A Novel Metallic Halide, Hg2As3Br: Synthesis and Crystal Structure, and Crystal Structure of Cd2As3Br

✍ Scribed by A.V. Shevelkov; E.V. Dikarev; B.A. Popovkin

• Publisher: Elsevier Science
• Year: 1994
• Tongue: English
• Weight: 183 KB
• Volume: 113
• Category: Article
• ISSN: 0022-4596
• DOI: 10.1006/jssc.1994.1348

✦ Synopsis

A new mercury arsenidobromide, (\mathrm{Hg}{2} \mathrm{As}{3} \mathrm{Br}), was prepared using a standard ampoule technique. It crystallizes in a monoclinic space group (C 2 / c) with cell dimensions (a=8.0914(8), b=9.300(1)), (c=8.1084(7) \AA, \beta=99.323(0)^{\circ}, z=4). The structure was refined based on single crystal (\mathrm{X})-ray diffraction data to (\boldsymbol{R} \boldsymbol{\mathbf { 0 }} \mathbf{0 . 0 5 3}) and (R_{w}=\mathbf{0 . 0 5 8}) for 739 reflections having (I>3 \sigma(I) . \mathrm{Hg}{2} \mathrm{As}{3} \mathrm{Br}) was shown to exhibit metallic conductivity from (80 \mathrm{~K}) to room temperature. A redetermination of the crystal structure of (\mathrm{Cd}{2} \mathrm{As}{3} \mathrm{Br}) (previously reported as crystallized in space group (C c) ) was performed in space group (C 2 / c) with cell dimensions (a=8.281(1), b=) 9.411(1), (c=7.993(1) \AA, \beta=101.49(1)^{\circ}, z=4). The structure was refined to (R=0.027) and (R_{\mathrm{w}}=0.029) for 485 reflections having (I>3 \sigma(I)). Differences between the two structures are discussed. 1994 Academic Press, Inc.