Cationic borohydrido-neodymium complex: Synthesis, characterization and its application as an efficient pre-catalyst for isoprene polymerisation

The cationic borohydrido lanthanide complex [Nd(BH4)(2)(THF)(5)][B(C6F5)(4)] 1, prepared from the reaction of Nd(BH4)(3)(THF)(3) with [HNMe2Ph][B(C6F5)(4)], is highly active towards isoprene polymerisation upon activation with Al(i-Bu)(3), whereas the in situ prepared ternary catalytic combination Nd(BH4)(3)(THF)(3)/[HNMe2Ph][B(C6F5)(4)]/Al(i-Bu)(3), albeit less active, displays higher cis- selectivity and better control in terms of macromolecular data.