2005
Structure
D 2000
35- 003
Syntheses and Crystal Structures of Four New Ammoniates with Heptaarsenide
(As37 ) Anions. — The structures of the new heptaarsenides (III) (orthorhombic, space
group Pna21, Z = 4), (V) (monoclinic, P21/n, Z = 4), (VII) (trigonal, R3c, Z = 18), and
(VIII) (monoclinic, P21/c, Z = 4) are determined by single crystal XRD. While compound (III) contains isolated A s37 - polyanions, As—M contacts (M: Rb, Cs) lead to neutral [Rb(18-crown-6)]3As 7 units in (V), a three-dimensional, extended network in (VII),
and infinite [CsAs27 ] chains in (VIII), respectively. The structure of the As7 unit is
analogous to nortricyclane in all four compounds. — (HANAUER, T.; GROTHE, M.;
REIL, M.; KORBER*, N.; Helv. Chim. Acta 88 (2005) 5, 950-961; Inst. Anorg.
Chem., Univ. Regensburg, D-93053 Regensburg, Germany; Eng.) — Schramke