LaS_1.9, CeS_1.9, PrS_1.9, NdS_1.9 und GdS_1.9: Fünf neue Lanthanoidpolysulfide – Synthese und Kristallstrukturen und ihre Strukturbeziehung zum ZrSSi‐Typ

Abstract

LaS1.9, CeS1.9, PrS1.9, NdS1.9, and GdS1.9: Five new Lanthanide Polysulfides – Syntheses, Crystal Structures and their Structural Relationship to the ZrSSi TypeCrystals of the five new lanthanide polysulfides LaS1.9, CeS1.9, PrS1.9, NdS1.9, and GdS1.9 have been prepared by different synthetic routes. According to X‐ray structure analyses, the compounds adopt the tetragonal CeSe1.9 type structure (space group: P42/n, no. 86) with the lattice parameters a = 9.111(1) Å, c = 16.336(2) Å (LaS1.9), a = 9.015(3) Å, c = 16.168(4) Å (CeS1.9), a = 8.947(3) Å, c = 16.054(4) Å (PrS1.9), a = 8.901(3) Å, c = 16.022(4) Å (NdS1.9), and a = 8.714(1) Å, c = 15.791(1) Å (GdS1.9), respectively. The crystal structure consists of puckered [LnS] double slabs and planar sulfur layers alternating along [001]. Each planar sulfur layer contains disulfide dumbbells, isolated anions and ordered vacancies.

High‐Pressure Synthesis, Crystal Structure, and Properties of GdS2 with Thermodynamic Investigations in the Phase Diagram Gd–S

“…The release of sulfur has only consequences for the planar chalcogen layers of the polysulfide. In GdS 2 the planar sulfide layers consists of S 2 2– dumbbells only whereas in GdS 1.9 dimeric S 2 2– anions, single S 2– anions and vacancies can be found in the layers 3. The structure of GdS 1.85 is not yet known, it might either adopt the modulated PrSe 1.85 type 7 or a defect variant of the Gd 8 Se 15 structure, a 24‐fold superstructure of the ZrSSi type 5.…”

“…For gadolinium polysulfide GdS 1.9 a solid state metathesis reaction was used 3, see Equation (11). GdCl 3 (99.9 %, Strem) and Na 2 S 2 were mixed and filled in silica ampoules with glassy carbon crucibles.…”

Specific Induced Circular Dichroism and Enhanced B to Z Transitions of Duplexes Stabilized by Chromophore‐Linked Alkynylnucleoside Residues

“…The disulfide anions exhibit an S–S distance of 2.140 Å and their atoms interact with three symmetry‐related neighbors through S ··· S contacts of length 2.960 Å (×2) and 3.186 Å (×1). The CeS 1.9 structure type is a 10‐fold commensurate superstructure of the ZrSSi aristotype in which the planar sulfur layers$\rm^{1}_{\infty}$ [(S 2– )(S 2 2– ) 4 □] (Figure 4) contain isolated S 2– dianions and ordered vacancies (□) in addition to disulfide dumbbells 35. Additional vacancies and occupational disorder of S 2 2– dianions are observed for polysulfides with higher δ values such as LnS 1.8625 (Ln = Dy, Ho) and LnS 1.85 (Ln = Tb, Y) 36.…”

Microwave‐Assisted Synthesis, Characterization, and Thermal Decomposition of Rare‐Earth Metal Disulfides RES2 (RE = La, Pr, Nd)

“…Polysulfides RE S 2– δ ( RE = Y, La–Nd, Sm, Gd–Lu; 0 ≤ δ < 0.3) of trivalent rare‐earth metals have been intensively studied in the last years with focus on synthesis, crystal structures, thermal properties, and thermodynamic data 1–7. The structures of these compounds generally consist of puckered [ RE S] + double slabs and planar [S] 1– δ layers and can be related to the tetragonal ZrSSi type ( P 4/ nmm , a 0 ≈ 3.8 Å, c 0 ≈ 8 Å8).…”

“…Two commensurate superstructures of the aristotype are known for sulfur deficient rare‐earth metal polysulfides RE S 2– δ : the CeS 1.9 type, a tenfold superstructure with δ = 0.1 (i.e. ten percent chalcogen defects in the planar layers)1,11 and the Gd 8 Se 15 type, a 24‐fold superstructure ideally with δ = 0.125 (12.5 % chalcogen defects in the planar layers) 6…”