Squaratides: A tunable platform for anion binding in peptide inspired macrocycles
Elmes, Robert B. P.; Tong, Hua; Mohammed, Farhad Ali; Hawes, Chris Samuel; Bhattacharya, Shayon; Thompson, Damien; Jolliffe, Katrina A.; Chemical Communications  (2026) –; doi:10.1039/D6CC00836D

data_7135677
_publ_section_title
;
 Squaratides: a tunable platform for anion binding in peptide-inspired
 macrocycles.
;
_journal_issue                   33
_journal_name_full               'Chemical communications (Cambridge, England)'
_journal_page_first              8417
_journal_page_last               8421
_journal_paper_doi               10.1039/d6cc00836d
_journal_volume                  62
_journal_year                    2026
_chemical_absolute_configuration ad
_chemical_formula_moiety         '2(C2 H6 O S), C18 H22 N6 O6'
_chemical_formula_sum            'C22 H34 N6 O8 S2'
_chemical_formula_weight         574.67
_space_group_crystal_system      monoclinic
_space_group_IT_number           4
_space_group_name_Hall           'P 2yb'
_space_group_name_H-M_alt        'P 1 21 1'
_atom_sites_solution_hydrogens   geom
_atom_sites_solution_primary     dual
_audit_creation_date             2022-03-24
_audit_creation_method
;
Olex2 1.3
(compiled 2020.11.12 svn.r5f609507 for OlexSys, GUI svn.r6408)
;
_audit_update_record
;
2023-08-07 deposited with the CCDC.	2026-03-26 downloaded from the CCDC.
;
_cell_angle_alpha                90
_cell_angle_beta                 103.0770(10)
_cell_angle_gamma                90
_cell_formula_units_Z            2
_cell_length_a                   8.8611(3)
_cell_length_b                   10.5198(4)
_cell_length_c                   15.0198(5)
_cell_measurement_reflns_used    9752
_cell_measurement_temperature    150.0
_cell_measurement_theta_max      30.532
_cell_measurement_theta_min      2.454
_cell_volume                     1363.79(8)
_computing_cell_refinement       'SAINT V8.40B (?, 2016)'
_computing_data_reduction        'SAINT V8.40B (?, 2016)'
_computing_molecular_graphics    'Olex2 1.3 (Dolomanov et al., 2009)'
_computing_publication_material  'Olex2 1.3 (Dolomanov et al., 2009)'
_computing_structure_refinement  'XL  (Sheldrick, 2008)'
_computing_structure_solution    'SHELXT 2014/5 (Sheldrick, 2014)'
_diffrn_ambient_temperature      150.0
_diffrn_measured_fraction_theta_full 0.984
_diffrn_measured_fraction_theta_max 0.990
_diffrn_measurement_device_type  'Bruker D8 Quest ECO'
_diffrn_measurement_method       '\f and \w scans'
_diffrn_radiation_type           MoK\a
_diffrn_radiation_wavelength     0.71073
_diffrn_reflns_av_R_equivalents  0.0228
_diffrn_reflns_av_unetI/netI     0.0182
_diffrn_reflns_Laue_measured_fraction_full 0.984
_diffrn_reflns_Laue_measured_fraction_max 0.990
_diffrn_reflns_limit_h_max       12
_diffrn_reflns_limit_h_min       -12
_diffrn_reflns_limit_k_max       15
_diffrn_reflns_limit_k_min       -15
_diffrn_reflns_limit_l_max       21
_diffrn_reflns_limit_l_min       -21
_diffrn_reflns_number            38125
_diffrn_reflns_point_group_measured_fraction_full 0.984
_diffrn_reflns_point_group_measured_fraction_max 0.989
_diffrn_reflns_theta_full        25.242
_diffrn_reflns_theta_max         30.531
_diffrn_reflns_theta_min         3.053
_diffrn_source_current           20.0
_diffrn_source_power             1.0
_diffrn_source_voltage           50.0
_diffrn_standards_number         0
_exptl_absorpt_coefficient_mu    0.252
_exptl_absorpt_correction_T_max  0.7461
_exptl_absorpt_correction_T_min  0.6729
_exptl_absorpt_correction_type   multi-scan
_exptl_absorpt_process_details
;
SADABS-2016/2 (Bruker,2016/2) was used for absorption correction.
wR2(int) was 0.0489 before and 0.0418 after correction.
The Ratio of minimum to maximum transmission is 0.9019.
The \l/2 correction factor is Not present.
;
_exptl_crystal_colour            colourless
_exptl_crystal_colour_primary    colourless
_exptl_crystal_density_diffrn    1.399
_exptl_crystal_description       block
_exptl_crystal_F_000             608
_exptl_crystal_size_max          0.36
_exptl_crystal_size_mid          0.29
_exptl_crystal_size_min          0.16
_refine_diff_density_max         0.286
_refine_diff_density_min         -0.294
_refine_diff_density_rms         0.036
_refine_ls_abs_structure_details
;
 Flack x determined using 3722 quotients [(I+)-(I-)]/[(I+)+(I-)]
 (Parsons, Flack and Wagner, Acta Cryst. B69 (2013) 249-259).
;
_refine_ls_abs_structure_Flack   0.002(9)
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.047
_refine_ls_hydrogen_treatment    constr
_refine_ls_matrix_type           full
_refine_ls_number_parameters     349
_refine_ls_number_reflns         8257
_refine_ls_number_restraints     1
_refine_ls_restrained_S_all      1.047
_refine_ls_R_factor_all          0.0255
_refine_ls_R_factor_gt           0.0246
_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^)+(0.0418P)^2^+0.1430P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.0658
_refine_ls_wR_factor_ref         0.0664
_reflns_Friedel_coverage         0.903
_reflns_Friedel_fraction_full    0.985
_reflns_Friedel_fraction_max     0.988
_reflns_number_gt                8045
_reflns_number_total             8257
_reflns_threshold_expression     'I > 2\s(I)'
_cod_data_source_file            d6cc00836d2.cif
_cod_data_source_block           SQ-2-Ala
_cod_depositor_comments          'Adding full bibliography for 7135677.cif.'
_cod_database_code               7135677
_shelx_shelxl_version_number     2018/3
_shelx_estimated_absorpt_t_max   0.961
_shelx_estimated_absorpt_t_min   0.915
_olex2_refinement_description
;
1. Fixed Uiso
 At 1.2 times of:
  All C(H) groups, All C(H,H) groups, All N(H) groups
 At 1.5 times of:
  All C(H,H,H) groups
2.a Ternary CH refined with riding coordinates:
 C8(H8), C17(H17)
2.b Secondary CH2 refined with riding coordinates:
 C5(H5A,H5B), C6(H6A,H6B), C14(H14A,H14B), C15(H15A,H15B)
2.c Aromatic/amide H refined with riding coordinates:
 N1(H1), N2(H2), N3(H3), N4(H4), N5(H5), N6(H6)
2.d Idealised Me refined as rotating group:
 C19(H19A,H19B,H19C), C20(H20A,H20B,H20C), C21(H21A,H21B,H21C), C22(H22A,H22B,
 H22C), C9(H9A,H9B,H9C), C18(H18A,H18B,H18C)
;
_shelx_res_checksum              65907
_shelx_hkl_checksum              94624
_olex2_submission_special_instructions 'No special instructions were received'