[Micro TV lense stroboscopy with possibilities of determining amplitudes (author's transl)].

A brief historic overview of Pt/Sn-catalyzed hydroformylation as well as recent advances in the hydroformylation of internal alkenes is provided. This serves as background for the results obtained with the [Pt(Sixantphos)Cl2] system, for which the mol. structure and the spectroscopic data are described. In situ UV/Vis-spectroscopic studies have revealed rapid formation of the corresponding Pt-stannate complex upon reaction with SnCl2, whereas high-pressure in situ IR-spectroscopy showed formation of a Pt-CO species and a short-lived Pt-H species under syngas, as well as rapid evolution of aldehyde product upon addn. of 1-octene to the preformed catalyst in the IR autoclave. The hydroformylation of 1-octene and the i-octenes has been performed. For the internal alkenes, selective tandem isomerization/hydroformylation towards n-nonanal is obsd. with this catalyst system.