Diamagnetic Ru2+ in Na2La2Ti2RuO10–x (0 < x < 2): A Series of Complex Oxides Prepared by Topochemical Reduction

• Published in: Inorganic chemistry 2015-11, Vol.54 (22), p.10993-10997
• Main Authors: Pratt, Jacob A, Shepherd, Ashley M, Hayward, Michael A
• Format: Article
• Language: English
• ISSN: 0020-1669; 1520-510X
• DOI: 10.1021/acs.inorgchem.5b02100

Reaction of the n = 3 Ruddlesden–Popper phase Na2La2Ti2RuO10 with a 5% H2/95% N2 atmosphere between 300 and 900 °C leads to the formation of phases of composition Na2La2Ti2RuO10–x (0 < x < 2) via topochemical reduction. Magnetization data collected from Na2La2Ti2RuO10–x samples in the range 0 < x < 1 show a rapid decline in susceptibility with increasing x, consistent with the conversion of S = 1, Ru4+ centers at x = 0 to S = 0, Ru2+ centers at x = 1. We believe this is the first report of diamagnetic Ru2+ centers in an extended oxide phase. Further reduction of Na2La2Ti2RuO9 leads to the reduction of Ti4+ to Ti3+; however, Na2La2Ti2RuO10–x samples in the range 1 < x < 2 exhibit only a very weak paramagnetic response. Given the highly insulating nature of the phases, this suggests the electrons added on reduction of titanium are paired within a local Ti–Ti bonding network in a manner analogous to that observed for Ti n O2n–1 phases.