The phase Y10I13C2 is synthesized by the reaction at ∼800°C of powdered Y and YI3 with impure Y2O3, the vital carbon component resulting from incomplete decomposition of the yttrium oxalate precursor. The phase has not been obtained from more conventional carbon sources. The identity of carbon as the interstitial is supported by these syntheses, microprobe analyses of Y10I13C2 vs Y6I7C2, and both the occupancy and the dimensions of the yttrium cavity in which carbon occurs. The phase occurs in space group C2/m, Z = 2; a = 21.317 (6) Å; b = 3.957 (1) Å; c = 19.899 (5) Å; β = 97.40 (2)°; R/Rw = 3.3%/3.9% for 838 independent reflections with 2θ ≤ 50° (Mo Kα). The compound consists of centered Y6I12C- and empty Y6I8-type clusters condensed by edge sharing into commensurate double and single chains, respectively. The chains are further cross-linked by additional iodine atoms. The two chain types are very similar to those known individually in the phases Y6I7C2 and Y4Cl6 and are presumably metallic and semiconducting, respectively. The Y4I6 chain is the first iodide example of condensed Y6X8-type clusters. This feature appears to be stabilized in this structure by a sterically less demanding means of bridging these chains between sheets of a Y6I7C2-like arrangement.
|Original language||English (US)|
|Number of pages||5|
|State||Published - 1990|
ASJC Scopus subject areas
- Inorganic Chemistry