Efficient pure white tight emission based on a three-component La:Eu,Tb-doped luminescent lanthanide metal-organic framework

A series of novel similar lanthanide metal-organic frameworks, namely, [Ln(2)L1(2)L2((4-x-y)L3(x)L4(y))]center dot nH(2)O (LnMOF-1-13) (LnMOF-1: Ln = La, x = 0.7, y = 1.3, n = 4.7; LnMOF-2: Ln = Ce, x = 0.7, y = 1.3, n = 4.7; LnMOF-3: 1.11 = Pr, x = 1, y = 1, n = 5; LnMOF-4: Ln = Sm, x = 1, y = 1, n = 2.5; LnMOF-5: Ln = Eu, x = 1, y = 1,n = 3; LnMOE-6: Ln = Tb,x = 0, y = 2,n = 2; LnMOE-7: Ln = Dy,x= 1, y = 1, n = 3; LnMOE-8: Ln - Er, x = 0, y = 1, n = 3; LnMOE-9: Ln = Nd, x = 1.4, y = 1.4, n = 3.6; LnMOE-10: Ln = Gd, x = 1, y = 1, n = 3; LnMOF-11: Ln = Ho, x = 1.6, y = 0, n = 3; LnMOF-12: Ln = La0.44Eu0.10Tb0.46, x = 1, y = 1, n = 7; LnMOF-13: Ln = La0.66Eu0.11Tb0.23, x = 1, y = 1, n = 7; Li = 5-((4-formylphenoxy)methyl)isophthalic acid anion, L2 = C3H7ON, L3 = H2O, L4 = HCOOH), have been prepared using a solvothermal method and characterized by single crystal and powder X-ray diffraction, IR spectroscopy, elemental analysis and thermogravimetric analysis. All structures are similar and possess a 3D binodal (3,6)-connected net with the point symbol (4(2).6)(2) (4(4).6(2).8(7).10(2)). Furthermore, the luminescence measurements indicate that compounds LnMOF-5 and LnMOF-6 display intense characteristic red and yellowish-green emission with quantum yields of 23.30% & 28.25%, respectively. And the three-component La:Eu,Tb-doped compounds exhibit white emission under UV irradiation, especially the compound LnMOF-12 which exhibits the Commission International de l'Eclairage (CIE) chromaticity coordinate (0.332, 0.333) with pure white light emission (phi = 11.22% at 345 nm). Additionally, the magnetic properties of LnMOE-10 are also investigated.