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_2312732
_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 H8 O4'
_chemical_formula_moiety         'C6 H8 O4'
_chemical_formula_sum            'C6 H8 O4'
_chemical_formula_weight         144.12
_chemical_name_systematic
;
Dimethyl (<i>E</i>)-but-2-enedioate
;
_space_group_crystal_system      triclinic
_space_group_IT_number           2
_space_group_name_Hall           '-P 1'
_space_group_name_H-M_alt        'P -1'
_atom_sites_solution_hydrogens   mixed
_atom_sites_solution_primary     direct
_atom_sites_solution_secondary   difmap
_audit_creation_method           SHELXL-2019/3
_cell_angle_alpha                100.642(16)
_cell_angle_beta                 100.42(2)
_cell_angle_gamma                105.73(2)
_cell_formula_units_Z            1
_cell_length_a                   3.8726(11)
_cell_length_b                   5.6546(10)
_cell_length_c                   8.3778(18)
_cell_measurement_reflns_used    712
_cell_measurement_temperature    112(2)
_cell_measurement_theta_max      32.0320
_cell_measurement_theta_min      3.9420
_cell_volume                     168.30(7)
_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      112(2)
_diffrn_detector                 'CCD plate'
_diffrn_detector_area_resol_mean 15.9809
_diffrn_measured_fraction_theta_full 0.987
_diffrn_measured_fraction_theta_max 0.990
_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  0.0152
_diffrn_reflns_av_unetI/netI     0.0247
_diffrn_reflns_limit_h_max       5
_diffrn_reflns_limit_h_min       -5
_diffrn_reflns_limit_k_max       7
_diffrn_reflns_limit_k_min       -5
_diffrn_reflns_limit_l_max       11
_diffrn_reflns_limit_l_min       -10
_diffrn_reflns_number            1403
_diffrn_reflns_theta_full        25.242
_diffrn_reflns_theta_max         28.277
_diffrn_reflns_theta_min         4.071
_diffrn_source_current           40
_diffrn_source_voltage           50
_exptl_absorpt_coefficient_mu    0.121
_exptl_absorpt_correction_T_max  1.00000
_exptl_absorpt_correction_T_min  0.57859
_exptl_absorpt_correction_type   multi-scan
_exptl_absorpt_process_details
;
(CrysAlis PRO; Rigaku OD, 2020)
;
_exptl_crystal_colour            colorless
_exptl_crystal_density_diffrn    1.422
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       plate
_exptl_crystal_F_000             76
_exptl_crystal_size_max          0.523
_exptl_crystal_size_mid          0.458
_exptl_crystal_size_min          0.345
_refine_diff_density_max         0.515
_refine_diff_density_min         -0.240
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.040
_refine_ls_hydrogen_treatment    mixed
_refine_ls_matrix_type           full
_refine_ls_number_parameters     51
_refine_ls_number_reflns         825
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      1.040
_refine_ls_R_factor_all          0.0540
_refine_ls_R_factor_gt           0.0475
_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^)+(0.1042P)^2^+0.0039P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.1338
_refine_ls_wR_factor_ref         0.1441
_reflns_number_gt                703
_reflns_number_total             825
_reflns_threshold_expression     'I > 2\s(I)'
_cod_data_source_file            oj3025.cif
_cod_data_source_block           IV
_cod_database_code               2312732
_shelx_estimated_absorpt_t_min   0.939
_shelx_estimated_absorpt_t_max   0.959
_shelx_hkl_checksum              3731
_shelx_res_checksum              29055