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Structural Studies of New Sulfito Mercurates(II) with General Formula xM [ X HgSO 3 ]middot; y Hg X 2 · zM X· n H 2 O ( M = NH 4 , K; X = Cl, Br)
Author(s) -
Weil Matthias,
Baumann Stefan,
Breitinger Dietrich K.
Publication year - 2008
Publication title -
zeitschrift für anorganische und allgemeine chemie
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.354
H-Index - 66
eISSN - 1521-3749
pISSN - 0044-2313
DOI - 10.1002/zaac.200800159
Subject(s) - isostructural , triclinic crystal system , crystallography , crystal structure , lattice constant , lattice (music) , chemistry , type (biology) , solid solution , diffraction , physics , ecology , organic chemistry , acoustics , optics , biology
Several solid phases with the general formula xM [ X HgSO 3 ]· y Hg X 2 · zMX · n H 2 O were obtained from aqueous solutions during phase formation studies in the systems M 2 SO 3 /Hg X 2 ( M = NH 4 , K; X = Cl, Br). All phases were structurally characterized on the basis of single crystal X‐ray diffraction data and adopt new structure types. Compounds with x , y , z = 1 and n = 0 are isostructural (structure type I ) and crystallise with two formula units in space group P 2 1 / m and lattice parameters of a ≈ 9.7, b ≈ 6.2, c ≈ 10.4Å, β ≈ 111°. Compounds with x , y = 1 and z , n = 0 (structure type II ) crystallize in space group Cmc 2 1 with four formula units and lattice parameters of a ≈ 5.9, b ≈ 22.0, c ≈ 6.9Å. The structures with x = 2, y , z = 1 and n = 0 are likewise isostructural (stucture type III ) and consist of four formula units in space group Pnma with lattice parameters of a ≈ 22.2, b ≈ 6.1, c ≈ 12.4Å. K[HgSO 3 Cl]·KCl·H 2 O is the only representative where x = 1, y = 0, z = 1 and n = 1 (structure type IV ). It is triclinic (space group $P{\bar 1}$ ) with four formula units and lattice parameters of a = 6.1571(8), b = 7.1342(9), c = 10.6491(14) Å, α = 76.889(2), β = 88.364(2), γ = 69.758(2)°. Characteristic for all structures types is the segregation of the M + cations and the anions and/or Hg X 2 molecules into layers. The [ X HgSO 3 ] − anions are present in all structures and have m symmetry, except for K[HgSO 3 Cl]·KCl·H 2 O with 1 symmetry (but very close to m symmetry). The different [ X HgSO 3 ] units exhibit very similar Hg‐S distances (average 2.372Å) and are more or less bent with ∠( X ‐Hg‐S) angles ranging from 159.7 to 173.7°. The molecular Hg X 2 entities present in structure types I ‐ III deviate only slightly from linearity with ∠( X ‐Hg‐ X ) angles ranging from 174 to 179°. The structures are stabilised by interaction of the K + or NH 4 + cations that are located between the anionic layers or in the vacancies of the framework, by K‐O contacts or, in case of ammonium compounds, by medium to weak hydrogen bonding interactions of the type N‐H···O.