Polymorphism in metformin embonate salt – recurrence of dimeric and tetrameric guanidinium–carboxylate synthons
Nanubolu, Jagadeesh Babu; Sridhar, Balasubramanian; Ravikumar, Krishnan; Sawant, Kamlesh D.; Naik, Tushar A.; Patkar, Laxmikant N.; Cherukuvada, Suryanarayan; Sreedhar, Bojja; CrystEngComm 15 (2013) 4448–; doi:10.1039/c3ce26986h

data_7210086
_publ_section_title
;
 Polymorphism in metformin embonate salt -- recurrence of dimeric and
 tetrameric guanidinium--carboxylate synthons
;
_journal_issue                   22
_journal_name_full               CrystEngComm
_journal_page_first              4448
_journal_paper_doi               10.1039/c3ce26986h
_journal_volume                  15
_journal_year                    2013
_chemical_formula_moiety         '2(C4 H12 N5 +), C23 H14 O6 2-'
_chemical_formula_sum            'C31 H38 N10 O6'
_chemical_formula_weight         646.71
_space_group_IT_number           2
_symmetry_cell_setting           triclinic
_symmetry_space_group_name_Hall  '-P 1'
_symmetry_space_group_name_H-M   'P -1'
_atom_sites_solution_hydrogens   geom
_atom_sites_solution_primary     direct
_atom_sites_solution_secondary   difmap
_audit_creation_method           SHELXL-97
_cell_angle_alpha                73.334(1)
_cell_angle_beta                 83.171(1)
_cell_angle_gamma                82.666(1)
_cell_formula_units_Z            2
_cell_length_a                   7.4680(6)
_cell_length_b                   13.8016(11)
_cell_length_c                   16.2856(13)
_cell_measurement_reflns_used    6331
_cell_measurement_temperature    294(2)
_cell_measurement_theta_max      28.11
_cell_measurement_theta_min      2.29
_cell_volume                     1588.9(2)
_computing_cell_refinement       'SAINT (Bruker, 2001)'
_computing_data_collection       'SMART (Bruker, 2001)'
_computing_data_reduction        SAINT
_computing_molecular_graphics    'SHELXTL/PC (Sheldrick, 1990)'
_computing_publication_material  SHELXL97
_computing_structure_refinement  'SHELXL-97 (Sheldrick, 2008)'
_computing_structure_solution    'SHELXS-97 (Sheldrick, 2008)'
_diffrn_ambient_temperature      294(2)
_diffrn_measured_fraction_theta_full 0.996
_diffrn_measured_fraction_theta_max 0.996
_diffrn_measurement_device       'Bruker SMART APEX CCD area-detector'
_diffrn_measurement_device_type  'CCD Area Detector'
_diffrn_measurement_method       '\w scan'
_diffrn_radiation_monochromator  graphite
_diffrn_radiation_source         'fine-focus sealed tube'
_diffrn_radiation_type           MoK\a
_diffrn_radiation_wavelength     0.71073
_diffrn_reflns_av_R_equivalents  0.0186
_diffrn_reflns_av_sigmaI/netI    0.0203
_diffrn_reflns_limit_h_max       8
_diffrn_reflns_limit_h_min       -8
_diffrn_reflns_limit_k_max       16
_diffrn_reflns_limit_k_min       -16
_diffrn_reflns_limit_l_max       19
_diffrn_reflns_limit_l_min       -19
_diffrn_reflns_number            15328
_diffrn_reflns_theta_full        24.99
_diffrn_reflns_theta_max         24.99
_diffrn_reflns_theta_min         1.73
_diffrn_standards_number         0
_exptl_absorpt_coefficient_mu    0.097
_exptl_absorpt_correction_type   none
_exptl_crystal_colour            colorless
_exptl_crystal_density_diffrn    1.352
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       plate
_exptl_crystal_F_000             684
_exptl_crystal_size_max          0.21
_exptl_crystal_size_mid          0.19
_exptl_crystal_size_min          0.08
_refine_diff_density_max         0.156
_refine_diff_density_min         -0.194
_refine_diff_density_rms         0.045
_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     484
_refine_ls_number_reflns         5579
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      1.040
_refine_ls_R_factor_all          0.0405
_refine_ls_R_factor_gt           0.0363
_refine_ls_shift/su_max          0.001
_refine_ls_shift/su_mean         0.000
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'calc w=1/[\s^2^(Fo^2^)+(0.0673P)^2^+0.2113P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.1040
_refine_ls_wR_factor_ref         0.1083
_reflns_number_gt                4917
_reflns_number_total             5579
_reflns_threshold_expression     I>2\s(I)
_cod_data_source_file            c3ce26986h.txt
_cod_data_source_block           ao97m
_cod_database_code               7210086