Four Simple Pyridazin-3(2<i>H</i>)-ones
Blake, A. J.; McNab, H.; Acta Crystallographica Section C 52 (1996) 2622–2627; doi:10.1107/S0108270196005355

data_2005446
_publ_section_title
;
 Four Simple Pyridazin-3(2<i>H</i>)-ones
;
_journal_issue                   10
_journal_name_full               'Acta Crystallographica Section C'
_journal_page_first              2622
_journal_page_last               2627
_journal_paper_doi               10.1107/S0108270196005355
_journal_volume                  52
_journal_year                    1996
_chemical_formula_moiety         'C5 H6 N2 O'
_chemical_formula_sum            'C5 H6 N2 O'
_chemical_formula_weight         110.12
_chemical_melting_point          427.0(10)
_chemical_name_common            'Compound 5'
_chemical_name_systematic
;
 4-methylpyridazin-3(2H)-one
;
_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'
_audit_creation_method           SHELXL
_cell_angle_alpha                90.00
_cell_angle_beta                 90.00
_cell_angle_gamma                90.00
_cell_formula_units_Z            8
_cell_length_a                   11.8328(16)
_cell_length_b                   7.5583(14)
_cell_length_c                   12.387(3)
_cell_measurement_reflns_used    '62 (at +-\w)'
_cell_measurement_temperature    295(2)
_cell_measurement_theta_max      18
_cell_measurement_theta_min      12
_cell_volume                     1107.8(4)
_computing_cell_refinement       DIF4
_computing_data_collection       'DIF4 (Stoe & Cie, 1990)'
_computing_data_reduction        'X-RED (Stoe & Cie, 1995)'
_computing_molecular_graphics    'SHELXTL/PC (Sheldrick, 1995)'
_computing_publication_material  SHELXL93
_computing_structure_refinement  'SHELXL93 (Sheldrick, 1993)'
_computing_structure_solution    'SHELXS86 (Sheldrick, 1990)'
_diffrn_ambient_temperature      295(2)
_diffrn_measurement_device       'Stoe Stadi-4 four-circle diffractometer'
_diffrn_measurement_method
'\w-2\q scans with \w width given by (1.8+0.35tan\q)\%'
_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  0.0563
_diffrn_reflns_av_sigmaI/netI    0.1288
_diffrn_reflns_limit_h_max       14
_diffrn_reflns_limit_h_min       -1
_diffrn_reflns_limit_k_max       9
_diffrn_reflns_limit_k_min       -1
_diffrn_reflns_limit_l_max       1
_diffrn_reflns_limit_l_min       -14
_diffrn_reflns_number            1510
_diffrn_reflns_theta_max         25.05
_diffrn_reflns_theta_min         3.29
_diffrn_standards_decay_%        15
_diffrn_standards_interval_time  120
_diffrn_standards_number         3
_exptl_absorpt_coefficient_mu    0.096
_exptl_absorpt_correction_type   none
_exptl_crystal_colour            colourless
_exptl_crystal_density_diffrn    1.320
_exptl_crystal_density_meas      ?
_exptl_crystal_description       plate
_exptl_crystal_F_000             464
_exptl_crystal_size_max          0.54
_exptl_crystal_size_mid          0.47
_exptl_crystal_size_min          0.02
_refine_diff_density_max         0.14
_refine_diff_density_min         -0.17
_refine_ls_extinction_coef       0.002(2)
_refine_ls_extinction_method     'SHELXL93 (Sheldrick, 1993)'
_refine_ls_goodness_of_fit_all   0.933
_refine_ls_goodness_of_fit_obs   1.075
_refine_ls_hydrogen_treatment
;
Hydrogen atoms attached to N2, C5 and C6 were initially placed
in calculated positions with U~iso~(H) = 1.2U~eq~(C,N).  Methyl group
H atoms were located in a difference Fourier map and thereafter
treated as part of a rigid methyl group allowed to rotate about the
C4-C4m vector with U~iso~(H) = 1.5U~eq~(C4m).
;
_refine_ls_matrix_type           full
_refine_ls_number_parameters     74
_refine_ls_number_reflns         936
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      0.964
_refine_ls_restrained_S_obs      1.075
_refine_ls_R_factor_all          0.2070
_refine_ls_R_factor_obs          0.0566
_refine_ls_shift/esd_max         0.009
_refine_ls_shift/esd_mean        0.002
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'w=1/[\s^2^(Fo^2^)+(0.064P)^2^] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_all         0.1738
_refine_ls_wR_factor_obs         0.1085
_reflns_number_observed          340
_reflns_number_total             943
_reflns_observed_criterion       >2sigma(I)
_cod_data_source_file            ab1367.cif
_cod_data_source_block           5
_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 2.4.1 from 2010-06-29.

Automatic conversion script
Id: cif_fix_enum 1527 2010-12-29 10:47:43Z saulius 

The following automatic conversions were performed:

'_chemical_melting_point' value '426-428K' was changed to '427.0(10)'
- the average value was taken and precision was
estimated.

'_symmetry_cell_setting' value 'Orthorhombic' changed to
'orthorhombic' according to
/home/saulius/struct/CIF-dictionaries/cif_core.dic dictionary named
'cif_core.dic' version 2.4.1 from
2010-06-29.

'_exptl_absorpt_correction_type' value 'None' changed to
'none' according to
/home/saulius/struct/CIF-dictionaries/cif_core.dic dictionary named
'cif_core.dic' version 2.4.1 from 2010-06-29.

'_geom_bond_publ_flag'
value 'No' changed to 'no' according to
/home/saulius/struct/CIF-dictionaries/cif_core.dic dictionary named
'cif_core.dic' version 2.4.1 from 2010-06-29 (8
times).

'_geom_angle_publ_flag' value 'No' changed to 'no' according
to /home/saulius/struct/CIF-dictionaries/cif_core.dic dictionary
named 'cif_core.dic' version 2.4.1 from 2010-06-29 (10 times).

Automatic conversion script
Id: cif_fix_values 1715 2011-07-08 13:25:40Z adriana 

The following automatic conversions were performed:

'_exptl_crystal_density_meas' value 'not measured' was changed to '?'
- the value is perceived as not measured.

Automatic conversion script
Id: cif_fix_values 3008 2015-01-20 13:52:24Z robertas 

The following automatic conversions were performed:

'_refine_ls_weighting_scheme' value 'calc
w=1/[\s^2^(Fo^2^)+(0.064P)^2^] where P=(Fo^2^+2Fc^2^)/3' was changed
to 'calc'. New tag '_refine_ls_weighting_details' was created. The
value of the new tag was set to 'w=1/[\s^2^(Fo^2^)+(0.064P)^2^] where
P=(Fo^2^+2Fc^2^)/3'.

Automatic conversion script
Id: cif_fix_values 3143 2015-03-26 13:38:13Z robertas 
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_cod_database_code               2005446