#------------------------------------------------------------------------------ #$Date: 2025-08-19 15:49:58 +0100 (Tue, 19 Aug 2025) $ #$Revision: 301806 $ #$URL: svn://www.crystallography.net/cod/cif/2/23/90/2239079.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_2239079 loop_ _publ_author_name 'Sreeja, P. B.' 'Sithambaresan, M.' 'Aiswarya, N.' 'Kurup, M. R. Prathapachandra' _publ_section_title ; N'-[(1E)-1-(2-Fluorophenyl)ethylidene]pyridine-3-carbohydrazide ; _journal_issue 2 _journal_name_full 'Acta Crystallographica Section E' _journal_page_first o115 _journal_paper_doi 10.1107/S1600536813035009 _journal_volume 70 _journal_year 2014 _chemical_formula_moiety 'C14 H12 F N3 O' _chemical_formula_sum 'C14 H12 F N3 O' _chemical_formula_weight 257.27 _chemical_name_systematic ; N'-[(1E)-1-(2-Fluorophenyl)ethylidene]pyridine-3-carbohydrazide ; _space_group_IT_number 60 _symmetry_cell_setting orthorhombic _symmetry_space_group_name_Hall '-P 2n 2ab' _symmetry_space_group_name_H-M 'P b c n' _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 18.926(3) _cell_length_b 8.0486(9) _cell_length_c 16.337(3) _cell_measurement_reflns_used 2433 _cell_measurement_temperature 296(2) _cell_measurement_theta_max 22.644 _cell_measurement_theta_min 2.493 _cell_volume 2488.6(7) _computing_cell_refinement 'APEX2 and SAINT (Bruker, 2004)' _computing_data_collection 'APEX2 (Bruker, 2004)' _computing_data_reduction 'SAINT and XPREP (Bruker, 2004)' _computing_molecular_graphics ; ORTEP-3 for Windows (Farrugia, 2012) and DIAMOND (Brandenburg, 2010) ; _computing_publication_material 'SHELXL-97 (Sheldrick, 2008) and publCIF (Westrip, 2010)' _computing_structure_refinement 'SHELXL-97 (Sheldrick, 2008)' _computing_structure_solution 'SHELXS-97 (Sheldrick, 2008)' _diffrn_ambient_temperature 296(2) _diffrn_detector_area_resol_mean 8.33 _diffrn_measured_fraction_theta_full 0.997 _diffrn_measured_fraction_theta_max 0.997 _diffrn_measurement_device_type 'Bruker ApexII CCD' _diffrn_measurement_method '\w and \f scan' _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 0.0561 _diffrn_reflns_av_sigmaI/netI 0.0408 _diffrn_reflns_limit_h_max 25 _diffrn_reflns_limit_h_min -24 _diffrn_reflns_limit_k_max 10 _diffrn_reflns_limit_k_min -10 _diffrn_reflns_limit_l_max 21 _diffrn_reflns_limit_l_min -21 _diffrn_reflns_number 19111 _diffrn_reflns_theta_full 28.00 _diffrn_reflns_theta_max 28.00 _diffrn_reflns_theta_min 2.49 _diffrn_standards_number 0 _exptl_absorpt_coefficient_mu 0.100 _exptl_absorpt_correction_T_max 0.9803 _exptl_absorpt_correction_T_min 0.9517 _exptl_absorpt_correction_type multi-scan _exptl_absorpt_process_details '(SADABS; Bruker, 2004)' _exptl_crystal_colour colourless _exptl_crystal_density_diffrn 1.373 _exptl_crystal_density_method 'not measured' _exptl_crystal_description needle _exptl_crystal_F_000 1072 _exptl_crystal_size_max 0.50 _exptl_crystal_size_mid 0.25 _exptl_crystal_size_min 0.20 _refine_diff_density_max 0.285 _refine_diff_density_min -0.223 _refine_ls_extinction_coef 0.0048(13) _refine_ls_extinction_expression Fc^*^=kFc[1+0.001xFc^2^\l^3^/sin(2\q)]^-1/4^ _refine_ls_extinction_method SHELXL _refine_ls_goodness_of_fit_ref 1.012 _refine_ls_hydrogen_treatment mixed _refine_ls_matrix_type full _refine_ls_number_parameters 188 _refine_ls_number_reflns 2999 _refine_ls_number_restraints 1 _refine_ls_restrained_S_all 1.012 _refine_ls_R_factor_all 0.0978 _refine_ls_R_factor_gt 0.0508 _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^)+(0.0806P)^2^+0.3159P] where P=(Fo^2^+2Fc^2^)/3' _refine_ls_weighting_scheme calc _refine_ls_wR_factor_gt 0.1294 _refine_ls_wR_factor_ref 0.1608 _reflns_number_gt 1755 _reflns_number_total 3009 _reflns_threshold_expression >2sigma(I) _iucr_refine_instructions_details ; TITL B_sreeja in Pbcn CELL 0.71073 18.9260 8.0486 16.3375 90.000 90.000 90.000 ZERR 8.00 0.0025 0.0009 0.0025 0.000 0.000 0.000 LATT 1 SYMM 1/2 + X, 1/2 - Y, - Z SYMM - X, Y, 1/2 - Z SYMM 1/2 - X, 1/2 - Y, 1/2 + Z SFAC C H N O F UNIT 112 96 24 8 8 MERG 2 OMIT 2 2 3 OMIT 5 2 1 OMIT 2 0 0 OMIT -3.00 56.00 L.S. 20 EXTI 0.00479 ACTA BOND $H FMAP 2 PLAN 7 CONF EQIV $1 -x+1/2, y-1/2, z HTAB N2 O1_$1 HTAB N2 N1_$1 HTAB DFIX 0.88 0.01 N2 H2' SIZE 0.20 0.25 0.50 WGHT 0.080600 0.315900 FVAR 0.129360 0.632120 TEMP 23.00 O1 4 0.163694 1.084913 0.928950 11.000000 0.059440 0.034500 = 0.075210 -0.011240 -0.012760 0.011620 N1 3 0.282974 1.043039 1.013010 11.000000 0.049530 0.024680 = 0.039350 -0.002220 -0.002250 -0.005680 N2 3 0.252495 0.914845 0.969430 11.000000 0.049950 0.022230 = 0.043090 -0.003130 -0.007010 -0.000380 N3 3 0.056709 0.661897 0.841937 11.000000 0.072430 0.092420 = 0.083370 -0.022530 -0.006470 -0.024470 PART 1 F1 5 0.264047 1.248920 1.148153 21.000000 0.043370 0.059950 = 0.063930 -0.018580 0.005800 0.000940 PART 2 F1B 5 0.482012 1.107196 1.049349 -21.000000 0.053020 0.072050 = 0.103140 -0.023430 0.025940 -0.003930 PART 0 C6 1 0.442691 1.191904 1.092376 11.000000 0.050690 0.050760 = 0.058320 -0.002680 0.001980 -0.008520 PART 1 AFIX 43 H6 2 0.471888 1.118044 1.064585 21.000000 -1.200000 AFIX 0 PART 0 C2 1 0.330594 1.272837 1.138574 11.000000 0.050790 0.040640 = 0.042600 -0.003170 -0.005580 0.001480 PART 2 AFIX 43 H2 2 0.282204 1.254823 1.142952 -21.000000 -1.200000 AFIX 0 PART 0 C5 1 0.472601 1.328806 1.128989 11.000000 0.057920 0.055920 = 0.087680 -0.004100 -0.014570 -0.017980 AFIX 43 H5 2 0.521077 1.346612 1.125850 11.000000 -1.200000 AFIX 0 C4 1 0.430393 1.438144 1.169944 11.000000 0.079810 0.049470 = 0.085960 -0.011280 -0.031550 -0.014060 AFIX 43 H4 2 0.450133 1.531739 1.194263 11.000000 -1.200000 AFIX 0 C3 1 0.359201 1.410983 1.175470 11.000000 0.085100 0.041190 = 0.062070 -0.018180 -0.015690 0.009520 AFIX 43 H3 2 0.330487 1.485007 1.203825 11.000000 -1.200000 AFIX 0 C1 1 0.370910 1.159645 1.095225 11.000000 0.047940 0.030570 = 0.034740 0.000930 -0.001910 -0.005890 C7 1 0.339783 1.013554 1.052368 11.000000 0.042320 0.030670 = 0.038380 -0.000910 0.003430 -0.004090 C8 1 0.377634 0.850435 1.057625 11.000000 0.052760 0.037410 = 0.075110 -0.011710 -0.009740 0.005020 AFIX 137 H8A 2 0.344124 0.763466 1.068119 11.000000 -1.500000 H8B 2 0.411556 0.854389 1.101269 11.000000 -1.500000 H8C 2 0.401479 0.828921 1.006857 11.000000 -1.500000 AFIX 0 C9 1 0.192123 0.948677 0.928666 11.000000 0.047940 0.026210 = 0.041730 -0.002120 -0.000150 -0.000090 C10 1 0.161415 0.808491 0.880310 11.000000 0.044880 0.030470 = 0.036760 0.001830 -0.005860 0.000060 C11 1 0.089703 0.782219 0.883505 11.000000 0.048950 0.056130 = 0.058420 -0.010760 -0.003150 -0.001990 AFIX 43 H11 2 0.062650 0.851907 0.916362 11.000000 -1.200000 AFIX 0 C12 1 0.098286 0.565316 0.794766 11.000000 0.106160 0.073900 = 0.068650 -0.023890 -0.011980 -0.032990 AFIX 43 H12 2 0.076883 0.479507 0.765808 11.000000 -1.200000 AFIX 0 C13 1 0.169348 0.584535 0.786540 11.000000 0.083250 0.047710 = 0.049230 -0.019440 0.000340 -0.003410 AFIX 43 H13 2 0.195371 0.515550 0.752239 11.000000 -1.200000 AFIX 0 C14 1 0.201241 0.707952 0.830092 11.000000 0.049600 0.042820 = 0.045650 -0.007010 -0.001890 -0.001280 AFIX 43 H14 2 0.249756 0.724219 0.825907 11.000000 -1.200000 AFIX 0 H2' 2 0.269194 0.813664 0.972178 11.000000 0.051020 HKLF 4 1.0 1.00 0.00 0.00 0.00 1.00 0.00 0.00 0.00 1.00 END Q1 1 0.144300 0.540700 0.795500 11.000000 0.050000 0.28 Q2 1 0.177700 0.860900 0.903000 11.000000 0.050000 0.23 Q3 1 0.357700 1.093600 1.073700 11.000000 0.050000 0.22 Q4 1 0.176300 0.659300 0.792000 11.000000 0.050000 0.22 Q5 1 0.191200 0.518200 0.793500 11.000000 0.050000 0.22 Q6 1 0.180200 0.600800 0.828000 11.000000 0.050000 0.22 Q7 1 0.353000 1.198700 1.121700 11.000000 0.050000 0.20 ; _cod_data_source_file zl2571sup1.cif _cod_data_source_block I _cod_database_code 2239079 _cod_database_fobs_code 2239079 loop_ _symmetry_equiv_pos_as_xyz 'x, y, z' 'x+1/2, -y+1/2, -z' '-x, y, -z+1/2' '-x+1/2, -y+1/2, z+1/2' '-x, -y, -z' '-x-1/2, y-1/2, z' 'x, -y, z-1/2' 'x-1/2, y-1/2, -z-1/2' loop_ _atom_site_type_symbol _atom_site_label _atom_site_fract_x _atom_site_fract_y _atom_site_fract_z _atom_site_U_iso_or_equiv _atom_site_adp_type _atom_site_calc_flag _atom_site_refinement_flags _atom_site_occupancy _atom_site_symmetry_multiplicity _atom_site_disorder_assembly _atom_site_disorder_group O O1 0.16369(8) 1.08491(17) 0.92895(10) 0.0564(5) Uani d . 1 1 . . N N1 0.28297(9) 1.04304(17) 1.01301(10) 0.0379(4) Uani d . 1 1 A . N N2 0.25250(9) 0.91485(18) 0.96943(10) 0.0384(4) Uani d D 1 1 . . N N3 0.05671(13) 0.6619(3) 0.84194(16) 0.0827(8) Uani d . 1 1 . . F F1 0.26405(10) 1.2489(2) 1.14815(13) 0.0557(7) Uani d P 0.632(4) 1 A 1 F F1B 0.4820(2) 1.1072(5) 1.0493(3) 0.0761(16) Uani d P 0.368(4) 1 A 2 C C6 0.44269(12) 1.1919(3) 1.09238(15) 0.0533(6) Uani d . 1 1 . . H H6 0.4719 1.1180 1.0646 0.064 Uiso calc PR 0.632(4) 1 A 1 C C2 0.33059(12) 1.2728(2) 1.13857(13) 0.0447(5) Uani d . 1 1 . . H H2 0.2822 1.2548 1.1430 0.054 Uiso calc PR 0.368(4) 1 A 2 C C5 0.47260(14) 1.3288(3) 1.12899(17) 0.0672(7) Uani d . 1 1 A . H H5 0.5211 1.3466 1.1259 0.081 Uiso calc R 1 1 . . C C4 0.43039(15) 1.4381(3) 1.16994(18) 0.0717(8) Uani d . 1 1 . . H H4 0.4501 1.5317 1.1943 0.086 Uiso calc R 1 1 A . C C3 0.35920(15) 1.4110(3) 1.17547(16) 0.0628(7) Uani d . 1 1 A . H H3 0.3305 1.4850 1.2038 0.075 Uiso calc R 1 1 . . C C1 0.37091(10) 1.1596(2) 1.09523(12) 0.0378(5) Uani d . 1 1 A . C C7 0.33978(10) 1.0136(2) 1.05237(12) 0.0371(4) Uani d . 1 1 . . C C8 0.37763(12) 0.8504(2) 1.05763(16) 0.0551(6) Uani d . 1 1 A . H H8A 0.3441 0.7635 1.0681 0.083 Uiso calc R 1 1 . . H H8B 0.4116 0.8544 1.1013 0.083 Uiso calc R 1 1 . . H H8C 0.4015 0.8289 1.0069 0.083 Uiso calc R 1 1 . . C C9 0.19212(11) 0.9487(2) 0.92867(12) 0.0386(5) Uani d . 1 1 . . C C10 0.16141(11) 0.8085(2) 0.88031(11) 0.0374(5) Uani d . 1 1 . . C C11 0.08970(12) 0.7822(3) 0.88351(15) 0.0545(6) Uani d . 1 1 . . H H11 0.0626 0.8519 0.9164 0.065 Uiso calc R 1 1 . . C C12 0.09829(18) 0.5653(4) 0.79477(19) 0.0829(9) Uani d . 1 1 . . H H12 0.0769 0.4795 0.7658 0.099 Uiso calc R 1 1 . . C C13 0.16935(14) 0.5845(3) 0.78654(15) 0.0601(6) Uani d . 1 1 . . H H13 0.1954 0.5155 0.7522 0.072 Uiso calc R 1 1 . . C C14 0.20124(11) 0.7080(2) 0.83009(13) 0.0460(5) Uani d . 1 1 . . H H14 0.2498 0.7242 0.8259 0.055 Uiso calc R 1 1 . . H H2' 0.2692(10) 0.8137(15) 0.9722(14) 0.051(6) Uiso d D 1 1 . . 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 O1 0.0594(10) 0.0345(8) 0.0752(12) 0.0116(7) -0.0128(8) -0.0112(7) N1 0.0495(10) 0.0247(7) 0.0393(9) -0.0057(7) -0.0023(8) -0.0022(6) N2 0.0499(10) 0.0222(7) 0.0431(9) -0.0004(7) -0.0070(8) -0.0031(6) N3 0.0724(15) 0.0924(17) 0.0834(18) -0.0245(13) -0.0065(13) -0.0225(14) F1 0.0434(13) 0.0599(13) 0.0639(14) 0.0009(9) 0.0058(9) -0.0186(10) F1B 0.053(2) 0.072(3) 0.103(3) -0.0039(19) 0.026(2) -0.023(2) C6 0.0507(13) 0.0508(13) 0.0583(14) -0.0085(11) 0.0020(11) -0.0027(11) C2 0.0508(13) 0.0406(11) 0.0426(11) 0.0015(9) -0.0056(10) -0.0032(8) C5 0.0579(15) 0.0559(14) 0.088(2) -0.0180(12) -0.0146(14) -0.0041(13) C4 0.0798(19) 0.0495(14) 0.086(2) -0.0141(13) -0.0316(16) -0.0113(13) C3 0.0851(19) 0.0412(12) 0.0621(15) 0.0095(12) -0.0157(13) -0.0182(11) C1 0.0479(12) 0.0306(9) 0.0347(10) -0.0059(8) -0.0019(9) 0.0009(7) C7 0.0423(11) 0.0307(9) 0.0384(10) -0.0041(8) 0.0034(9) -0.0009(7) C8 0.0528(13) 0.0374(11) 0.0751(16) 0.0050(10) -0.0097(12) -0.0117(10) C9 0.0479(11) 0.0262(9) 0.0417(11) -0.0001(8) -0.0002(9) -0.0021(7) C10 0.0449(11) 0.0305(9) 0.0368(10) 0.0001(8) -0.0059(8) 0.0018(7) C11 0.0489(13) 0.0561(13) 0.0584(15) -0.0020(11) -0.0031(11) -0.0108(11) C12 0.106(2) 0.0739(18) 0.0687(18) -0.0330(18) -0.0120(17) -0.0239(15) C13 0.0832(18) 0.0477(12) 0.0492(13) -0.0034(12) 0.0003(12) -0.0194(10) C14 0.0496(12) 0.0428(11) 0.0457(12) -0.0013(9) -0.0019(10) -0.0070(9) loop_ _atom_type_symbol _atom_type_description _atom_type_scat_dispersion_real _atom_type_scat_dispersion_imag _atom_type_scat_source C C 0.0033 0.0016 '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' N N 0.0061 0.0033 'International Tables Vol C Tables 4.2.6.8 and 6.1.1.4' O O 0.0106 0.0060 'International Tables Vol C Tables 4.2.6.8 and 6.1.1.4' F F 0.0171 0.0103 '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 C7 N1 N2 118.26(15) C9 N2 N1 117.22(15) C9 N2 H2' 121.3(14) N1 N2 H2' 121.2(14) C11 N3 C12 115.8(2) F1B C6 C5 116.3(3) F1B C6 C1 120.6(3) C5 C6 C1 122.7(2) F1B C6 H6 6.8 C5 C6 H6 118.7 C1 C6 H6 118.7 F1 C2 C3 117.0(2) F1 C2 C1 120.32(19) C3 C2 C1 122.6(2) F1 C2 H2 2.6 C3 C2 H2 118.7 C1 C2 H2 118.7 C4 C5 C6 119.3(2) C4 C5 H5 120.4 C6 C5 H5 120.4 C5 C4 C3 120.4(2) C5 C4 H4 119.8 C3 C4 H4 119.8 C4 C3 C2 119.2(2) C4 C3 H3 120.4 C2 C3 H3 120.4 C2 C1 C6 115.79(18) C2 C1 C7 122.84(18) C6 C1 C7 121.36(18) N1 C7 C1 115.06(16) N1 C7 C8 126.53(17) C1 C7 C8 118.40(17) C7 C8 H8A 109.5 C7 C8 H8B 109.5 H8A C8 H8B 109.5 C7 C8 H8C 109.5 H8A C8 H8C 109.5 H8B C8 H8C 109.5 O1 C9 N2 123.50(17) O1 C9 C10 120.55(18) N2 C9 C10 115.94(15) C11 C10 C14 118.21(19) C11 C10 C9 118.68(18) C14 C10 C9 123.06(18) N3 C11 C10 123.6(2) N3 C11 H11 118.2 C10 C11 H11 118.2 N3 C12 C13 124.6(2) N3 C12 H12 117.7 C13 C12 H12 117.7 C12 C13 C14 118.0(2) C12 C13 H13 121.0 C14 C13 H13 121.0 C13 C14 C10 119.8(2) C13 C14 H14 120.1 C10 C14 H14 120.1 loop_ _geom_bond_atom_site_label_1 _geom_bond_atom_site_label_2 _geom_bond_distance O1 C9 1.221(2) N1 C7 1.275(2) N1 N2 1.380(2) N2 C9 1.350(3) N2 H2' 0.875(9) N3 C11 1.338(3) N3 C12 1.348(4) F1 C2 1.284(3) F1B C6 1.230(4) C6 C5 1.376(3) C6 C1 1.384(3) C6 H6 0.9300 C2 C3 1.376(3) C2 C1 1.383(3) C2 H2 0.9300 C5 C4 1.364(4) C5 H5 0.9300 C4 C3 1.368(4) C4 H4 0.9300 C3 H3 0.9300 C1 C7 1.490(3) C7 C8 1.498(3) C8 H8A 0.9600 C8 H8B 0.9600 C8 H8C 0.9600 C9 C10 1.495(3) C10 C11 1.375(3) C10 C14 1.377(3) C11 H11 0.9300 C12 C13 1.360(4) C12 H12 0.9300 C13 C14 1.363(3) C13 H13 0.9300 C14 H14 0.9300 loop_ _geom_hbond_atom_site_label_D _geom_hbond_atom_site_label_H _geom_hbond_atom_site_label_A _geom_hbond_site_symmetry_A _geom_hbond_distance_DH _geom_hbond_distance_HA _geom_hbond_distance_DA _geom_hbond_angle_DHA N2 H2' O1 6_655 0.875(9) 2.346(13) 3.163(2) 156(2) N2 H2' N1 6_655 0.875(9) 2.483(17) 3.148(2) 133.4(17) 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 C7 N1 N2 C9 179.58(18) F1B C6 C5 C4 172.7(4) C1 C6 C5 C4 0.0(4) C6 C5 C4 C3 0.8(4) C5 C4 C3 C2 -0.6(4) F1 C2 C3 C4 177.3(2) C1 C2 C3 C4 -0.5(4) F1 C2 C1 C6 -176.5(2) C3 C2 C1 C6 1.2(3) F1 C2 C1 C7 4.8(3) C3 C2 C1 C7 -177.5(2) F1B C6 C1 C2 -173.4(3) C5 C6 C1 C2 -1.0(3) F1B C6 C1 C7 5.3(4) C5 C6 C1 C7 177.7(2) N2 N1 C7 C1 177.76(16) N2 N1 C7 C8 -0.9(3) C2 C1 C7 N1 42.7(3) C6 C1 C7 N1 -135.9(2) C2 C1 C7 C8 -138.5(2) C6 C1 C7 C8 42.9(3) N1 N2 C9 O1 -0.3(3) N1 N2 C9 C10 178.48(16) O1 C9 C10 C11 -44.3(3) N2 C9 C10 C11 136.9(2) O1 C9 C10 C14 133.2(2) N2 C9 C10 C14 -45.7(3) C12 N3 C11 C10 -0.5(4) C14 C10 C11 N3 1.6(3) C9 C10 C11 N3 179.1(2) C11 N3 C12 C13 -1.0(5) N3 C12 C13 C14 1.3(5) C12 C13 C14 C10 -0.1(4) C11 C10 C14 C13 -1.2(3) C9 C10 C14 C13 -178.7(2) loop_ _cod_related_entry_id _cod_related_entry_database _cod_related_entry_code 1 PubChem 9781871