Calixarene Complexes of Anion-bridged Oligouranyl Species

The syntheses and structures of uranyl complexes of p-t-Bu-calix[6]arene (calix[6]H-6) and p-t-Bu-calix[9]arene (calix[9]H-9) are reported, further developing the role of calixarenes as 'cluster keepers'. The calix[6]arene complex, formulated as [(HO){UO2(calix[6]H-4)(dmso)}(3)H], is trinuclear and linked symmetrically by the hydroxyl 0 atom. The calix[9]arene complex is binuclear, with a carbonate atom bridging between the two uranyl cations to give the complex, (HNEt3)(3)[(OCO2)(UO2)(3)(calix[9]H-4)].