Three
series of lanthanide coordination polymers, {[Ln(L)(H2O)2]·NO3·2H2O }
n
(Ln = La 1, Pr 2), {[Ln2(L)2(NO3)(H2O)2]·Cl·6H2O}
n
(Ln = Nd 3),
{[Ln(L)(H2O)2]·Cl·3H2O}
n
(Ln = Sm 4, Eu 5, Gd 6, Tb 7, Dy 8, Ho 9, Er 10, Tm 11, Yb 12, and Lu 13) (H3L = 4-carboxy-1-(3,5-dicarboxy-benzyl)-pyridinium
chloride), have been successfully synthesized under hydro(solvo)thermally
conditions. Single-crystal X-ray diffraction analyses revealed that
compounds 1–3 all crystallize in
triclinic space group P1̅, but they display
different three-dimensional structures with diverse dinuclear subunits.
In contrast, compounds 4–13 display
the same layer structures in the triclinic space group P1̅. The structural difference of these two classes of compounds
is derived from the effect of lanthanide contraction. Powder X-ray
diffraction (PXRD) and thermogravimetric analyses of compounds 1–13 have also been investigated and discussed
in detail. The solid-state luminescent properties of compounds 4, 5, 7, and 8 were
characterized, and the results revealed that they exhibit characteristic
Sm(III), Eu(III), Tb(III), and Dy(III) emissions in the pink, red,
green, and yellow light regions, respectively. More interestingly,
the luminescence colors of the Tb(1–x)(L):xEu can easily be tuned from green to
green-yellow, yellow, orange,
and red-orange due to the energy transfer from Tb3+ to
Eu3+ ions by adjusting the doping concentration of Eu3+ ions.