Thorium(IV) and Uranium(IV) Complexes with Cucurbit[5]uril.

Tetravalent thorium and uranium complexes with cucurbit[5]uril (Q[5]) were investigated with eight new complexes being synthesized and structurally characterized. [Th(Q[5])(OH)(HO)]·18NO· nHO (1) has a hexagonal nanowheel structure with each of the six Th ions being cap-coordinated by a Q[5] and monodentate-coordinated to the nearby Q[5]. [Th(Q[5])(HCOO)(HO)][Th(NO)(HO)][Th(NO)(HCOO)(HO)]·NO· nHO (2) has a heteroleptic mononuclear structure with a Th ion cap-coordinated on one side of the Q[5] portal and monodentate-coordinated to a formate anion inside the Q[5] cavity. [KTh(Q[5])Cl(NO)][Th(NO)(HO)]·2NO·2.5HO (3) has a heterometallic structure with both Th and K ions each occupying one side of the two Q[5] portals forming a capsule. [CsTh(Q[5])Cl(NO)(HO)]·2NO· nHO (4) has a heterometallic 1D polymeric structure with both Th and Cs ions each occupying one side of the two Q[5] portals, forming monomers which are linked together by sharing two water molecules and one carbonyl oxygen atom between Th and Cs ions. [Th(Q[5])Cl(HO)][CdCl][CdCl]·0.5HCl·4HO (5), [Th(Q[5])Cl(HO)][RuOCl(HO)]·0.5HCl·9.5HO (6), [Th(Q[5])Cl(HO)][IrCl]·3HO (7), and [U(Q[5])Cl(HO)][ZnCl(HO)][(ZnCl)]·8HO (8) have similar 1D polymeric structures with Th/U ions cap-coordinated on one side of a Q[5] and bidentate coordinated to the nearby Q[5]. The transition metal chlorides act as anions for charge compensation as well as structure inducers via cation-anion interactions forming various anion patterns around the 1D polymers. Actinide contraction has been observed in the early actinide series.