Variable nuclearity in lanthanoid coordination chemistry

A series of lanthanoid and iodine containing compounds of formulae [Ln(IPhacac)3(dmf)2], [K(dmf)2{Ln(IPhacac)4}]n and [Ln5(OH)5(IPhacac)10] {(IPhacac) = bis(para-iododibenzoyl)methanide} have been prepared and structurally characterised. X-ray crystallography establishes that the compounds exist as monomers [Ln(IPhacac)3(dmf)2] {Ln = Pr (1), Nd (2), Tb (5), Dy (6)} and [Yb(IPhacac)3(dmf)2][Yb(IPhacac)3(dmf)(H2O)] (7) (dmf = N,N-dimethylformamide), polymers [K(dmf)2{Ln(IPhacac)4}]n {Ln = Nd (2a), Eu (3a), Gd (4a), Tb (5a), Dy (6a)} and pentanuclear clusters [Ln5(OH)5(IPhacac)10] {Ln = Tb (5b), Dy (6b), Yb (7b)}