Acidities of 3d and 4f element sulfides are the key factor governing the type of phase diagram in MS-Ln(2)S(3) (M = Mn, Fe; Ln = La-Lu) systems

作者：Andreev O V^*; Monina L N

来源：Russian Journal of Inorganic Chemistry, 2014, 59(9): 971-978.

DOI：10.1134/S0036023614090034

An equation to calculate the acidity of simple sulfides and a relative acidity scale are proposed. A correlation between the type of phase diagram and the acid-base properties of constituent simple sulfides of the system is postulated. The similarity of the acid-base properties of simple sulfides provides that they have a eutectic-type diagram. Complex sulfides are formed when the difference between the relative acidities of simple sulfides exceeds some threshold value. The complex compounds formed in MnS-Ln(2)S(3) (Ln = La, Ce) systems, namely Mn2La6S11 and MnCe2S4, are classified with thiomanganates. The compounds formed in FeS-Ln(2)S(3) (Ln = La, Ce, Pr) systems, namely FeLn(2)S(4) (Ln = La, Ce) and FeLn(4)S(7) (Ln = La-Pr), are classified with thioferrates. The strengthening of acidic properties in the Ln(2)S(3) (Ln = La-Lu) series results in the formation of thiolanthanates: MnLn(2)S(4) (Ln = Dy-Lu), MnLn(4)S(7) (Ln = Tb-Tm), FeLu2S4, FeLn(4)S(7) (Ln = Ho-Yb), and Fe(4)Ln(2)S(7) (Ln = Tm, Yb, Lu).

• 出版日期2014-9