Metal-free access to 4-indolyl coumarin from coumarin 3-carboxylic acid and indole <i>via</i> a Michael addition-decarboxylation and dehydrogenation protocol: a photo-physical study and utility as an invisible ink.
Chakraborty, Sourav; Bhattachrjyya, Arghyadeep; Paul, Bhaswati; Das, Barnali; Natarajan, Ramalingam; Majumdar, Swapan; RSC advances 15 (2025) 37888–37898; doi:10.1039/d5ra05851a

data_7251041
_publ_section_title
;
 Metal-free access to 4-indolyl coumarin from coumarin 3-carboxylic acid
 and indole <i>via</i> a Michael addition-decarboxylation and
 dehydrogenation protocol: a photo-physical study and utility as an
 invisible ink.
;
_journal_issue                   45
_journal_name_full               'RSC advances'
_journal_page_first              37888
_journal_page_last               37898
_journal_paper_doi               10.1039/d5ra05851a
_journal_volume                  15
_journal_year                    2025
_chemical_absolute_configuration ad
_chemical_formula_moiety         'C18 H12 Cl N O3, O'
_chemical_formula_sum            'C18 H12 Cl N O4'
_chemical_formula_weight         341.74
_chemical_name_systematic        RN_BP_SC235
_space_group_crystal_system      monoclinic
_space_group_IT_number           4
_space_group_name_Hall           'P 2yb'
_space_group_name_H-M_alt        'P 1 21 1'
_atom_sites_solution_hydrogens   geom
_atom_sites_solution_primary     dual
_audit_creation_date             2023-12-08
_audit_creation_method
;FinalCif V131 by Daniel Kratzert, Freiburg 2023, 
https://dkratzert.de/finalcif.html
;
_audit_update_record
;
2024-01-19 deposited with the CCDC.	2025-09-23 downloaded from the CCDC.
;
_cell_angle_alpha                90
_cell_angle_beta                 111.475(5)
_cell_angle_gamma                90
_cell_formula_units_Z            4
_cell_length_a                   14.6606(14)
_cell_length_b                   7.2869(7)
_cell_length_c                   16.3207(16)
_cell_measurement_reflns_used    9865
_cell_measurement_temperature    120.0
_cell_measurement_theta_max      67.008
_cell_measurement_theta_min      2.9095
_cell_volume                     1622.5(3)
_computing_cell_refinement       'Bruker SAINT V8.38A (Bruker AXS)'
_computing_data_collection       'Bruker APEX3 ver.2018.7-2(Bruker AXS)'
_computing_data_reduction        'Bruker SAINT V8.38A (Bruker AXS)'
_computing_molecular_graphics    'Olex2 1.5 (Dolomanov et al., 2009)'
_computing_publication_material  'Olex2 1.5 (Dolomanov et al., 2009)'
_computing_structure_refinement  'SHELXL 2018/3 (Sheldrick, 2015)'
_computing_structure_solution    'SHELXD  (Sheldrick, 2008)'
_diffrn_ambient_temperature      120.0
_diffrn_detector                 'CPAD area detector'
_diffrn_detector_area_resol_mean 7.407
_diffrn_detector_type            'Bruker Photon III'
_diffrn_measured_fraction_theta_full 0.977
_diffrn_measured_fraction_theta_max 0.974
_diffrn_measurement_device       'four-circle diffractometer'
_diffrn_measurement_device_type  'Bruker D8 VENTURE'
_diffrn_measurement_method       '\w and \f scans'
_diffrn_radiation_collimation    '0.5 mm double-pinhole'
_diffrn_radiation_monochromator  'mirror optics'
_diffrn_radiation_probe          x-ray
_diffrn_radiation_type           'Cu K\a'
_diffrn_radiation_wavelength     1.54178
_diffrn_reflns_av_R_equivalents  0.0690
_diffrn_reflns_av_unetI/netI     0.0409
_diffrn_reflns_Laue_measured_fraction_full 0.977
_diffrn_reflns_Laue_measured_fraction_max 0.974
_diffrn_reflns_limit_h_max       16
_diffrn_reflns_limit_h_min       -17
_diffrn_reflns_limit_k_max       8
_diffrn_reflns_limit_k_min       -8
_diffrn_reflns_limit_l_max       19
_diffrn_reflns_limit_l_min       -19
_diffrn_reflns_number            52627
_diffrn_reflns_point_group_measured_fraction_full 0.912
_diffrn_reflns_point_group_measured_fraction_max 0.908
_diffrn_reflns_theta_full        67.679
_diffrn_reflns_theta_max         68.046
_diffrn_reflns_theta_min         3.473
_diffrn_source                   'microfocus sealed X-ray tube'
_diffrn_source_current           1.2
_diffrn_source_power             0.06
_diffrn_source_type              'Incoatec I\ms Diamond'
_diffrn_source_voltage           50.0
_diffrn_standards_number         0
_exptl_absorpt_coefficient_mu    2.282
_exptl_absorpt_correction_T_max  0.7531
_exptl_absorpt_correction_T_min  0.5503
_exptl_absorpt_correction_type   multi-scan
_exptl_absorpt_process_details
;SADABS-2016/2 - Bruker AXS area detector scaling and absorption correction: 
Krause, L., Herbst-Irmer, R., Sheldrick G.M. & Stalke D., J. Appl. Cryst. 48 
(2015) 3-10
;
_exptl_crystal_colour            yellow
_exptl_crystal_colour_primary    yellow
_exptl_crystal_density_diffrn    1.399
_exptl_crystal_description       block
_exptl_crystal_F_000             704
_exptl_crystal_size_max          0.1
_exptl_crystal_size_mid          0.02
_exptl_crystal_size_min          0.01
_refine_diff_density_max         0.503
_refine_diff_density_min         -0.319
_refine_diff_density_rms         0.080
_refine_ls_abs_structure_details
;
 Flack x determined using 1793 quotients [(I+)-(I-)]/[(I+)+(I-)]
 (Parsons, Flack and Wagner, Acta Cryst. B69 (2013) 249-259).
;
_refine_ls_abs_structure_Flack   0.141(8)
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.111
_refine_ls_hydrogen_treatment    constr
_refine_ls_matrix_type           full
_refine_ls_number_parameters     447
_refine_ls_number_reflns         5379
_refine_ls_number_restraints     7
_refine_ls_restrained_S_all      1.115
_refine_ls_R_factor_all          0.0691
_refine_ls_R_factor_gt           0.0625
_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^)+(0.0661P)^2^+2.4309P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.1571
_refine_ls_wR_factor_ref         0.1607
_reflns_Friedel_coverage         0.719
_reflns_Friedel_fraction_full    0.835
_reflns_Friedel_fraction_max     0.831
_reflns_number_gt                4903
_reflns_number_total             5379
_reflns_threshold_expression     'I > 2\s(I)'
_cod_data_source_file            d5ra05851a2.cif
_cod_data_source_block           rn_bp_sc235_0m_a
_cod_database_code               7251041
_olex2_refinement_description
;
1. Fixed Uiso
 At 1.2 times of:
  All C(H) groups, All N(H) groups
 At 1.5 times of:
  All C(H,H,H) groups
2. Uiso/Uaniso restraints and constraints
O1A_3: within 2A with sigma of 0.01 and sigma for terminal atoms of 0.02 within
2A
Uanis(O1B_4) \\sim Ueq: with sigma of 0.01 and sigma for terminal atoms of 0.02
3. Rigid body (RIGU) restrains
 O1A_3
 with sigma for 1-2 distances of 0.001 and sigma for 1-3 distances of 0.001
4. Others
 Sof(O1B)=1-FVAR(1)
 Sof(O1A)=FVAR(1)
5.a Aromatic/amide H refined with riding coordinates:
 N1(H1), C3(H3), C4(H4), C7(H7), C9(H9), C11(H11), C15(H15), C17(H17),
 C18(H18), N1(H1), C3(H3), C4(H4), C7(H7), C9(H9), C11(H11), C15(H15), C17(H17),
  C18(H18)
5.b Idealised Me refined as rotating group:
 C1(H1A,H1B,H1C), C1(H1A,H1B,H1C)
;
_olex2_submission_special_instructions 'No special instructions were received'
_shelx_shelxl_version_number     2018/3
_shelx_estimated_absorpt_t_min   0.804
_shelx_estimated_absorpt_t_max   0.978
_shelx_res_checksum              55404
_publcif_funding_html
;
;