Luminescent lanthanide complexes with 4-acetamidobenzoate: Synthesis, supramolecular assembly via hydrogen bonds, crystal structures and photoluminescence

Crystal structure of bis(μ2-benzoato-k2O:O′)-bis(μ2-benzoato-k3O,O′:O′)dinitrato-k2O,O′-bis(phenanthroline-k2 N,N′)dierbium(III), C52H36Er2N6O14

C52H36Er2N6O14, triclinic, P 1 ‾ $\overline{1}$ (no. 2), a = 10.6499(5) Å, b = 11.0111(5) Å, c = 11.0380(6) Å, α = 85.030(4)°, β = 81.502(4)°, γ = 68.925(4)°, V = 1193.77(11) Å3, Z = 2, R gt (F) = 0.0263, wR ref (F 2) = 0.0592, T = 150.0 K.

Cinnamal Sensing and Luminescence Color Tuning in a Series of Rare-Earth Metal-Organic Frameworks with Trans-1,4-cyclohexanedicarboxylate

Three isostructural metal-organic frameworks ([Ln2(phen)2(NO3)2(chdc)2]·2DMF (Ln3+ = Y3+ for 1, Eu3+ for 2 or Tb3+ for 3; phen = 1,10-phenanthroline; H2chdc = trans-1,4-cyclohexanedicarboxylic acid) were synthesized and characterized. The compounds are based on a binuclear block {M2(phen)2(NO3)2(OOCR)4} assembled into a two-dime nsional square-grid network containing tetragonal channels with 26% total solvent-accessible volume. Yttrium (1)-, europium (2)- and terbium (3)-based structures emit in the blue, red and green regions, respectively, representing the basic colors of the standard RGB matrix. A doping of Eu3+ and/or Tb3+ centers into the Y3+-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 3 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.