Tunable white-light emission from mixed lanthanide (Eu³⁺, Gd³⁺, Tb³⁺) coordination polymers derived from 4-(dipyridin-2-yl)aminobenzoate

Abstract

Herein, we have developed a series of isostructural mixed Ln(3+)-4-(dipyridin-2-yl)aminobenzoate coordination polymers [Ln(3+) = Eu(3+) (1), Tb(3+) (2), and Gd(3+) (3)], and characterized and investigated their photophysical properties. The results demonstrated that by gently tuning the excitation wavelength of these mixed lanthanide complexes, white light emission can be realized with the Commission Internationale de I'Eclairage coordinates (0.32, 0.34). Furthermore, by changing the concentration profiles of lanthanide ions stoichiometrically in mixed-lanthanide complexes and exciting at particular wavelengths, various emission colours can also be successfully obtained. The antenna ligand, 4-(dipyridin-2-yl)aminobenzoic acid, provides an efficient energy transfer for the sensitization of Eu(3+) and Tb(3+) complexes and exhibits red and green emissions, respectively. Most importantly, due to the high energy (32,150 cm(-1)) of the Gd(3+) ion lowest-lying emission level, the corresponding Gd(3+) complex displays ligand-centered visible emission in the blue light region, and hence it acts as a blue emitter. Therefore, Eu(3+) and Tb(3+) complexes in conjunction with a Gd(3+) complex is a suitable choice to obtain tunable white-light-emission from Ln(3+) coordination polymers. The morphological analyses of the mixed lanthanide coordination polymers by transmission electron microscopy (TEM) disclose that these compounds exist as unique crystalline nano-rods with an average diameter of 200 nm. The developed mixed lanthanide complexes also exhibit high thermal stability (~420 °C).

Flexible composite nanobelts: facile electrospinning construction, structure and color-tunable photoluminescence

“…At present, Many kinds of materials have been adopted for color-tunable luminescence, including inorganic phosphors [6,7], metal-organic frameworks [8,9], functional organic materials [10,11], semiconductor quantum dots [12], rare earth (RE) organic complexes [13], etc.…”

Synthesis and characterization of the novel color-tunable Eu/Tb(BPA)3phen composites

“…Recently, the color-tunable luminescent materials for their potential applications in flat panel display systems, full-color displays [1], next-generation lighting sources [2], biomakers, imaging [3,4] and so on, has been paid much attention. Many kinds of color-tunable materials have been investigated, including inorganic phosphors [5,6], metal-organic frameworks [7,8], functional organic materials [9,10], rare earth (RE) organic complexes [11], etc. Among which, rare earth ions possess luminescence characteristics like narrow spectral widths, long luminescence lifetimes, large Stokes shifts and large strong binding with biological molecules.…”

Synthesis and photophysical properties of a highly luminescent Eu III -containing hybrid thin film

“…The photoluminescent properties of lanthanoid compounds have drawn extensive attention due to their attractive features, such as characteristic sharp-line emissions, long emission lifetimes and high quantum yields [1][2][3][4]. These features make Ln III -based materials suitable for use in a wide range of applications, such as sensing [5][6][7][8][9][10][11], imaging [12,13], and phosphors in lighting [14][15][16][17][18]. Due to the nature of the 4f-4f transition, the direct excitation of Ln III is rather inefficient.…”