#------------------------------------------------------------------------------
#$Date: 2026-05-14 00:24:51 +0200 (Thu 14 de May de 2026) $
#$Revision: 305959 $
#$URL: svn://saulius.grazulis.lt/cod-secondary/cif/1/57/72/1577260.cif $
#------------------------------------------------------------------------------
#
# This file is available in the Crystallography Open Database (COD),
# http://www.crystallography.net/
#
# All data on this site have been placed in the public domain by the
# contributors.
#
data_1577260
loop_
_publ_author_name
'Lennox, Cameron B.'
'Taylor, Christopher'
'Huskić, Igor'
'Vainauskas, Jogirdas'
'Nickels, Christopher'
'Stein, Robin S.'
'Borchers, Tristan H.'
'Lutton Gething, A.R. Bonnie J.'
'Marrett, Joseph M.'
'Day, Graeme Matthew'
'Friščić, Tomislav'
_publ_section_title
;
 The elusive endo-product of the archetypal Diels-Alder reaction of furan
 and maleic anhydride -- observed in the solid state at last
;
_journal_name_full               'Chemical Science'
_journal_paper_doi               10.1039/D5SC06724C
_journal_year                    2026
_chemical_formula_moiety         'C8 H6 O4'
_chemical_formula_sum            'C16 H12 O8'
_chemical_formula_weight         332.2660
_chemical_name_systematic
'7-oxabicyclo(2.2.1)-5-heptene-2,3-dicarboxylic anhydride cocrystal'
_chemical_properties_physical    moisture-sensitive
_space_group_crystal_system      monoclinic
_space_group_IT_number           7
_space_group_name_Hall           'P -2yac'
_space_group_name_H-M_alt        'P 1 n 1'
_atom_sites_solution_hydrogens   geom
_audit_creation_date             2023-09-11
_audit_creation_method
;
Olex2 1.3
(compiled 2020.11.12 svn.r5f609507 for OlexSys, GUI svn.r6408)
;
_audit_update_record
;
2024-11-06 deposited with the CCDC.	2026-05-12 downloaded from the CCDC.
;
_cell_angle_alpha                90
_cell_angle_beta                 110.600(2)
_cell_angle_gamma                90
_cell_formula_units_Z            2
_cell_length_a                   11.9547(5)
_cell_length_b                   5.4149(2)
_cell_length_c                   12.0064(5)
_cell_measurement_reflns_used    6752
_cell_measurement_temperature    298(2)
_cell_measurement_theta_max      144.348
_cell_measurement_theta_min      8.986
_cell_volume                     727.52(5)
_computing_cell_refinement       'SAINT V8.35A, Bruker-AXS'
_computing_data_collection       'APEX 2, Bruker-AXS'
_computing_data_reduction        'SAINT V8.35A, Bruker-AXS'
_computing_molecular_graphics    'Olex2 1.3 (Dolomanov et al., 2009)'
_computing_publication_material  'Olex2 1.3 (Dolomanov et al., 2009)'
_computing_structure_refinement  'SHELXL-2018/3 (Sheldrick, 2018)'
_computing_structure_solution    'SHELXT 2014/5 (Sheldrick, 2014)'
_diffrn_ambient_pressure         1013
_diffrn_ambient_temperature      298(2)
_diffrn_measured_fraction_theta_full 0.965
_diffrn_measured_fraction_theta_max 0.960
_diffrn_measurement_device_type  'Bruker PHOTON 100 CMOS'
_diffrn_measurement_method       'omega scans'
_diffrn_radiation_probe          x-ray
_diffrn_radiation_type           CuK\a
_diffrn_radiation_wavelength     1.54178
_diffrn_reflns_av_R_equivalents  0.0660
_diffrn_reflns_av_unetI/netI     0.0760
_diffrn_reflns_Laue_measured_fraction_full 0.965
_diffrn_reflns_Laue_measured_fraction_max 0.960
_diffrn_reflns_limit_h_max       14
_diffrn_reflns_limit_h_min       -14
_diffrn_reflns_limit_k_max       6
_diffrn_reflns_limit_k_min       -6
_diffrn_reflns_limit_l_max       14
_diffrn_reflns_limit_l_min       -14
_diffrn_reflns_number            5522
_diffrn_reflns_point_group_measured_fraction_full 0.794
_diffrn_reflns_point_group_measured_fraction_max 0.774
_diffrn_reflns_theta_full        67.679
_diffrn_reflns_theta_max         72.401
_diffrn_reflns_theta_min         4.489
_diffrn_source                   'sealed x-ray tube'
_diffrn_source_type              'Bruker D8 Venture'
_exptl_absorpt_coefficient_mu    1.066
_exptl_absorpt_correction_T_max  0.7536
_exptl_absorpt_correction_T_min  0.6385
_exptl_absorpt_correction_type   multi-scan
_exptl_absorpt_process_details   'SADABS-2012/1, G. Sheldrick'
_exptl_crystal_colour            colourless
_exptl_crystal_colour_primary    colourless
_exptl_crystal_density_diffrn    1.517
_exptl_crystal_description       block
_exptl_crystal_F_000             344
_exptl_crystal_recrystallization_method neat
_exptl_crystal_size_max          0.3
_exptl_crystal_size_mid          0.2
_exptl_crystal_size_min          0.2
_refine_diff_density_max         0.390
_refine_diff_density_min         -0.358
_refine_diff_density_rms         0.089
_refine_ls_abs_structure_details
;
 Flack x determined using 681 quotients [(I+)-(I-)]/[(I+)+(I-)]
 (Parsons, Flack and Wagner, Acta Cryst. B69 (2013) 249-259).
;
_refine_ls_abs_structure_Flack   0.24(16)
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.149
_refine_ls_hydrogen_treatment    constr
_refine_ls_matrix_type           full
_refine_ls_number_parameters     217
_refine_ls_number_reflns         2231
_refine_ls_number_restraints     2
_refine_ls_restrained_S_all      1.148
_refine_ls_R_factor_all          0.0960
_refine_ls_R_factor_gt           0.0448
_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)+(0.0820P)²+0.2428P] where P=(Fo²+2Fc²)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.1199
_refine_ls_wR_factor_ref         0.1627
_reflns_Friedel_coverage         0.609
_reflns_Friedel_fraction_full    0.621
_reflns_Friedel_fraction_max     0.587
_reflns_number_gt                1908
_reflns_number_total             2231
_reflns_threshold_expression     'I > 2σ(I)'
_cod_data_source_file            d5sc06724c7.cif
_cod_data_source_block           (endo-1)(exo-1)-298K
_cod_database_code               1577260
_shelx_shelxl_version_number     2018/3
_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.
;
_olex2_refinement_description
;
1.a Ternary CH refined with riding coordinates:
 C3(H3), C4(H4), C5(H5), C6(H6), C11(H11), C12(H12), C13(H13), C14(H14)
1.b Aromatic/amide H refined with riding coordinates:
 C7(H7), C8(H8), C15(H15), C16(H16)
;
_olex2_submission_special_instructions 'No special instructions were received'
loop_
_space_group_symop_operation_xyz
'x, y, z'
'x+1/2, -y, z+1/2'
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 0.2667(4) 0.9119(6) 0.3806(4) 0.0512(9) Uani 1 1 d . . . . .
C1 C 0.3704(5) 0.7782(10) 0.4314(5) 0.0538(13) Uani 1 1 d . . . . .
O8 O 0.9125(3) 0.6890(6) 0.5320(4) 0.0528(9) Uani 1 1 d . . . . .
O2 O 0.4644(4) 0.8666(10) 0.4378(5) 0.0845(16) Uani 1 1 d . . . . .
C2 C 0.1703(5) 0.7793(10) 0.3844(5) 0.0526(13) Uani 1 1 d . . . . .
O3 O 0.0724(4) 0.8653(10) 0.3407(5) 0.0766(14) Uani 1 1 d . . . . .
C3 C 0.3428(5) 0.5343(9) 0.4748(5) 0.0491(12) Uani 1 1 d . . . . .
H3 H 0.367959 0.394859 0.437091 0.059 Uiso 1 1 calc R U . . .
C4 C 0.2074(5) 0.5400(9) 0.4448(5) 0.0467(12) Uani 1 1 d . . . . .
H4 H 0.167540 0.401002 0.393998 0.056 Uiso 1 1 calc R U . . .
O4 O 0.2974(4) 0.3526(7) 0.6270(4) 0.0643(11) Uani 1 1 d . . . . .
O5 O 0.6601(4) 0.4586(6) 0.5000(4) 0.0542(9) Uani 1 1 d . . . . .
C5 C 0.3891(6) 0.5098(12) 0.6153(6) 0.0633(17) Uani 1 1 d . . . . .
H5 H 0.471118 0.449458 0.652732 0.076 Uiso 1 1 calc R U . . .
O6 O 0.6189(5) 0.5152(9) 0.3060(4) 0.0737(13) Uani 1 1 d . . . . .
C6 C 0.2004(5) 0.5195(10) 0.5731(5) 0.0529(14) Uani 1 1 d . . . . .
H6 H 0.122916 0.466163 0.575463 0.064 Uiso 1 1 calc R U . . .
C7 C 0.3620(7) 0.7512(13) 0.6611(6) 0.0723(19) Uani 1 1 d . . . . .
H7 H 0.416357 0.873870 0.699422 0.087 Uiso 1 1 calc R U . . .
O7 O 0.7159(5) 0.4981(11) 0.6943(4) 0.0821(15) Uani 1 1 d . . . . .
C8 C 0.2467(7) 0.7545(11) 0.6363(5) 0.0611(16) Uani 1 1 d . . . . .
H8 H 0.202353 0.879089 0.654430 0.073 Uiso 1 1 calc R U . . .
C9 C 0.6595(5) 0.5989(9) 0.4034(5) 0.0486(12) Uani 1 1 d . . . . .
C10 C 0.7104(6) 0.5886(10) 0.6038(6) 0.0582(15) Uani 1 1 d . . . . .
C11 C 0.7208(5) 0.8401(8) 0.4438(5) 0.0433(11) Uani 1 1 d . . . . .
H11 H 0.671618 0.982942 0.406291 0.052 Uiso 1 1 calc R U . . .
C12 C 0.7552(5) 0.8350(9) 0.5803(5) 0.0463(12) Uani 1 1 d . . . . .
H12 H 0.722013 0.973867 0.610946 0.056 Uiso 1 1 calc R U . . .
C13 C 0.8479(5) 0.8445(9) 0.4338(5) 0.0498(13) Uani 1 1 d . . . . .
H13 H 0.850841 0.794286 0.356485 0.060 Uiso 1 1 calc R U . . .
C14 C 0.8942(5) 0.8383(9) 0.6233(5) 0.0502(12) Uani 1 1 d . . . . .
H14 H 0.935642 0.782600 0.705228 0.060 Uiso 1 1 calc R U . . .
C15 C 0.9006(5) 1.0959(10) 0.4775(6) 0.0544(14) Uani 1 1 d . . . . .
H15 H 0.910890 1.225969 0.431394 0.065 Uiso 1 1 calc R U . . .
C16 C 0.9288(5) 1.0933(9) 0.5936(5) 0.0523(13) Uani 1 1 d . . . . .
H16 H 0.962839 1.220859 0.646490 0.063 Uiso 1 1 calc R U . . .
loop_
_atom_type_symbol
_atom_type_description
_atom_type_scat_dispersion_real
_atom_type_scat_dispersion_imag
_atom_type_scat_source
C C 0.0181 0.0091 'International Tables Vol C Tables 4.2.6.8 and 6.1.1.4'
O O 0.0492 0.0322 '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'
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
C2 O1 C1 110.2(4) . . ?
O1 C1 C3 110.1(4) . . ?
O2 C1 O1 119.7(5) . . ?
O2 C1 C3 130.2(6) . . ?
C13 O8 C14 96.6(4) . . ?
O1 C2 C4 111.4(5) . . ?
O3 C2 O1 119.1(5) . . ?
O3 C2 C4 129.5(6) . . ?
C1 C3 H3 112.2 . . ?
C1 C3 C4 104.1(4) . . ?
C1 C3 C5 114.0(5) . . ?
C4 C3 H3 112.2 . . ?
C4 C3 C5 101.3(4) . . ?
C5 C3 H3 112.2 . . ?
C2 C4 C3 104.1(4) . . ?
C2 C4 H4 111.9 . . ?
C2 C4 C6 115.6(4) . . ?
C3 C4 H4 111.9 . . ?
C3 C4 C6 100.6(4) . . ?
C6 C4 H4 111.9 . . ?
C5 O4 C6 96.1(4) . . ?
C10 O5 C9 110.6(4) . . ?
C3 C5 H5 115.7 . . ?
O4 C5 C3 99.3(5) . . ?
O4 C5 H5 115.7 . . ?
O4 C5 C7 102.2(5) . . ?
C7 C5 C3 106.1(5) . . ?
C7 C5 H5 115.7 . . ?
C4 C6 H6 115.1 . . ?
O4 C6 C4 100.0(4) . . ?
O4 C6 H6 115.1 . . ?
O4 C6 C8 102.3(5) . . ?
C8 C6 C4 107.5(4) . . ?
C8 C6 H6 115.1 . . ?
C5 C7 H7 127.0 . . ?
C8 C7 C5 106.0(6) . . ?
C8 C7 H7 127.0 . . ?
C6 C8 H8 126.9 . . ?
C7 C8 C6 106.2(6) . . ?
C7 C8 H8 126.9 . . ?
O5 C9 C11 110.5(5) . . ?
O6 C9 O5 119.7(5) . . ?
O6 C9 C11 129.7(5) . . ?
O5 C10 C12 110.9(4) . . ?
O7 C10 O5 119.4(5) . . ?
O7 C10 C12 129.7(6) . . ?
C9 C11 H11 113.2 . . ?
C9 C11 C12 104.3(4) . . ?
C9 C11 C13 111.5(4) . . ?
C12 C11 H11 113.2 . . ?
C12 C11 C13 100.3(4) . . ?
C13 C11 H11 113.2 . . ?
C10 C12 C11 103.6(4) . . ?
C10 C12 H12 113.1 . . ?
C10 C12 C14 111.0(4) . . ?
C11 C12 H12 113.1 . . ?
C11 C12 C14 101.9(4) . . ?
C14 C12 H12 113.1 . . ?
O8 C13 C11 100.6(3) . . ?
O8 C13 H13 115.3 . . ?
O8 C13 C15 101.9(5) . . ?
C11 C13 H13 115.3 . . ?
C15 C13 C11 106.5(4) . . ?
C15 C13 H13 115.3 . . ?
O8 C14 C12 99.8(4) . . ?
O8 C14 H14 115.6 . . ?
O8 C14 C16 101.8(4) . . ?
C12 C14 H14 115.6 . . ?
C16 C14 C12 106.2(4) . . ?
C16 C14 H14 115.6 . . ?
C13 C15 H15 126.9 . . ?
C16 C15 C13 106.1(5) . . ?
C16 C15 H15 126.9 . . ?
C14 C16 H16 127.2 . . ?
C15 C16 C14 105.7(5) . . ?
C15 C16 H16 127.2 . . ?
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 C1 1.378(7) . ?
O1 C2 1.372(7) . ?
C1 O2 1.199(7) . ?
C1 C3 1.498(7) . ?
O8 C13 1.433(7) . ?
O8 C14 1.440(7) . ?
C2 O3 1.196(8) . ?
C2 C4 1.475(8) . ?
C3 H3 0.9800 . ?
C3 C4 1.531(7) . ?
C3 C5 1.586(9) . ?
C4 H4 0.9800 . ?
C4 C6 1.576(7) . ?
O4 C5 1.433(8) . ?
O4 C6 1.433(7) . ?
O5 C9 1.384(7) . ?
O5 C10 1.373(8) . ?
C5 H5 0.9800 . ?
C5 C7 1.497(10) . ?
O6 C9 1.187(7) . ?
C6 H6 0.9800 . ?
C6 C8 1.485(9) . ?
C7 H7 0.9300 . ?
C7 C8 1.304(11) . ?
O7 C10 1.172(7) . ?
C8 H8 0.9300 . ?
C9 C11 1.493(7) . ?
C10 C12 1.501(7) . ?
C11 H11 0.9800 . ?
C11 C12 1.544(7) . ?
C11 C13 1.565(7) . ?
C12 H12 0.9800 . ?
C12 C14 1.557(8) . ?
C13 H13 0.9800 . ?
C13 C15 1.514(7) . ?
C14 H14 0.9800 . ?
C14 C16 1.519(7) . ?
C15 H15 0.9300 . ?
C15 C16 1.314(8) . ?
C16 H16 0.9300 . ?
