ˈɪɹɪdˌoʊsiːn ɪnvˈɑːlvɪŋ ɪɹˈɪdiəm wʊd pɹɪzˈuːməbli biː stˈɪl mˈoːɹ pˈoʊtənt, bˌʌt ɪz nˌɑːt vˈɛɹi wˈɛlstˈʌdid dˈuː tʊ ɪts ɪnstəbˈɪlᵻɾi.
Iridocene (involving iridium) would presumably be still more potent, but is not very well-studied due to its instability.