Investigations into the formation and stability of cationic rhodium diphosphane η6-arene complexes.
Rhodium-η(6)-arene complexes can be generated in the presence of arenes following the hydrogenation of the diolefin in rhodium catalyst precursors of the type [Rh(PP*)(diolefin)]X (PP* = chelating diphosphane, X = noncoordinating anion). In this paper we report the characterization of such arene complexes with the ligands DuPhos, dipamp, dppe, Tangphos, dppf, and diop by means of NMR spectroscopy ((31)P, (103)Rh) and X-ray analysis. A procedure that follows the approach to equilibrium as a function of time monitored by using an UV/Vis diode array was used to determine 20 stability constants. Analyses were accomplished directly from the spectra by either a numeric and/or a new analytic solution of the underlying system of differential equations. Additionally thermodynamic parameters were determined in the temperature range between 278 and 318 K.
Leibniz-Institut für Katalyse e.V. Albert-Einstein-Strasse 29a, 18059 Rostock, Germany.
Christian
C
Fischer
Richard
R
Thede
Hans-Joachim
HJ
Drexler
Anja
A
König
Wolfgang
W
Baumann
Detlef
D
Heller
D002384:Catalysis; D002412:Cations / Q000737:chemistry*; D002614:Chelating Agents / Q000737:chemistry*; D007700:Kinetics; D015394:Molecular Structure; D009942:Organometallic Compounds / Q000737:chemistry*; D012238:Rhodium / Q000737:chemistry*; D013237:Stereoisomerism
D002412:Cations; D002614:Chelating Agents; D009942:Organometallic Compounds; D012238:Rhodium