| Abstract
| - A new transition-metal-containing Zintl phase, Ba11Cd8Bi14, has been synthesized by a Cd-flux reaction, and itsstructure has been determined by a single-crystal X-ray diffraction. Ba11Cd8Bi14 crystallizes in the monoclinic spacegroup C2/m (No. 12, Z = 2) with a = 28.193(8) Å, b = 4.8932(14) Å, c = 16.823(5) Å, and β = 90.836(4)°,taken at −150 °C (R1 = 0.0407, wR2 = 0.1016). The structure can be described as being built of complexpolyanionic [Cd8Bi14]22- layers running along the b axis, which are separated by the Ba2+ cations. An interestingfeature of these layers is that they are composed of novel centrosymmetric chains of corner- and edge-sharedCdBi4 tetrahedra, interconnected through exo-Bi−Bi bonds. These bonds connect terminal Bi atoms from adjacentchains in such a way that infinite zigzag chains of bismuth parallel to the same direction are formed. Electronicband structure calculations performed using the TB-LMTO-ASA method show a very small band gap, suggestinga narrow-gap semiconducting or poor metallic behavior for Ba11Cd8Bi14. The crystal orbital Hamilton population(COHP) analysis on the homo- and heteroatomic interactions in this structure is reported as well.
- The new ternary compound, Ba11Cd8Bi14, has been synthesized from the corresponding elements, and its structure was determined from single-crystal X-ray diffraction studies. The compound crystallizes with a new C-centered monoclinic structure, which can be viewed as layers of [Cd8Bi14]22- with Ba cations occupying the space between them. The polyanionic network is composed of corner- and edge-shared CdBi4 tetrahedra that are further interconnected through Bi−Bi bonds, forming a unique zigzag chain. Electronic band structure calculations suggest Ba11Cd8Bi14 to be a charge-balanced compound (i.e., a Zintl phase).
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