Molecular Crystals and Liquid Crystals Science and Technology. Section A. Molecular Crystals and Liquid Crystals, Vol.342, 57-62, 2000
Synthesis and properties of europium complex of polybenzimidazole containing N-Eu bond
NaH promoted deprotonation of the NH groups in poly(benzimidazole)s, [-Im-C6H4-](n) (1a) (Im: 5,5'-dibenzimidazole-2,2'-diyl) and [{-Im-(CH2)(11)O(CH2)(11)(-)}0.98{-Im-(CH2)(10)}(0.02)-](n) (Ib) followed by addition of 4 equiv. of EuCl3 gave new soluble Eu complexes of poly(benzimidazole)s (2a and 2b) having N-Eu bonds in 66 and 42% yields, respectively. The Eu polymer complexes 2a and 2b have two molecules of Cl and DMSO as ligands, which was revealed from IR and H-1 NMR spectra and elemental analysis. Energy transfer from the benzimidazole group in polymer main chain to the Eu(III) metal was occurred upon irradiation with UV light in the solid state. This resulted in light emission from both the polymer chain and the Eu(III) center, although the Eu(III) itself could not be excitated by irradiation with the UV light.