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_1576602
_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         'C17 H12 N2 O S'
_chemical_formula_sum            'C17 H12 N2 O S'
_chemical_formula_weight         292.35
_space_group_crystal_system      monoclinic
_space_group_IT_number           15
_space_group_name_Hall           '-C 2yc'
_space_group_name_H-M_alt        'C 1 2/c 1'
_atom_sites_solution_hydrogens   geom
_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                 94.1020(10)
_cell_angle_gamma                90
_cell_formula_units_Z            8
_cell_length_a                   13.64030(10)
_cell_length_b                   7.84000(10)
_cell_length_c                   25.3454(2)
_cell_measurement_reflns_used    20335
_cell_measurement_temperature    150.00(10)
_cell_measurement_theta_max      79.4670
_cell_measurement_theta_min      3.4800
_cell_volume                     2703.49(5)
_computing_cell_refinement       'CrysAlisPro 1.171.44.98a (Rigaku OD, 2025)'
_computing_data_collection
'CrysAlisPro system (CCD 43.101a 64-bit (release 13-12-2023))'
_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 1.000
_diffrn_measured_fraction_theta_max 0.997
_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     20.00  45.00   0.50    0.50    --   46.94 -95.00 -42.00   50
  2  \w    -74.00  20.00   0.50    0.50    --  -49.44  95.00  66.00  188
  3  \w    -26.00  31.00   0.50    0.50    --  -49.44  19.00-180.00  114
  4  \w   -120.00 -75.00   0.50    0.50    --  -49.44-125.00  90.00   90
  5  \w    -48.00 -11.00   0.50    0.50    --  -84.69  95.00  66.00   74
  6  \w    -79.00 -53.00   0.50    0.50    --  -84.69  95.00  66.00   52
  7  \w    -32.00  -2.00   0.50    0.50    --  -84.69  30.00-150.00   60
  8  \w    -42.00 -16.00   0.50    0.50    --  -84.69  77.00   0.00   52
  9  \w    -34.00  -3.00   0.50    0.50    --  -84.69  30.00 -90.00   62
 10  \w    -34.00  -3.00   0.50    0.50    --  -84.69  30.00 -30.00   62
 11  \w    -51.00  -6.00   0.50    0.50    --  -84.69  45.00  60.00   90
 12  \w   -123.00 -98.00   0.50    0.50    --  -84.69 -95.00 -42.00   50
 13  \w    -51.00  -6.00   0.50    0.50    --  -84.69  45.00   0.00   90
 14  \w    -91.00 -66.00   0.50    0.50    --  -84.69  77.00   0.00   50
 15  \w     53.00 106.00   0.50    0.50    --  110.85 -95.00 -42.00  106
 16  \w    106.00 143.00   0.50    0.50    --  110.85  95.00  66.00   74
 17  \w     43.00  68.00   0.50    0.50    --  110.85 -61.00-180.00   50
 18  \w     59.00  85.00   0.50    0.50    --  110.85 -77.00   0.00   52
 19  \w     34.00  59.00   0.50    0.50    --  110.85 -61.00 150.00   50
 20  \w    121.00 147.00   0.50    0.50    --  113.75  16.00 -21.15   52
 21  \w     66.00 115.00   0.50    0.50    --  113.75  24.00  11.43   98
 22  \w     45.00  82.00   0.50    0.50    --  113.75  16.00 -21.15   74
 23  \w     45.00  71.00   0.50    0.50    --  113.75 -86.00-179.62   52
 24  \w     51.00 116.00   0.50    0.50    --  113.75 -84.00  40.65  130
 25  \w     41.00 176.00   0.50    0.50    --  113.75   5.00 106.17  270
 26  \w    105.00 130.00   0.50    0.50    --  113.75 -87.00 -69.93   50
 27  \w     47.00  77.00   0.50    0.50    --  113.75 -87.00 -69.93   60
 28  \w    102.00 142.00   0.50    0.50    --  113.75  24.00-176.85   80
 29  \w    110.00 136.00   0.50    0.50    --  113.75 -88.00 111.10   52
 30  \w     81.00 136.00   0.50    0.50    --  113.75 -87.00 153.37  110
 31  \w     68.00  93.00   0.50    0.50    --  113.75  24.00-176.85   50
 32  \w    117.00 143.00   0.50    0.50    --  113.75 -86.00-179.62   52
 33  \w     49.00  74.00   0.50    0.50    --  113.75 -84.00  27.05   50
 34  \w     46.00  92.00   0.50    0.50    --  113.75 -87.00  23.87   92
 35  \w     57.00  96.00   0.50    0.50    --  113.75  13.00 132.01   78
 36  \w    146.00 172.00   0.50    0.50    --  113.75  13.00 132.01   52
 37  \w     45.00  78.00   0.50    0.50    --  113.75 -83.00  89.32   66
 38  \w     49.00  95.00   0.50    0.50    --  113.75 -79.00 115.26   92
 39  \w    149.00 177.00   0.50    0.50    --  113.75  16.00 -21.15   56
 40  \w    106.00 143.00   0.50    0.50    --  113.75 -85.00-107.80   74
 41  \w     50.00  82.00   0.50    0.50    --  113.75 -88.00 111.10   64
 42  \w     72.00  99.00   0.50    0.50    --  110.85 -79.00-154.00   54
 43  \w   -117.00 -74.00   0.50    0.50    --  -49.44-125.00-180.00   86
 44  \w   -114.00 -67.00   0.50    0.50    --  -49.44 -77.00-150.00   94
 45  \w    -53.00 -27.00   0.50    0.50    --  -49.44 -77.00-150.00   52
 46  \w    -32.00  -6.00   0.50    0.50    --  -84.69  30.00 -60.00   52
 47  \w    -32.00  -6.00   0.50    0.50    --  -84.69  30.00  30.00   52
 48  \w    -67.00 -41.00   0.50    0.50    --  -84.69  77.00-120.00   52
 49  \w   -100.00 -62.00   0.50    0.50    --  -84.69  77.00  60.00   76
 50  \w    -34.00  -3.00   0.50    0.50    --  -84.69  30.00-180.00   62
 51  \w    -98.00 -72.00   0.50    0.50    --  -84.69  77.00-120.00   52
 52  \w    -43.00 -17.00   0.50    0.50    --  -84.69  77.00  60.00   52
 53  \w    -64.00 -39.00   0.50    0.50    --  -84.69 125.00  90.00   50
 54  \w    -35.00 -10.00   0.50    0.50    --  -84.69  30.00-120.00   50
 55  \w    123.00 149.00   0.50    0.50    --  110.85  77.00  60.00   52
 56  \w     66.00 111.00   0.50    0.50    --  110.85-125.00 120.00   90
 57  \w     42.00  70.00   0.50    0.50    --  110.85-125.00 -90.00   56
 58  \w     57.00  83.00   0.50    0.50    --  110.85 -95.00 120.00   52
 59  \w     62.00  88.00   0.50    0.50    --  110.85 -95.00-180.00   52
 60  \w     34.00  59.00   0.50    0.50    --  110.85 -61.00 -90.00   50
 61  \w    142.00 168.00   0.50    0.50    --  110.85  61.00   0.00   52
 62  \w     83.00 109.00   0.50    0.50    --  110.85-125.00-180.00   52
 63  \w     86.00 111.00   0.50    0.50    --  110.85-125.00 -90.00   50
 64  \w     76.00 102.00   0.50    0.50    --  110.85 -95.00 150.00   52
 65  \w     54.00  80.00   0.50    0.50    --  110.85-125.00   0.00   52
 66  \w     87.00 113.00   0.50    0.50    --  110.85  61.00   0.00   52
 67  \w     51.00  76.00   0.50    0.50    --  110.85-125.00-180.00   50
 68  \w     42.00  68.00   0.50    0.50    --  110.85 -77.00 150.00   52
 69  \w     47.00  75.00   0.50    0.50    --  113.75 -88.00 153.95   56
 70  \w    126.00 151.00   0.50    0.50    --  113.75 -87.00  69.39   50
 71  \w     50.00  83.00   0.50    0.50    --  113.75 -87.00  69.39   66
 72  \w    106.00 138.00   0.50    0.50    --  113.75 -88.00 153.95   64
 73  \w     56.00 108.00   0.50    0.50    --  113.75-107.00 150.47  104
 74  \w    103.00 128.00   0.50    0.50    --  113.75 -88.00  -2.49   50
 75  \w     49.00  74.00   0.50    0.50    --  113.75 -87.00 -93.43   50
 76  \w     52.00  78.00   0.50    0.50    --  113.75 -88.00  -2.49   52
 77  \w    118.00 143.00   0.50    0.50    --  113.75 -79.00 115.19   50
 78  \w     49.00  84.00   0.50    0.50    --  113.75 -83.00  99.02   70
 79  \w     49.00  74.00   0.50    0.50    --  113.75 -80.00 -17.91   50
 80  \w    105.00 131.00   0.50    0.50    --  113.75  20.00  98.15   52
 81  \w     91.00 117.00   0.50    0.50    --  113.75-132.00  68.62   52
 82  \w     53.00  93.00   0.50    0.50    --  113.75  20.00  98.15   80
 83  \w    109.00 135.00   0.50    0.50    --  113.75  19.00 -36.86   52
 84  \w     49.00  83.00   0.50    0.50    --  113.75  19.00 -36.86   68
 85  \w    116.00 142.00   0.50    0.50    --  113.75 -88.00-137.43   52
 86  \w     46.00  71.00   0.50    0.50    --  113.75 -88.00-137.43   50
 87  \w     46.00  72.00   0.50    0.50    --  113.75 -80.00  51.42   52
 88  \w     83.00 109.00   0.50    0.50    --  113.75-118.00 -55.10   52
 89  \w    119.00 144.00   0.50    0.50    --  113.75 -83.00  89.29   50
 90  \w    118.00 144.00   0.50    0.50    --  113.75  24.00 139.85   52
 91  \w     75.00 100.00   0.50    0.50    --  113.75  24.00 139.85   50
 92  \w    120.00 149.00   0.50    0.50    --  113.75 -84.00  26.95   58
 93  \w     45.00  71.00   0.50    0.50    --  113.75 -82.00-112.71   52
 94  \w     48.00  74.00   0.50    0.50    --  113.75-118.00 -55.10   52
;
_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      0.0456048000
_diffrn_orient_matrix_UB_12      -0.1795183000
_diffrn_orient_matrix_UB_13      -0.0018595000
_diffrn_orient_matrix_UB_21      -0.0624523000
_diffrn_orient_matrix_UB_22      -0.0373873000
_diffrn_orient_matrix_UB_23      -0.0517790000
_diffrn_orient_matrix_UB_31      0.0826631000
_diffrn_orient_matrix_UB_32      0.0707080000
_diffrn_orient_matrix_UB_33      -0.0320991000
_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  0.0282
_diffrn_reflns_av_unetI/netI     0.0132
_diffrn_reflns_Laue_measured_fraction_full 1.000
_diffrn_reflns_Laue_measured_fraction_max 0.997
_diffrn_reflns_limit_h_max       17
_diffrn_reflns_limit_h_min       -15
_diffrn_reflns_limit_k_max       9
_diffrn_reflns_limit_k_min       -9
_diffrn_reflns_limit_l_max       31
_diffrn_reflns_limit_l_min       -32
_diffrn_reflns_number            26066
_diffrn_reflns_point_group_measured_fraction_full 1.000
_diffrn_reflns_point_group_measured_fraction_max 0.997
_diffrn_reflns_theta_full        67.684
_diffrn_reflns_theta_max         79.839
_diffrn_reflns_theta_min         3.497
_diffrn_source                   'micro-focus sealed X-ray tube'
_diffrn_source_type              'PhotonJet (Cu) X-ray Source'
_exptl_absorpt_coefficient_mu    2.118
_exptl_absorpt_correction_T_max  1.00000
_exptl_absorpt_correction_T_min  0.78909
_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    1.437
_exptl_crystal_description       prism
_exptl_crystal_F_000             1216
_exptl_crystal_size_max          0.16
_exptl_crystal_size_mid          0.15
_exptl_crystal_size_min          0.1
_refine_diff_density_max         0.307
_refine_diff_density_min         -0.312
_refine_diff_density_rms         0.043
_refine_ls_extinction_coef       0.00029(6)
_refine_ls_extinction_expression Fc^*^=kFc[1+0.001xFc^2^\l^3^/sin(2\q)]^-1/4^
_refine_ls_extinction_method     'SHELXL-2019/2 (Sheldrick 2019)'
_refine_ls_goodness_of_fit_ref   1.136
_refine_ls_hydrogen_treatment    constr
_refine_ls_matrix_type           full
_refine_ls_number_parameters     192
_refine_ls_number_reflns         2929
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      1.136
_refine_ls_R_factor_all          0.0336
_refine_ls_R_factor_gt           0.0333
_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^)+(0.0431P)^2^+2.2756P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.0921
_refine_ls_wR_factor_ref         0.0923
_reflns_Friedel_coverage         0.000
_reflns_number_gt                2879
_reflns_number_total             2929
_reflns_threshold_expression     'I > 2\s(I)'
_cod_data_source_file            d5sc08074f2.cif
_cod_data_source_block           09am23jcw203
_cod_depositor_comments
'Adding full bibliography for 1576602--1576604.cif.'
_cod_database_code               1576602
_shelx_shelxl_version_number     2019/3
_chemical_oxdiff_formula         'C8 H10 S1 N2 O1'
_shelx_estimated_absorpt_t_max   0.816
_shelx_estimated_absorpt_t_min   0.728
_diffrn_oxdiff_digest_hkl
;
434cf34aec18010e23cff91aa52a5bc2a6e5a5
;
_diffrn_oxdiff_digest_od_ed
;

;
_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:
 C4(H4), C5(H5), C6(H6), C7(H7), C9(H9), C13(H13), C14(H14), C15(H15), C16(H16)
2.b Idealised Me refined as rotating group:
 C2(H2A,H2B,H2C)
;
_shelx_res_checksum              22174
_shelx_hkl_checksum              8111
_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 1.509
_oxdiff_exptl_absorpt_empirical_full_min 0.586