Heteroaryl iminothioindoxyl (HA-ITI) photoswitches <i>via</i> regioselective aza-Wittig synthesis: unifying red-shifted absorption, large <i>E</i>/<i>Z</i> band separation, and tunable thermal recovery.
Chen-Wu, Jialei; Benitez-Martin, Carlos; González-Delgado, José A; de Jong, Flip; Fron, Eduard; Steurs, Gert; Martínez-Martínez, Antonio J; Nájera, Francisco; Grøtli, Morten; Hofkens, Johan; Andréasson, Joakim; Pischel, Uwe; Chemical science 17 (2026) 3658–3668; doi:10.1039/d5sc08074f

data_1576603
_publ_section_title
;
 Heteroaryl iminothioindoxyl (HA-ITI) photoswitches <i>via</i>
 regioselective aza-Wittig synthesis: unifying red-shifted absorption,
 large <i>E</i>/<i>Z</i> band separation, and tunable thermal recovery.
;
_journal_issue                   7
_journal_name_full               'Chemical science'
_journal_page_first              3658
_journal_page_last               3668
_journal_paper_doi               10.1039/d5sc08074f
_journal_volume                  17
_journal_year                    2026
_chemical_formula_moiety         'C15 H9 N3 O S'
_chemical_formula_sum            'C15 H9 N3 O S'
_chemical_formula_weight         279.31
_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             2025-03-14
_audit_creation_method
;
Olex2 1.5-ac7-014
(compiled 2025.02.27 svn.r6f4c0eaf for Rigaku Oxford Diffraction, GUI svn.r7171)
;
_audit_update_record
;
2025-03-14 deposited with the CCDC.	2025-12-15 downloaded from the CCDC.
;
_cell_angle_alpha                90
_cell_angle_beta                 101.070(2)
_cell_angle_gamma                90
_cell_formula_units_Z            8
_cell_length_a                   19.7360(4)
_cell_length_b                   4.87140(10)
_cell_length_c                   26.2576(4)
_cell_measurement_reflns_used    18483
_cell_measurement_temperature    150.00(10)
_cell_measurement_theta_max      33.7260
_cell_measurement_theta_min      2.3750
_cell_volume                     2477.49(8)
_computing_cell_refinement       'CrysAlisPro 1.171.44.98a (Rigaku OD, 2025)'
_computing_data_collection
'CrysAlisPro system (CCD 43.111a 64-bit (release 27-02-2024))'
_computing_data_reduction        'CrysAlisPro 1.171.44.98a (Rigaku OD, 2025)'
_computing_molecular_graphics    'Olex2 1.5-ac7-014 (Dolomanov et al., 2009)'
_computing_publication_material  'Olex2 1.5-ac7-014 (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      150.00(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 0.999
_diffrn_measured_fraction_theta_max 0.897
_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    -11.00  80.00   0.50   40.00    --    8.84  67.00  32.00  182
  2  \w    -62.00  29.00   0.50   40.00    --    8.84 -67.00-101.00  182
  3  \w    -68.00  23.00   0.50   40.00    --    8.84 -38.00 -90.00  182
  4  \w    -58.00  33.00   0.50   40.00    --    8.84 -77.00  30.00  182
  5  \w    -58.00  33.00   0.50   40.00    --    8.84 -77.00  30.00  182
  6  \w    -23.00  28.00   0.50   40.00    --   -9.15 -99.00 -90.00  102
  7  \w    -23.00  28.00   0.50   40.00    --   -9.15 -99.00  30.00  102
  8  \w    -23.00  28.00   0.50   40.00    --   -9.15 -99.00 120.00  102
  9  \w    -23.00  22.00   0.50   40.00    --    8.84 -99.00-180.00   90
;
_diffrn_measurement_device       'four-circle diffractometer'
_diffrn_measurement_device_type  'XtaLAB Synergy, Dualflex, HyPix-Arc 100'
_diffrn_measurement_method       '\w scans'
_diffrn_orient_matrix_type
'CrysAlisPro convention (1999,Acta A55,543-557)'
_diffrn_orient_matrix_UB_11      0.0090252000
_diffrn_orient_matrix_UB_12      -0.0915420000
_diffrn_orient_matrix_UB_13      0.0212272000
_diffrn_orient_matrix_UB_21      0.0329145000
_diffrn_orient_matrix_UB_22      0.0630551000
_diffrn_orient_matrix_UB_23      0.0066058000
_diffrn_orient_matrix_UB_31      -0.0132784000
_diffrn_orient_matrix_UB_32      0.0940707000
_diffrn_orient_matrix_UB_33      0.0162239000
_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  0.0301
_diffrn_reflns_av_unetI/netI     0.0194
_diffrn_reflns_Laue_measured_fraction_full 0.999
_diffrn_reflns_Laue_measured_fraction_max 0.897
_diffrn_reflns_limit_h_max       26
_diffrn_reflns_limit_h_min       -29
_diffrn_reflns_limit_k_max       7
_diffrn_reflns_limit_k_min       -7
_diffrn_reflns_limit_l_max       39
_diffrn_reflns_limit_l_min       -39
_diffrn_reflns_number            33247
_diffrn_reflns_point_group_measured_fraction_full 0.999
_diffrn_reflns_point_group_measured_fraction_max 0.897
_diffrn_reflns_theta_full        25.242
_diffrn_reflns_theta_max         33.846
_diffrn_reflns_theta_min         2.376
_diffrn_source                   'micro-focus sealed X-ray tube'
_diffrn_source_type              'PhotonJet (Mo) X-ray Source'
_exptl_absorpt_coefficient_mu    0.259
_exptl_absorpt_correction_T_max  1.00000
_exptl_absorpt_correction_T_min  0.87132
_exptl_absorpt_correction_type   multi-scan
_exptl_absorpt_process_details
;
CrysAlisPro 1.171.44.98a (Rigaku Oxford Diffraction, 2025)
Empirical absorption correction using spherical harmonics,
implemented in SCALE3 ABSPACK scaling algorithm.
;
_exptl_crystal_colour            red
_exptl_crystal_colour_primary    red
_exptl_crystal_density_diffrn    1.498
_exptl_crystal_description       block
_exptl_crystal_F_000             1152
_exptl_crystal_size_max          0.21
_exptl_crystal_size_mid          0.055
_exptl_crystal_size_min          0.05
_refine_diff_density_max         0.444
_refine_diff_density_min         -0.205
_refine_diff_density_rms         0.055
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.045
_refine_ls_hydrogen_treatment    mixed
_refine_ls_matrix_type           full
_refine_ls_number_parameters     185
_refine_ls_number_reflns         4492
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      1.045
_refine_ls_R_factor_all          0.0469
_refine_ls_R_factor_gt           0.0380
_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^)+(0.0568P)^2^+1.3079P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.1024
_refine_ls_wR_factor_ref         0.1070
_reflns_Friedel_coverage         0.000
_reflns_number_gt                3768
_reflns_number_total             4492
_reflns_threshold_expression     'I > 2\s(I)'
_cod_data_source_file            d5sc08074f2.cif
_cod_data_source_block           maf02
_cod_depositor_comments
'Adding full bibliography for 1576602--1576604.cif.'
_cod_database_code               1576603
_shelx_shelxl_version_number     2019/3
_chemical_oxdiff_formula         'C15 H9 N3 O1 S1 '
_diffrn_oxdiff_digest_hkl
;
439bffcd13249911e68b7e689dad21b3a4d399
;
_diffrn_oxdiff_digest_od_ed
;

;
_olex2_refinement_description
;
1. Fixed Uiso
 At 1.2 times of:
  All C(H) groups
2.a Aromatic/amide H refined with riding coordinates:
 C3(H3), C14(H14), C6(H6), C11(H11), C5(H5), C4(H4), C12(H12), C13(H13)
;
_shelx_res_checksum              14653
_shelx_hkl_checksum              78110
_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 1.222
_oxdiff_exptl_absorpt_empirical_full_min 0.812