Experimental and spectroscopic evidence of the hidden triplet transition state of quinone methide: a new reactivity paradigm.
Tiwari, Shashikant; Sharma, Ritika; Rawat, Diwan S.; Chemical communications (Cambridge, England) 62 (2026) 2343–2347; doi:10.1039/d5cc06672g

data_7135532
_publ_section_title
;
 Experimental and spectroscopic evidence of the hidden triplet transition
 state of quinone methide: a new reactivity paradigm.
;
_journal_issue                   7
_journal_name_full               'Chemical communications (Cambridge, England)'
_journal_page_first              2343
_journal_page_last               2347
_journal_paper_doi               10.1039/d5cc06672g
_journal_volume                  62
_journal_year                    2026
_chemical_formula_moiety         'C35 H37 N O4 S'
_chemical_formula_sum            'C35 H37 N O4 S'
_chemical_formula_weight         567.71
_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
_audit_creation_date             2024-10-10
_audit_creation_method
;
Olex2 1.3
(compiled 2020.11.12 svn.r5f609507 for OlexSys, GUI svn.r6408)
;
_audit_update_record
;
2024-10-28 deposited with the CCDC.	2025-12-22 downloaded from the CCDC.
;
_cell_angle_alpha                90
_cell_angle_beta                 99.353(3)
_cell_angle_gamma                90
_cell_formula_units_Z            4
_cell_length_a                   10.4934(3)
_cell_length_b                   17.6933(5)
_cell_length_c                   16.8167(5)
_cell_measurement_reflns_used    18640
_cell_measurement_temperature    142(60)
_cell_measurement_theta_max      31.1200
_cell_measurement_theta_min      3.3580
_cell_volume                     3080.73(16)
_computing_cell_refinement       'CrysAlisPro 1.171.43.106a (Rigaku OD, 2024)'
_computing_data_collection       'CrysAlisPro 1.171.43.106a (Rigaku OD, 2024)'
_computing_data_reduction        'CrysAlisPro 1.171.43.106a (Rigaku OD, 2024)'
_computing_molecular_graphics    'Olex2 1.3 (Dolomanov et al., 2009)'
_computing_publication_material  'Olex2 1.3 (Dolomanov et al., 2009)'
_computing_structure_refinement  'SHELXL 2016/4 (Sheldrick, 2015)'
_diffrn_ambient_environment      N~2~
_diffrn_ambient_temperature      142(60)
_diffrn_detector                 'Hybrid Pixel Array Detector'
_diffrn_detector_area_resol_mean 10.0000
_diffrn_detector_type            HyPix
_diffrn_measured_fraction_theta_full 0.998
_diffrn_measured_fraction_theta_max 0.804
_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     -3.00  26.00   0.50    6.09    --    5.69  29.00  -1.00   58
  2  \w    -68.00  18.00   0.50    6.09    --    5.69 -29.00-162.00  172
  3  \w    -11.00  27.00   0.50    6.09    --   -5.53 -99.00  90.00   76
  4  \w    -22.00  12.00   0.50    6.09    --   -5.53 -99.00-120.00   68
  5  \w    -19.00  18.00   0.50    6.09    --   -5.53  38.00-180.00   74
  6  \w     30.00  59.00   0.50    6.09    --   -5.53  38.00-180.00   58
  7  \w     32.00  79.00   0.50    6.09    --    5.69  29.00  -1.00   94
;
_diffrn_measurement_device       'four-circle diffractometer'
_diffrn_measurement_device_type
'XtaLAB Synergy, Single source at home/near, HyPix'
_diffrn_measurement_method       '\w scans'
_diffrn_orient_matrix_type
'CrysAlisPro convention (1999,Acta A55,543-557)'
_diffrn_orient_matrix_UB_11      -0.0654678000
_diffrn_orient_matrix_UB_12      0.0026908000
_diffrn_orient_matrix_UB_13      0.0055013000
_diffrn_orient_matrix_UB_21      -0.0199254000
_diffrn_orient_matrix_UB_22      -0.0154465000
_diffrn_orient_matrix_UB_23      -0.0389376000
_diffrn_orient_matrix_UB_31      0.0035923000
_diffrn_orient_matrix_UB_32      -0.0368852000
_diffrn_orient_matrix_UB_33      0.0167493000
_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  0.0596
_diffrn_reflns_av_unetI/netI     0.0493
_diffrn_reflns_Laue_measured_fraction_full 0.998
_diffrn_reflns_Laue_measured_fraction_max 0.804
_diffrn_reflns_limit_h_max       13
_diffrn_reflns_limit_h_min       -13
_diffrn_reflns_limit_k_max       24
_diffrn_reflns_limit_k_min       -22
_diffrn_reflns_limit_l_max       21
_diffrn_reflns_limit_l_min       -24
_diffrn_reflns_number            32307
_diffrn_reflns_point_group_measured_fraction_full 0.998
_diffrn_reflns_point_group_measured_fraction_max 0.804
_diffrn_reflns_theta_full        25.242
_diffrn_reflns_theta_max         31.276
_diffrn_reflns_theta_min         3.107
_diffrn_source                   'micro-focus sealed X-ray tube'
_diffrn_source_type              'PhotonJet (Mo) X-ray Source'
_exptl_absorpt_coefficient_mu    0.144
_exptl_absorpt_correction_T_max  1.00000
_exptl_absorpt_correction_T_min  0.80331
_exptl_absorpt_correction_type   multi-scan
_exptl_absorpt_process_details
;
CrysAlisPro 1.171.43.106a (Rigaku Oxford Diffraction, 2024)
Empirical absorption correction using spherical harmonics,
implemented in SCALE3 ABSPACK scaling algorithm.
;
_exptl_crystal_colour            'clear reddish red'
_exptl_crystal_colour_lustre     clear
_exptl_crystal_colour_modifier   reddish
_exptl_crystal_colour_primary    red
_exptl_crystal_density_diffrn    1.224
_exptl_crystal_description       needle
_exptl_crystal_F_000             1208
_exptl_crystal_size_max          0.1
_exptl_crystal_size_mid          0.07
_exptl_crystal_size_min          0.05
_refine_diff_density_max         0.580
_refine_diff_density_min         -0.474
_refine_diff_density_rms         0.056
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.157
_refine_ls_hydrogen_treatment    constr
_refine_ls_matrix_type           full
_refine_ls_number_parameters     377
_refine_ls_number_reflns         8098
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      1.157
_refine_ls_R_factor_all          0.0669
_refine_ls_R_factor_gt           0.0531
_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^)+(0.0785P)^2^+0.2276P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.1470
_refine_ls_wR_factor_ref         0.1543
_reflns_Friedel_coverage         0.000
_reflns_number_gt                6253
_reflns_number_total             8098
_reflns_threshold_expression     'I > 2\s(I)'
_cod_data_source_file            d5cc06672g2.cif
_cod_data_source_block           mv-68_auto
_cod_database_code               7135532
_shelx_shelxl_version_number     2016/4
_chemical_oxdiff_formula         'C H N O S'
_chemical_oxdiff_usercomment     07-03-2024
_shelx_estimated_absorpt_t_max   0.993
_shelx_estimated_absorpt_t_min   0.986
_reflns_odcompleteness_completeness 99.74
_reflns_odcompleteness_iscentric 1
_reflns_odcompleteness_theta     26.32
_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:
 C24(H24), C6(H6), C2(H2), C12(H12), C35(H35), C25(H25), C31(H31), C26(H26),
 C34(H34), C41(H41), C32(H32), C37(H37), C33(H33), C40(H40), C39(H39), C38(H38)
2.b Idealised Me refined as rotating group:
 C29(H29A,H29B,H29C), C19(H19A,H19B,H19C), C15(H15A,H15B,H15C), C20(H20A,H20B,
 H20C), C21(H21A,H21B,H21C), C16(H16A,H16B,H16C), C17(H17A,H17B,H17C)
;
_shelx_res_checksum              77444
_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 1.306
_oxdiff_exptl_absorpt_empirical_full_min 0.754