Design, synthesis, and evaluation of 1,4,7,10-tetraazacyclododecane-1,4,7-triacetic acid derived, redox-sensitive contrast agents for magnetic resonance imaging.
Raghunand, Natarajan; Guntle, Gerald P.; Gokhale, Vijay; Nichol, Gary S.; Mash, Eugene A.; Jagadish, Bhumasamudram; Journal of medicinal chemistry 53 (2010) 6747–6757; doi:10.1021/jm100592u

data_1502664
_publ_section_title
;
 Design, synthesis, and evaluation of
 1,4,7,10-tetraazacyclododecane-1,4,7-triacetic acid derived,
 redox-sensitive contrast agents for magnetic resonance imaging.
;
_journal_issue                   18
_journal_name_full               'Journal of medicinal chemistry'
_journal_page_first              6747
_journal_page_last               6757
_journal_paper_doi               10.1021/jm100592u
_journal_volume                  53
_journal_year                    2010
_chemical_formula_moiety         'N H4 +, C25 H44 Gd N4 O8 S -, 2 H2 O'
_chemical_formula_sum            'C25 H52 Gd N5 O10 S'
_chemical_formula_weight         772.04
_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   difmap
_atom_sites_solution_primary     Patterson
_atom_sites_solution_secondary   difmap
_audit_creation_method           SHELXL-97
_cell_angle_alpha                76.573(3)
_cell_angle_beta                 86.307(3)
_cell_angle_gamma                88.816(3)
_cell_formula_units_Z            2
_cell_length_a                   8.0364(13)
_cell_length_b                   10.4906(17)
_cell_length_c                   21.799(4)
_cell_measurement_reflns_used    8063
_cell_measurement_temperature    223(2)
_cell_measurement_theta_max      28.15
_cell_measurement_theta_min      2.41
_cell_volume                     1783.8(5)
_computing_cell_refinement       'SAINT (Bruker, 2007)'
_computing_data_collection       'SMART (Bruker, 2007)'
_computing_data_reduction        SAINT
_computing_molecular_graphics    'ORTEP3 for Windows (Farrugia, 1997)'
_computing_publication_material  'SHELXTL and local programs'
_computing_structure_refinement  SHELXTL
_computing_structure_solution    'SHELXTL (Sheldrick, 2008)'
_diffrn_ambient_temperature      223(2)
_diffrn_measured_fraction_theta_full 0.989
_diffrn_measured_fraction_theta_max 0.989
_diffrn_measurement_device_type  'Bruker SMART 1000 CCD diffractometer'
_diffrn_measurement_method       'thin-slice \w scans'
_diffrn_radiation_monochromator  graphite
_diffrn_radiation_source         'sealed tube'
_diffrn_radiation_type           MoK\a
_diffrn_radiation_wavelength     0.71073
_diffrn_reflns_av_R_equivalents  0.0216
_diffrn_reflns_av_sigmaI/netI    0.0356
_diffrn_reflns_limit_h_max       9
_diffrn_reflns_limit_h_min       -9
_diffrn_reflns_limit_k_max       12
_diffrn_reflns_limit_k_min       -12
_diffrn_reflns_limit_l_max       26
_diffrn_reflns_limit_l_min       0
_diffrn_reflns_number            6582
_diffrn_reflns_theta_full        25.50
_diffrn_reflns_theta_max         25.50
_diffrn_reflns_theta_min         1.92
_diffrn_standards_number         0
_exptl_absorpt_coefficient_mu    1.970
_exptl_absorpt_correction_T_max  0.9079
_exptl_absorpt_correction_T_min  0.4331
_exptl_absorpt_correction_type   numerical
_exptl_absorpt_process_details   'SADABS 2007/4; Sheldrick, 1996'
_exptl_crystal_colour            colourless
_exptl_crystal_density_diffrn    1.437
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       plate
_exptl_crystal_F_000             794
_exptl_crystal_size_max          0.51
_exptl_crystal_size_mid          0.23
_exptl_crystal_size_min          0.05
_platon_squeeze_details
;
SQUEEZE used to remove...
;
_refine_diff_density_max         0.785
_refine_diff_density_min         -0.524
_refine_diff_density_rms         0.078
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.074
_refine_ls_hydrogen_treatment    mixed
_refine_ls_matrix_type           full
_refine_ls_number_parameters     486
_refine_ls_number_reflns         6582
_refine_ls_number_restraints     343
_refine_ls_restrained_S_all      1.080
_refine_ls_R_factor_all          0.0331
_refine_ls_R_factor_gt           0.0275
_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^)+(0.0389P)^2^+0.0000P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.0672
_refine_ls_wR_factor_ref         0.0690
_reflns_number_gt                5884
_reflns_number_total             6582
_reflns_threshold_expression     I>2\s(I)
_cod_data_source_file            jm100592u_si_002.cif
_cod_data_source_block           eam105
_cod_database_code               1502664