1148-79-4 2,2',2''-Terpyridine 2,2',2''-Terpyridyl 2,2',2''-Tripyridyl 2,2'2''-Tripyridyl 2,2':6',2''-Terpyridine 2,6-Bis(2-pyridyl)pyridine 27269-04-1 Ba 2799 CCRIS 3429 EINECS 214-559-5 NSC 36755 NSC 3905 Tripyridine Tripyridyl