Heterocyclic compounds containing two or more hetero rings, at least one ring having selenium, tellurium, or halogen atoms as ring hetero atoms containing two hetero rings directly linked by a ring-member-to-ring-member bond
Heterocyclic compounds containing two or more hetero rings, at least one ring having selenium, tellurium, or halogen atoms as ring hetero atoms containing two hetero rings directly linked by a ring-member-to-ring-member bond