Gem-dimethyl peptide nucleic acid (α/β/γ-<i>gdm</i>-PNA) monomers: synthesis and the role of <i>gdm</i>-substituents in preferential stabilisation of <i>Z</i>/<i>E</i>-rotamers.
Kulkarni, Pradnya; Datta, Dhrubajyoti; Ramabhadran, Raghunath O.; Ganesh, Krishna; Organic & biomolecular chemistry 19 (2021) 6534–6545; doi:10.1039/d1ob01097b

data_7158161
_publ_section_title
;
 Gem-dimethyl peptide nucleic acid (\a/\b/\g-<i>gdm</i>-PNA) monomers:
 synthesis and the role of <i>gdm</i>-substituents in preferential
 stabilisation of <i>Z</i>/<i>E</i>-rotamers.
;
_journal_issue                   29
_journal_name_full               'Organic &amp; biomolecular chemistry'
_journal_page_first              6534
_journal_page_last               6545
_journal_paper_doi               10.1039/d1ob01097b
_journal_volume                  19
_journal_year                    2021
_chemical_formula_moiety         'C19 H30 N4 O7, 5(O)'
_chemical_formula_sum            'C19 H30 N4 O12'
_chemical_formula_weight         506.47
_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   geom
_audit_creation_method           SHELXL-2014/7
_audit_update_record
;
2021-01-08 deposited with the CCDC.	2021-07-05 downloaded from the CCDC.
;
_cell_angle_alpha                89.931(4)
_cell_angle_beta                 89.940(4)
_cell_angle_gamma                89.969(5)
_cell_formula_units_Z            8
_cell_length_a                   8.694(2)
_cell_length_b                   18.217(4)
_cell_length_c                   34.494(9)
_cell_measurement_reflns_used    2433
_cell_measurement_temperature    296(2)
_cell_measurement_theta_max      20.56
_cell_measurement_theta_min      2.36
_cell_volume                     5463(2)
_computing_structure_refinement  'SHELXL-2014/7 (Sheldrick, 2014)'
_diffrn_ambient_temperature      296(2)
_diffrn_measured_fraction_theta_full 1.000
_diffrn_measured_fraction_theta_max 0.989
_diffrn_measurement_device_type  'fine-focus sealed tube'
_diffrn_radiation_type           MoK\a
_diffrn_radiation_wavelength     0.71073
_diffrn_reflns_av_R_equivalents  0.3248
_diffrn_reflns_av_unetI/netI     0.4966
_diffrn_reflns_Laue_measured_fraction_full 1.000
_diffrn_reflns_Laue_measured_fraction_max 0.989
_diffrn_reflns_limit_h_max       12
_diffrn_reflns_limit_h_min       -8
_diffrn_reflns_limit_k_max       25
_diffrn_reflns_limit_k_min       -25
_diffrn_reflns_limit_l_max       48
_diffrn_reflns_limit_l_min       -48
_diffrn_reflns_number            112152
_diffrn_reflns_point_group_measured_fraction_full 1.000
_diffrn_reflns_point_group_measured_fraction_max 0.989
_diffrn_reflns_theta_full        25.242
_diffrn_reflns_theta_max         30.164
_diffrn_reflns_theta_min         1.118
_exptl_absorpt_coefficient_mu    0.103
_exptl_crystal_colour            colourless
_exptl_crystal_density_diffrn    1.232
_exptl_crystal_description       rodshape
_exptl_crystal_F_000             2144.0
_refine_diff_density_max         0.483
_refine_diff_density_min         -0.449
_refine_diff_density_rms         0.118
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   0.912
_refine_ls_hydrogen_treatment    constr
_refine_ls_matrix_type           full
_refine_ls_number_parameters     1289
_refine_ls_number_reflns         32012
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      0.912
_refine_ls_R_factor_all          0.3769
_refine_ls_R_factor_gt           0.1058
_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^)+(0.1000P)^2^+0.3571P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.2067
_refine_ls_wR_factor_ref         0.3326
_reflns_Friedel_coverage         0.000
_reflns_number_gt                7947
_reflns_number_total             32012
_reflns_threshold_expression     'I > 2\s(I)'
_cod_data_source_file            d1ob01097b2.cif
_cod_data_source_block           tri_a
_cod_depositor_comments          'Adding full bibliography for 7158161.cif.'
_cod_database_code               7158161
_shelx_shelxl_version_number     2014/7
_shelx_res_checksum              60745