Nitrogen dioxide metal atoms

The possible structures for isothiazoles are discussed in Section 4.01.1, and attention in this chapter will be directed mainly towards the aromatic systems, as defined in Section 4.01.1. The saturated isothiazole 1,1-dioxides (5) are known as sultams, and bicyclic compounds of structure (6) are called isopenems. Isothiazoles readily coordinate to metals (76MI41703, 78MI41701, 79MI41700, 80MI41701). Coordination usually takes place through the nitrogen atom, but sulfur coordination can occur with soft metals such as cadmium or mercury. Some specific coordination complexes are discussed in later sections. 

Catalytic activity in the homogeneous gas-phase conversion of nitrogen oxides and carbon monoxide to nitrogen and carbon dioxide was observed to be most effective for the atomic ions Fe+, Os+, and Ir+ out of the investigation of 29 different transition metal cations M+ [462]. The overall catalytic scheme that was established in this study consists of the three catalytic cycles shown in Fig. 1.94. The catalysis occurs in two steps in which NO is first reduced to N2O. An analogous three-step catalytic reduction of NO2, in which NO2 is first reduced to NO, was also discovered. The three cycles in Fig. 1.94 were characterized with laboratory measurements of reactions of each of the three nitrogen oxides NO2, NO, and N2O with the different transition metal ions in an inductively coupled plasma/selected-ion flow tube tandem mass spectrometer [462]. 

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