#------------------------------------------------------------------------------
#$Date: 2009-11-16 01:43:51 +0000 (Mon, 16 Nov 2009) $
#$Revision: 853 $
#$URL: svn://www.crystallography.net/cod/cif/2/2003691.cif $
#------------------------------------------------------------------------------
#
# This file is available in the Crystallography Open Database (COD),
# http://www.crystallography.net/
#
# All data on this site have been placed in the public domain by the
# contributors.
#
data_2003691
_journal_name_full               'Acta Crystallographica C'
_journal_volume                  51
_journal_year        1995
_journal_page_first    	1369
_journal_page_last    	1372
_publ_section_title
;
Adducts from the Pyrolysis of Cellulose: (1\a,2\b,6\b,7\a)-3,8-
Dioxatricyclo[5.3.1.1^2,6^]dodeca-4,9-diene-11,12-dione and (1R)-(1\a,2\b,
3\a,6\a,8\b,9\a)-5,13,14-Trioxatetracyclo[7.3.1.1^3,6^.0^2,8^]tetradeca-10-
ene-7,12-dione
;
_chemical_formula_sum    	'C10 H8 O4'
_chemical_formula_weight    	192.2
_space_group_IT_number           14
_symmetry_space_group_name_Hall  '-P 2ybc'
_symmetry_space_group_name_H-M   'P 1 21/c 1'
_[local]_cod_cif_authors_sg_H-M  'P 21/c'
loop_
    _symmetry_equiv_pos_as_xyz
    'x,y,z'
    'x,1/2-y,1/2+z'
    '-x,-y,-z'
    '-x,1/2+y,1/2-z'
_cell_length_a    	6.4574(12)
_cell_length_b    	11.1198(24)
_cell_length_c    	6.2652(11)
_cell_angle_alpha    	90
_cell_angle_beta    	114.382(14)
_cell_angle_gamma    	90
_cell_volume    	409.75(14)
_cell_formula_units_Z    	2
_exptl_crystal_density_diffrn    	1.560
_exptl_crystal_density_meas    	?
_diffrn_radiation_type    	'MoK\a'
_diffrn_radiation_wavelength    	0.71073
_cell_measurement_reflns_used    	25
_cell_measurement_theta_min    	3.5
_cell_measurement_theta_max    	15.0
_exptl_absorpt_coefficient_mu    	0.132
_cell_measurement_temperature    	291(2)
_exptl_crystal_description    	'needle'
_exptl_crystal_size_max    	0.235
_exptl_crystal_size_mid    	0.175
_exptl_crystal_size_min    	0.075
_exptl_crystal_size_rad    	?
_exptl_crystal_colour    	'colourless'
_chemical_compound_source    	'Furneaux, Mason & Miller (1984), compound (9)'
_diffrn_measurement_device    	'Nicolet R3m'
_diffrn_measurement_method    	'\q/2\q'
_exptl_absorpt_correction_type    	'none'
_exptl_absorpt_correction_T_min    	?
_exptl_absorpt_correction_T_max    	?
_diffrn_reflns_number    	870
_reflns_number_total    	725
_reflns_number_observed    	509
_reflns_observed_criterion    	F>4\s(F)
_diffrn_reflns_av_R_equivalents    	0.021
_diffrn_reflns_theta_max    	25.02
_diffrn_reflns_limit_h_min    	-7
_diffrn_reflns_limit_h_max    	7
_diffrn_reflns_limit_k_min    	0
_diffrn_reflns_limit_k_max    	13
_diffrn_reflns_limit_l_min    	0
_diffrn_reflns_limit_l_max    	7
_diffrn_standards_number    	3
_diffrn_standards_interval_count    	97
_diffrn_standards_interval_time    	?
_diffrn_standards_decay_%    	2
_refine_ls_structure_factor_coef    	Fsqd
_refine_ls_R_factor_obs    	0.041
_refine_ls_wR_factor_obs    	0.100
_refine_ls_goodness_of_fit_obs    	1.038
_refine_ls_number_reflns    	725
_refine_ls_number_parameters    	81
_refine_ls_hydrogen_treatment    	'refall isotropically'
_refine_ls_weighting_scheme
; 1/[\s^2^(F~o~)^2^+0.0423P^2^+0.11P] where P = [max(F~o~^2^,o)+2F~c~^2^]
;
_refine_ls_shift/esd_max    	0.012
_refine_diff_density_max    	0.177
_refine_diff_density_min    	-0.145
_refine_ls_extinction_method    	'Pseudo-secondary (SHELXL93; Sheldrick, 1993)'
_refine_ls_extinction_coef    	'secondary 0.080(13)'
_atom_type_scat_source    	'IntTabC'
loop_
    _atom_site_label
    _atom_site_fract_x
    _atom_site_fract_y
    _atom_site_fract_z
    _atom_site_U_iso_or_equiv
    C(1) .1131(3) .8844(2) .0364(4) .033(1)
    O(1) .2691(3) .8151(2) .1216(3) .051(1)
    C(2) .0680(4) .9563(2) -.1849(4) .036(1)
    O(3) -.1474(3) .9217(2) -.3698(2) .047(1)
    C(4) -.3121(4) .8865(2) -.2975(5) .044(1)
    C(5) -.2880(4) .8783(2) -.0801(4) .043(1)
    C(6) -.0660(4) .9091(2) .1255(4) .037(1)
    H(2) .1850(34) .9411(18) -.2487(33) .29(5)
    H(4) -.4498(38) .8673(23) -.4299(39) .47(7)
    H(5) -.4103(43) .8546(24) -.0482(42) .056(7)
    H(6) -.0333(35) .8629(22) .2630(42) .46(7)