Definition of tropylium in English:

tropylium

Pronunciation /trəʊˈpɪlɪəm/ /trəˈpɪlɪəm/

noun

Chemistry
  • The cation C₇ H₇ +, which consists of a planar ring of seven CH groups and has aromatic character. Chiefly attributive or as a formative element in chemical names.

Origin

1950s. From trop- + -yl + -ium.