Thermostable 1D Lanthanide 4-Phenylbenzoate Polymers [Ln(4-phbz)(3)](n) (Ln = Sm, Eu, Gd, Tb, Dy, Ho) with Isolated Metal Chains: Synthesis, Structure, Luminescence, and Magnetic Properties

摘要

New 1D polymers, with the general formula [Ln(4-phbz)(3)](n), where Ln = Sm, Eu, Gd, Tb, Dy, Ho, and 4-phbz is the 4-phenylbenzoate anion, were synthesized by the reaction of Ln(NO3)(3)center dot xH(2)O, 4-phenylbenzoic acid, and dry KOH. Thermal analysis shows that [Eu(4-phbz)(3)](n) is thermally stable under an inert gas up to 350 degrees C, and it melts at 297 degrees C. It is shown that the 4-phenylbenzoate anion [E(T-1) approximate to 22500 cm(-1)] in [Ln(4-phbz)(3)](n) can play the role of an antenna and sensitize the luminescence of Eu3+ and Tb3+ ions. Analysis of the magnetic data of the [Gd(4-phbz)(3)](n) complex reveals weak antiferromagnetic coupling between Gd3+ ions (J = -0.053 cm(-1)). The [Dy(4-phbz)(3)](n) compound shows noticeable frequency-dependent chi '' signals, indicating slow magnetic relaxation and single-molecule magnet behavior, with an energy barrier of Delta E-eff/k(B) = 5 K.