Eightfold Superstructure in K2Gd2Sb2Se9 and K2La2Sb2S9 Caused by Three-Dimensional Ordering of the 5s2 Lone Pair of Sb3+ Ions

Synthesis and Crystal Structure of a New Quaternary Chalcoantimonide: KLa2Sb3S9and KSm2Sb3Se8

“…The coordination geometry of La (1) is a tricapped trigonal prism with the La(1)-S distances in the range of 2.895(5)-3.265(5) Å. One of the capping sulfur atoms, S(3), forms a S-S dimer with one of prismatic sulfur atoms, S(6), at a distance of 2.139(7) Å; this is in the range of typical dimeric S-S bond distance, a range of 2.096(5)-2.14(1) Å 7,8,9 ( Fig. 2(a)).…”

“…5 Compared to the diversity of the ternary Bi and Sb chalcoantimonide compounds, rare-earth quaternary phases in this class are quite limited. Reported rare-earth chalcoantimonides are K 2 (RE) 2-x Sb 4+x Se 12 (RE=La, Ce, Pr, Gd), 6 AU 2 SbQ 8 (A=K, Rb; Q=S, Se), 7 KThSb 2 Se 6 , 8 K 2 Gd 2 Sb 2 Se 9 , K 2 La 2 Sb 2 S 9 , 9 and Na 9 Gd 5 Sb 8 S 26 , 10 and Bi compounds are BaLaBi 2 S 6 , 8 Eu 2 Pb 2 Bi 6 Se 13 , 11 and ALn 1±x Bi 4±x S 8 (A=K, Rb; Ln=La, Ce, Pr, Nd). 12 Here we report on the synthesis and structure of the new quaternary rare-earth chalcoantimonides, KLa 2 Sb 3 S 9 and KSm 2 Sb 3 Se 8 .…”

“…That the distorted environments around Sb atoms involved 5s lone pair electrons of Sb was stereochemically expressed and tended toward the longer Sb-Se bonds. 9 The Sb(1)Se 6 , Sb(2)Se 6 and Sb(3)Se 6 octahedra were alternatively located by sharing Se atoms in the basal planes to form a rectangular-shaped tunnel running along the b-axis (Figure 3). This kind of fragment is prevalent in M 2 Q 3 (M=As, Sb, Bi; Q=S, Se, Te) 17 and also found in Cs 2 Sb 4 Se 8 18 and K 2 (RE) 2-x Sb 4+x Se 12 (RE=La, Ce, Pr, Gd).…”

Synthesis, Crystal and Electronic Structure, and Optical Property of the Quaternary Selenide: La3Sb0.33SiSe7

“…[5][6][7][8][9] Moreover, noncentrosymmetric structural arrangements of these coordinated asymmetrically SbQ n (n = 3, 4, 5, 6; Q = chalcogenides) polyhedra are known to be conducive for second-harmonic generation (SHG) activity. [5,[10][11][12] However, rare earth-antimony-chalcogenides are less studied, only several compounds are known, such as La 7 Sb 9 S 24 , [13] Pr 8 Sb 2 S 15 , [14] EuSbSe 3 , [15] K 2 RE 2-x Sb 4+x Se 12 (RE = La, Ce, Pr, Gd), [16] K 2 RE 2 Sb 2 Q 9 (RE = La, Q = S; RE = Gd, Q = Se), [17] Na 9 Gd 5 Sb 8 S 26 , [18] and Ba 4 LaGe 3 SbSe 13 . [19] Recently, many efforts in the quaternary RE/M/Sb/Q (RE = rare earth metal, M = main group or transition metal, Q = chalcogenides) system have yielded several compounds with structural diversity and technologically important properties, such as La 4 FeSb 2 S 10 , RE 2 Mn 3 Sb 4 S 12 (RE = Pr, Nd, Sm, Gd), [20] RE 4 GaSbS 9 (RE = Pr, Nd, Sm, Gd-Ho) [21] with strong SHG 1 hedra running parallel to the c direction surrounded by the discrete SiSe 4 tetrahedra and La cations.…”

Solvothermal synthesis and optical property of novel lanthanide(III) coordination polymers involving inorganic tridentate μ-η1,η2-SbS4 S-donor ligand

“…5). Both band gaps are larger than those of multinary lanthanide polythioantimonates (III) free of organic ligands, K 2 La 2 Sb 2 S 9 (2.20 eV) [24], La 2 SbS 5 Br (2.08 eV) and CeLaSbS 5 Br (2.07 eV) [25]. The electronic transitions are likely results of charge transfer from the S 2− -dominated valence band to the Ln 3+ -dominated conduction band, as occurred in the multinary chalcogenometalates [26].…”