Nitration of thiacalix[4]arene using nitrosium nitrate complexes:: synthesis and characterization of tetranitro-, tetraamino-, and tetra(4-pyridylimino)tetrahydroxythiacalix[4]arene

The chemistry of the family of thiacalixarenes remains poorly documented although the potentiality of these molecules for complexing reactions or optical applications has been demonstrated. The reaction and the mechanism of the nitration of tetrahydroxythiacalixarene are reported in this paper. The synthesis and structural characterization of 5,11,17,23-tetranitro-25,26,27,28-tetrahydroxythiacalix[4] arene, as well as its reduction to tetraaminotetrahydroxythiacalix[4] arene and the formation of tetra(4-pyridylimino)tetrahydroxythiacalix[4]arene are discussed in this article.