A novel 1

3-disubstitued indolyl ligand was designed and synthesized

and furtherly

a series of corresponding rare-earth metal complexes were obtained. The complexes were characterized by X-ray single crystal diffraction

nuclear magnetic resonance (NMR) spectroscopy

Fourier transform infrared (FTIR) spectroscopy as well as elemental analysis. The results indicated that the ligand coordinated to the metal in NCN tridentate mode to form a mononuclear penta-coordination geometry

adding two alkyl groups. The complexes could efficiently catalyze the isoprene polymerization with AlMe

3

and [Ph

3

C][B(C

6

F

5

)

4

] as co-catalysts to obtain 1

4-

cis

polymer.