[(η 6 ‐Cyclooctatetraene){η 5 ‐(+)‐neomenthylcyclopentadienyl}ruthenium( II )] Hexafluorophosphate: Synthesis and Characterization of a Chiral Mixed Sandwich Complex

Three different {η 5 ‐(+)‐neomenthylcyclopentadienyl}ruthenium complexes have been synthesized from (−)‐menthol: [(η 6 ‐benzene){η 5 ‐(+)‐neomenthylcyclopentadienyl}ruthenium( II )] hexafluorophosphate ( 1 ), [tris(acetonitrile){η 5 ‐(+)‐neomenthylcyclopentadienyl}ruthenium( II )] hexafluorophosphate ( 2 ) and [(η 6 ‐cyclooctatetraene){η 5 ‐(+)‐neomenthylcyclopentadienyl}ruthenium( II )] hexafluorophosphate ( 3 ). X‐ray structural determination (space group P 2 1 2 1 2 1 ) and NMR spectroscopic studies of 3 show it exists as a single stereoisomer in both the solid and solution phase, with [α] 20 D = +92.5. The chiral modification of the Cp ligand induces anisochrony for all of the magnetically active nuclei of the unsubstituted COT ligand. (© Wiley‐VCH Verlag GmbH & Co KGaA, 69451 Weinheim, Germany, 2003)