Planarisation or a twist? Using steric engineering to unlock the origin of mechanofluorochromic red-shifts.
McDonald, Peter W.; Goerigk, Lars; Ritchie, Chris; Chemical science 16 (2025) 15320–15332; doi:10.1039/d5sc04257g

data_1575184
_publ_section_title
;
 Planarisation or a twist? Using steric engineering to unlock the origin
 of mechanofluorochromic red-shifts.
;
_journal_issue                   34
_journal_name_full               'Chemical science'
_journal_page_first              15320
_journal_page_last               15332
_journal_paper_doi               10.1039/d5sc04257g
_journal_volume                  16
_journal_year                    2025
_chemical_formula_moiety         'C19 H18 N2'
_chemical_formula_sum            'C19 H18 N2'
_chemical_formula_weight         274.35
_chemical_name_systematic        2,6-dimethyl-N,N-diphenylpyridin-4-amine
_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
_atom_sites_solution_primary     dual
_audit_creation_date             2025-05-25
_audit_creation_method
;
Olex2 1.5
(compiled 2025.04.05 svn.rf049d14d for OlexSys, GUI svn.r7224)
;
_audit_update_record
;
2025-06-06 deposited with the CCDC.	2025-07-18 downloaded from the CCDC.
;
_cell_angle_alpha                90
_cell_angle_beta                 93.387(2)
_cell_angle_gamma                90
_cell_formula_units_Z            4
_cell_length_a                   8.0182(2)
_cell_length_b                   17.9791(5)
_cell_length_c                   10.2551(2)
_cell_measurement_reflns_used    6188
_cell_measurement_temperature    123.00(10)
_cell_measurement_theta_max      76.8340
_cell_measurement_theta_min      4.9970
_cell_volume                     1475.79(6)
_computing_cell_refinement       'CrysAlisPro 1.171.41.93a (Rigaku OD, 2020)'
_computing_data_collection       'CrysAlisPro 1.171.41.93a (Rigaku OD, 2020)'
_computing_data_reduction        'CrysAlisPro 1.171.41.93a (Rigaku OD, 2020)'
_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      123.00(10)
_diffrn_detector                 'Hybrid Pixel Array Detector'
_diffrn_detector_area_resol_mean 10.0000
_diffrn_detector_type            HyPix
_diffrn_measured_fraction_theta_full 0.999
_diffrn_measured_fraction_theta_max 0.975
_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     25.00 118.00   0.50    0.19    --   47.70  77.00   0.00  186
  2  \w    104.00 148.00   0.50    0.77    --  107.75 111.00   3.00   88
  3  \w     33.00  66.00   0.50    0.77    --  107.75 -30.00 -90.00   66
  4  \w     33.00  66.00   0.50    0.77    --  107.75 -30.00 -60.00   66
  5  \w     33.00  66.00   0.50    0.77    --  107.75 -30.00 -30.00   66
  6  \w     33.00  64.00   0.50    0.77    --  107.75 -30.00  30.00   62
  7  \w     48.00  75.00   0.50    0.77    --  107.75 -45.00  60.00   54
  8  \w     39.00  66.00   0.50    0.77    --  107.75 -30.00  60.00   54
  9  \w     36.00  65.00   0.50    0.77    --  107.75 -30.00  90.00   58
 10  \w     34.00  66.00   0.50    0.77    --  107.75 -30.00 150.00   64
 11  \w     33.00  66.00   0.50    0.77    --  107.75 -30.00 120.00   66
 12  \w     36.00 100.00   0.50    0.77    --  107.75 -94.00  60.00  128
 13  \w     45.00 102.00   0.50    0.77    --  107.75 -94.00 -30.00  114
 14  \w     81.00 106.00   0.50    0.77    --  107.75 -94.00 -60.00   50
 15  \w     56.00 106.00   0.50    0.77    --  107.75-111.00 -89.00  100
 16  \w     73.00 108.00   0.50    0.77    --  107.75-125.00-150.00   70
 17  \w     30.00  79.00   0.50    0.19    --   47.70-111.00 -89.00   98
 18  \w     35.00  66.00   0.50    0.77    --  107.75 -94.00 -60.00   62
 19  \w     54.00  79.00   0.50    0.77    --  107.75 -94.00   0.00   50
 20  \w     34.00  66.00   0.50    0.77    --  107.75 -30.00-120.00   64
 21  \w     33.00  64.00   0.50    0.77    --  107.75 -30.00-150.00   62
 22  \w    -73.00 -18.00   0.50    0.19    --  -47.70 111.00   3.00  110
 23  \w    -72.00 -47.00   0.50    0.77    --  -86.25 111.00   3.00   50
 24  \w   -130.00-104.00   0.50    0.77    --  -86.25-111.00 -89.00   52
 25  \w   -117.00 -78.00   0.50    0.19    --  -47.70-125.00  30.00   78
 26  \w   -118.00 -85.00   0.50    0.19    --  -47.70-125.00 120.00   66
;
_diffrn_measurement_device       'four-circle diffractometer'
_diffrn_measurement_device_type  'XtaLAB Synergy, Dualflex, HyPix'
_diffrn_measurement_method       '\w scans'
_diffrn_orient_matrix_type
'CrysAlisPro convention (1999,Acta A55,543-557)'
_diffrn_orient_matrix_UB_11      0.1138267000
_diffrn_orient_matrix_UB_12      -0.0610576000
_diffrn_orient_matrix_UB_13      0.0620828000
_diffrn_orient_matrix_UB_21      0.1401942000
_diffrn_orient_matrix_UB_22      0.0575392000
_diffrn_orient_matrix_UB_23      0.0258267000
_diffrn_orient_matrix_UB_31      -0.0666707000
_diffrn_orient_matrix_UB_32      0.0170361000
_diffrn_orient_matrix_UB_33      0.1347522000
_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  0.0328
_diffrn_reflns_av_unetI/netI     0.0377
_diffrn_reflns_Laue_measured_fraction_full 0.999
_diffrn_reflns_Laue_measured_fraction_max 0.975
_diffrn_reflns_limit_h_max       9
_diffrn_reflns_limit_h_min       -10
_diffrn_reflns_limit_k_max       22
_diffrn_reflns_limit_k_min       -21
_diffrn_reflns_limit_l_max       12
_diffrn_reflns_limit_l_min       -9
_diffrn_reflns_number            9907
_diffrn_reflns_point_group_measured_fraction_full 0.999
_diffrn_reflns_point_group_measured_fraction_max 0.975
_diffrn_reflns_theta_full        67.684
_diffrn_reflns_theta_max         77.203
_diffrn_reflns_theta_min         4.920
_diffrn_source                   'micro-focus sealed X-ray tube'
_diffrn_source_type              'PhotonJet (Cu) X-ray Source'
_exptl_absorpt_coefficient_mu    0.560
_exptl_absorpt_correction_T_max  1.00000
_exptl_absorpt_correction_T_min  0.67130
_exptl_absorpt_correction_type   multi-scan
_exptl_absorpt_process_details
;
CrysAlisPro 1.171.41.93a (Rigaku Oxford Diffraction, 2020)
Empirical absorption correction using spherical harmonics,
implemented in SCALE3 ABSPACK scaling algorithm.
;
_exptl_crystal_colour            'clear light colourless'
_exptl_crystal_colour_lustre     clear
_exptl_crystal_colour_modifier   light
_exptl_crystal_colour_primary    colourless
_exptl_crystal_density_diffrn    1.235
_exptl_crystal_description       irregular
_exptl_crystal_F_000             584
_exptl_crystal_preparation       oil
_exptl_crystal_recrystallization_method dichloromethane/methanol
_refine_diff_density_max         0.240
_refine_diff_density_min         -0.209
_refine_diff_density_rms         0.045
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.066
_refine_ls_hydrogen_treatment    constr
_refine_ls_matrix_type           full
_refine_ls_number_parameters     192
_refine_ls_number_reflns         3045
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      1.066
_refine_ls_R_factor_all          0.0470
_refine_ls_R_factor_gt           0.0414
_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^)+(0.0538P)^2^+0.3957P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.1075
_refine_ls_wR_factor_ref         0.1128
_reflns_Friedel_coverage         0.000
_reflns_number_gt                2636
_reflns_number_total             3045
_reflns_threshold_expression     'I > 2\s(I)'
_cod_data_source_file            d5sc04257g2.cif
_cod_data_source_block           dimethyl_diphenyl_pyr
_cod_depositor_comments
'Adding full bibliography for 1575172--1575185.cif.'
_cod_database_code               1575184
_shelx_shelxl_version_number     2019/3
_diffrn_oxdiff_ac3_digest_hkl    419dab79ce25226b74c60275f723f50d98bcc0
_olex2_refinement_description
;
1. Fixed Uiso
 At 1.2 times of:
  All C(H) groups
 At 1.5 times of:
  All C(H,H,H) groups
2.a Aromatic/amide H refined with riding coordinates:
 C14(H14), C17(H17), C12(H12), C4(H4), C2(H2), C8(H8), C6(H6), C1(H1),
 C11(H11), C9(H9), C5(H5), C10(H10)
2.b Idealised Me refined as rotating group:
 C18(H18A,H18B,H18C), C19(H19A,H19B,H19C)
;
_shelx_res_checksum              34395
_olex2_exptl_crystal_mounting_method oil
_olex2_submission_original_sample_id '6 123 K'
_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 1.903
_oxdiff_exptl_absorpt_empirical_full_min 0.642