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Title: Syntheses, crystal structures, and optical properties of K{sub 3}V{sub 0.32}Ta{sub 0.68}S{sub 4}, K{sub 6}Nb{sub 1.07}Ta{sub 2.93}S{sub 22}, K{sub 6}Nb{sub 2.97}Ta{sub 1.03}S{sub 25}, K{sub 3}Cu{sub 3}Nb{sub 0.98}Ta{sub 1.02}S{sub 8}, and KCu{sub 2}Nb{sub 0.53}Ta{sub 0.47}S{sub 4}

Journal Article · · Journal of Solid State Chemistry
OSTI ID:21015888
 [1];  [1]
  1. Institut fuer Anorganische Chemie, Universitaet Kiel, Olshausenstr. 40, D-24098 Kiel (Germany)

The new compounds K{sub 3}V{sub 0.32}Ta{sub 0.68}S{sub 4} (1), K{sub 6}Nb{sub 1.07}Ta{sub 2.93}S{sub 22} (2), K{sub 6}Nb{sub 2.97}Ta{sub 1.03}S{sub 25} (3), K{sub 3}Cu{sub 3}Nb{sub 0.98}Ta{sub 1.02}S{sub 8} (4), and KCu{sub 2}Nb{sub 0.53}Ta{sub 0.47}S{sub 4} (5) have been synthesized by the reactive flux method. Their crystal structures were determined by single crystal X-ray diffraction. Crystal data: 1: space group Pnma, a=9.2354(7), b=10.6920(6), c=9.2991(5) A, Z=4; 2: space group P2{sub 1}/c, a=7.6412(4), b=8.7572(5), c=24.5772(14) A, {beta}=98.559(6){sup o}, Z=2; 3: space group P2{sub 1}/n, a=15.7147(10), b=12.9840(9), c=18.2363(12) A, {beta}=104.123(8){sup o}, Z=4; 4: space group C2/c, a=23.5934(19), b=5.5661(2), c=14.2373(12) A, {beta}=120.631(9){sup o}, Z=4; 5: space group Ama2, a=7.4615(4), b=18.2902(16), c=5.5320(6) A, Z=4. The structure of compound 1 is based on discrete tetrahedral MS{sub 4} (M=V/Ta) anions, which are separated by K{sup +} cations. The structure of 2 consists of K{sup +} cations and [M {sub 4}S{sub 22}]{sup 6-} (M=Nb/Ta) anions, in which two M {sub 2}S{sub 11} building blocks are linked via terminal sulfur ligands. In 3 the complex anion [M {sub 4}S{sub 25}]{sup 6-} (M=Nb/Ta) is observed which comprises two M {sub 2}S{sub 11} subunits bridged by a S{sub 3} chain. In 4 {sup 1} {sub {infinity}}[Cu{sub 3} M {sub 2}S{sub 8}]{sup 3-} (M=Nb/Ta) anionic chains are found which are formed by corner sharing of CuS{sub 4} tetrahedra and edge sharing between CuS{sub 4} and MS{sub 4} tetrahedra. The structure of 5 consists of [Cu{sub 2} MS{sub 4}]{sup -} (M=Nb/Ta) anionic layers separated by K{sup +} cations. The CuS{sub 4} and MS{sub 4} tetrahedra share edges and corners yielding layers. All compounds were characterized with Raman spectroscopy and the compound 2-5 with UV/vis diffuse reflectance spectroscopy. - Graphical abstract: The five compounds K{sub 3}V{sub 0.32}Ta{sub 0.68}S{sub 4}, K{sub 6}Nb{sub 1.07}Ta{sub 2.93}S{sub 22}, K{sub 6}Nb{sub 2.97}Ta{sub 1.03}S{sub 25}, K{sub 3}Cu{sub 3}Nb{sub 0.98}Ta{sub 1.02}S{sub 8}, and KCu{sub 2}Nb{sub 0.53}Ta{sub 0.47}S{sub 4} have been prepared in polychalcogenide melts. The structures of these compounds base on discrete tetrahedra [MS{sub 4}]{sup 3-} (M=V/Ta), complex [M {sub 4}S{sub 22}]{sup 6-} and [M {sub 4}S{sub 25}]{sup 6-} anions comprised of two M {sub 2}S{sub 11} subunits bridged by a S{sub 2} or S{sub 3} chain, {sup 1} {sub {infinity}}[Cu{sub 3} M {sub 2}S{sub 8}]{sup 3-} anionic chains, and {sup 2} {sub {infinity}}[Cu{sub 2} MS{sub 4}]{sup -} (M=Nb/Ta) anionic layers formed by corner sharing and edge sharing between CuS{sub 4} and MS{sub 4} tetrahedra.

OSTI ID:
21015888
Journal Information:
Journal of Solid State Chemistry, Vol. 180, Issue 7; Other Information: DOI: 10.1016/j.jssc.2007.05.015; PII: S0022-4596(07)00201-0; Copyright (c) 2007 Elsevier Science B.V., Amsterdam, The Netherlands, All rights reserved; Country of input: International Atomic Energy Agency (IAEA); ISSN 0022-4596
Country of Publication:
United States
Language:
English