X-Ray crystal structures of Mg2+ and Ca2+ dimers of the antibacterial drug norfloxacin
Chen, Zhen-Feng; Xiong, Ren-Gen; Zuo, Jing-Lin; Guo, Zijian; You, Xiao-Zeng; Fun, Hoong-Kun; Journal of the Chemical Society, Dalton Transactions  (2000) 4013–; doi:10.1039/b006806n

data_7010197
_publ_section_title
;
 X-Ray crystal structures of Mg2+ and Ca2+ dimers of the antibacterial
 drug norfloxacin
;
_journal_issue                   22
_journal_name_full
'Journal of the Chemical Society, Dalton Transactions'
_journal_page_first              4013
_journal_paper_doi               10.1039/b006806n
_journal_year                    2000
_chemical_formula_sum            'C96 H128 Ca2 Cl4 F6 N18 O28'
_chemical_formula_weight         2318.12
_chemical_name_systematic
; 
 ? 
;
_space_group_IT_number           15
_symmetry_cell_setting           monoclinic
_symmetry_space_group_name_Hall  '-C 2yc'
_symmetry_space_group_name_H-M   'C 1 2/c 1'
_atom_sites_solution_hydrogens   geom
_atom_sites_solution_primary     direct
_atom_sites_solution_secondary   difmap
_audit_creation_method           SHELXL-97
_cell_angle_alpha                90.00
_cell_angle_beta                 109.244(1)
_cell_angle_gamma                90.00
_cell_formula_units_Z            4
_cell_length_a                   26.4943(1)
_cell_length_b                   15.3545(1)
_cell_length_c                   27.8604(2)
_cell_measurement_reflns_used    6238
_cell_measurement_temperature    293(2)
_cell_measurement_theta_max      29.68
_cell_measurement_theta_min      1.55
_cell_volume                     10700.51(13)
_computing_cell_refinement       'SAINT (Siemens, 1996)'
_computing_data_collection       'SMART (Siemens, 1996)'
_computing_data_reduction        SAINT
_computing_molecular_graphics    SHELXTL
_computing_publication_material
;
SHELXTL, PARST (Nardelli, 1995) and PLATON (Spek, 1990)
;
_computing_structure_refinement  SHELXTL
_computing_structure_solution    'SHELXTL (Sheldrick, 1997)'
_diffrn_ambient_temperature      293(2)
_diffrn_detector_area_resol_mean 8.33
_diffrn_measured_fraction_theta_full 0.995
_diffrn_measured_fraction_theta_max 0.995
_diffrn_measurement_device_type
;
Siemens SMART CCD area detector diffractometer
;
_diffrn_measurement_method       '\w scans'
_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  0.1220
_diffrn_reflns_av_sigmaI/netI    0.1438
_diffrn_reflns_limit_h_max       34
_diffrn_reflns_limit_h_min       -34
_diffrn_reflns_limit_k_max       9
_diffrn_reflns_limit_k_min       -19
_diffrn_reflns_limit_l_max       35
_diffrn_reflns_limit_l_min       -36
_diffrn_reflns_number            35821
_diffrn_reflns_theta_full        27.50
_diffrn_reflns_theta_max         27.50
_diffrn_reflns_theta_min         1.55
_exptl_absorpt_coefficient_mu    0.301
_exptl_absorpt_correction_T_max  0.9822
_exptl_absorpt_correction_T_min  0.9152
_exptl_absorpt_correction_type   empirical
_exptl_absorpt_process_details   'SADABS (Sheldrick, 1996)'
_exptl_crystal_colour            colourless
_exptl_crystal_density_diffrn    1.439
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       slab
_exptl_crystal_F_000             4864
_exptl_crystal_size_max          0.30
_exptl_crystal_size_mid          0.12
_exptl_crystal_size_min          0.06
_refine_diff_density_max         0.796
_refine_diff_density_min         -0.990
_refine_diff_density_rms         0.099
_refine_ls_extinction_coef       0.00147(13)
_refine_ls_extinction_expression Fc^*^=kFc[1+0.001xFc^2^\l^3^/sin(2\q)]^-1/4^
_refine_ls_extinction_method     SHELXL
_refine_ls_goodness_of_fit_ref   0.945
_refine_ls_hydrogen_treatment    mixed
_refine_ls_matrix_type           full
_refine_ls_number_parameters     720
_refine_ls_number_reflns         12224
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      0.945
_refine_ls_R_factor_all          0.1447
_refine_ls_R_factor_gt           0.0771
_refine_ls_shift/su_max          0.181
_refine_ls_shift/su_mean         0.007
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'calc w=1/[\s^2^(Fo^2^)+(0.0882P)^2^+0.0000P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.1736
_refine_ls_wR_factor_ref         0.2005
_reflns_number_gt                6500
_reflns_number_total             12224
_reflns_threshold_expression     'I > 2\s(I)'
_cod_data_source_file            b006806n.txt
_cod_data_source_block           2
_cod_original_cell_volume        10700.50(11)
_cod_original_sg_symbol_H-M      C2/c
_cod_database_code               7010197