Hydrothermal Synthesis, Crystal Structure, and Magnetism of Na₂[Ir(OH)₆] and its Dehydration to Na₂IrO₃

Yellow single-crystals of Na2[Ir(OH)6] were obtained by hydrothermal synthesis in 20 m sodium hydroxide solution at 473 K within 5 hours. X-ray diffraction on a single-crystal revealed the trigonal space group (Formula presented.) (no. 148) with lattice parameters a=582.76(3) pm and c=1399.30(8) pm at 100(1) K. Na2[Ir(OH)6] crystallizes in a hettotype of Mg(OH)2 (brucite) and is isostructural to Na2[Sn(OH)6]. The oxygen atoms are arranged in a hexagonal close packing, Na+ and Ir4+ ions occupy the octahedral voids in every second layer in an ordered manner, the voids of the next layers remain empty. The hydroxidometalate layer can be seen as isolated [Ir(OH)6]2− octahedra, which are embedded in a honeycomb net of alkali metal cations. Temperature-dependent magnetic measurements revealed paramagnetic behavior with an effective moment of 1.9 μB per iridium ion. The thermal decomposition of Na2[Ir(OH)6] in air starts at about 220 °C and results in pure Na2IrO3. © 2021 The Authors. Zeitschrift für anorganische und allgemeine Chemie published by Wiley-VCH Gmb

ESTIMATING MONETARY POLICY RULES FOR SOUTH AFRICA

The paper combines the estimation of the Monetary Conditions Index (MCI) with the theoretic modelling of optimal monetary policy in South Africa. The idea that monetary policy is not only interested in optimal monetary conditions but also in external stability, provides the basis for the analysis. The paper introduces the concept of the MCI and estimates the relative influence of interest rates and exchange rates on the output gap. The estimated weights are 1.9:1. This estimation results is used to specify operating target rules for South African monetary policy. Copyright (c) 2006 The Author. Journal compilation (c) 2006 Economic Society of South Africa.

Regional Differences in the Efficiency of German Savings Banks

German savings banks play a key role in financing German SMEs. Accordingly, the analysis of their efficiency is of economic importance. We apply data envelopment analysis to explore the influence of the financial crisis (2007 to 2008) as well as the Eurozone crisis (since the end of 2009) on the efficiency of German savings banks. Although the Malmquist index, as a measure of efficiency change and technological change, is on average below one in our sample from 2003 to 2014, we conclude from our efficiency results that German savings banks recovered quickly after the financial crisis as well as the Eurozone crisis. We test for and explain regional efficiency differences between Eastern and Western German savings banks. Since Eastern and Western Germany represent two socio-economically different environments, we control for environmental variables. Our results show that Eastern German savings banks are less inefficient than Western German savings banks since other earning assets, i. e., securities and advances to banks, and refinancing costs are advantageous for their efficiency