TY - JOUR
T1 - Ca14GaAs11
T2 - A new compound containing discrete GaAs4 tetrahedra and a hypervalent As3 polyatomic unit
AU - Kauzlarich, Susan M.
AU - Thomas, Michele M.
AU - Odink, Debra A.
AU - Olmstead, Marilyn M.
PY - 1991
Y1 - 1991
N2 - In the course of investigating the synthesis and properties of several ternary Ga-As Zintl compounds, a new Zintl compound has been prepared: Ca14GaAs11. This compound has been prepared in high yield from the stoichiometric combination of the elements in a sealed Nb tube, sealed in an evacuated quartz ampule, at 1100 °C for 4 days. It crystallizes in the tetragonal space group I41/acd with lattice parameters a = 15.642 (2) Å and c = 21.175 (4) Å (room temperature). Single-crystal X-ray diffraction data were collected at 130 K (I41/acd, Z = 8, a = 15.620 (3) Å, and c = 21.138 (4) Å). Its structure is composed of isolated GaAs4 tetrahedra that are separated by As3 linear units, As and Ca. The As3 units are situated between the tetrahedra and alternate by 90° down the c axis. Although the As-As distance in the As3 unit is rather long (2.956 (2) Å), it is consistent with the long I-I distance observed in the isoelectronic, hypervalent I3
- anion and therefore is considered to be formally an As3
7- anion. Optical data are consistent with a semiconducting compound, indicating an optical band gap of about 1.49 eV, slightly higher in energy than that observed for GaAs. The synthesis, structure, and bonding in this compound will be discussed.
AB - In the course of investigating the synthesis and properties of several ternary Ga-As Zintl compounds, a new Zintl compound has been prepared: Ca14GaAs11. This compound has been prepared in high yield from the stoichiometric combination of the elements in a sealed Nb tube, sealed in an evacuated quartz ampule, at 1100 °C for 4 days. It crystallizes in the tetragonal space group I41/acd with lattice parameters a = 15.642 (2) Å and c = 21.175 (4) Å (room temperature). Single-crystal X-ray diffraction data were collected at 130 K (I41/acd, Z = 8, a = 15.620 (3) Å, and c = 21.138 (4) Å). Its structure is composed of isolated GaAs4 tetrahedra that are separated by As3 linear units, As and Ca. The As3 units are situated between the tetrahedra and alternate by 90° down the c axis. Although the As-As distance in the As3 unit is rather long (2.956 (2) Å), it is consistent with the long I-I distance observed in the isoelectronic, hypervalent I3
- anion and therefore is considered to be formally an As3
7- anion. Optical data are consistent with a semiconducting compound, indicating an optical band gap of about 1.49 eV, slightly higher in energy than that observed for GaAs. The synthesis, structure, and bonding in this compound will be discussed.
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M3 - Article
AN - SCOPUS:0001361965
VL - 113
SP - 7205
EP - 7208
JO - Journal of the American Chemical Society
JF - Journal of the American Chemical Society
SN - 0002-7863
IS - 19
ER -