Molecular box treats chemists to a strained surprise
Introducing pillar[4]pyridinium – the first of a new family of macrocycles
Scientists in Poland have made the most compact multiply charged macrocycle to date. Pillar[4]pyridinium is a cyclic tetramer consisting of four pyridyl units with methylene bridges between their nitrogens and para carbons. The quadruply charged molecule has a very symmetrical and incredibly strained structure.