Nd2[MoC2] and RE2[WC2], RE=Ce, Pr, Nd: New carbometalates with Pr2[MoC2] structure type

• Main Author: Enkhtsetseg Dashjav, Yurii Prots, Guido Kreiner, Walter Schnelle, Frank R. Wagner and Rüdiger Kniep
• Format: Article
• Language: English
• Published: Taylor & Francis Group 2007-01-01
• Series: Science and Technology of Advanced Materials
• Online Access: http://www.iop.org/EJ/abstract/1468-6996/8/5/A06

Four new ternary rare-earth-metal carbometalates, Nd2[MoC2] and RE2[WC2] with RE=Ce, Pr, Nd, have been synthesized by argon arc melting and subsequent heat treatment at 1170 K for 30 days. They crystallize with the Pr2[MoC2] structure type with isolated C4− species and are typical carbometalates with (i) low metal-to-carbon ratio, (ii) tetrahedral coordination of the transition metals (T) by carbon, and (iii) a polyanionic network ∞2[(TC2)6-]. According to resistivity measurements the compounds are bad metals. Volume chemistry and magnetic susceptibility measurements indicate Pr3+, Nd3+, and Ce4+ species, respectively. In the latter case, the additional electron is not transferred to the polyanionic network, instead it mainly populates the Ce partial structure.