Metal-metal vs tellurium-tellurium bonding in WTe{sub 2} and its ternary variants TaIrTe{sub 4} and NbIrTe{sub 4}

Journal Article · Tue Nov 03 23:00:00 EST 1992 · Journal of the American Chemical Society

DOI:https://doi.org/10.1021/ja00049a029· OSTI ID:570195

Mar, A; Jobic, S; Ibers, J A ^[1]

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1. Northwestern Univ., Evanston, IL (United States)

The new ternary transition-metal tellurides TaIrTe{sub 4} and NbIrTe{sub 4} are ordered variants of the WTe{sub 2} structure, which in turn is based on a distortion of the CdI{sub 2}-type layered structure. The layers in WTe{sub 2} consist of buckled sheets of Te atoms, with the metal atoms residing in distorted octahedral sites. Through single-crystal X-ray diffraction methods, the structure of TaIrTe{sub 4} has been determined and that of WTe{sub 2} has been redetermined. The compounds TaIrTe{sub 4} and WTe{sub 2} belong to the space group C{sup 7}{sub 2{nu}}-Pmn2{sub 1} of the orthorhombic system with four formula units in cells of dimensions a = 3.770 (1), b = 12.421 (6), and c = 13.184 (6) {angstrom} and a = 3.477 (2), b = 6.249 (4), and c = 14.018 (9) {angstrom}, respectively at 113 K. While metal-metal bonding is a structural feature common to all three compounds, Te-Te bonding is observed only in the ternary compounds. The trends of increasing metal-metal and decreasing Te-Te distances on progressing from WTe{sub 2} to TaIrTe{sub 4} and NbIrTe{sub 4} have been rationalized by electronic band (extended Hueckel) calculations. These trends are related to the creation of Te-Te bonds, ensuring the stability of the WTe{sub 2} structure type even when addition of more d electrons leads to a weakening of metal-metal bonds. This concept is generalized to an entire series of compounds MM{prime}Te{sub 4} (M = Nb, Ta; M{prime} = Ru, Os, Rh, Ir). 75 refs., 7 figs., 6 tabs.

• Sponsoring Organization: USDOE
• OSTI ID: 570195
• Journal Information: Journal of the American Chemical Society, Journal Name: Journal of the American Chemical Society Journal Issue: 23 Vol. 114; ISSN JACSAT; ISSN 0002-7863
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
40 CHEMISTRY
ANISOTROPY
BINDING ENERGY
BOND ANGLE
BOND LENGTHS
CHALCOGENIDES
CHARGE DENSITY
CHEMICAL BONDS
COVALENCE
CRYSTAL STRUCTURE
METALS
MOLECULAR STRUCTURE
NIOBIUM TELLURIDES
PHYSICAL PROPERTIES
STABILITY
STOICHIOMETRY
SUPERCONDUCTIVITY
TANTALUM TELLURIDES
TELLURIDES
TELLURIUM
TERNARY ALLOY SYSTEMS
TRANSITION ELEMENTS
X-RAY DIFFRACTION