Estudo sobre a influência das ligações [pi] na luminescência de novos complexos contendo íons lantanídeos

Abstract

Researches about lanthanides ions have a growing interest in consequence of its photophysic properties, through several applications, among them; lasers, contrast agents, etc. These properties elapse from energy absorption of binder and emission in visible region because of metal type as example Eu3+ complexes which emit in red region. This process of energy transfer is called Antenna Effect. The carboxilate groups bond skillfully with these trivalent cations, for being Pearson’s hard bases and usually present high absorption and energy transfer. Some energy binder-metal transfer mechanisms are known, in which its study is necessary to creation of much more luminescence complexes, thus as spectroscopic studies and knowledge about binder’s triplet states, wherein such states are obtained from Gd3+ complexes’ phosphorescence. Because of that were synthetize complexes of trans-3(3-tienil)-acrylic acid and 4(2-tienil)-butyric acid with Eu3+ and Gd3+, mixing proportions; 3:1 and 4:1. The acids, carboxilates and all complexes were characterized by Infrared Spectroscopy, and done a spectroscopic study through Eletronic Luminescense Spectroscopy. In which were noticed the symmetric and asymmetric bands of group OCO-, besides maximum of excitation and emission of each Eu3+ complex. The emissions intensity on 5D0 -7F2 hypersensible transitions from ion were higher in Eu-ATA-3:1 and Eu-ATB-4:1, with diference between state T1 of binder and state D2 of ion near 440 cm-1 e 550 cm-1, respectively.