Synthesis, structure, and properties of ternary transition metal sulfides, chloridesulfides, and nitrides.

摘要

Several new compounds have been prepared, each yielding interesting structural aspects that are unique to sulfide literature. The correct compositions and structural characteristics of the rare-earth chromium sulfide and chloridesulfide phases have now been determined. Single-phase La15.9(2)Cr 5.4(2)S32 was synthesized and extensively analyzed, proving to be an excellent model for the determination of the chloride incorporated analogues. By exchanging the rare-earth metal in La15.9(2)Cr 5.4(2)S32 and adding a source of chloride to the reaction mixture, the compounds Ce15.8(2)Cr5.6(2)S32-x Clx, Pr15.8(2)Cr5.6(2)S32-x Clx, and Nd15.8(2)Cr5.6(2)S32-x Clx can be prepared in single-crystal form. An extremely strict and unforgiving synthesis is used to obtain these products as single-phase materials. Upon heating, the metastable chloride incorporated phases reported in the literature. The title phases all contain Cr2S9 12- face-shared bioctahedra that are connected to one another by cubic clusters of rare-earth and transition metal atoms. In La15.9(2) Cr5.4(2)S32, the Cr2S9 12- bioctahedral units are observed to be antiferromagnetically coupled, resulting in an overall spin state of almost zero at low temperatures.;The ternary yttrium chromium sulfide family of compounds was revisited to find new phases existing between known stoichiometric end-member phases. The isolation and analyses of previously reported compounds yielded important crystallographic and magnetic data aiding in such investigations. In the course of study, a new phase having the formula Y6Cr2S 11 was produced. This compound proves to be isostructural with the erbium analogue. It has been previously determined that known compounds in the erbium series are isostructural to the corresponding yttrium analogues.;Anion metathesis reactions involving ZrNCl were performed resulting in the production of two unique compounds, ZrN(CN) and Zr2N2 S. These compounds have been isolated as single-phase material and were characterized by a multitude of different analytical techniques confirming the compositions. Single-crystals were synthetically unobtainable for both compounds; however, significant analyses were performed on the isolated polycrystalline powders revealing structure and composition.