Dinitrogen Reduction, Sulfur Reduction, and Isoprene Polymerization via Photochemical Activation of Trivalent Bis(cyclopentadienyl) Rare-Earth-Metal Allyl Complexes

Article abstract of DOI:10.1021/acs.organomet.5b00613

Dinitrogen can be reduced by photochemical activation of the trivalent rare-earth-metal bis(pentamethylcyclopentadienyl) allyl complexes (C₅Me₅)₂Ln(η³-C₃H₄R) (Ln = Y, Lu; R = H, Me) to form the (N=N)^2- complexes [(C₅Me₅)₂Ln]₂(μ-η²:η²-N₂). This demonstrates that productive organolanthanide photochemistry is not limited to complexes of the unusual (η³-C₅Me₄H)^- ligand in the heteroleptic complexes (C₅Me₅)₂(C₅Me₄H)Ln and (C₅Me₅)(C₅Me₄H)₂Ln. Photolytic activation of (C₅Me₅)₂Ln(η³-C₃H₅) (Ln = Y, Lu) in the presence of isoprene provides a rare photopolymerization route to polyisoprene. Sulfur can also be reduced by photolysis of (C₅Me₅)₂Ln(η³-C₃H₅) (Ln = Y, Lu) to generate the (S)^2- complexes, [(C₅Me₅)₂Ln]₂(μ-S), which have variable Ln-S-Ln angles depending on crystallization conditions.