LAYERED STRUCTURE OF CRYSTALLINE COMPOUNDS AGSR

The insoluble silver thiolate compounds AgS(CH2)2CH3 (1), AgS(CH2)3CH3 (2), AgS(CH2)5CH3 (3), AgS(CH2)7CH3 (4), AgSC6H5 (5), AgSC6H4-4-F (6), AgSC6H4-4-Cl (7), AgSC6H4-4-Br (8), AgSC6H4-4-CH3 (9) and AgSC6H4-4-OCH3 (10) have not yielded crystals suitable for full diffraction analysis, but do reveal the essential features of their two-dimensionally nonmolecular structure in their powder diffraction patterns. For each compound, a strongly developed progression of axial reflections {OkO} shows that there are 2-infinity{AgSR} layers in which substituents extend perpendicular to both sides of a central slab of Ag and S atoms. These data, together with the nonaxial reflections, allow assignment of an approximate monoclinic unit cell as a almost-equal-to 8.7 angstrom, b in proportion to the length of the substituent, c almost-equal-to 4.35 angstrom, and beta almost-equal-to 120-degrees. The thickness of the central Ag,S slab and the small degree of interpenetration of substituents at the interface between layers can be estimated. More sterically demanding substituents R do not permit this layer structure. All attempts to form intercalation compounds, with guests between the distal atoms of the substituents on adjacent layers, were unsuccessful.