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_1575173
_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         'C12 H9 F4 N O2'
_chemical_formula_sum            'C12 H9 F4 N O2'
_chemical_formula_weight         275.20
_chemical_name_systematic
2-(3,5-dimethylpyridin-1-ium-1-yl)-4,4,5,5-tetrafluoro-3-oxocyclopent-1-en-1-olate
_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             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                 92.8070(10)
_cell_angle_gamma                90
_cell_formula_units_Z            4
_cell_length_a                   9.97700(10)
_cell_length_b                   8.39590(10)
_cell_length_c                   13.3658(2)
_cell_measurement_reflns_used    9782
_cell_measurement_temperature    123.00(10)
_cell_measurement_theta_max      79.3680
_cell_measurement_theta_min      4.3950
_cell_volume                     1118.25(2)
_computing_cell_refinement       'CrysAlisPro 1.171.42.70a (Rigaku OD, 2022)'
_computing_data_collection       'CrysAlisPro 1.171.42.70a (Rigaku OD, 2022)'
_computing_data_reduction        'CrysAlisPro 1.171.42.70a (Rigaku OD, 2022)'
_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  (Sheldrick, 2015)'
_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 1.000
_diffrn_measured_fraction_theta_max 0.982
_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    -79.00 -20.00   0.50    0.20    --  -90.00  96.00-104.00  118
  2  \w    -78.00  19.00   0.50    0.20    --  -50.51  96.00-104.00  194
  3  \w    -99.00 -44.00   0.50    0.20    --  -50.51   0.00  60.00  110
  4  \w    -68.00 -17.00   0.50    0.20    --  -90.00  30.00 120.00  102
  5  \w   -160.00 -84.00   0.50    0.20    --  -90.00 -96.00 146.00  152
  6  \w   -119.00 -73.00   0.50    0.20    --  -50.51-125.00   0.00   92
  7  \w   -119.00 -73.00   0.50    0.20    --  -50.51-125.00 -90.00   92
  8  \w   -119.00 -73.00   0.50    0.20    --  -50.51-125.00-150.00   92
  9  \w   -119.00 -73.00   0.50    0.20    --  -50.51-125.00-180.00   92
 10  \w     40.00  66.00   0.50    0.20    --  111.50 -30.00 -60.00   52
 11  \w     41.00  76.00   0.50    0.20    --  111.50 -45.00-150.00   70
 12  \w     41.00  76.00   0.50    0.20    --  111.50 -45.00-180.00   70
 13  \w     41.00  76.00   0.50    0.20    --  111.50 -45.00 -30.00   70
 14  \w     41.00  76.00   0.50    0.20    --  111.50 -45.00   0.00   70
 15  \w     40.00  66.00   0.50    0.20    --  111.50 -30.00  30.00   52
 16  \w     66.00 101.00   0.50    0.20    --  111.50 -61.00 150.00   70
 17  \w     41.00  76.00   0.50    0.20    --  111.50 -45.00 150.00   70
 18  \w     41.00  74.00   0.50    0.20    --  111.50 -45.00 120.00   66
 19  \w     40.00  66.00   0.50    0.20    --  111.50 -30.00 150.00   52
 20  \w     40.00  66.00   0.50    0.20    --  111.50 -30.00 120.00   52
 21  \w     40.00  66.00   0.50    0.20    --  111.50 -30.00  90.00   52
 22  \w     40.00  65.00   0.50    0.20    --  111.50 -30.00 -30.00   50
 23  \w     43.00 111.00   0.50    0.20    --  111.50-125.00 -90.00  136
 24  \w     41.00 106.00   0.50    0.20    --  111.50 -94.00-150.00  130
 25  \w     42.00 105.00   0.50    0.20    --  111.50 -96.00 146.00  126
 26  \w     -7.00  78.00   0.50    0.20    --   50.51 -96.00 146.00  170
 27  \w     63.00 118.00   0.50    0.20    --  111.50   0.00 -60.00  110
 28  \w    106.00 178.00   0.50    0.20    --  111.50  96.00-104.00  144
 29  \w     95.00 178.00   0.50    0.20    --  111.50 125.00  30.00  166
 30  \w    108.00 178.00   0.50    0.20    --  111.50  30.00 150.00  140
;
_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      -0.0288816000
_diffrn_orient_matrix_UB_12      -0.1605908000
_diffrn_orient_matrix_UB_13      -0.0525035000
_diffrn_orient_matrix_UB_21      0.1402439000
_diffrn_orient_matrix_UB_22      -0.0603011000
_diffrn_orient_matrix_UB_23      0.0355512000
_diffrn_orient_matrix_UB_31      -0.0584326000
_diffrn_orient_matrix_UB_32      -0.0651137000
_diffrn_orient_matrix_UB_33      0.0963761000
_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  0.0279
_diffrn_reflns_av_unetI/netI     0.0175
_diffrn_reflns_Laue_measured_fraction_full 1.000
_diffrn_reflns_Laue_measured_fraction_max 0.982
_diffrn_reflns_limit_h_max       12
_diffrn_reflns_limit_h_min       -12
_diffrn_reflns_limit_k_max       9
_diffrn_reflns_limit_k_min       -10
_diffrn_reflns_limit_l_max       17
_diffrn_reflns_limit_l_min       -13
_diffrn_reflns_number            11826
_diffrn_reflns_point_group_measured_fraction_full 1.000
_diffrn_reflns_point_group_measured_fraction_max 0.982
_diffrn_reflns_theta_full        67.684
_diffrn_reflns_theta_max         79.831
_diffrn_reflns_theta_min         5.408
_diffrn_source                   'micro-focus sealed X-ray tube'
_diffrn_source_type              'PhotonJet (Cu) X-ray Source'
_exptl_absorpt_coefficient_mu    1.380
_exptl_absorpt_correction_T_max  1.00000
_exptl_absorpt_correction_T_min  0.79833
_exptl_absorpt_correction_type   multi-scan
_exptl_absorpt_process_details
;
CrysAlisPro 1.171.42.70a (Rigaku Oxford Diffraction, 2022)
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    1.635
_exptl_crystal_description       block
_exptl_crystal_F_000             560
_exptl_crystal_preparation       oil
_exptl_crystal_recrystallization_method dichloromethane
_exptl_crystal_size_max          0.22
_exptl_crystal_size_mid          0.18
_exptl_crystal_size_min          0.1
_refine_diff_density_max         1.522
_refine_diff_density_min         -0.360
_refine_diff_density_rms         0.072
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.057
_refine_ls_hydrogen_treatment    constr
_refine_ls_matrix_type           full
_refine_ls_number_parameters     174
_refine_ls_number_reflns         2397
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      1.057
_refine_ls_R_factor_all          0.0539
_refine_ls_R_factor_gt           0.0528
_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^)+(0.0848P)^2^+1.1310P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.1482
_refine_ls_wR_factor_ref         0.1492
_reflns_Friedel_coverage         0.000
_reflns_number_gt                2314
_reflns_number_total             2397
_reflns_threshold_expression     'I > 2\s(I)'
_cod_data_source_file            d5sc04257g2.cif
_cod_data_source_block           pm3_30_dcmb_auto
_cod_depositor_comments
'Adding full bibliography for 1575172--1575185.cif.'
_cod_database_code               1575173
_shelx_shelxl_version_number     2019/3
_chemical_oxdiff_formula         C12H9F4NO2
_shelx_estimated_absorpt_t_max   0.874
_shelx_estimated_absorpt_t_min   0.751
_diffrn_oxdiff_digest_hkl
;
0100a5d67c229857fe8c0a5595ac45265af380
;
_reflns_odcompleteness_completeness 99.80
_reflns_odcompleteness_iscentric 1
_reflns_odcompleteness_theta     74.33
_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:
 C3(H3), C4(H4), C1(H1)
2.b Idealised Me refined as rotating group:
 C6(H6A,H6B,H6C), C7(H7A,H7B,H7C)
;
_shelx_res_checksum              40556
_olex2_exptl_crystal_mounting_method oil
_olex2_submission_original_sample_id 'Lut-bet 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 1.386
_oxdiff_exptl_absorpt_empirical_full_min 0.797