Heterocyclic inorganic ring systems

Heteroboranes, structure prediction for. 802-807 Heterocatenation. 741-742 Heterocyclic inorganic ring systems, 775-780 Heterogeneous catalysts, 705 Heteronuclear diatomic molecules. molecular orbitals in, 167-175... 

The criterion of ipsocentric ring current has been used to assess aromaticity in S-N heterocycles (and related inorganic ring systems). Current density maps indicate that the ten r-electron systems [SsNs], [S4N3] " and [S4N4] ", and the fourteen r-electron system [S5N5] " support diatropic k currents, reinforced by a circulations. 

I. Haiduc, The Chemistry of Inorganic Ring Systems, Part 2, (sulfur-nitrogen heterocycles), pp. 909-83, Wiley, London, 1970. 

Sulfur-nitrogen heterocycles provide the most commonly encountered examples of interactions involving inorganic ring systems. For example,... 

The formation of anion radicals by chemical or electrochemical reduction may provide information about electron delocalisation in an inorganic ring system through the determination of the EPR spectrum in conjunction with molecular orbital calculations. In practice, however, the LUMO of the homo- or heterocycle is often an antibonding orbital. Consequently, occupation of the LUMO... 

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