Chiral glycine cation equivalents: N-acyliminium species derived from diketopiperazines
Bull, Steven D.; Davies, Stephen G.; Christopher Garner, A.; O'Shea, Michael D.; Savory, Edward D.; Snow, Emma J.; Journal of the Chemical Society, Perkin Transactions 1  (2002) 2442–; doi:10.1039/b207457p

data_7204506
_publ_section_title
;
 Chiral glycine cation equivalents: N-acyliminium species derived from
 diketopiperazines
;
_journal_issue                   22
_journal_name_full
'Journal of the Chemical Society, Perkin Transactions 1'
_journal_page_first              2442
_journal_paper_doi               10.1039/b207457p
_journal_year                    2002
_chemical_compound_source
;
?
;
_chemical_formula_moiety         ' C25 H30 N2 O6 '
_chemical_formula_sum            'C25 H30 N2 O6'
_chemical_formula_weight         454.52
_chemical_melting_point          ?
_space_group_IT_number           19
_symmetry_cell_setting           orthorhombic
_symmetry_space_group_name_Hall  'P 2ac 2ab'
_symmetry_space_group_name_H-M   'P 21 21 21'
_atom_sites_solution_hydrogens   geom
_atom_sites_solution_primary     direct
_audit_creation_date             01-12-10
_audit_creation_method           CRYSTALS_ver_12-03-99
_cell_angle_alpha                90
_cell_angle_beta                 90
_cell_angle_gamma                90
_cell_formula_units_Z            4
_cell_length_a                   7.4482(1)
_cell_length_b                   10.8159(2)
_cell_length_c                   29.5153(4)
_cell_measurement_reflns_used    2961
_cell_measurement_temperature    190
_cell_measurement_theta_max      27
_cell_measurement_theta_min      1
_cell_volume                     2377.72(6)
_computing_cell_refinement
; 
Denzo/Scalepack (Otwinowski & Minor, 1996) 
;
_computing_data_collection
; 
COLLECT (Nonius BV, 1997) 
;
_computing_data_reduction
; 
Denzo/Scalepack (Otwinowski & Minor, 1996) 
;
_computing_molecular_graphics
; 
CAMERON (Watkin et al 1996) 
;
_computing_publication_material
; 
CRYSTALS (Watkin et all 2001) 
;
_computing_structure_refinement
; 
CRYSTALS (Watkin et all 2001) 
;
_computing_structure_solution
; 
SIR92 (Altomare et al, 1994) 
;
_diffrn_ambient_temperature      190
_diffrn_measured_fraction_theta_max 1.000
_diffrn_measurement_device_type
; 
Enraf Nonius Kappa CCD 
;
_diffrn_measurement_method       \w
_diffrn_radiation_monochromator  graphite
_diffrn_radiation_type           'Mo K\a'
_diffrn_radiation_wavelength     0.71073
_diffrn_reflns_av_R_equivalents  0.01
_diffrn_reflns_limit_h_max       9
_diffrn_reflns_limit_h_min       -9
_diffrn_reflns_limit_k_max       14
_diffrn_reflns_limit_k_min       -13
_diffrn_reflns_limit_l_max       38
_diffrn_reflns_limit_l_min       -37
_diffrn_reflns_number            5227
_diffrn_reflns_theta_max         27.50
_diffrn_reflns_theta_min         4.55
_diffrn_standards_decay_%        0.00
_diffrn_standards_interval_count 0
_diffrn_standards_interval_time  0
_diffrn_standards_number         0
_exptl_absorpt_coefficient_mu    0.091
_exptl_absorpt_correction_T_max  0.96
_exptl_absorpt_correction_T_min  0.96
_exptl_absorpt_correction_type   multi-scan
_exptl_absorpt_process_details
; 
Denzo/Scalepack (Otwinowski & Minor, 1996) 
;
_exptl_crystal_colour            ' colourless '
_exptl_crystal_density_diffrn    1.270
_exptl_crystal_density_meas      ?
_exptl_crystal_description       ' block '
_exptl_crystal_F_000             968.280
_exptl_crystal_size_max          0.40
_exptl_crystal_size_mid          0.40
_exptl_crystal_size_min          0.40
_refine_diff_density_max         0.18
_refine_diff_density_min         -0.16
_refine_ls_extinction_method     None
_refine_ls_goodness_of_fit_ref   1.0654
_refine_ls_hydrogen_treatment    noref
_refine_ls_matrix_type           full
_refine_ls_number_parameters     298
_refine_ls_number_reflns         2646
_refine_ls_R_factor_gt           0.0325
_refine_ls_shift/su_max          0.000796
_refine_ls_structure_factor_coef F
_refine_ls_weighting_details
;
Chebychev polynomial with 4 parameters, Carruthers & Watkin , 1979, 
0.681    -.781    0.267    -.395    
;
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_ref         0.0201
_reflns_limit_h_max              9
_reflns_limit_h_min              0
_reflns_limit_k_max              14
_reflns_limit_k_min              0
_reflns_limit_l_max              38
_reflns_limit_l_min              0
_reflns_number_gt                2646
_reflns_number_total             3044
_reflns_threshold_expression     >3.00\s(I)
_cod_data_source_file            b207457p.txt
_cod_data_source_block           CRYSTALS_cif
_cod_depositor_comments
;
The following automatic conversions were performed:
'_symmetry_cell_setting' value 'Orthorhombic ' changed to 'orthorhombic'
according to '/home/adriana/struct/CIF-dictionaries/cif_core.dic'
dictionary named 'cif_core.dic' version 2.4.1 from 2010-06-29.

Automatic conversion script
Id: cif_fix_enum 1555 2011-01-17 13:19:09Z saulius 

The following automatic conversions were performed:

'_chemical_melting_point' value 'not measured' was changed to '?' -
the value is undefined or not given.

Automatic conversion script
Id: cif_fix_values 1569 2011-02-09 13:29:24Z adriana 
;
_cod_original_cell_volume        2377.7
_cod_original_sg_symbol_H-M      'P 21 21 21 '
_cod_original_formula_sum        ' C25 H30 N2 O6 '
_cod_database_code               7204506