Ring contraction during the 6π-electrocyclisation of naphthopyran valence tautomers
Gabbutt, Christopher D.; Heron, B. Mark; Kolla, Suresh B.; Kilner, Colin; Coles, Simon J.; Horton, Peter N.; Hursthouse, Michael B.; Organic & Biomolecular Chemistry 6 (2008) 3096–3104; doi:10.1039/b807744d

data_7150968
_publ_section_title
;
 Ring contraction during the 6\p-electrocyclisation of naphthopyran
 valence tautomers
;
_journal_issue                   17
_journal_name_full               'Organic &amp; Biomolecular Chemistry'
_journal_page_first              3096
_journal_page_last               3104
_journal_paper_doi               10.1039/b807744d
_journal_volume                  6
_journal_year                    2008
_chemical_formula_moiety         'C25 H16 O3 S'
_chemical_formula_sum            'C25 H16 O3 S'
_chemical_formula_weight         396.44
_space_group_IT_number           14
_symmetry_cell_setting           monoclinic
_symmetry_space_group_name_Hall  '-P 2yn'
_symmetry_space_group_name_H-M   'P 1 21/n 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                 101.1430(7)
_cell_angle_gamma                90.00
_cell_formula_units_Z            4
_cell_length_a                   7.97170(10)
_cell_length_b                   20.6854(3)
_cell_length_c                   11.1804(2)
_cell_measurement_reflns_used    24270
_cell_measurement_temperature    150(2)
_cell_measurement_theta_max      27.48
_cell_measurement_theta_min      1.00
_cell_volume                     1808.87(5)
_computing_cell_refinement       'DENZO-SMN (Otwinowski & Minor, 1996)'
_computing_data_collection       'COLLECT (Nonius, 2004)'
_computing_data_reduction
;
DENZO-SMN and COLLECT (Otwinowski & Minor, 1996)
;
_computing_molecular_graphics
;
ORTEP-III Version 1.08 (Farrugia, 2005)
;
_computing_publication_material
;
enCIFer: A program for viewing, editing and visualising CIFs.
F. H. Allen, O. Johnson, G. P. Shields, B. R. Smith, M. Towler,
J. Applied Cryst., 37, 331-334, 2004
;
_computing_structure_refinement  'SHELXL-97 (Sheldrick, 1997)'
_computing_structure_solution
;
SIR92
Altomare, A.; Burla, M. C.; Camalli, G.; Cascarano, G.;
Giacovazzo, C.; Guagliardi, A.; Polidori, G.
J. Appl. Cryst. 1994, 27, 435-436.
;
_diffrn_ambient_temperature      150(2)
_diffrn_detector_area_resol_mean 9
_diffrn_measured_fraction_theta_full 0.999
_diffrn_measured_fraction_theta_max 0.999
_diffrn_measurement_device_type
;
Nonius KappaCCD area-detector diffractometer
;
_diffrn_measurement_method
;
phi and omega scans to fill the asymmetric unit
;
_diffrn_radiation_detector       'CCD plate'
_diffrn_radiation_monochromator  graphite
_diffrn_radiation_probe          x-ray
_diffrn_radiation_source         'fine-focus sealed tube'
_diffrn_radiation_type           MoK\a
_diffrn_radiation_wavelength     0.71073
_diffrn_reflns_av_R_equivalents  0.0840
_diffrn_reflns_av_sigmaI/netI    0.0327
_diffrn_reflns_limit_h_max       9
_diffrn_reflns_limit_h_min       -9
_diffrn_reflns_limit_k_max       25
_diffrn_reflns_limit_k_min       -25
_diffrn_reflns_limit_l_max       13
_diffrn_reflns_limit_l_min       -13
_diffrn_reflns_number            34563
_diffrn_reflns_theta_full        26.00
_diffrn_reflns_theta_max         26.00
_diffrn_reflns_theta_min         2.71
_diffrn_standards_decay_%        0
_diffrn_standards_interval_count 0
_diffrn_standards_interval_time  0
_diffrn_standards_number         0
_exptl_absorpt_coefficient_mu    0.205
_exptl_absorpt_correction_type   none
_exptl_crystal_colour            'pale brown'
_exptl_crystal_density_diffrn    1.456
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       plate
_exptl_crystal_F_000             824
_exptl_crystal_size_max          0.31
_exptl_crystal_size_mid          0.20
_exptl_crystal_size_min          0.08
_refine_diff_density_max         0.298
_refine_diff_density_min         -0.545
_refine_diff_density_rms         0.067
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.058
_refine_ls_hydrogen_treatment    constr
_refine_ls_matrix_type           full
_refine_ls_number_parameters     262
_refine_ls_number_reflns         3553
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      1.058
_refine_ls_R_factor_all          0.0483
_refine_ls_R_factor_gt           0.0396
_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^)+(0.0568P)^2^+0.7477P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.1011
_refine_ls_wR_factor_ref         0.1084
_reflns_number_gt                3006
_reflns_number_total             3553
_reflns_threshold_expression     >2sigma(I)
_cod_data_source_file            b807744d.txt
_cod_data_source_block           compound_6
_cod_original_sg_symbol_H-M      P21/n
_cod_database_code               7150968