# Supplementary Information (SI) for RSC Advances.
# This journal is © The Royal Society of Chemistry 2025

####################################################################### 
# 
# This file contains crystal structure data downloaded from the 
# Cambridge Structural Database (CSD) hosted by the Cambridge 
# Crystallographic Data Centre (CCDC).
# 
# Full information about CCDC data access policies and citation 
# guidelines are available at http://www.ccdc.cam.ac.uk/access/V1 
# 
# Audit and citation data items may have been added by the CCDC. 
# Please retain this information to preserve the provenance of 
# this file and to allow appropriate attribution of the data. 
# 
#######################################################################

data_r20231017c
_database_code_depnum_ccdc_archive 'CCDC 2416300'
loop_
_audit_author_name
_audit_author_address
'Kai Yang'
;School of Chemistry and Chemical Engineering, Shandong University of Technology
China
;
_audit_update_record             
;
2025-01-11 deposited with the CCDC.	2025-02-06 downloaded from the CCDC.
;
_audit_creation_date             2023-10-18
_audit_creation_method           
;
Olex2 1.5
(compiled 2023.03.06 svn.rbb2c1857 for OlexSys, GUI svn.r6748)
;
_shelx_SHELXL_version_number     2018/3
_chemical_name_common            ?
_chemical_name_systematic        ?
_chemical_formula_moiety         'C6 H8 O4'
_chemical_formula_sum            'C6 H8 O4'
_chemical_formula_weight         144.12
_chemical_absolute_configuration unk
_chemical_melting_point          ?
loop_
_atom_type_symbol
_atom_type_description
_atom_type_scat_dispersion_real
_atom_type_scat_dispersion_imag
_atom_type_scat_source
C C 0.0033 0.0016 'International Tables Vol C Tables 4.2.6.8 and 6.1.1.4'
H H 0.0000 0.0000 'International Tables Vol C Tables 4.2.6.8 and 6.1.1.4'
O O 0.0106 0.0060 'International Tables Vol C Tables 4.2.6.8 and 6.1.1.4'

_shelx_space_group_comment       
;
The symmetry employed for this shelxl refinement is uniquely defined
by the following loop, which should always be used as a source of
symmetry information in preference to the above space-group names.
They are only intended as comments.
;
_space_group_crystal_system      orthorhombic
_space_group_IT_number           19
_space_group_name_H-M_alt        'P 21 21 21'
_space_group_name_Hall           'P 2ac 2ab'
loop_
_space_group_symop_operation_xyz
'x, y, z'
'-x+1/2, -y, z+1/2'
'-x, y+1/2, -z+1/2'
'x+1/2, -y+1/2, -z'

_cell_length_a                   6.2271(2)
_cell_length_b                   8.9744(3)
_cell_length_c                   10.7641(3)
_cell_angle_alpha                90
_cell_angle_beta                 90
_cell_angle_gamma                90
_cell_volume                     601.55(3)
_cell_formula_units_Z            4
_cell_measurement_reflns_used    2492
_cell_measurement_temperature    113.15
_cell_measurement_theta_max      31.7260
_cell_measurement_theta_min      3.9670
_shelx_estimated_absorpt_T_max   0.973
_shelx_estimated_absorpt_T_min   0.962
_exptl_absorpt_coefficient_mu    0.136
_exptl_absorpt_correction_T_max  1.00000
_exptl_absorpt_correction_T_min  0.37375
_exptl_absorpt_correction_type   multi-scan
_exptl_absorpt_process_details   
'CrysAlisPro 1.171.39.46e (Rigaku Oxford Diffraction, 2018)'
_exptl_absorpt_special_details   ?
_exptl_crystal_colour            ?
_exptl_crystal_density_diffrn    1.591
_exptl_crystal_density_meas      ?
_exptl_crystal_density_method    ?
_exptl_crystal_description       block
_exptl_crystal_F_000             304
_exptl_crystal_size_max          0.29
_exptl_crystal_size_mid          0.25
_exptl_crystal_size_min          0.2
_exptl_transmission_factor_max   ?
_exptl_transmission_factor_min   ?
_diffrn_reflns_av_R_equivalents  0.0383
_diffrn_reflns_av_unetI/netI     0.0492
_diffrn_reflns_Laue_measured_fraction_full 0.994
_diffrn_reflns_Laue_measured_fraction_max 0.890
_diffrn_reflns_limit_h_max       8
_diffrn_reflns_limit_h_min       -6
_diffrn_reflns_limit_k_max       12
_diffrn_reflns_limit_k_min       -13
_diffrn_reflns_limit_l_max       10
_diffrn_reflns_limit_l_min       -16
_diffrn_reflns_number            4277
_diffrn_reflns_point_group_measured_fraction_full 0.995
_diffrn_reflns_point_group_measured_fraction_max 0.871
_diffrn_reflns_theta_full        25.242
_diffrn_reflns_theta_max         32.193
_diffrn_reflns_theta_min         3.786
_diffrn_ambient_temperature      113.15
_diffrn_detector                 'CCD plate'
_diffrn_detector_area_resol_mean ?
_diffrn_measured_fraction_theta_full 0.994
_diffrn_measured_fraction_theta_max 0.890
_diffrn_measurement_details      
;
List of Runs (angles in degrees, time in seconds):

  # Type    Start    End  Width  tₑₓₚ   ω     θ     κ     φ   Frames
#--------------------------------------------------------------------------
  1  ω     10.00  37.00   0.50    1.00    --    5.00  56.00  77.00   54
  2  ω    -24.00  72.00   0.50    1.00    --  -16.40  56.00  77.00  192
  3  ω    -32.00  73.00   0.50    1.00    --  -16.40  38.00-180.00  210
;
_diffrn_measurement_device       'four-circle diffractometer'
_diffrn_measurement_device_type  'Rigaku MM007 Saturn944+'
_diffrn_measurement_method       'ω scans'
_diffrn_orient_matrix_type       
'CrysAlisPro convention (1999,Acta A55,543-557)'
_diffrn_orient_matrix_UB_11      -0.0475885000
_diffrn_orient_matrix_UB_12      0.0484797000
_diffrn_orient_matrix_UB_13      0.0441538000
_diffrn_orient_matrix_UB_21      0.0980506000
_diffrn_orient_matrix_UB_22      0.0398442000
_diffrn_orient_matrix_UB_23      0.0049248000
_diffrn_orient_matrix_UB_31      -0.0332643000
_diffrn_orient_matrix_UB_32      0.0479542000
_diffrn_orient_matrix_UB_33      -0.0486952000
_diffrn_radiation_monochromator  mirror
_diffrn_radiation_probe          x-ray
_diffrn_radiation_type           'Mo K\a'
_diffrn_radiation_wavelength     0.71073
_diffrn_source                   'Rotating-anode X-ray tube'
_diffrn_source_type              'Rigaku (Mo) X-ray Source'
_reflns_Friedel_coverage         0.668
_reflns_Friedel_fraction_full    0.998
_reflns_Friedel_fraction_max     0.844
_reflns_number_gt                1702
_reflns_number_total             1852
_reflns_special_details          
;
 Reflections were merged by SHELXL according to the crystal
 class for the calculation of statistics and refinement.
 
 _reflns_Friedel_fraction is defined as the number of unique
 Friedel pairs measured divided by the number that would be
 possible theoretically, ignoring centric projections and
 systematic absences.
;
_reflns_threshold_expression     'I > 2σ(I)'
_computing_cell_refinement       'CrysAlisPro 1.171.39.46e (Rigaku OD, 2018)'
_computing_data_collection       'CrysAlisPro 1.171.39.46e (Rigaku OD, 2018)'
_computing_data_reduction        'CrysAlisPro 1.171.39.46e (Rigaku OD, 2018)'
_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    'SHELXT 2018/2 (Sheldrick, 2018)'
_refine_diff_density_max         0.369
_refine_diff_density_min         -0.228
_refine_diff_density_rms         0.060
_refine_ls_abs_structure_details 
;
 Flack x determined using 598 quotients [(I+)-(I-)]/[(I+)+(I-)]
 (Parsons, Flack and Wagner, Acta Cryst. B69 (2013) 249-259).
;
_refine_ls_abs_structure_Flack   -0.9(7)
_refine_ls_extinction_coef       .
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.054
_refine_ls_hydrogen_treatment    constr
_refine_ls_matrix_type           full
_refine_ls_number_parameters     92
_refine_ls_number_reflns         1852
_refine_ls_number_restraints     0
_refine_ls_R_factor_all          0.0483
_refine_ls_R_factor_gt           0.0448
_refine_ls_restrained_S_all      1.054
_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/[σ²(Fo²)+(0.0626P)²+0.0237P] where P=(Fo²+2Fc²)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.1092
_refine_ls_wR_factor_ref         0.1132
_refine_special_details          ?
_olex2_refinement_description    
;
1. Fixed Uiso
 At 1.2 times of:
  All C(H) groups, All C(H,H) groups
 At 1.5 times of:
  All O(H) groups
2.a Ternary CH refined with riding coordinates:
 C1(H1A), C2(H2), C3(H3), C5(H5), C6(H6)
2.b Secondary CH2 refined with riding coordinates:
 C4(H4A,H4B)
2.c Idealised tetrahedral OH refined as rotating group:
 O1(H1)
;
_atom_sites_solution_hydrogens   geom
_atom_sites_solution_primary     dual
_atom_sites_solution_secondary   ?
loop_
_atom_site_label
_atom_site_type_symbol
_atom_site_fract_x
_atom_site_fract_y
_atom_site_fract_z
_atom_site_U_iso_or_equiv
_atom_site_adp_type
_atom_site_occupancy
_atom_site_site_symmetry_order
_atom_site_calc_flag
_atom_site_refinement_flags_posn
_atom_site_refinement_flags_adp
_atom_site_refinement_flags_occupancy
_atom_site_disorder_assembly
_atom_site_disorder_group
O1 O 0.9145(2) 0.66960(15) 0.67833(12) 0.0200(3) Uani 1 1 d . . . . .
H1 H 0.942750 0.742908 0.632657 0.030 Uiso 1 1 calc R U . . .
O2 O 0.6247(2) 0.32583(14) 0.62475(13) 0.0199(3) Uani 1 1 d . . . . .
O3 O 0.4566(2) 0.59477(14) 0.48003(11) 0.0173(3) Uani 1 1 d . . . . .
O4 O 0.5841(2) 0.48775(14) 0.78353(12) 0.0186(3) Uani 1 1 d . . . . .
C1 C 0.7782(3) 0.57000(19) 0.61383(16) 0.0134(4) Uani 1 1 d . . . . .
H1A H 0.841109 0.540403 0.531989 0.016 Uiso 1 1 calc R U . . .
C2 C 0.7383(3) 0.43437(19) 0.69657(17) 0.0160(4) Uani 1 1 d . . . . .
H2 H 0.871633 0.394577 0.736333 0.019 Uiso 1 1 calc R U . . .
C3 C 0.4097(3) 0.3859(2) 0.61108(16) 0.0153(4) Uani 1 1 d . . . . .
H3 H 0.295614 0.315443 0.639794 0.018 Uiso 1 1 calc R U . . .
C4 C 0.3702(3) 0.4445(2) 0.48123(16) 0.0170(4) Uani 1 1 d . . . . .
H4A H 0.444018 0.381553 0.418922 0.020 Uiso 1 1 calc R U . . .
H4B H 0.214596 0.445565 0.462381 0.020 Uiso 1 1 calc R U . . .
C5 C 0.5457(3) 0.62685(18) 0.59923(15) 0.0126(4) Uani 1 1 d . . . . .
H5 H 0.532298 0.734757 0.621058 0.015 Uiso 1 1 calc R U . . .
C6 C 0.4258(3) 0.52640(19) 0.69208(17) 0.0149(4) Uani 1 1 d . . . . .
H6 H 0.286965 0.566357 0.724850 0.018 Uiso 1 1 calc R U . . .


_geom_special_details            
;
 All esds (except the esd in the dihedral angle between two l.s. planes)
 are estimated using the full covariance matrix.  The cell esds are taken
 into account individually in the estimation of esds in distances, angles
 and torsion angles; correlations between esds in cell parameters are only
 used when they are defined by crystal symmetry.  An approximate (isotropic)
 treatment of cell esds is used for estimating esds involving l.s. planes.
;
loop_
_geom_bond_atom_site_label_1
_geom_bond_atom_site_label_2
_geom_bond_distance
_geom_bond_site_symmetry_2
_geom_bond_publ_flag
O1 H1 0.8400 . ?
O1 C1 1.414(2) . ?
O2 C2 1.431(2) . ?
O2 C3 1.450(2) . ?
O3 C4 1.452(2) . ?
O3 C5 1.427(2) . ?
O4 C2 1.424(2) . ?
O4 C6 1.436(2) . ?
C1 H1A 1.0000 . ?
C1 C2 1.529(2) . ?
C1 C5 1.543(3) . ?
C2 H2 1.0000 . ?
C3 H3 1.0000 . ?
C3 C4 1.514(2) . ?
C3 C6 1.536(2) . ?
C4 H4A 0.9900 . ?
C4 H4B 0.9900 . ?
C5 H5 1.0000 . ?
C5 C6 1.539(2) . ?
C6 H6 1.0000 . ?

loop_
_geom_angle_atom_site_label_1
_geom_angle_atom_site_label_2
_geom_angle_atom_site_label_3
_geom_angle
_geom_angle_site_symmetry_1
_geom_angle_site_symmetry_3
_geom_angle_publ_flag
C1 O1 H1 109.5 . . ?
C2 O2 C3 104.97(13) . . ?
C5 O3 C4 108.87(11) . . ?
C2 O4 C6 95.38(13) . . ?
O1 C1 H1A 111.4 . . ?
O1 C1 C2 108.34(14) . . ?
O1 C1 C5 113.82(14) . . ?
C2 C1 H1A 111.4 . . ?
C2 C1 C5 99.78(13) . . ?
C5 C1 H1A 111.4 . . ?
O2 C2 C1 107.92(14) . . ?
O2 C2 H2 113.5 . . ?
O4 C2 O2 104.51(14) . . ?
O4 C2 C1 102.99(13) . . ?
O4 C2 H2 113.5 . . ?
C1 C2 H2 113.5 . . ?
O2 C3 H3 112.9 . . ?
O2 C3 C4 111.90(15) . . ?
O2 C3 C6 100.80(13) . . ?
C4 C3 H3 112.9 . . ?
C4 C3 C6 104.44(14) . . ?
C6 C3 H3 112.9 . . ?
O3 C4 C3 105.70(13) . . ?
O3 C4 H4A 110.6 . . ?
O3 C4 H4B 110.6 . . ?
C3 C4 H4A 110.6 . . ?
C3 C4 H4B 110.6 . . ?
H4A C4 H4B 108.7 . . ?
O3 C5 C1 112.92(15) . . ?
O3 C5 H5 112.0 . . ?
O3 C5 C6 106.09(14) . . ?
C1 C5 H5 112.0 . . ?
C6 C5 C1 101.27(13) . . ?
C6 C5 H5 112.0 . . ?
O4 C6 C3 103.61(14) . . ?
O4 C6 C5 104.69(14) . . ?
O4 C6 H6 116.0 . . ?
C3 C6 C5 98.26(13) . . ?
C3 C6 H6 116.0 . . ?
C5 C6 H6 116.0 . . ?

loop_
_geom_torsion_atom_site_label_1
_geom_torsion_atom_site_label_2
_geom_torsion_atom_site_label_3
_geom_torsion_atom_site_label_4
_geom_torsion
_geom_torsion_site_symmetry_1
_geom_torsion_site_symmetry_2
_geom_torsion_site_symmetry_3
_geom_torsion_site_symmetry_4
_geom_torsion_publ_flag
O1 C1 C2 O2 -172.40(14) . . . . ?
O1 C1 C2 O4 77.42(17) . . . . ?
O1 C1 C5 O3 139.90(15) . . . . ?
O1 C1 C5 C6 -107.07(15) . . . . ?
O2 C3 C4 O3 -83.77(18) . . . . ?
O2 C3 C6 O4 -28.73(15) . . . . ?
O2 C3 C6 C5 78.66(14) . . . . ?
O3 C5 C6 O4 145.31(14) . . . . ?
O3 C5 C6 C3 38.81(17) . . . . ?
C1 C5 C6 O4 27.22(16) . . . . ?
C1 C5 C6 C3 -79.28(14) . . . . ?
C2 O2 C3 C4 105.96(16) . . . . ?
C2 O2 C3 C6 -4.54(16) . . . . ?
C2 O4 C6 C3 49.59(15) . . . . ?
C2 O4 C6 C5 -52.91(15) . . . . ?
C2 C1 C5 O3 -104.93(15) . . . . ?
C2 C1 C5 C6 8.10(15) . . . . ?
C3 O2 C2 O4 37.16(16) . . . . ?
C3 O2 C2 C1 -71.98(17) . . . . ?
C4 O3 C5 C1 84.33(18) . . . . ?
C4 O3 C5 C6 -25.72(19) . . . . ?
C4 C3 C6 O4 -144.91(15) . . . . ?
C4 C3 C6 C5 -37.52(18) . . . . ?
C5 O3 C4 C3 0.7(2) . . . . ?
C5 C1 C2 O2 68.32(16) . . . . ?
C5 C1 C2 O4 -41.85(15) . . . . ?
C6 O4 C2 O2 -53.81(15) . . . . ?
C6 O4 C2 C1 58.89(15) . . . . ?
C6 C3 C4 O3 24.4(2) . . . . ?

_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 1.739
_oxdiff_exptl_absorpt_empirical_full_min 0.532
