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Four K, Cs, Ag(I), and Tl(I) compounds with a nitrosodicyanomethanide ONC(CN)(2)(-) anion have been obtained and characterized using IR spectroscopy; UV-visible spectroscopy; room temperature, solid-state photoluminescence; and solutions electrical conductivity measurements. Cesium and thallium(I) complexes were obtained for the first time, and crystal structures were determined for Cs{ONC(CN)(2)}, Ag{ONC(CN)(2)}, and Tl{ONC(CN)(2)}. These structures indicate the formation of completely different 3D polymeric networks in which the anion acts as a bridging ligand of different capacity. The cyanoxime ligand in all complexes studied is in the nitroso form and adopts a planar configuration. The structure of the cesium salt is ionic. The structure of Ag{ONC(CN)(2)} represents a 3D coordination polymer where the anion acts as a tetradentate ligand with all four bonds between Ag(I) and donor atoms (three N and one O) significantly shorter than the sum of the ionic radii for these elements. The silver(I) atom in this compound has a distorted tetrahedral surrounding. Additionally, Ag{ONC(CN)(2)} is remarkably UV- and visible-light-insensitive. However, after exposure of the solid complex to gases such as H(2), CO, NO, C(2)H(2), and C(2)H(4), the surface of the compound becomes visible-light-sensitive and changes color with significant darkening, which indicates reduction of the metal. This is reflected in a dramatic decrease of intensity of the photoluminescence of Ag[ONC(CN)(2)] in the presence of these gases, which might be utilized for nonelectric sensor applications. The Tl[ONC(CN)(2)] complex represents a transitional species between ionic (Cs) and covalent (Ag) compounds. The thallium(I) center has four shorter bonds than the sum of the ionic radii bonds (three with N and one with O atoms) and three longer electrostatic (ionic) contacts with the anion. The 6s(2) lone pair is stereoactive, and the coordination polyhedron is best described as a distorted square pyramid. Room temperature diffusion reflectance spectra of solid K{ONC(CN)(2)}, Ag{ONC(CN)(2)}, and Tl{ONC(CN)(2)} demonstrated a bathochromic shift of the band's lambda(max) depending on the atomic number of the metal center, indicating a significant role of metal centers in electronic transitions in these compounds. This phenomenon was observed for the first time. The latter complex at 293 K exhibited structured metal-based red photoluminescence in the range of 690-800 nm that depends on the excitation wavelengths.

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Crystals of XeF+AsF6-are monoclinic, space group P 2 , / n , a = 6.308 (3) A, b = 6.275 (3) A, c = 16.023 (5) A, p = 99.97 (5)', I/ = 624.66 A3, Z = 4, and d, = 3.61 g ~m -~, at 24 'C. X-ray diffraction data were measured with counter methods and Mo Ka radiation. With anisotropic temperature factors for all atoms, R = 0.033 for 777 independent reflections ( I > 36). The structure consists of ion pairs connected by a bridging fluorine atom into FXeFAsF5 units. The FXeF portion of the molecule is linear (angle = 178.9 (7)') with Xe-F = 1.873 (6) A (terminal) and 2.212 (5) 8, (bridging). The FAsF5 portion of the molecule is roughly octahedral with cis F-As-F angles ranging from 85.3 (3) to 94.6 (5)'; the five terminal As-F distances range from 1.676 (5) to 1.690 (8) 8, and the bridging As-F distance is 1.813 (6) A. The bridge Xe-F-As angle is 134.8 (2)'.