Johnson Katherine R, Vittardi Sebastian B, Gracia-Nava Manuel A, Rack Jeffrey J, de Bettencourt-Dias Ana
Department of Chemistry, University of Nevada, Reno, Reno, NV, 89557, USA.
Department of Chemistry and Chemical Biology, University of New Mexico, Albuquerque, NM, 87131, USA.
Chemistry. 2020 Jun 5;26(32):7274-7280. doi: 10.1002/chem.202000587. Epub 2020 May 19.
Lanthanide ion (Ln ) complexes, [Ln(3Tcbx) ] (Ln =Yb , Nd , Er ) are isolated with a new pyridine-bis(carboxamide)-based ligand with a 2,2':5',2''-terthiophene pendant (3TCbx), and their resulting photophysical properties are explored. Upon excitation of the complexes at 490 nm, only Ln emission is observed with efficiencies of 0.29 % at 976 nm for Ln =Yb and 0.16 % at 1053 nm for Ln =Nd . Er emission is observed but weak. Upon excitation at 400 nm, concurrent O formation is seen, with efficiencies of 11 % for the Yb and Nd complexes and 13 % for the Er complex. Owing to the concurrent generation of O , as expected, the efficiency of metal-centered emission decreases to 0.02 % for Yb and 0.05 % for Nd . The ability to control O generation through the excitation wavelength indicates that the incorporation of 2,2':5',2''-terthiophene results in access to multiple sensitization pathways. These energy pathways are unraveled through transient absorption spectroscopy.
镧系离子（Ln ）配合物[Ln(3Tcbx) ]（Ln =Yb 、Nd 、Er ）是通过一种带有2,2':5',2''-三联噻吩侧基的新型吡啶-双（羧酰胺）基配体（3TCbx）分离得到的，并对其产生的光物理性质进行了研究。在490 nm处激发配合物时，仅观察到Ln发射，对于Ln =Yb ，在976 nm处的发射效率为0.29%，对于Ln =Nd ，在1053 nm处的发射效率为0.16%。观察到了Er发射，但较弱。在400 nm处激发时，同时会生成单线态氧（ O），Yb和Nd配合物的生成效率为11%，Er配合物的生成效率为13%。正如预期的那样，由于同时生成单线态氧，以金属为中心的发射效率对于Yb降至0.02%，对于Nd降至0.05%。通过激发波长控制单线态氧生成的能力表明，2,2':5',2''-三联噻吩的引入导致了多种敏化途径。这些能量途径通过瞬态吸收光谱得以揭示。
