Organometallic complexes analogous to uranocene are known also for other actinides, such as thorium, protactinium, neptunium, plutonium and americium. Molecular orbital theory predicts a stable "curocene" complex (η8-C8H8)2Cm, but it has not been reported experimentally yet.[74][75]
Formation of the complexes of the type Cm(n-C3H7-BTP)3, where BTP stands for 2,6-di(1,2,4-triazin-3-yl)pyridine, in solutions containing n-C3H7-BTP and Cm3+ ions has been confirmed by EXAFS. Some of these BTP-type complexes selectively interact with curium and therefore are useful in its selective separation from lanthanides and another actinides.[25][76] Dissolved Cm3+ ions bind with many organic compounds, such as hydroxamic acid,[77] urea,[78] fluorescein[79] and adenosine triphosphate.[80] Many of these compounds are related to biological activity of various microorganisms. The resulting complexes exhibit strong yellow-orange emission under UV light excitation, which is convenient not only for their detection, but also for studying the interactions between the Cm3+ ion and the ligands via changes in the half-life (of the order ~0.1 ms) and spectrum of the fluorescence.[26][77][78][79][80]
Curium has no biological significance.[81] There are a few reports on biosorption of Cm3+ by bacteria and archaea, however no evidence for incorporation of curium into them