2-Thienyl- and 2,2'-bithienyl-5-yltropylium ions, as well as 2,5-thien
ylenebis(tropylium), 2,2'-bithienyl-5,5'-diylbis(tropylium), and 2,2':
5',2 '':-5 '',2triple prime-quaterthienyl-5,5triple prime-diylbis(trop
ylium) ions have been synthesized and their electronic structures in t
he ground and excited states have been clarified.