LAUSR

Exploring lanthanide complexes as luminescence sensors is an interesting topic. By utilizing 2-(4-carboxyphenyl)imidazo[4,5-f][1,10]phenanthroline (Hcpip) and 2-phenylimidazo[4,5-f][1,10]phenanthroline (pip), two series of lanthanide complexes, one-dimensional [Ln2(cpip)2(OAc)4]n (1-Ln; Ln = Sm, Eu) and zero-dimensional [Ln2(pip)2(OAc)6] (0-Ln; Ln = Sm, Eu, Tb, Dy), have been synthesized and crystallographically characterized. The in situ hydrothermal hydrolysis of acetonitrile yields the acetate anions. For both series, the main feature is the existence of [Ln2(μ-η1:η2-COO)2(μ-η1:η1-OAc)2(η2-OAc)2] subunits, in which μ-η1:η2-COO− refers to the carboxylate group when the ditopic Hcpip is used, but in the case of the monotopic pip, μ-η1:η2-COO− comes from the acetate. Insoluble polymeric 1-Eu in its water suspension exhibits specific but slow luminescence response (emission colour changes from red to bluish green). As an improvement, the dimeric 0-Eu is soluble in DMSO and shows the luminescence response immediately.