Tetrathiatetraza-azulene

Abstract

Dedicated with warm regards to Professor Gurnos AbstractTetrasulfur tetranitride 1 reacts with phenyl vinyl sulfoxide 3 or sulfone or phenyl vinyl sulfonate to give the planar delocalised 14 P electron aromatic system 1 λ4δ2 , 3,5,7 λ4δ2 -tetrathia-2,4,6,8-tetraza-azulene 4 as stable dark metallic lustrous crystals. All the sulfur and nitrogen atoms of S 4 N 4 have been retained and a C-C P bond incorporated, the 12 P cage structure of S 4 N 4 being converted into the planar bicyclic system. A mechanism is proposed for this transformation. The ability of the vinyl component to act as an acetylene equivalent and to suffer dehydrogenation to give the aromatic product appear to be necessary for this type of reaction since more highly substituted sulfoxides lead only to decomposition. Optimum conditions for the reaction of phenyl vinyl sulfoxide with S 4 N 4 (3.6 equiv.) in refluxing xylene for 7.5 h give the tetrathiatetrazaazulene 4 in 35%.

Breathing Some New Life into an Old Topic: Chalcogen-Nitrogen π-Heterocycles as Electron Acceptors

“…Besides 1,2,5-chalcogenadiazoles, there is very interesting group of miscellaneous chalcogen-nitrogen π-heterocycles covering their isomers, 1,2,6-thia(selena)diazines and some other systems partially represented in Table 2, Table 3, Table 4, Table 5 and Table 6 and expected to be precursors of stable RAs. Some of these compounds are known for a long time [83,84,85,159,160,161,162,163,85,159] but did not attract attention within RA chemistry for various reasons. Selection of 1,2,6-thia(selena)diazines discussed below is based on their involvement in ongoing research by the authors.…”

“…In some important aspects, this new field conceptually overlaps with, and continues development of, the chemistry of polysulfur-nitrogen heterocyclic compounds, i.e. , compounds with unusually high proportions of sulfur and nitrogen atoms with respect to carbon atoms, originated by Charles W. Rees in the early 1980s [82,83,84,85,86].…”