PUB - Publikationen an der Universität Bielefeld

Some new Rh(I), Rh(III), Ir(I), and Ir(III) complexes containing the 1-(2-(dimethylamino)-ethyl)-2,3,4,5-tetramethylcyclopentadienyl (Cp^) ligand are described. The bis(ethene) complexes Cp^Rh(C2H4)2 (2) and Cp^Ir(C2H4)2 (3) with a noncoordinating dimethylamino function are synthesized by reaction of [(C2H4)2RhCl]2 with Cp^Li and by reaction of [(COE)2IrCl]2 with Cp^Li/C2H4, respectively. Addition of iodine to 2 or 3 results in the formation of the respective diiodo complexes Cp^RhI2 (4) and Cp^IrI2 (5) with intramolecular amino coordination. In the presence of CO, 4 or 5 can easily be transferred into the carbonyl complexes Cp^RhI2(CO) (6) and Cp^IrI2(CO) (7), respectively, with a noncoordinating amino function. The reverse reaction is successful for both 6 and 7, but under differing conditions. In the reaction of 4 and 5 with PMe3, PPh3, and CNtBu, the corresponding substitution products Cp^MI2L (8-12) are formed. Reduction of 4 and 5 with sodium amalgam under a CO atmosphere leads to the carbonyl complexes Cp^Rh(CO)2 (13) and Cp^Ir(CO)2 (14), respectively, with a noncoordinating amino group. In the reaction of 4 and 5 with Ag2C2O4, the oxalato complexes Cp^RhC2O4 (15) and Cp^IrC2O4 (16), respectively, are formed. The coordinating amino group in 15 and 16 can be replaced by the PMe3 ligand (compounds Cp^(PMe3)RhC2O4 (17) and Cp^(PMe3)IrC2O4 (18)). Structure investigations on 4 (crystal system monoclinic; space group P2(1)/n; a = 8.775(5) Å; b = 14.053(6) Å; c = 13.880(7) Å; [beta] = 103.64(4)-degrees; Z = 4) and 5 (crystal system monoclinic; space group P2(1)/n; a = 8.828(2) , b = 14.006(4) Å; c = 13.823(4) Å; [beta] = 103.14(2)-degrees; Z = 4) confirm the intramolecular coordination of the dimethylamino group.