Supporting Information. Rajamani Nagarajan*, Shahzad Ahmad and Poonam Singh. Materials Chemistry Group, Department of Chemistry

Transcription

1 Supporting Information Topochemical Oxidation of perovskite KCoF 3 to K 2 PtCl 6 structure type oxyfluoride Rajamani Nagarajan*, Shahzad Ahmad and Poonam Singh Materials Chemistry Group, Department of Chemistry University of Delhi, Delhi , INDIA * Author to whom correspondence should be addressed Prof. Rajamani Nagarajan: rnagarajan@chemistry.du.ac.in Dr. Shahzad Ahmad: shahzadncfm@gmail.com Ms. Poonam Singh: pnms30@gmail.com S1

2 Details of synthesis and characterization Typically, 0.3 g of KCoF 3, synthesized by the established procedure, 1 was initially suspended in a solution containing 50 ml of 30% H 2 O 2 (Merck, 30% EMPARTA) and 40 ml of methanol (Merck 99% EMPLURA) in a round bottom flask coated with teflon. The suspension was refluxed for 7 h. A second lot of 50 ml of 30% H 2 O 2 and 40 ml of methanol were added and the refluxing continued for 16 h. Solid was obtained there after separating the solvent-oxidant mixture by drying at 60 C. Yield of the sample was 26% by weight. PXRD patterns were recorded using high-resolution PANanalytical Empereyan diffractometer (with PIXcel 3D detector) as well as Bruker D8 Advance (TXS Rotating Anode) diffractometer (with Lynx-eye position sensitive detector) employing Cu K α radiation (λ = Å) with a scan rate of sec/step and step size of over the range of 2θ = Thermo gravimetric analysis was conducted using the Pyris 1 TGA in the range C under flowing nitrogen (50 ml min -1 ) at a heating rate of 5 C min -1. FTIR spectra of the samples were recorded using a Perkin-Elmer 2000 FTIR spectrometer employing KBr disks. Raman spectrum was collected using a Renishaw via a microscope system with an Ar + laser (λ = nm). Absorption behaviour of the samples was recorded using Perkin- Elmer UV-Visible spectrophotometer-35(in solid form). Photoluminescence spectroscopy measurements were performed on solid samples using Horiba Jobin Yvon Fluorolog spectrometer employing a CW xenon lamp source at room temperature. XPS measurements were carried out using VG Microtech Multilab ESCA 3000 XPS instrument at a pressure better than 10 9 Torr. Firstly, the sample taken in the sample compartment was cleaned with the help of Argon gas (Argon ion Bombardment) to insure that the surface was absolutely clean and without any contamination, followed by its transfer to the analyzing chamber. The core-level spectra were recorded using Al K α radiation at a pass energy of 50 ev, an electron take off angle of 90, and a resolution of 0.1 ev. The core level spectra were fitted after S2

3 adjusting the baseline relative to the signal background. The chemically distinct species were resolved using a Gaussian distribution fitting procedure with the peak positions, and areas were determined. The C 1s core-level spectra at ev were taken as reference for the charge correction in the core-level spectra, and the peak positions were calibrated with respect to it. Concentration of potassium and cobalt in the sample was determined from ICP measurements employing Vista MPX Varian ICP-OES. Additionally, concentration of cobalt in the samples was estimated by complexometric titrimetry. For this, 50 mg of the compound was dissolved in 10 ml of 1:1 HCl and made up to 100 ml. 20 ml of the sample solution was titrated against standardized EDTA solution using xylenol orange (0.1% solution in ethanol) indicator. The ph was maintained at around 6 by the addition powdered hexamine as buffer. The complete complexation was indicated by the color change from orange to lemon yellow colour. Accuracy of the cobalt estimation was confirmed to be better than 0.5%. The amount of cobalt obtained from these trials was matching with the results from ICP-OES measurements. Fluorine content was determined by the ion selective electrode technique using Cole-Parmer (ORION) F-ion selective electrode (94-09). Using a stock solution of sodium fluoride (1000 µmol l -1 ), a linear calibration curve was generated using series of NaF standard (10 ppm, 100 ppm, 1000 ppm) solutions. Total ionic strength of the solution was adjusted using TISAB. The ph was adjusted to 5.5 using 15% sodium acetate (m/v) solution. The fluoride ion content was measured by immersing the electrodes directly in the test sample and the readings were taken after allowing 1-2 minutes for equilibration. The readings were evaluated by comparing the observed potential with the generated calibration graph. Three measurements at different time intervals were performed. The magnetic measurements were carried out using a Quantum Design MPMS SQUID magnetometer under an applied field of 5000 Oe in the temperature range of K. S3

4 Figure S1: Survey XPS spectrum of the sample from the oxidation of KCoF 3. Figure S2 Rietveld refinement of the sample from the reaction of KCoF 3 with H 2 O 2 under refluxing conditions. Refinement was carried out with K 2 CoF 6 as the starting model. Observed, calculated (profile matching), and difference profiles given respectively as red, green and pink lines Bragg positions as black vertical lines. S4

5 Figure S3 Expanded portion of the Raman spectrum of the oxidized sample from KCoF 3. Inset shows the deconvolution. Figure S4 Thermo gravimetric trace of (a) KCoF 3 and (b) its oxidized product under flowing nitrogen atmosphere. S5

6 Figure S5 (a) PXRD pattern of KNiF 3 (1) and the product from the oxidation of it with H 2 O 2 (2), (b) FTIR spectrum along with the Raman spectrum of the oxidized sample (inset). Figure S6 (a) PXRD pattern of KMnF 3 (1) and the product from the oxidation of it with H 2 O 2 (2), (b) FTIR spectrum along with the Raman spectrum of the oxidized sample (inset). S6

7 Table S1: Crystallographic data of cubic K 2 CoOF 4 Formula K 2 CoOF 4 Crystal system Cubic Space Group Fm-3m (#225) a [Å] (3) V [Å 3 ] (1) Z 4 Molecular Weight (4) ρ calc [g/cm 3 ] 2.84(2) Temperature [ K] 298 χ R p (%) R wp (%) GoF 1.97 Step size/ Step time / sec per step Number of data points (2θ = º) Number of parameters 28 Table S2: Refined atomic parameters after the final cycle of refinement. Atom Site S.O.F x y z U [Å 3 ] K 8c (2) Co 4a (3) O 24e (4) (3) (1) F 24e (1) (3) (1) S7

8 data_cooxi_publ _pd_block_id T18:44 COOXI Overall _audit_creation_method "from EXP file using GSAS2CIF" _audit_creation_date T18:44 _audit_author_name "" _audit_update_record T18:44 Initial CIF as created by GSAS2CIF #============================================================= ================ # this information describes the project, paper etc. for the CIF # # Acta Cryst. Section C papers and editorial correspondence is generated # # from the information in this section # # # # (from) CIF submission form for Rietveld refinements (Acta Cryst. C) # S8

9 # Version 14 December 1998 # #============================================================= ================ # 1. SUBMISSION DETAILS _publ_contact_author_name? # Name of author for correspondence _publ_contact_author_address # Address of author for correspondence? _publ_contact_author_ ? _publ_contact_author_fax? _publ_contact_author_phone? _publ_contact_letter? _publ_requested_journal? _publ_requested_coeditor_name? _publ_requested_category? # Acta C: one of CI/CM/CO/FI/FM/FO S9

10 #============================================================= ================= # 2. PROCESSING SUMMARY (IUCr Office Use Only) _journal_data_validation_number? _journal_date_recd_electronic? _journal_date_to_coeditor? _journal_date_from_coeditor? _journal_date_accepted? _journal_date_printers_first? _journal_date_printers_final? _journal_date_proofs_out? _journal_date_proofs_in? _journal_coeditor_name? _journal_coeditor_code? _journal_coeditor_notes? _journal_techeditor_code? _journal_techeditor_notes? _journal_coden_astm? _journal_name_full? S10

11 _journal_year? _journal_volume? _journal_issue? _journal_page_first? _journal_page_last? _journal_paper_category? _journal_suppl_publ_number? _journal_suppl_publ_pages? #============================================================= ================= # 3. TITLE AND AUTHOR LIST _publ_section_title? _publ_section_title_footnote? # The loop structure below should contain the names and addresses of all # authors, in the required order of publication. Repeat as necessary. S11

12 loop publ_author_name _publ_author_footnote _publ_author_address? #<--'Last name, first name'?? #============================================================= ================= # 4. TEXT _publ_section_synopsis? _publ_section_abstract? _publ_section_comment? S12

13 _publ_section_exptl_prep # Details of the preparation of the sample(s) # should be given here.? _publ_section_exptl_refinement? _publ_section_references? _publ_section_figure_captions? _publ_section_acknowledgements? #============================================================= ================ # 5. OVERALL REFINEMENT & COMPUTING DETAILS _refine_special_details? _pd_proc_ls_special_details S13

14 ? # The following items are used to identify the programs used. _computing_molecular_graphics? _computing_publication_material? _refine_ls_weighting_scheme? _refine_ls_weighting_details? _refine_ls_hydrogen_treatment? _refine_ls_extinction_method? _refine_ls_extinction_coef? _refine_ls_number_constraints? _refine_ls_restrained_s_all? _refine_ls_restrained_s_obs? #============================================================= ================= # 6. SAMPLE PREPARATION DATA # (In the unusual case where multiple samples are used in a single # Rietveld study, this information should be moved into the phase # blocks) S14

15 # The following three fields describe the preparation of the material. # The cooling rate is in K/min. The pressure at which the sample was # prepared is in kpa. The temperature of preparation is in K. _pd_prep_cool_rate? _pd_prep_pressure? _pd_prep_temperature? _pd_char_colour? # use ICDD colour descriptions data_cooxi_overall _refine_ls_shift/su_max 0.05 _refine_ls_shift/su_mean 0.01 _computing_structure_refinement GSAS _refine_ls_number_parameters 22 _refine_ls_goodness_of_fit_all 1.97 _refine_ls_number_restraints 0 _refine_ls_matrix_type full # pointers to the phase blocks loop pd_phase_block_id T18:44 COOXI_phase1 S15

16 # pointers to the diffraction patterns loop pd_block_diffractogram_id? # Information for phase 1 data_cooxi_phase_1 _pd_block_id T18:44 COOXI_phase1 #============================================================= ================= # 7. CHEMICAL, STRUCTURAL AND CRYSTAL DATA _pd_char_particle_morphology? _chemical_name_systematic? _chemical_name_common? _chemical_formula_moiety? _chemical_formula_structural? _chemical_formula_analytical? _chemical_melting_point? _chemical_compound_source? # for minerals and # natural products S16

17 _symmetry_space_group_name_hall? _exptl_crystal_f_000? _exptl_crystal_density_diffrn? _exptl_crystal_density_meas? _exptl_crystal_density_method? _cell_measurement_temperature? _cell_special_details? _geom_special_details? # The following item identifies the program(s) used (if appropriate). _computing_structure_solution? #============================================================= ================= # 8. Phase information from GSAS _pd_phase_name cubic _cell_length_a (33) S17

18 _cell_length_b _cell_length_c _cell_angle_alpha 90.0 _cell_angle_beta 90.0 _cell_angle_gamma 90.0 _cell_volume (7) _symmetry_cell_setting cubic _symmetry_space_group_name_h-m "F m -3 m" loop symmetry_equiv_pos_site_id _symmetry_equiv_pos_as_xyz 1 +x,+y,+z 2 +z,+x,+y 3 +y,+z,+x 4 +x,+y,-z 5 -z,+x,+y 6 +y,-z,+x 7 -z,+x,-y 8 -y,-z,+x 9 +y,-z,-x 10 -x,+y,-z 11 -z,-x,+y 12 +x,-y,-z 13 +y,+x,+z 14 +z,+y,+x 15 +x,+z,+y 16 +y,+x,-z 17 -z,+y,+x S18

19 18 +x,-z,+y 19 -z,+y,-x 20 -x,-z,+y 21 +x,-z,-y 22 -y,+x,-z 23 -z,-y,+x 24 +y,-x,-z -1 -x,-y,-z -2 -z,-x,-y -3 -y,-z,-x -4 -x,-y,+z -5 +z,-x,-y -6 -y,+z,-x -7 +z,-x,+y -8 +y,+z,-x -9 -y,+z,+x -10 +x,-y,+z -11 +z,+x,-y -12 -x,+y,+z -13 -y,-x,-z -14 -z,-y,-x -15 -x,-z,-y -16 -y,-x,+z -17 +z,-y,-x -18 -x,+z,-y -19 +z,-y,+x S19

20 -20 +x,+z,-y -21 -x,+z,+y -22 +y,-x,+z -23 +z,+y,-x -24 -y,+x,+z 101 +x,+y+1/2,+z+1/ z,+x+1/2,+y+1/ y,+z+1/2,+x+1/ x,+y+1/2,-z+1/ z,+x+1/2,+y+1/ y,-z+1/2,+x+1/ z,+x+1/2,-y+1/ y,-z+1/2,+x+1/ y,-z+1/2,-x+1/ x,+y+1/2,-z+1/ z,-x+1/2,+y+1/ x,-y+1/2,-z+1/ y,+x+1/2,+z+1/ z,+y+1/2,+x+1/ x,+z+1/2,+y+1/ y,+x+1/2,-z+1/ z,+y+1/2,+x+1/ x,-z+1/2,+y+1/ z,+y+1/2,-x+1/ x,-z+1/2,+y+1/ x,-z+1/2,-y+1/2 S20

21 122 -y,+x+1/2,-z+1/ z,-y+1/2,+x+1/ y,-x+1/2,-z+1/ x,-y+1/2,-z+1/ z,-x+1/2,-y+1/ y,-z+1/2,-x+1/ x,-y+1/2,+z+1/ z,-x+1/2,-y+1/ y,+z+1/2,-x+1/ z,-x+1/2,+y+1/ y,+z+1/2,-x+1/ y,+z+1/2,+x+1/ x,-y+1/2,+z+1/ z,+x+1/2,-y+1/ x,+y+1/2,+z+1/ y,-x+1/2,-z+1/ z,-y+1/2,-x+1/ x,-z+1/2,-y+1/ y,-x+1/2,+z+1/ z,-y+1/2,-x+1/ x,+z+1/2,-y+1/ z,-y+1/2,+x+1/ x,+z+1/2,-y+1/ x,+z+1/2,+y+1/ y,-x+1/2,+z+1/ z,+y+1/2,-x+1/2 S21

22 -124 -y,+x+1/2,+z+1/ x+1/2,+y,+z+1/ z+1/2,+x,+y+1/ y+1/2,+z,+x+1/ x+1/2,+y,-z+1/ z+1/2,+x,+y+1/ y+1/2,-z,+x+1/ z+1/2,+x,-y+1/ y+1/2,-z,+x+1/ y+1/2,-z,-x+1/ x+1/2, +y,-z+1/ z+1/2,-x, +y+1/ x+1/2,-y,-z+1/ y+1/2, +x, +z+1/ z+1/2, +y, + x+1/ x+1/2, +z, + y+1/ y+1/2, +x,-z+1/ z+1/2, +y,+x+1/ x+1/2,-z, +y+1/ z+1/2, +y,-x+1/ x+1/2,-z, +y+1/ x+1/2,-z,-y+1/ y+1/2, +x,-z+1/ z+1/2,-y, +x+1/ y+1/2,-x,-z+1/ x+1/2,-y,-z+1/2 S22

23 -202 -z+1/2,-x,-y+1/ y+1/2,-z,-x+1/ x+1/2,-y, +z+1/ z+1/2,-x,-y+1/ y+1/2, +z,-x+1/ z+1/2,-x, +y+1/ y+1/2, +z,-x+1/ y+1/2, +z, +x+1/ x+1/2,-y, +z+1/ z+1/2, +x,-y+1/ x+1/2, +y,+z+1/ y+1/2,-x,-z+1/ z+1/2,-y,-x+1/ x+1/2,-z,-y+1/ y+1/2,-x, +z+1/ z+1/2,-y,-x+1/ x+1/2,+z,-y+1/ z+1/2,-y,+x+1/ x+1/2, +z,-y+1/ x+1/2, +z,+y+1/ y+1/2,-x, +z+1/ z+1/2, +y,-x+1/ y+1/2, +x,+z+1/ x+1/2, +y+1/2, +z 302 +z+1/2, +x+1/2, +y 303 +y+1/2, +z+1/2, +x S23

24 304 +x+1/2, +y+1/2,-z 305 -z+1/2, +x+1/2, +y 306 +y+1/2,-z+1/2, +x 307 -z+1/2, +x+1/2,-y 308 -y+1/2,-z+1/2, +x 309 +y+1/2,-z+1/2,-x 310 -x+1/2, +y+1/2,-z 311 -z+1/2,-x+1/2,+y 312 +x+1/2,-y+1/2,-z 313 +y+1/2, +x+1/2, +z 314 +z+1/2, +y+1/2, +x 315 +x+1/2, +z+1/2, +y 316 +y+1/2, +x+1/2,-z 317 -z+1/2, +y+1/2, +x 318 +x+1/2,-z+1/2, +y 319 -z+1/2, +y+1/2,-x 320 -x+1/2,-z+1/2, +y 321 +x+1/2,-z+1/2,-y 322 -y+1/2, +x+1/2,-z 323 -z+1/2,-y+1/2, +x 324 +y+1/2,-x+1/2,-z x+1/2,-y+1/2,-z z+1/2,-x+1/2,-y y+1/2,-z+1/2,-x x+1/2,-y+1/2, +z z+1/2,-x+1/2,-y S24

25 -306 -y+1/2, +z+1/2,-x z+1/2,-x+1/2, +y y+1/2, +z+1/2,-x y+1/2, +z+1/2, +x x+1/2,-y+1/2, +z z+1/2, +x+1/2,-y x+1/2, +y+1/2, +z y+1/2,-x+1/2,-z z+1/2,-y+1/2,-x x+1/2,-z+1/2,-y y+1/2,-x+1/2, +z z+1/2,-y+1/2,-x x+1/2, +z+1/2,-y z+1/2,-y+1/2, +x x+1/2, +z+1/2,-y x+1/2, +z+1/2, +y y+1/2,-x+1/2, +z z+1/2, +y+1/2,-x y+1/2,+x+1/2,+z # ATOMIC COORDINATES AND DISPLACEMENT PARAMETERS loop atom_site_type_symbol _atom_site_label S25

26 _atom_site_fract_x _atom_site_fract_y _atom_site_fract_z _atom_site_occupancy _atom_site_thermal_displace_type _atom_site_u_iso_or_equiv _atom_site_symmetry_multiplicity K K Uiso Co Co Uiso O O Uiso F F Uiso loop atom_type_symbol _atom_type_number_in_cell K 8.0 Co 4.0 O 4.0 S26

27 F 16.0 # If you change Z, be sure to change all 3 of the following _chemical_formula_sum "Co F4.00 K2 O1.00" _chemical_formula_weight _cell_formula_units_z 4 # MOLECULAR GEOMETRY loop geom_bond_atom_site_label_1 _geom_bond_atom_site_label_2 _geom_bond_distance _geom_bond_site_symmetry_1 _geom_bond_site_symmetry_2 _geom_bond_publ_flag?????? loop geom_angle_atom_site_label_1 _geom_angle_atom_site_label_2 _geom_angle_atom_site_label_3 _geom_angle _geom_angle_site_symmetry_1 _geom_angle_site_symmetry_2 _geom_angle_site_symmetry_3 S27

28 _geom_angle_publ_flag???????? #--eof--eof--eof--eof--eof--eof--eof--eof--eof--eof--eof--eof- -eof--eof--eof--# References: (1) Tyagi, N. Ghanti, E. Gupta, N. Lalla, N. P. Nagarajan, R. Bull. Mater. Sci. 2009, 32, S28