Inorganic Chemistry, Vol.55, No.13, 6609-6615, 2016
Control of Lanthanide Coordination Environment: Synthesis, Structure, and Oxygen-Sensitive Luminescence Properties of an Eight-Coordinate Tb(III) Complex
Coordination environment of the Tb3+ ion in oxygen-sensitive luminescent complexes can be successfully controlled through the size of alkyl substituents on ligands {((ArOH)-Ar-Rme)(4)cyclen} (R = tBu or Me; cyclen = 1,4,7,10-tetraazacyclododecane); a newly prepared eight-coordinate complex 1(tBu) shows higher oxygen sensitivity (K-SV = 17 600) and lower luminescence quantum yield (Phi = 0.67 under N-2) = than those of the previously reported seven-coordinate analogues 1(Me) and [{((ArO)-Ar-MeMe)(3)tacn}Tb-III(THF)] (K-SV = 12 600 and 8300, Phi = 0.91 and 0.91 under N-2, respectively; tacn = 1,4,7-triazacyclononane; THF = tetrahydrofuran). The oxygen-sensitive mechanism is discussed on the basis of the photophysical properties of the corresponding Gd(III) complexes.