Abstract
The reactions of the imino-functionalized indolyl ligand (HL, L = 3-(4-Me2N-C6H4CH=N-CH2CH2)C8H5N) with the rare-earth metal amides [(Me3Si)2N]3RE(µ-Cl)Li(THF)3 producing different types of rare-earth metal amido complexes were investigated. The reactions of HL with 1 equiv. of [(Me3Si)2N]3RE(µ-Cl)Li(THF)3 generated a series of hetero-nuclear bimetallic rare-earth metal amino complexes {[η1:µ-η2-3-(4-Me2N-C6H4CH=N-CH2CH2)C8H5]RE[N(SiMe3)2]2(µ-Cl)Li(THF)} (RE = Y(1), Sm(2), Gd(3), Er(4), Yb(5)). By extending the reaction time, only the reaction of HL with [(Me3Si)2N]3Gd(µ-Cl)Li(THF)3 gave an unexpected binuclear rare-earth metal complex {[(µ-η5:η1):η1:η1-3-[(Me2N)2-C14H9]-(NCH2CH2-C8H5N)2]Gd2[N(SiMe3)2]3} (6) incorporating a novel polycyclic ligand through C-C and C-N coupling. Treatment of HL with [(Me3Si)2N]3Sm(µ-Cl)Li(THF)3 in a 2:1 ratio generated the bis(indolyl) heteronuclear bimetallic rare-earth metal amino complex {(η1:η1-[µ-η2:η1-3-(4-Me2N-C6H4CH=N-CH2CH2)C8H5]Li[µ-η2:η1-3-(4-Me2N-C6H4CH=N-CH2CH2)C8H5])Sm[N(SiMe3)2]2} (7) in low yield probably due to accompanying with the formation of the complex 2. The above results indicated that reaction conditions play important roles in the formation of different coordination modes of the imino-functionalized indolyl rare-earth metal amido complexes. All new complexes 1−7 are fully characterized including X-ray structural determination. The catalytic activity of complexes 1-7 for the addition of amines to carbodiimides was explored. The results showed that all complexes displayed an excellent activity towards the addition of amines to carbodiimides producing guanidine under solvent-free condition.
Published Version
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call