The crystal structures of methyl prop-2-ynoate, dimethyl fumarate and their protonated species.
Hollenwäger, Dirk; Bockmair, Valentin; Kornath, Andreas J.; Acta crystallographica. Section C, Structural chemistry 81 (2025) –; doi:10.1107/S2053229624011653

data_2312733
_publ_section_title
;
 The crystal structures of methyl prop-2-ynoate, dimethyl fumarate and
 their protonated species.
;
_journal_coeditor_code           OJ3025
_journal_issue                   1
_journal_name_full
'Acta crystallographica. Section C, Structural chemistry'
_journal_paper_doi               10.1107/S2053229624011653
_journal_volume                  81
_journal_year                    2025
_chemical_formula_iupac          'C6 H9 O4 +, B F4 -, 2H F'
_chemical_formula_moiety         'C6 H9 O4 +, B F4 -, 2(F H)'
_chemical_formula_sum            'C6 H11 B F6 O4'
_chemical_formula_weight         271.96
_chemical_name_systematic
;
1,4-Dimethoxy-4-oxobut-2-en-1-ylidene]oxidanium tetrafluoroborate--hydrogen
fluoride (1/2)
;
_space_group_crystal_system      orthorhombic
_space_group_IT_number           61
_space_group_name_Hall           '-P 2ac 2ab'
_space_group_name_H-M_alt        'P b c a'
_atom_sites_solution_hydrogens   mixed
_atom_sites_solution_primary     direct
_atom_sites_solution_secondary   difmap
_audit_creation_method           SHELXL-2018/3
_cell_angle_alpha                90
_cell_angle_beta                 90
_cell_angle_gamma                90
_cell_formula_units_Z            8
_cell_length_a                   12.8759(5)
_cell_length_b                   11.8899(4)
_cell_length_c                   14.6252(7)
_cell_measurement_reflns_used    2510
_cell_measurement_temperature    101(2)
_cell_measurement_theta_max      31.8510
_cell_measurement_theta_min      2.6910
_cell_volume                     2239.02(16)
_computing_cell_refinement
;
CrysAlis PRO (Rigaku OD, 2020)
;
_computing_data_collection
;
CrysAlis PRO (Rigaku OD, 2020)
;
_computing_data_reduction
;
CrysAlis PRO (Rigaku OD, 2020)
;
_computing_molecular_graphics
;
ORTEP-3 for Windows (Farrugia, 2012)
;
_computing_publication_material
;
PLATON (Spek, 2020)
;
_computing_structure_refinement
;
SHELXL2018 (Sheldrick, 2015<i>b</i>)
;
_computing_structure_solution
;
SHELXT (Sheldrick, 2015<i>a</i>)
;
_diffrn_ambient_temperature      101(2)
_diffrn_detector                 'CCD plate'
_diffrn_detector_area_resol_mean 15.9809
_diffrn_measured_fraction_theta_full 0.999
_diffrn_measured_fraction_theta_max 0.999
_diffrn_measurement_device       'CCD camera on \k-goniostat'
_diffrn_measurement_device_type  'Rigaku Xcalibur Sapphire3'
_diffrn_measurement_method       '\w scans'
_diffrn_radiation_monochromator  graphite
_diffrn_radiation_source         'Enhance (Mo) X-ray Source'
_diffrn_radiation_type           'Mo K\a'
_diffrn_radiation_wavelength     0.71073
_diffrn_reflns_av_R_equivalents  0.0258
_diffrn_reflns_av_unetI/netI     0.0204
_diffrn_reflns_limit_h_max       11
_diffrn_reflns_limit_h_min       -14
_diffrn_reflns_limit_k_max       6
_diffrn_reflns_limit_k_min       -13
_diffrn_reflns_limit_l_max       16
_diffrn_reflns_limit_l_min       -16
_diffrn_reflns_number            7514
_diffrn_reflns_theta_full        23.811
_diffrn_reflns_theta_max         23.811
_diffrn_reflns_theta_min         2.716
_diffrn_source_current           40
_diffrn_source_voltage           50
_exptl_absorpt_coefficient_mu    0.186
_exptl_absorpt_correction_T_max  1.00000
_exptl_absorpt_correction_T_min  0.88460
_exptl_absorpt_correction_type   multi-scan
_exptl_absorpt_process_details
;
(CrysAlis PRO; Rigaku OD, 2020)
;
_exptl_crystal_colour            colorless
_exptl_crystal_density_diffrn    1.614
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       plate
_exptl_crystal_F_000             1104
_exptl_crystal_size_max          0.283
_exptl_crystal_size_mid          0.175
_exptl_crystal_size_min          0.114
_refine_diff_density_max         0.767
_refine_diff_density_min         -0.351
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.047
_refine_ls_hydrogen_treatment    mixed
_refine_ls_matrix_type           full
_refine_ls_number_parameters     176
_refine_ls_number_reflns         1717
_refine_ls_number_restraints     1
_refine_ls_restrained_S_all      1.047
_refine_ls_R_factor_all          0.0473
_refine_ls_R_factor_gt           0.0396
_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^)+(0.0431P)^2^+2.1459P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.0950
_refine_ls_wR_factor_ref         0.0999
_reflns_number_gt                1478
_reflns_number_total             1717
_reflns_threshold_expression     'I > 2\s(I)'
_cod_data_source_file            oj3025.cif
_cod_data_source_block           VI
_cod_database_code               2312733
_shelx_estimated_absorpt_t_min   0.949
_shelx_estimated_absorpt_t_max   0.979
_shelx_hkl_checksum              97346
_shelx_res_checksum              35571