Lanthanide Aminoisophthalate Coordination Polymers: A Promising System for Tunable Luminescent Properties

Reactions in water between the disodium salt of 5-amino-1,3-benzenedicarboxylic acid or 5-aminoisophthalate (Na(2)aip) and lanthanide chlorides lead to two families of coordination polymers with the respective general chemical formulae {[Ln(6)(aip)(7)(H2O)(24)]center dot 2(aip)center dot 6H(2)O}(infinity) in which Ln = Tm or Yb (Family 1) and {[Ln(2)(aip)(2)(H2O)(10)]center dot(aip)center dot 4H(2)O}(infinity) in which Ln = La-Er (except Pm) or Y (Family 2). Compounds belonging to Family 1 are isostructural. The crystal structure has been solved for the Er-containing compound. This compound crystallizes in the monoclinic system, space group P2(1)/n (n degrees 14) with a = 13.3439(3) angstrom, b = 27.3332(8) angstrom, c = 15.7191(4) angstrom, beta = 97.90(1)degrees, V = 5680.41(82) angstrom(3) and Z = 4. The crystal structure can be described as the juxtaposition of double helicoidal chains. Additional aminoisophthalate ions insuring the electroneutrality of the network are lying in the interchain space. Compounds belonging to Family 2 are isostructural. The crystal structure has been solved for the Eu-containing compound. This compound crystallizes in the monoclinic system, space group Pn (n degrees 7) with a = 11.3427(2) angstrom, b = 10.6663(1) angstrom, c = 15.1639(3) angstrom, beta = 97.8998(9), V = 1817.19(5) angstrom(3) and Z = 2. The crystal structure can be described as the juxtaposition of zigzag double chains. Additional aminoisophthalate ligands are lying in the interchain space insuring the electroneutrality of the network. The luminescent properties under UV irradiation of these compounds have been explored. In particular, quantum yields, lifetimes and colorimetric coordinates of the Tb-, the Sm-, and the Dy-containing coordination polymers have been determined.