- Detection of free monomeric silver(I) and gold(I) cyanides, AgCN and AuCN: Microwave spectra and molecular structure
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The chemistry of the group 11 metal cyanide system has been of considerable interest because of the commercial importance of some of the complexes formed in this system. These metal cyanides contain one-dimensional linear -M-CN-M-CN-M- chains in the solid
- Okabayashi, Toshiaki,Okabayashi, Emi Y.,Koto, Fumi,Ishida, Toshimasa,Tanimoto, Mitsutoshi
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p. 11712 - 11718
(2009/12/08)
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- Polymorphism of Zn[Au(CN)2]2 and its luminescent sensory response to NH3 vapor
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Four polymorphic forms of the complex Zn[Au(CN)2]2 have been synthesized and both structurally and spectroscopically characterized. In each of the four polymorphs, a zinc center in a tetrahedral geometry with a Au(CN)2- unit at each tetrahedral vertex is observed. All four structures contain three-dimensional networks based on corner-sharing tetrahedra. Because of the long Au(CN)2- bridging unit, the extra space not occupied by one network is filled by two to five additional interpenetrated networks. Short gold-gold bonds with lengths ranging from 3.11 to 3.33 A hold the interpenetrated networks together. Three of the four polymorphs are luminescent, having solid-state emissions with wavelengths ranging from 390 to 480 nm. A linear correlation between the emission energy and the gold-gold distance was observed. Upon exposure to ammonia vapor, the polymers altered their structures and emission energies, with the emission wavelength shifting to 500 nm for {Zn(NH3)2[Au(CN) 2]2}, which adopts a two-dimensional layer structure with octahedral, trans-oriented NH3 groups. The adsorption route is dependent on the polymorph used, with NH3 detection limits as low as 1 ppb. Desorption of the ammonia occurred over 30 min at room temperature.
- Katz, Michael J.,Ramnial, Taramatee,Yu, Hua-Zhong,Leznoff, Daniel B.
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p. 10662 - 10673
(2009/02/05)
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- Thermal decomposition of trialkyl/arylphospfflne gold(I) cyanide complexes
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Combined TG/DTA techniques have been used to study the thermal decomposition of R3PAuCN (where R is ethyl, cyclohexyl, o-tolyl, m-tolyl, p-tolyl, allyl, cyanoethyl, 1-naphthyl and phenyl) complexes. It was observed that all of these complexes underwant decomposition cum redox reactions in the range of 200-600°C with evolution of both trans ligands, which are phosphine and cyanide, leaving metallic gold as a residue. The thermal decomposition of o-Tol3PAuCN has revealed that this is a stepwise process. In the first step decomposition takes place with evolution of phosphine and generation of AuCN, which in second step undergoes a redox reaction to produce metallic gold. The DTA curves have also confirmed these results.
- Akhtar,Isab,Hassan
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p. 119 - 125
(2008/10/08)
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