217795-98-7Relevant academic research and scientific papers
Rhodium COD complexes of mixed donor set tripod ligands: Coordination chemistry and catalysis
Jacobi, Albrecht,Huttner, Gottfried,Winterhalter, Ute
, p. 231 - 241 (2007/10/03)
The reaction of the novel mixed tripod ligands RCH2C(CH2X)(CH2Y)(CH2Z) 1-6 (X, Y, Z=PPh2, NR2, pyrazol-1-yl; R=H, OH) with [RhI(COD)Cl]2 is investigated. The resulting rhodium COD complexes [(1-6)Rh(COD)]PF6, 7 are characterized by NMR spectroscopy, mass spectra and elemental analysis. In addition, X-ray structure analysis is performed on several compounds 7, where in contrast to the behavior of the parent compound triphos [MeC(CH2PPh2)3], the potential tripod ligands 2-6 are found to coordinate in a bidentate mode. {η2-P,O-[HOCH2C(CH2PPh2)(CH 2NEt2)2]Rh(COD)]}PF6, 7i exhibits the first structurally characterized example of an intramolecular hydrogen bond between a non-coordinated and a coordinated donor atom. The activities of the complexes 7 as catalyst precursors in the homogeneous hydrogenation of diphenylacetylene and (Z)-α-N-acetamidocinnamic acid are tested and rationalized with respect to a proposed reaction mechanism.
