Hydrothermal single-crystal growth in the systemAG/Hg/X/O (X=V(V), As(V): Crystal structures of comppounds I, II and IV (see )b stract) with the unusual tetrahedral cluster cations (Ag3Hg)3 and (Ag2H2)4+ and crystal structure of compound III
- Autor(en)
- Matthias Weil, Ekkehart Tillmanns, Dmitry Y. Pushcharovsky
- Abstrakt
Single crystals of (Ag3Hg)VO4 (I), (Ag 2Hg2)3(VO4)4 (II), AgHgVO4 (III), and (Ag2Hg2) 2(HgO2)(AsO4)2 (IV) were grown under hydrothermal conditions (250°C, 5 d) from starting mixtures of elementary mercury, silver nitrate, ammonium vanadate, and disodium hydrogenarsenate, respectively. All crystal structures were determined from X-ray diffraction data, and their chemical compositions were confirmed by electron microprobe analysis. I crystallizes in the tillmannsite structure, whereas II-IV adopt new structure types: (I) I4, Z = 2, a = 7.7095(2) A°, c = 4.6714(2) A°, 730 structure factors, 24 parameters, R[F2 > 2s(F 2)] = 0.0365; (II) I42d, Z = 4, a = 12.6295(13) A°, c = 12.566(3) A°, 1524 structure factors, 55 parameters, R[F2 > 2s(F2)] = 0.0508; (III) C2, Z = 4, a = 9.9407(18) A°, b = 5.5730(8) A°, c = 7.1210(19) A°, = 94.561(10)°, 1129 structure factors, 48 parameters, R[F2 > 2s(F2)] = 0.0358; (IV) P31c, Z = 2, a = 6.0261(9) A°, c = 21.577(4) A°, 1362 structure factors, 52 parameters, R[F2 > 2s(F2)] = 0.0477. The most striking structural features of I, II, and IV are the formation of tetrahedral cluster cations (Ag3Hg)3+ and (Ag 2Hg2)4+, respectively, built of statistically distributed Ag and Hg atoms with a metal-metal distance of about 2.72 A°. The electronic structure of these clusters can formally be considered as two-electron-four-center bonding. The crystal structure of III differs from the protrusive structure types insofar as silver and mercury are located on distinct crystallographic sites without a notable metal-metal interaction >3.55 A°. All crystal structures are completed by tetrahedral oxo anions XO 43- (X = VV, AsV) and for IV additionally by a mercurate group, HgO22-. Œ 2005 American Chemical Society.
- Organisation(en)
- Institut für Mineralogie und Kristallographie
- Externe Organisation(en)
- Technische Universität Wien, Lomonosov Moscow State University (MSU)
- Journal
- Inorganic Chemistry
- Band
- 44
- Seiten
- 1443-1451
- Anzahl der Seiten
- 9
- ISSN
- 0020-1669
- Publikationsdatum
- 2005
- Peer-reviewed
- Ja
- ÖFOS 2012
- 105113 Kristallographie
- Link zum Portal
- https://ucrisportal.univie.ac.at/de/publications/8a7a8083-cc9d-4954-b3c2-32934f62f164