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_2312730
_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          'C4 H4 O2'
_chemical_formula_moiety         'C4 H4 O2'
_chemical_formula_sum            'C4 H4 O2'
_chemical_formula_weight         84.07
_chemical_name_systematic
;
Methyl prop-2-ynoate
;
_space_group_crystal_system      monoclinic
_space_group_IT_number           14
_space_group_name_Hall           '-P 2yn'
_space_group_name_H-M_alt        'P 1 21/n 1'
_atom_sites_solution_hydrogens   difmap
_atom_sites_solution_primary     direct
_atom_sites_solution_secondary   difmap
_audit_creation_method           SHELXL-2019/3
_cell_angle_alpha                90
_cell_angle_beta                 99.910(12)
_cell_angle_gamma                90
_cell_formula_units_Z            4
_cell_length_a                   3.8409(5)
_cell_length_b                   15.593(2)
_cell_length_c                   7.6149(10)
_cell_measurement_reflns_used    1269
_cell_measurement_temperature    111(2)
_cell_measurement_theta_max      31.4840
_cell_measurement_theta_min      3.0100
_cell_volume                     449.26(10)
_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      111(2)
_diffrn_detector                 'CCD plate'
_diffrn_detector_area_resol_mean 15.9809
_diffrn_measured_fraction_theta_full 0.998
_diffrn_measured_fraction_theta_max 0.998
_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  0.0234
_diffrn_reflns_av_unetI/netI     0.0211
_diffrn_reflns_limit_h_max       5
_diffrn_reflns_limit_h_min       -5
_diffrn_reflns_limit_k_max       20
_diffrn_reflns_limit_k_min       -12
_diffrn_reflns_limit_l_max       10
_diffrn_reflns_limit_l_min       -10
_diffrn_reflns_number            3885
_diffrn_reflns_theta_full        25.242
_diffrn_reflns_theta_max         27.878
_diffrn_reflns_theta_min         3.013
_diffrn_source_current           40
_diffrn_source_voltage           50
_exptl_absorpt_coefficient_mu    0.101
_exptl_absorpt_correction_T_max  1.00000
_exptl_absorpt_correction_T_min  0.45717
_exptl_absorpt_correction_type   multi-scan
_exptl_absorpt_process_details
;
(CrysAlis PRO; Rigaku OD, 2020)
;
_exptl_crystal_colour            colorless
_exptl_crystal_density_diffrn    1.243
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       needle
_exptl_crystal_F_000             176
_exptl_crystal_size_max          0.997
_exptl_crystal_size_mid          0.557
_exptl_crystal_size_min          0.306
_refine_diff_density_max         0.175
_refine_diff_density_min         -0.148
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.053
_refine_ls_hydrogen_treatment    refall
_refine_ls_matrix_type           full
_refine_ls_number_parameters     71
_refine_ls_number_reflns         1060
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      1.053
_refine_ls_R_factor_all          0.0431
_refine_ls_R_factor_gt           0.0358
_refine_ls_shift/su_max          0.001
_refine_ls_shift/su_mean         0.000
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'w=1/[\s^2^(Fo^2^)+(0.0475P)^2^+0.0483P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.0920
_refine_ls_wR_factor_ref         0.0986
_reflns_number_gt                891
_reflns_number_total             1060
_reflns_threshold_expression     'I > 2\s(I)'
_cod_data_source_file            oj3025.cif
_cod_data_source_block           I
_cod_original_cell_volume        449.27(10)
_cod_original_sg_symbol_H-M      'P 21/n'
_cod_database_code               2312730
_shelx_estimated_absorpt_t_min   0.906
_shelx_estimated_absorpt_t_max   0.970
_shelx_hkl_checksum              95384
_shelx_res_checksum              96683