Cinnamal Sensing and Luminescence Color Tuning in a Series of Rare-Earth Metal−Organic Frameworks with Trans-1,4-cyclohexanedicarboxylate
oleh: Pavel A. Demakov, Alena A. Vasileva, Sergey S. Volynkin, Alexey A. Ryadun, Denis G. Samsonenko, Vladimir P. Fedin, Danil N. Dybtsev
| Format: | Article |
|---|---|
| Diterbitkan: | MDPI AG 2021-08-01 |
Deskripsi
Three isostructural metal–organic frameworks ([Ln<sub>2</sub>(phen)<sub>2</sub>(NO<sub>3</sub>)<sub>2</sub>(chdc)<sub>2</sub>]·2DMF (Ln<sup>3+</sup> = Y<sup>3+</sup> for <b>1</b>, Eu<sup>3+</sup> for <b>2</b> or Tb<sup>3+</sup> for <b>3</b>; phen = 1,10-phenanthroline; H<sub>2</sub>chdc = <i>trans</i>-1,4-cyclohexanedicarboxylic acid) were synthesized and characterized. The compounds are based on a binuclear block {M<sub>2</sub>(phen)<sub>2</sub>(NO<sub>3</sub>)<sub>2</sub>(OOCR)<sub>4</sub>} assembled into a two-dime nsional square-grid network containing tetragonal channels with 26% total solvent-accessible volume. Yttrium (<b>1</b>)-, europium (<b>2</b>)- and terbium (<b>3</b>)-based structures emit in the blue, red and green regions, respectively, representing the basic colors of the standard RGB matrix. A doping of Eu<sup>3+</sup> and/or Tb<sup>3+</sup> centers into the Y<sup>3+</sup>-based phase led to mixed-metal compositions with tunable emission color and high quantum yields (QY) up to 84%. The bright luminescence of a suspension of microcrystalline <b>3</b> in DMF (QY = 78%) is effectively quenched by diluted cinnamaldehyde (cinnamal) solutions at millimolar concentrations, suggesting a convenient and analytically viable sensing method for this important chemical.