt_correction_type   gaussian
_exptl_absorpt_process_details
;
CrysAlisPro 1.171.43.90 (Rigaku Oxford Diffraction, 2023)
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 yellowish colourless'
_exptl_crystal_colour_lustre     clear
_exptl_crystal_colour_modifier   yellowish
_exptl_crystal_colour_primary    colourless
_exptl_crystal_density_diffrn    1.101
_exptl_crystal_description       plate
_exptl_crystal_F_000             3336
_exptl_crystal_recrystallization_method
'Re-crystallisation from solvent: hexane'
_exptl_crystal_size_max          0.38
_exptl_crystal_size_mid          0.21
_exptl_crystal_size_min          0.14
_refine_diff_density_max         0.274
_refine_diff_density_min         -0.293
_refine_diff_density_rms         0.040
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.046
_refine_ls_hydrogen_treatment    mixed
_refine_ls_matrix_type           full
_refine_ls_number_parameters     575
_refine_ls_number_reflns         12839
_refine_ls_number_restraints     189
_refine_ls_restrained_S_all      1.043
_refine_ls_R_factor_all          0.0780
_refine_ls_R_factor_gt           0.0527
_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^)+(0.0640P)^2^+4.6977P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.1309
_refine_ls_wR_factor_ref         0.1411
_reflns_Friedel_coverage         0.000
_reflns_number_gt                9338
_reflns_number_total             12839
_reflns_threshold_expression     'I > 2\s(I)'
_cod_data_source_file            d6dt00276e3.cif
_cod_data_source_block           dippAmmesAlH2_11-Al
_cod_depositor_comments
'Adding full bibliography for 7720566--7720581.cif.'
_cod_database_code               7720577
_shelx_shelxl_version_number     2019/3
_chemical_oxdiff_formula         'C H N Al'
_shelx_estimated_absorpt_t_max   0.988
_shelx_estimated_absorpt_t_min   0.967
_diffrn_oxdiff_ac3_digest_hkl    413597714ce1e68f593af2164f043016223f7d
_olex2_refinement_description
;
1. Restrained distances
 C39-C40 = C41-C36 = C36-C37 = C37-C38
 1.39 with sigma of 0.02
 C39-C38 = C40-C41
 1.4 with sigma of 0.02
 C39-C43 = C41-C44 = C37-C42
 1.51 with sigma of 0.02
 C39-C41 = C39-C37 = C41-C37
 2.43 with sigma of 0.04
 C40-C36 = C36-C38
 2.39 with sigma of 0.04
 C40-C44
 2.53 with sigma of 0.04
 C36-C42
 2.52 with sigma of 0.04
 C39-C40 \\sim C40-C41 \\sim C41-C36 \\sim C36-C37 \\sim C37-C38 \\sim C38-C39
 with sigma of 0.02
 C39-C41 \\sim C41-C37 \\sim C37-C39 \\sim C40-C38 \\sim C40-C36 \\sim C36-C38
 with sigma of 0.04
 C39-C43 \\sim C41-C44 \\sim C37-C42
 with sigma of 0.02
 C40-C43 \\sim C38-C43 \\sim C38-C42 \\sim C36-C42 \\sim C36-C44 \\sim C40-C44
 with sigma of 0.04
 C51-C52 \\sim C51-C52A
 with sigma of 0.02
 C51-C53 \\sim C51-C53A
 with sigma of 0.02
2. Restrained planarity
 C39, C40, C41, C36, C37, C38, C43, C44, C42
 with sigma of 0.1
3. Uiso/Uaniso restraints and constraints
C39 \\sim C40 \\sim C41 \\sim C36 \\sim C37 \\sim C38 \\sim C43 \\sim C44 \\sim
C42: within 2A with sigma of 0.04 and sigma for terminal atoms of 0.08 within 2A
Uanis(C52A) = Uanis(C52) = Uanis(C53) = Uanis(C53A)
4. Rigid body (RIGU) restrains
 C39, C40, C41, C36, C37, C38, C43, C44, C42
 with sigma for 1-2 distances of 0.004 and sigma for 1-3 distances of 0.004
5. Others
 Sof(H51A)=Sof(C52A)=Sof(H52D)=Sof(H52E)=Sof(H52F)=Sof(C53A)=Sof(H53D)=
 Sof(H53E)=Sof(H53F)=1-FVAR(1)
 Sof(H51)=Sof(C52)=Sof(H52A)=Sof(H52B)=Sof(H52C)=Sof(C53)=Sof(H53A)=Sof(H53B)=
 Sof(H53C)=FVAR(1)
 Fixed Sof: C39(0.5) C40(0.5) H40(0.5) C41(0.5) C36(0.5) C37(0.5) C38(0.5)
 H38(0.5) C43(0.5) H43A(0.5) H43B(0.5) H43C(0.5) C44(0.5) H44A(0.5) H44B(0.5)
 H44C(0.5) C42(0.5) H42A(0.5) H42B(0.5) H42C(0.5)
6.a Ternary CH refined with riding coordinates:
 C17(H17), C32(H32), C20(H20), C29(H29), C54(H54), C51(H51), C51(H51A)
6.b Aromatic/amide H refined with riding coordinates:
 C6(H6), C15(H15), C26(H26), C14(H14), C27(H27), C13(H13), C4(H4), C25(H25),
 C40(H40), C38(H38), C47(H47), C48(H48), C49(H49)
6.c Idealised Me refined as rotating group:
 C10(H10A,H10B,H10C), C19(H19A,H19B,H19C), C18(H18A,H18B,H18C), C8(H8A,H8B,
 H8C), C22(H22A,H22B,H22C), C9(H9A,H9B,H9C), C21(H21A,H21B,H21C), C33(H33A,H33B,
 H33C), C34(H34A,H34B,H34C), C30(H30A,H30B,H30C), C31(H31A,H31B,H31C), C43(H43A,
 H43B,H43C), C44(H44A,H44B,H44C), C42(H42A,H42B,H42C), C56(H56A,H56B,H56C),
 C52(H52A,H52B,H52C), C53(H53A,H53B,H53C), C55(H55A,H55B,H55C), C52A(H52D,H52E,
 H52F), C53A(H53D,H53E,H53F)
;
_shelx_res_checksum              80596
_shelx_hkl_checksum              88886
_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 1.089
_oxdiff_exptl_absorpt_empirical_full_min 0.875