Neutral and cationic alkyl and alkynyl complexes of lanthanum: Synthesis, stability, and cis-selective linear alkyne dimerization

Neutral triazacyclononane-amide lanthanum dialkyl and dialkynyl complexes were synthesized and structurally characterized. A cationic triazacyclononane-amide lanthanum monoalkyl species was generated and found to be highly active (tof > 100 h(-1)) in the rare cis-selective catalytic linear dimerization of phenylacetylene.