Synthesis, structural characterization and optical properties of new compounds: Centrosymmetric Ba2GaMQ5 (M=Sb,Bi; Q=Se,Te), Ba2InSbTe5 and noncentrosymmetric Ba2InSbSe5

Ba2AsGaSe5: A New Quaternary Selenide with the Novel [AsGaSe5]4– Cluster and Interesting Photocatalytic Properties

“…The Ba 2+ cations are surrounded by a bicapped trigonal prism of eight Se atoms with the Ba−Se distances ranging from 3.344(1) to 3.458(1) Å, which are comparable to those of 3.409(2)−3.873(1) Å in BaAl 4 Se 7 , 34 3.261(6)− 3.740(6) Å in Ba 2 As 2 Se 5 , 35 3.228(1)−3.770(1) Å in Ba 6 Sn 6 Se 13 , 36 and 3.366(1)−3.509(1) Å in Ba 2 SbGaSe 5 . 37 Owing to the stereochemical activity of the 4s 2 electron lone pair, the As 3+ cations are trigonal pyramidally coordinated to three Se atoms. The As−Se distances within the AsSe 3 trigonal pyramid change from 2.393(6) to 2.463(5) Å, and the Se−As− Se bond angles vary from 95.99(1) to 98.659(3)°.…”

“…37 Among them, Ba 2 InSbSe 5 belongs to the noncentrosymmetric polar space group Cmc2 1 , while the other five crystallize in the same space group as Ba 2 GaAsSe 5 (Pnma). However, due to the much larger size of Sb and Bi, the Sb or Bi atoms are coordinated to heavily distorted octahedra of six Q atoms in those Sb-or Bi-containing compounds.…”

Synthesis, Crystal, and Electronic Structure of Ba3Sb2Q7 (Q = S, Se)

“…[18,19] In some cases, the presence of the electron lone pair results in the formation of non-centrosymmetric crystal structures with non-linear optical properties. [19][20][21][22] Centrosymmetric antimony chalcogenides also exhibit prospective thermoelectric [9,10,[23][24][25] and magnetic properties. [26,27] Despite the large number of known ternary, quaternary, and polyternary antimony chalcogenides, only a few compounds in the Ba-Sb-Q (Q = S, Se) systems have been reported: Ba 8 Sb 6 S 17 , [28] BaSb 2 S 4 , [29] Ba 3 Sb 4.67 S 10 , [30] Ba 4 Sb 4 Se 11 , [31] and BaSb 2 Se 4 .…”

Syntheses, structures, optical properties, and electronic structures of KBaMSe 3 (M = As, Sb)

“…Since the stereochemical activity of ns 2 lone pair of electrons of group 15 elements M (M = As, Sb, Bi) has profound effects on the crystal structures, electronic structures, and hence on the properties of the resultant compounds, the exploratory synthesis of new group 15 element-containing multinary chalcogenides has been an active area for years and with great efforts many chalcogenides with intriguing structures and properties have been discovered [2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][24][25][26][27]. For example, Ba 23-Ga 8 Sb 2 S 38 features an unusual zero-dimensional structure containing totally isolated GaS 4 tetrahedra and discrete SbS 3 pyramids [2]; Bi 3 In 4 S 10 and Bi 14.7 In 11.3 S 38 contain interesting chains of Bi atoms with alternating short Bi-Bi bonds of around 3.1 Å and longer distances of around 4.6 Å [3]; Cs 5 BiP 4 Se 12 [4], Rb 3 Ta 2 AsS 11 [5], La 4 InSbS 9 [6], and Sm 4 GaSbS 9 exhibit very strong second harmonic generation (SHG) responses in the IR range [7].…”