#------------------------------------------------------------------------------
#$Date: 2011-09-10 04:16:28 +0100 (Sat, 10 Sep 2011) $
#$Revision: 25271 $
#$URL: svn://www.crystallography.net/cod/cif/2/2006431.cif $
#------------------------------------------------------------------------------
#
# This file is available in the Crystallography Open Database (COD),
# http://www.crystallography.net/. The original data for this entry
# were provided by IUCr Journals, http://journals.iucr.org/.
#
# The file may be used within the scientific community so long as
# proper attribution is given to the journal article from which the
# data were obtained.
#
data_2006431
loop_
_publ_author_name
'Schade, B.'
'Fuhrhop, J.-H.'
'Hubert, V.'
'Weber, M.'
'Luger, P.'
_publ_contact_author
;
J.-H. Fuhrhop
Institut f\"ur Organische Chemie
Freie Universit\"at Berlin
Takustr. 3
D-14195 Berlin
Germany
;
_publ_section_title
;
Hydrogen-Bonding Networks Involving Water in Amphiphilic
N-Dodecanoyl-L-serine Monohydrate
;
_journal_issue 8
_journal_name_full 'Acta Crystallographica Section C'
_journal_page_first 1070
_journal_page_last 1073
_journal_volume 53
_journal_year 1997
_chemical_formula_structural 'C15H29O4N ,H2O'
_chemical_formula_sum 'C15 H31 N O5'
_chemical_formula_weight 305.41
_chemical_name_systematic
;
N-Dodecanoyl-L-Serine
;
_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'
_audit_creation_method SHELXL
_cell_angle_alpha 90.000(10)
_cell_angle_beta 90.00(2)
_cell_angle_gamma 90.00(2)
_cell_formula_units_Z 4
_cell_length_a 4.934(2)
_cell_length_b 7.4220(10)
_cell_length_c 48.5610(10)
_cell_measurement_reflns_used 67
_cell_measurement_temperature 293(2)
_cell_measurement_theta_max 40
_cell_measurement_theta_min 30
_cell_volume 1778.3(8)
_computing_cell_refinement DIF4
_computing_data_collection 'DIF4 (Stoe & Cie, 1991a)'
_computing_data_reduction 'REDU4 (Stoe & Cie, 1991b)'
_computing_molecular_graphics
'ORTEPII (Johnson, 1977) and SCHAKAL88 (Keller, 1988)'
_computing_publication_material 'SHELXL-93_ACTA (Sheldrick, 1993)'
_computing_structure_refinement 'SHELXL-93 (Sheldrick, 1993)'
_computing_structure_solution 'SIR92 (Altomare et al., 1994)'
_diffrn_ambient_temperature 293(2)
_diffrn_measurement_device 'Stoe four-circle diffractometer'
_diffrn_measurement_method '\w/2\q '
_diffrn_radiation_monochromator no
_diffrn_radiation_source 'fine-focus sealed tube'
_diffrn_radiation_type 'Ni-filtered CuK\a '
_diffrn_radiation_wavelength 1.54180
_diffrn_reflns_av_R_equivalents 0.0210
_diffrn_reflns_av_sigmaI/netI 0.0324
_diffrn_reflns_limit_h_max 5
_diffrn_reflns_limit_h_min 0
_diffrn_reflns_limit_k_max 8
_diffrn_reflns_limit_k_min 0
_diffrn_reflns_limit_l_max 58
_diffrn_reflns_limit_l_min -58
_diffrn_reflns_number 3852
_diffrn_reflns_theta_max 67.91
_diffrn_reflns_theta_min 3.64
_diffrn_standards_decay_% 3
_diffrn_standards_interval_time 90
_diffrn_standards_number 3
_exptl_absorpt_coefficient_mu 0.689
_exptl_absorpt_correction_T_max 0.974
_exptl_absorpt_correction_T_min 0.803
_exptl_absorpt_correction_type
'analytical, program ABSORB in Xtal2.2 (Hall, Flack & Stewart, 1992) '
_exptl_crystal_colour colourless
_exptl_crystal_density_diffrn 1.141
_exptl_crystal_density_meas 'not measured'
_exptl_crystal_description plate
_exptl_crystal_F_000 672
_exptl_crystal_size_max 1.05
_exptl_crystal_size_mid 0.32
_exptl_crystal_size_min 0.04
_refine_diff_density_max 0.162
_refine_diff_density_min -0.141
_refine_ls_abs_structure_details 'Flack (1983)'
_refine_ls_abs_structure_Flack -0.0(2)
_refine_ls_extinction_coef 0.0022(3)
_refine_ls_extinction_method 'SHELXL93 (Sheldrick, 1993)'
_refine_ls_goodness_of_fit_all 1.091
_refine_ls_goodness_of_fit_obs 1.097
_refine_ls_hydrogen_treatment refall
_refine_ls_matrix_type full
_refine_ls_number_parameters 313
_refine_ls_number_reflns 3217
_refine_ls_number_restraints 0
_refine_ls_restrained_S_all 1.091
_refine_ls_restrained_S_obs 1.097
_refine_ls_R_factor_all 0.0558
_refine_ls_R_factor_obs 0.0336
_refine_ls_shift/esd_max 0.034
_refine_ls_shift/esd_mean 0.004
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_scheme
'calc w = 1/[\s^2^(Fo^2^)+(0.0392P)^2^+0.2463P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_wR_factor_all 0.0883
_refine_ls_wR_factor_obs 0.0787
_reflns_number_observed 2596
_reflns_number_total 3217
_reflns_observed_criterion >4sigma(Fo)
_[local]_cod_data_source_file sk1078.cif
_[local]_cod_data_source_block amie2
_[local]_cod_chemical_formula_sum_orig 'C15 H29 N O4, H2 O'
_cod_database_code 2006431
loop_
_symmetry_equiv_pos_as_xyz
'x, y, z'
'-x+1/2, -y, z+1/2'
'x+1/2, -y+1/2, -z'
'-x, y+1/2, -z+1/2'
loop_
_atom_site_aniso_label
_atom_site_aniso_U_11
_atom_site_aniso_U_22
_atom_site_aniso_U_33
_atom_site_aniso_U_12
_atom_site_aniso_U_13
_atom_site_aniso_U_23
O11 0.0436(8) 0.0423(7) 0.0725(9) 0.0058(6) -0.0117(7) -0.0015(7)
O12 0.0571(9) 0.0404(7) 0.0691(9) 0.0125(7) -0.0127(7) -0.0192(7)
O3 0.0619(10) 0.0478(8) 0.0463(8) -0.0079(8) 0.0089(7) -0.0092(7)
O4 0.0296(6) 0.0427(7) 0.0620(8) 0.0059(6) -0.0035(6) -0.0102(6)
N4 0.0293(8) 0.0378(8) 0.0461(8) 0.0013(7) -0.0006(7) -0.0068(7)
C1 0.0340(9) 0.0335(9) 0.0447(9) 0.0012(8) 0.0039(8) 0.0031(8)
C2 0.0284(9) 0.0337(9) 0.0452(10) -0.0003(7) 0.0020(7) -0.0065(7)
C3 0.0399(10) 0.0407(10) 0.0482(11) 0.0071(9) -0.0064(9) -0.0052(9)
C4 0.0327(10) 0.0323(8) 0.0396(8) 0.0028(8) 0.0018(7) 0.0000(7)
C5 0.0386(11) 0.0408(11) 0.0474(11) 0.0011(9) -0.0018(9) -0.0074(9)
C6 0.0408(11) 0.0380(10) 0.0533(11) 0.0014(8) 0.0005(9) -0.0102(9)
C7 0.0467(11) 0.0427(10) 0.0511(11) -0.0012(10) 0.0008(10) -0.0073(9)
C8 0.0543(12) 0.0392(11) 0.0589(12) 0.0016(10) -0.0043(10) -0.0131(10)
C9 0.0582(14) 0.0399(11) 0.0615(13) -0.0031(10) -0.0053(11) -0.0096(10)
C10 0.0652(14) 0.0403(11) 0.0635(13) 0.0001(12) -0.0029(12) -0.0133(10)
C11 0.073(2) 0.0427(12) 0.0647(15) -0.0012(12) -0.0049(13) -0.0128(11)
C12 0.073(2) 0.0462(13) 0.067(2) -0.0028(12) 0.0034(13) -0.0165(11)
C13 0.097(2) 0.0498(14) 0.067(2) -0.001(2) 0.000(2) -0.0167(12)
C14 0.124(3) 0.059(2) 0.086(2) 0.004(2) 0.019(2) -0.0252(14)
C15 0.206(6) 0.071(2) 0.101(3) -0.012(3) 0.032(3) -0.042(2)
O1W 0.0511(9) 0.0339(7) 0.0553(8) 0.0035(7) 0.0039(7) 0.0008(6)
loop_
_atom_site_label
_atom_site_fract_x
_atom_site_fract_y
_atom_site_fract_z
_atom_site_U_iso_or_equiv
_atom_site_thermal_displace_type
_atom_site_calc_flag
_atom_site_occupancy
_atom_site_type_symbol
O11 0.9523(3) -0.4640(2) 0.31731(3) 0.0528(4) Uani d 1 O
O12 0.6643(3) -0.5877(2) 0.28766(3) 0.0555(4) Uani d 1 O
O3 0.7879(3) -0.1686(2) 0.26363(3) 0.0520(4) Uani d 1 O
O4 0.2471(3) -0.0304(2) 0.32571(3) 0.0447(3) Uani d 1 O
N4 0.6579(3) -0.1578(2) 0.32158(3) 0.0377(4) Uani d 1 N
C1 0.7494(4) -0.4565(2) 0.30387(4) 0.0374(4) Uani d 1 C
C2 0.5613(4) -0.2967(2) 0.30293(4) 0.0357(4) Uani d 1 C
C3 0.5322(4) -0.2272(3) 0.27349(4) 0.0429(4) Uani d 1 C
C4 0.4921(4) -0.0311(2) 0.33158(3) 0.0348(4) Uani d 1 C
C5 0.6156(4) 0.1090(3) 0.35020(4) 0.0423(5) Uani d 1 C
C6 0.4204(4) 0.2571(3) 0.35811(4) 0.0440(5) Uani d 1 C
C7 0.5448(5) 0.4011(3) 0.37647(5) 0.0469(5) Uani d 1 C
C8 0.3437(5) 0.5475(3) 0.38424(5) 0.0508(5) Uani d 1 C
C9 0.4604(5) 0.6938(3) 0.40255(5) 0.0532(5) Uani d 1 C
C10 0.2549(6) 0.8360(3) 0.41083(5) 0.0563(5) Uani d 1 C
C11 0.3684(6) 0.9826(3) 0.42949(5) 0.0600(6) Uani d 1 C
C12 0.1635(6) 1.1224(3) 0.43815(6) 0.0622(7) Uani d 1 C
C13 0.2765(7) 1.2700(3) 0.45637(6) 0.0714(7) Uani d 1 C
C14 0.0798(8) 1.4119(4) 0.46492(7) 0.0894(10) Uani d 1 C
C15 0.2040(16) 1.5568(6) 0.48300(10) 0.126(2) Uani d 1 C
H12O 0.804(6) -0.671(4) 0.2863(6) 0.093(9) Uiso d 1 H
H3O 0.813(6) -0.224(3) 0.2501(6) 0.073(9) Uiso d 1 H
H4N 0.830(4) -0.150(3) 0.3242(4) 0.035(5) Uiso d 1 H
H2 0.373(4) -0.333(2) 0.3083(3) 0.032(4) Uiso d 1 H
H3A 0.397(5) -0.122(3) 0.2733(4) 0.058(6) Uiso d 1 H
H3B 0.456(4) -0.327(3) 0.2620(4) 0.042(5) Uiso d 1 H
H5A 0.681(5) 0.054(3) 0.3662(4) 0.052(6) Uiso d 1 H
H5B 0.774(5) 0.153(3) 0.3410(4) 0.056(6) Uiso d 1 H
H6A 0.260(5) 0.208(3) 0.3680(4) 0.055(6) Uiso d 1 H
H6B 0.340(5) 0.316(4) 0.3398(5) 0.073(7) Uiso d 1 H
H7A 0.616(5) 0.350(3) 0.3922(5) 0.057(6) Uiso d 1 H
H7B 0.708(5) 0.453(3) 0.3671(4) 0.058(6) Uiso d 1 H
H8A 0.181(5) 0.492(3) 0.3935(5) 0.060(7) Uiso d 1 H
H8B 0.278(5) 0.603(3) 0.3657(5) 0.062(6) Uiso d 1 H
H9A 0.540(6) 0.641(3) 0.4192(5) 0.077(8) Uiso d 1 H
H9B 0.628(6) 0.749(3) 0.3943(5) 0.076(8) Uiso d 1 H
H10A 0.190(5) 0.894(3) 0.3937(5) 0.061(7) Uiso d 1 H
H10B 0.101(6) 0.778(3) 0.4188(5) 0.072(8) Uiso d 1 H
H11A 0.523(6) 1.048(3) 0.4192(5) 0.068(7) Uiso d 1 H
H11B 0.443(5) 0.926(3) 0.4461(5) 0.064(7) Uiso d 1 H
H12A 0.011(8) 1.058(5) 0.4478(7) 0.122(12) Uiso d 1 H
H12B 0.100(7) 1.174(4) 0.4211(7) 0.099(10) Uiso d 1 H
H13A 0.427(7) 1.321(5) 0.4478(7) 0.104(12) Uiso d 1 H
H13B 0.348(6) 1.211(4) 0.4735(7) 0.101(10) Uiso d 1 H
H14A 0.015(8) 1.464(5) 0.4459(7) 0.121 Uiso d 1 H
H14B -0.085(8) 1.342(5) 0.4747(7) 0.121 Uiso d 1 H
H15A 0.353(10) 1.620(6) 0.4726(9) 0.152(19) Uiso d 1 H
H15B 0.092(10) 1.629(7) 0.4885(9) 0.15(2) Uiso d 1 H
H15C 0.264(9) 1.501(5) 0.5005(8) 0.128(15) Uiso d 1 H
O1W 0.0114(3) 0.1433(2) 0.28131(3) 0.0468(3) Uani d 1 O
H1W -0.065(6) 0.059(4) 0.2753(6) 0.079(10) Uiso d 1 H
H2W 0.107(7) 0.105(5) 0.2972(7) 0.120(12) Uiso d 1 H
loop_
_atom_type_symbol
_atom_type_description
_atom_type_scat_dispersion_real
_atom_type_scat_dispersion_imag
_atom_type_scat_source
N N 0.0311 0.0180 'International Tables Vol C Tables 4.2.6.8 and 6.1.1.4'
C C 0.0181 0.0091 'International Tables Vol C Tables 4.2.6.8 and 6.1.1.4'
H H 0.0000 0.0000 'International Tables Vol C Tables 4.2.6.8 and 6.1.1.4'
O O 0.0492 0.0322 'International Tables Vol C Tables 4.2.6.8 and 6.1.1.4'
loop_
_geom_angle_atom_site_label_1
_geom_angle_atom_site_label_2
_geom_angle_atom_site_label_3
_geom_angle_site_symmetry_2
_geom_angle_site_symmetry_3
_geom_angle
_geom_angle_publ_flag
C1 O12 H12O . . 107.3(18) ?
C3 O3 H3O . . 105.(2) ?
C4 N4 C2 . . 121.6(2) ?
C4 N4 H4N . . 120.0(14) ?
C2 N4 H4N . . 117.7(13) ?
O11 C1 O12 . . 123.8(2) ?
O11 C1 C2 . . 124.7(2) ?
O12 C1 C2 . . 111.5(2) ?
N4 C2 C1 . . 109.72(15) ?
N4 C2 C3 . . 112.0(2) ?
C1 C2 C3 . . 110.63(15) ?
N4 C2 H2 . . 109.3(10) ?
C1 C2 H2 . . 110.7(11) ?
C3 C2 H2 . . 104.3(9) ?
O3 C3 C2 . . 109.7(2) ?
O3 C3 H3A . . 110.1(12) ?
C2 C3 H3A . . 109.1(12) ?
O3 C3 H3B . . 112.0(11) ?
C2 C3 H3B . . 107.8(10) ?
H3A C3 H3B . . 108.1(16) ?
O4 C4 N4 . . 121.0(2) ?
O4 C4 C5 . . 121.9(2) ?
N4 C4 C5 . . 117.1(2) ?
C4 C5 C6 . . 113.4(2) ?
C4 C5 H5A . . 109.6(13) ?
C6 C5 H5A . . 109.1(13) ?
C4 C5 H5B . . 106.5(13) ?
C6 C5 H5B . . 113.2(14) ?
H5A C5 H5B . . 104.7(19) ?
C5 C6 C7 . . 113.8(2) ?
C5 C6 H6A . . 111.1(13) ?
C7 C6 H6A . . 107.4(12) ?
C5 C6 H6B . . 108.7(14) ?
C7 C6 H6B . . 110.7(14) ?
H6A C6 H6B . . 104.8(18) ?
C8 C7 C6 . . 112.6(2) ?
C8 C7 H7A . . 109.6(14) ?
C6 C7 H7A . . 110.5(15) ?
C8 C7 H7B . . 111.4(14) ?
C6 C7 H7B . . 109.1(13) ?
H7A C7 H7B . . 103.(2) ?
C9 C8 C7 . . 114.2(2) ?
C9 C8 H8A . . 109.6(13) ?
C7 C8 H8A . . 109.7(13) ?
C9 C8 H8B . . 109.8(13) ?
C7 C8 H8B . . 105.9(13) ?
H8A C8 H8B . . 107.5(19) ?
C8 C9 C10 . . 113.5(2) ?
C8 C9 H9A . . 110.3(15) ?
C10 C9 H9A . . 109.1(16) ?
C8 C9 H9B . . 111.8(15) ?
C10 C9 H9B . . 111.7(15) ?
H9A C9 H9B . . 100.(2) ?
C9 C10 C11 . . 114.1(2) ?
C9 C10 H10A . . 107.2(14) ?
C11 C10 H10A . . 107.9(14) ?
C9 C10 H10B . . 109.1(15) ?
C11 C10 H10B . . 111.8(15) ?
H10A C10 H10B . . 106.(2) ?
C12 C11 C10 . . 114.3(2) ?
C12 C11 H11A . . 107.8(14) ?
C10 C11 H11A . . 108.7(14) ?
C12 C11 H11B . . 108.4(14) ?
C10 C11 H11B . . 108.9(14) ?
H11A C11 H11B . . 109.(2) ?
C11 C12 C13 . . 114.4(2) ?
C11 C12 H12A . . 108.(2) ?
C13 C12 H12A . . 110.3(19) ?
C11 C12 H12B . . 104.8(19) ?
C13 C12 H12B . . 109.3(19) ?
H12A C12 H12B . . 110.(3) ?
C14 C13 C12 . . 115.7(3) ?
C14 C13 H13A . . 111.(2) ?
C12 C13 H13A . . 109.(2) ?
C14 C13 H13B . . 107.8(18) ?
C12 C13 H13B . . 107.4(18) ?
H13A C13 H13B . . 105.(3) ?
C13 C14 C15 . . 113.5(4) ?
C13 C14 H14A . . 102.3(19) ?
C15 C14 H14A . . 112.(2) ?
C13 C14 H14B . . 106.(2) ?
C15 C14 H14B . . 112.9(19) ?
H14A C14 H14B . . 110.(3) ?
C14 C15 H15A . . 110.(3) ?
C14 C15 H15B . . 113.(4) ?
H15A C15 H15B . . 111.(4) ?
C14 C15 H15C . . 109.(2) ?
H15A C15 H15C . . 114.(4) ?
H15B C15 H15C . . 101.(4) ?
H1W O1W H2W . . 108.(3) no
C2 H2 O11 . 1_455 170.0(10) no
C1 O11 H2 . 1_655 128.5(4) no
O12 H12O O1W . 1_645 168(3) no
H12O O1W H1W 1_645 1_645 114(2) no
H12O O1W H2W 1_645 1_645 115(2) no
O1W H1W O3 . 1_455 171(3) no
C3 O3 H1W . 1_655 120.4(9) no
O3 H3O O1W . 4_645 163(3) no
H3O O1W H1W 4_645 4_645 108(2) no
H3O O1W H2W 4_645 4_645 124(3) no
N4 H4N O4 . 1_655 160(2) no
C4 O4 H4N . 1_455 154.1(5) no
O1W H2W O4 . . 164(3) no
C4 O4 H2W . . 123.0(10) no
loop_
_geom_bond_atom_site_label_1
_geom_bond_atom_site_label_2
_geom_bond_site_symmetry_2
_geom_bond_distance
_geom_bond_publ_flag
O11 C1 . 1.196(2) yes
O12 C1 . 1.321(2) yes
O12 H12O . 0.93(3) ?
O3 C3 . 1.418(3) yes
O3 H3O . 0.79(3) ?
O4 C4 . 1.242(2) yes
N4 C4 . 1.337(2) yes
N4 C2 . 1.453(2) yes
N4 H4N . 0.86(2) ?
C1 C2 . 1.507(2) yes
C2 C3 . 1.527(3) yes
C2 H2 . 1.00(2) ?
C3 H3A . 1.03(2) ?
C3 H3B . 1.00(2) ?
C4 C5 . 1.507(3) yes
C5 C6 . 1.511(3) yes
C5 H5A . 0.94(2) ?
C5 H5B . 0.96(2) ?
C6 C7 . 1.521(3) yes
C6 H6A . 0.99(2) ?
C6 H6B . 1.07(2) ?
C7 C8 . 1.519(3) yes
C7 H7A . 0.92(2) ?
C7 H7B . 1.00(2) ?
C8 C9 . 1.518(3) yes
C8 H8A . 1.01(3) ?
C8 H8B . 1.04(2) ?
C9 C10 . 1.518(3) yes
C9 H9A . 0.98(3) ?
C9 H9B . 1.00(3) ?
C10 C11 . 1.523(3) yes
C10 H10A . 0.99(2) ?
C10 H10B . 0.96(3) ?
C11 C12 . 1.509(3) yes
C11 H11A . 1.03(3) ?
C11 H11B . 0.98(2) ?
C12 C13 . 1.514(3) yes
C12 H12A . 1.01(4) ?
C12 H12B . 0.96(3) ?
C13 C14 . 1.491(4) yes
C13 H13A . 0.93(3) ?
C13 H13B . 1.00(3) ?
C14 C15 . 1.518(5) yes
C14 H14A . 1.05(3) ?
C14 H14B . 1.07(4) ?
C15 H15A . 1.01(5) ?
C15 H15B . 0.82(5) ?
C15 H15C . 0.99(4) ?
O1W H1W . 0.79(3) ?
O1W H2W . 0.95(4) ?
C2 O11 1_455 3.325(3) no
H2 O11 1_455 2.33(2) no
O12 O1W 1_645 2.649(2) no
H12O O1W 1_645 1.73(3) no
O1W O3 1_455 2.704(2) no
H1W O3 1_455 1.92(3) no
O3 O1W 4_645 2.774(2) no
H3O O1W 4_645 2.01(3) no
N4 O4 1_655 3.063(2) no
H4N O4 1_655 2.24(2) no
O1W O4 . 2.768(2) no
H2W O4 . 1.85(4) no
loop_
_geom_torsion_atom_site_label_1
_geom_torsion_atom_site_label_2
_geom_torsion_atom_site_label_3
_geom_torsion_atom_site_label_4
_geom_torsion
_geom_torsion_publ_flag
C4 N4 C2 C1 -157.8(2) yes
C4 N4 C2 C3 78.9(2) ?
O11 C1 C2 N4 -2.3(3) ?
O12 C1 C2 N4 178.4(2) yes
O11 C1 C2 C3 121.7(2) ?
O12 C1 C2 C3 -57.5(2) ?
N4 C2 C3 O3 60.9(2) yes
C1 C2 C3 O3 -61.9(2) yes
H4N N4 C4 O4 170.2(3) yes
C2 N4 C4 O4 1.7(3) ?
C2 N4 C4 C5 -178.5(2) ?
O4 C4 C5 C6 -6.1(3) ?
N4 C4 C5 C6 174.0(2) ?
C4 C5 C6 C7 -178.9(2) ?
C5 C6 C7 C8 -179.6(2) ?
C6 C7 C8 C9 -180.0(2) ?
C7 C8 C9 C10 -178.3(2) ?
C8 C9 C10 C11 179.3(2) ?
C9 C10 C11 C12 -179.0(2) ?
C10 C11 C12 C13 -179.1(2) ?
C11 C12 C13 C14 179.1(3) ?
C12 C13 C14 C15 -179.7(3) ?