Optically active transition metal complexes, 118 - Unusual crystal structures of (RRuRC/SRuRC)-(n(6)-p-cymene)Ru complexes - Diastereomers with opposite configuration at the metal center in the unit cell

Condensation of (R)-2-aminobutanol with salicylaldehyde and 2-pyrrolecarbal dehyde gave the chiral chelate Ligands HLL1* and HLL2*, respectively. The d iastereomeric complexes (R-Ru,R-C)- and (S-Ru,R-C)-[(eta(6)-arene)Ru(LL1*)C l], eta(6)-arene = p-cymene (1a/1b), eta(6)-arene = benzene (2a/2b), and (R -Ru,R-C)- and (S-Ru,R-C)-[(eta(6)-arene)Ru(LL2*)Cl], eta(6)-arene = p-cymen e (3a/b), eta(6)-arene = benzene (4a/4b), which only differ in the rutheniu m configuration, were prepared by the reaction of [(eta(6)-arene)RuCl2](2) with the anion of the corresponding Ligand HLL*. X-ray analyses of 1a/1b an d 3a/\3b showed a structural peculiarity. The unit cell of these complexes contained diastereomers with the same configuration at the carbon atoms but opposite configuration at the metal centers in a 1:1 ratio. Weak intramole cular O-H ... Cl hydrogen bridges were formed in all the complexes. H-1-NMR studies demonstrated me configurational lability at the Ru center. The iod o complexes (R-Ru,R-C)- and (S-Ru,R-C)-[(eta(6)-p-cymene)Ru(LL*)I], LL* = L L1* (5a/5b) and LL* = LL2* (6a/6b), were synthesized by halogen exchange.