Pyridazines in Crystal Engineering. A Systematic Evaluation of the Role of Isomerism and Steric Factors in Determining Crystal Packing and Nano/Microcrystal Morphologies
Varughese, Sunil; Draper, Sylvia M.; Crystal Growth & Design 10 (2010) 2571–; doi:10.1021/cg9015383

data_4502696
_publ_section_title
;
 Pyridazines in Crystal Engineering. A Systematic Evaluation of the Role
 of Isomerism and Steric Factors in Determining Crystal Packing and
 Nano/Microcrystal Morphologies
;
_journal_issue                   6
_journal_name_full               'Crystal Growth &amp; Design'
_journal_page_first              2571
_journal_paper_doi               10.1021/cg9015383
_journal_volume                  10
_journal_year                    2010
_chemical_formula_moiety         'C20 H14 N4'
_chemical_formula_sum            'C20 H14 N4'
_chemical_formula_weight         310.35
_space_group_IT_number           61
_symmetry_cell_setting           orthorhombic
_symmetry_space_group_name_Hall  '-P 2ac 2ab'
_symmetry_space_group_name_H-M   'P b c a'
_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                 90.00
_cell_angle_gamma                90.00
_cell_formula_units_Z            8
_cell_length_a                   7.466(7)
_cell_length_b                   10.534(1)
_cell_length_c                   38.576(4)
_cell_measurement_reflns_used    2286
_cell_measurement_temperature    123(2)
_cell_measurement_theta_max      49.282
_cell_measurement_theta_min      5.847
_cell_volume                     3034(3)
_computing_cell_refinement       'Bruker SMART'
_computing_data_collection       'Bruker SMART'
_computing_data_reduction        'Bruker SAINT'
_computing_molecular_graphics    'Bruker SHELXTL'
_computing_publication_material  'Bruker SHELXTL'
_computing_structure_refinement  'SHELXL-97 (Sheldrick, 1997)'
_computing_structure_solution    'SHELXS-97 (Sheldrick, 1990)'
_diffrn_ambient_temperature      123(2)
_diffrn_measured_fraction_theta_full 0.996
_diffrn_measured_fraction_theta_max 0.996
_diffrn_measurement_device_type  'CCD area detector'
_diffrn_measurement_method       'phi and omega 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  0.0488
_diffrn_reflns_av_sigmaI/netI    0.0362
_diffrn_reflns_limit_h_max       8
_diffrn_reflns_limit_h_min       -8
_diffrn_reflns_limit_k_max       12
_diffrn_reflns_limit_k_min       -11
_diffrn_reflns_limit_l_max       33
_diffrn_reflns_limit_l_min       -45
_diffrn_reflns_number            15932
_diffrn_reflns_theta_full        25.09
_diffrn_reflns_theta_max         25.09
_diffrn_reflns_theta_min         1.06
_exptl_absorpt_coefficient_mu    0.084
_exptl_absorpt_correction_T_max  0.9900
_exptl_absorpt_correction_T_min  0.9818
_exptl_absorpt_correction_type   multi-scan
_exptl_absorpt_process_details   'SADABS; Sheldrick, 1996'
_exptl_crystal_colour            Colorless
_exptl_crystal_density_diffrn    1.359
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       Blocks
_exptl_crystal_F_000             1296
_exptl_crystal_size_max          0.22
_exptl_crystal_size_mid          0.16
_exptl_crystal_size_min          0.12
_refine_diff_density_max         0.169
_refine_diff_density_min         -0.169
_refine_diff_density_rms         0.038
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.042
_refine_ls_hydrogen_treatment    constr
_refine_ls_matrix_type           full
_refine_ls_number_parameters     217
_refine_ls_number_reflns         2693
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      1.042
_refine_ls_R_factor_all          0.0534
_refine_ls_R_factor_gt           0.0382
_refine_ls_shift/su_max          0.000
_refine_ls_shift/su_mean         0.000
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'calc w=1/[\s^2^(Fo^2^)+(0.0382P)^2^+0.9354P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.0864
_refine_ls_wR_factor_ref         0.0939
_reflns_number_gt                2126
_reflns_number_total             2693
_reflns_threshold_expression     >2sigma(I)
_cod_data_source_file            cg9015383_si_003.cif
_cod_data_source_block           1c
_cod_depositor_comments
;
The following automatic conversions were performed:

'_symmetry_cell_setting' value 'Orthorhombic' changed to
'orthorhombic' according to
/home/saulius/struct/CIF-dictionaries/cif_core.dic dictionary named
'cif_core.dic' version 2.4.2 from
2011-04-26.

'_exptl_absorpt_correction_type' value 'Multi-scan'
changed to 'multi-scan' according to
/home/saulius/struct/CIF-dictionaries/cif_core.dic dictionary named
'cif_core.dic' version 2.4.2 from 2011-04-26.

Automatic conversion script
Id: cif_fix_values 1715 2011-07-08 13:25:40Z adriana 
;
_cod_original_sg_symbol_H-M      Pbca
_cod_database_code               4502696