Abstract: | Carbometalates: Complex Anions equation/tex2gif-stack-4.gif MoC4/26—] in the Crystal Structure of Pr equation/tex2gif-stack-5.gif MoIIC2] Criteria for the existence of carbometalates are established and discussed in a broader context. The concept is then applied to the novel compound Pr2MoC2], which is characterized by chemical analyses, X‐ray diffraction and metallography. The crystal structure (tetragonal, P42/mnm, Z = 4, a = 581.29(8) pm, c = 1032.53(14) pm) consists of layered polyanions equation/tex2gif-stack-6.gifMoC4/26—] of distorted vertex and edge sharing MoC4 tetrahedra. Praseodymium is also in a distorted tetrahedral coordination by carbon. The physical properties show “bad metal” behaviour and localized magnetic 4f‐moments in agreement with the existence of Pr3+‐species. A detailed bonding analysis using both the electron localization function ELF and the COHP method justifies the interpretation of the title compound as a carbomolybdate(II). |