Lanthanide Complexes with Photochromic Organoboron Ligand: Synthesis and Luminescence Study.

A novel, photochromic N^C-chelate organoboron functionalized dipicolinic acid (H2L) has been designed and synthesized. Lanthanide(III) complexes based on this ligand (L) with the general formula [NBu4]3[LnL3] (Ln = Eu or Tb) were prepared. The new ligand was found to be effective in both sensitizing and photomodulating the emission of a Eu(III) ion. The photoisomerization conversion of the boryl chromophore attached to the ligand of the lanthanide complex was determined to be quantitative by NMR analysis of the La(III) analogue.