Mixed‐Metal Monophosphate Tungsten Bronzes Containing Rhodium and Iridium. Issue 15 (9th April 2021)

• Record Type: Journal Article
• Authors: Karbstein, Alexander; Weber, Markus; Lahr, Dominic; Daniels, Jörg; Assenmacher, Wilfried; Mader, Werner; Rosowski, Frank; Schunk, Stephan A.; Glaum, Robert
• Is Part Of: European journal of inorganic chemistry. Issue 15(2021)
• Page Start: 1459
• Page End: 1469
• Publication Date: 2021-04-09
• Subjects: Equilibrium relations -- MPTB -- Rhodium -- Iridium -- Solid-state chemistry -- Solid-state structure; Chemistry, Inorganic -- Periodicals; Organometallic chemistry -- Periodicals; Bioinorganic chemistry -- Periodicals; Solid state chemistry -- Periodicals; 546
• DOI: 10.1002/ejic.202100047
• Languages: English
• ISSNs: 1434-1948

Abstract

Abstract: Solution combustion synthesis followed by annealing in air led to the MPTB‐related phosphates (Rh1/6 W5/6 O3 )8 (PO2 )4, (Ir1/6 W5/6 O3 )8 (PO2 )4 ( a =5.258(2) Å, b =6.538(3) Å, c =17.322(8) Å), (Rh1/9 W8/9 O3 )12 (PO2 )4 and (Rh2/21 W19/21 O3 )14 (PO2 )4 . Single‐crystals of the mixed‐metal (Rh, W)‐MPTBs at m =4 and at m =7 were grown by chemical vapor transport (CVT). Their crystal structures have been refined from X‐ray single‐crystal data {(Rh, W)‐MPTB at m =4 : P 21 21 21, Z =1, a =5.2232(3) Å, b =6.4966(3) Å, c =17.3819(9) Å, R1 =0.032, wR2 =0.075 for 1714 unique reflections, 1524 with F o >4 σ ( F o ), 66 variables, 1 constraint, composition from refinement (Rh0.15 W0.85 O3 )8 (PO2 )4 ; (Rh, W)‐MPTB at m =7 : P 21 / n, Z =1, a =5.2510(4) Å, b =6.4949(5) Å, c =26.685(2) Å, β =90.30(1)°, R1 =0.060, wR2 =0.163 for 2074 unique reflections, 1894 with F o >4 σ ( F o ), 100 variables, comp. from ref. (Rh0.07 W0.93 O3 )14 (PO2 )4 }. These structure refinements show unexpected distribution of Rh and W over the available metal sites. Further characterization (powder reflectance and magnetic measurements) of the (Rh, W)‐MPTB at m =4 and at m =7 suggest for both phases a homogeneity range with respect to the Rh/W ratio and the presence of small amounts of W 5+ besides Rh 3+ and W 6+ . Results of the ligand field analysis for the reference material Rh(PO3 )3, which is containing the octahedral chromophore [Rh III O6 ], are reported ( Δo =23200 cm −1, B =490 cm −1 ). Abstract : Incorporation of rhodium or iridium in phosphates of the MPTB structure family is possible. SXRD analysis of (Rh1/6 W5/6 O3 )8 (PO2 )4 and (Rh2/21 W19/21 O3 )14 (PO2 )4 reveals an unexpected distribution pattern for Rh 3+ over the available metal sites. Results of further characterization by TEM, powder reflectance spectroscopy and magnetic measurements are reported.