Site-selective DNA photocleavage involving unusual photoinitiated tautomerization of chiral tridentate vanadyl(V) complexes derived from N-salicylidene alpha-amino acids.
Chen, Chien-Tien; Lin, Jin-Sheng; Kuo, Jen-Huang; Weng, Shiue-Shien; Cuo, Ting-Shen; Lin, Yi-Wen; Cheng, Chien-Chung; Huang, Yan-Chen; Yu, Jen-Kan; Chou, Pi-Tai; Organic letters 6 (2004) 4471–4474; doi:10.1021/ol048156h

data_1506943
_publ_section_title
;
 Site-selective DNA photocleavage involving unusual photoinitiated
 tautomerization of chiral tridentate vanadyl(V) complexes derived from
 N-salicylidene alpha-amino acids.
;
_journal_issue                   24
_journal_name_full               'Organic letters'
_journal_page_first              4471
_journal_page_last               4474
_journal_paper_doi               10.1021/ol048156h
_journal_volume                  6
_journal_year                    2004
_chemical_formula_moiety         'C20 H22 N1 O4 V1'
_chemical_formula_sum            'C18 H22 N O6 V'
_chemical_formula_weight         399.31
_space_group_IT_number           5
_symmetry_cell_setting           monoclinic
_symmetry_space_group_name_Hall  'C 2y'
_symmetry_space_group_name_H-M   'C 1 2 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                 103.211(2)
_cell_angle_gamma                90.00
_cell_formula_units_Z            4
_cell_length_a                   34.1740(17)
_cell_length_b                   6.5450(3)
_cell_length_c                   8.9390(6)
_cell_measurement_reflns_used    7748
_cell_measurement_temperature    293(2)
_cell_measurement_theta_max      25.028
_cell_measurement_theta_min      2.037
_cell_volume                     1946.46(19)
_computing_cell_refinement       'HKL Scalepack (Otwinowski & Minor 1997)'
_computing_data_collection       'Collect (Nonius BV, 1997-2000)'
_computing_data_reduction        HKLDenzoandScalepack(Otwinowski&Minor19)
_computing_molecular_graphics    'Ortep-3 for Windows (Farrugia, 1997)'
_computing_publication_material  'WinGX publication routines (Farrugia, 1999)'
_computing_structure_refinement  'SHELXL-97 (Sheldrick, 1997)'
_computing_structure_solution    'SHELXS-97 (Sheldrick, 1997)'
_diffrn_ambient_temperature      293(2)
_diffrn_measured_fraction_theta_full 0.984
_diffrn_measured_fraction_theta_max 0.984
_diffrn_measurement_device_type  KappaCCD
_diffrn_measurement_method       'CCD rotation images, thick slices'
_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  0.0477
_diffrn_reflns_av_sigmaI/netI    0.0785
_diffrn_reflns_limit_h_max       40
_diffrn_reflns_limit_h_min       -31
_diffrn_reflns_limit_k_max       7
_diffrn_reflns_limit_k_min       -6
_diffrn_reflns_limit_l_max       10
_diffrn_reflns_limit_l_min       -10
_diffrn_reflns_number            5489
_diffrn_reflns_theta_full        25.08
_diffrn_reflns_theta_max         25.08
_diffrn_reflns_theta_min         2.34
_exptl_absorpt_coefficient_mu    0.542
_exptl_absorpt_correction_T_max  0.9622
_exptl_absorpt_correction_T_min  0.905
_exptl_absorpt_correction_type   multi-scan
_exptl_absorpt_process_details
;
 ?
;
_exptl_crystal_colour            black
_exptl_crystal_density_diffrn    1.363
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       prism
_exptl_crystal_F_000             832
_exptl_crystal_size_max          0.42
_exptl_crystal_size_mid          0.05
_exptl_crystal_size_min          0.04
_refine_diff_density_max         0.626
_refine_diff_density_min         -0.736
_refine_diff_density_rms         0.249
_refine_ls_abs_structure_details 'Flack H D (1983), Acta Cryst. A39, 876-881'
_refine_ls_abs_structure_Flack   -0.03(6)
_refine_ls_extinction_coef       0.045(4)
_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   1.152
_refine_ls_hydrogen_treatment    mixed
_refine_ls_matrix_type           full
_refine_ls_number_parameters     236
_refine_ls_number_reflns         3144
_refine_ls_number_restraints     1
_refine_ls_restrained_S_all      1.152
_refine_ls_R_factor_all          0.1029
_refine_ls_R_factor_gt           0.0742
_refine_ls_shift/su_max          0.006
_refine_ls_shift/su_mean         0.001
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'calc w=1/[\s^2^(Fo^2^)+(0.1074P)^2^+0.0000P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.1643
_refine_ls_wR_factor_ref         0.1972
_reflns_number_gt                2325
_reflns_number_total             3144
_reflns_threshold_expression     >2sigma(I)
_cod_data_source_file            ol048156hsi20040913_083401.cif
_cod_data_source_block           2912
_cod_original_sg_symbol_H-M      'C 2'
_cod_database_code               1506943