LnCl(CN₂) with Ln = La, Ce, and Pr: Synthesis and Structure of a New Lanthanide Chloride Cyanamide Related to the PbFCl‐Type Structure

Abstract

Solid state metathesis reactions between LaCl3 and Li2(CN2) carried out in silica ampoules at 600 °C over two days resulted in the formation of a light gray powder, later identified to be lanthanum chloride cyanamide. Single crystals were obtained as colourless transparent plates using a LiCl‐KCl flux. The crystal structure of LaCl(CN2) was solved and refined from X‐ray single crystal data (P21/m (no. 11), Z = 2, a = 5.330(1) Å, b = 4.0305(8) Å, c = 7.545(1) Å, V = 159.24(5) Å3, β = 100.75(2)°). The structure of LaCl(CN2) is closely related to the tetragonal LaOCl (PbFCl type) structure and contains a [La2Cl2]4+ block layer and two layers of (CN2)2‐ ions in an alternating sequence. The La3+ ion in LaCl(CN2) is situated in a polyhedron composed of four chloride ions on one side and five cyanamide ions on the other side. Cerium and praseodymium analogues were identified from indexed powder patterns with analogous unit cells, assuming them to form isostructural compounds.

Precursor Approach to Lanthanide Dioxo Monocarbodiimides Ln2O2CN2 (Ln=Y, Ho, Er, Yb) by Insertion of CO2 into Organometallic Ln–N Compounds

“…To obtain higher crystallinity a LiCl/KCl flux was applied by analogy to recent reports in lanthanide carbodiimide chemistry. [27,39,40] After the first decomposition stage at 250 8C the product was mixed with a eutectic mixture of LiCl and KCl. After annealing at 700 8C, a gray-purple product was obtained.…”

A Luminescent Material: La3Cl(CN2)O3 Doped with Eu3+ or Tb3+ Ions

“…[1] The compound LaCl(CN 2 ) was obtained from LaCl 3 and Li 2 (CN 2 ) at 600°C [Reaction (4)]. [25] …”

An Experimental Study of a Flux Modulated Solid State Metathesis Reaction

“…Reactions like these usually perform quantitatively without the formation of related compositions in the Li– RE –Cl–(CN 2 ) system, such as RE Cl(CN 2 )10 or Li RE (CN 2 ) 2 11. The coproduced LiCl can be removed from the reaction product by extraction with water to obtain single‐phase rare‐earth carbodiimide.…”