Premium
Syntheses, Crystal Structures, and Properties of New Ternary Chalcogenides of Group 4 Metals: Rb 4 Ti 3 S 14 , Cs 4 Zr 3 S 14 , K 4 Hf 3 Se 14 , and K 4 ZrHf 2 Se 14
Author(s) -
Tillinski Ralf,
Rumpf Christian,
Bensch Wolfgang
Publication year - 2001
Publication title -
zeitschrift für anorganische und allgemeine chemie
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.354
H-Index - 66
eISSN - 1521-3749
pISSN - 0044-2313
DOI - 10.1002/1521-3749(200106)627:6<1405::aid-zaac1405>3.0.co;2-d
Subject(s) - chalcogen , crystallography , ternary operation , chemistry , alkali metal , polysulfide , transition metal , crystal structure , metal , antimony , stereochemistry , inorganic chemistry , catalysis , organic chemistry , electrode , computer science , electrolyte , programming language
The new ternary compounds Rb 4 Ti 3 S 14 , Cs 4 Zr 3 S 14 , K 4 Hf 3 Se 14 , and K 4 ZrHf 2 Se 14 were prepared by reacting the respective transition metals in alkali metal polychalcogenide melts. Two crystallographically independent transition metal cations are present that are coordinated by eight chalcogen atoms (Q) in an irregular fashion or by seven chalcogen atoms yielding a distorted pentagonal bipyramid. The M(1)Q 8 and M(2)Q 7 polyhedra are connected by sharing common edges or trigonal faces leading to the formation of infinite linear one‐dimensional anionic chains running parallel to the [101] direction. The chains are separated by alkali metal cations. The optical band gaps determined are 1.59 eV for Rb 4 Ti 3 S 14 , 2.35 eV for Cs 4 Zr 3 S 14 , and 2.02 eV for K 4 Hf 3 Se 14 . In‐situ X‐ray powder diffractometry demonstrates that Rb 4 Ti 3 S 14 decomposes at 430 °C into Rb 2 S 5 and TiS. During the cooling cycle the re‐formation of the polysulfide is observed. According to this result the polysulfide could be prepared using TiS instead of metallic Ti as well.