Dissertation

|4 Summary|
In particular, a detailed isomer analysis with NMR investigations was used to characterize
the inisochronical atropisomers of the ruthenium complexes which are caused by the
sterical hindrance of the rotation about the connecting single bond. In a time-dependent
NMR-investigation, using the obtained single crystals of ∆R a /ΛS a -Ru(bbip), a half-life
of t 1/2 = 1.99 h for the interconversion into the ∆S a /ΛR a -configured rotamers could be
calculated. The absorption and emission behavior indicated the formation of the typical
[Ru 3+ (̂LL - )(̂LL) 2 ]-type transient species and additional new photoproducts in the platinum
free complexes upon MLCT excitation.
4. The performed photophysical and electrochemical investigation indicated suitable redox
potentials and a fair electronic communication between the two phenanthroline moieties.
Thus, catalysis experiments with Ru(phenphen)Pt were performed under standard
conditions (in TEA:ACN:H 2 O / 6:3:1) and moderate amounts of hydrogen were detected.
The observed TONs are still low but lie in the same order of magnitude as observed for the
catalyst [(tbbpy) 2 Ru(µ-tpphz)PtCl 2 ] 2+ . Furthermore, a water concentration dependency of
the activity with a maximum at 5% water content was observed.
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