Abstract
The present thesis aims at spherical dendrimers with generation-specifically incorporated fluorescent solvatation
probes. Knowledge of solvatation of the area between the core and the periphery should contribute essentially to the
basic understanding of these macromolecules. In particular, the role of solvatation in directed energy and charge
transfer processes is not known sufficiently.
Firstly, the development of new phenylene alkylene dendrons via palladium catalyzed Suzuki-Miyaura cross-coupling
of aryl halogenides and in situ prepared alkyl boranes by an orthogonal, convergent approach is demonstrated. The
3,5-dihalogen homoallyl benzenes 15 and 28 were found to be suitable in the synthesis of the G2 dendron 32 on a
gram scale.
The main part introduces a concept that schedules for the incorporation of solvatochromic, selectively excitable
phenyl pyrene derivatives in a specific generation and the equipment of all others by an inactive alkyl pyrene analogue,
the so-called volume dummy. According to this a series of phenyl pyrenes 45b-n and corresponding alkyl-bridged
compounds 47 and 57 were synthesized and investigated by photophysical methods in detail. As a suitable pair of
probe and dummy the two benzonitrile derivatives 45b and 57 were chosen. 45b can be excited exclusively in the
presence of even an excess of 47 with light of lexc ? 360 nm and shows a positive solvatochromism of lmax = 36 nm
(methyl cyclohexane vs. acetonitrile) in the fluorescence. Both compounds were functionalized by a second
substitution at the pyrene and connected to the benzylic alcohols 84 and 85 via ether bond formation to give the
branching units 86-88 on a 10 g scale. From these the complementary G2 phenylene alkylene dendrons 91 and 92
were synthesized. Their structures were unequivocally confirmed by NMR, MALDI-TOF-MS, and SEC. Test
reactions indicated the possible threefold connection to a benzene core to yield the dendrimers 93 and 94. Most of
the reactions used in the 14-step sequence generating the target compounds 93 and 94 (in each case) proceeded in
good or very good yields. The concept presented seems to be capable of bearing the goal.
Other parts of this thesis deal with the synthesis of the tris(bipyridine) ruthenium(II) complex 100 that contains a
pyrene substituent at one of the ligands 5-positions (crystal structure), first steps to a multiple alkylated pyrene core
molecule and the exploration of the Suzuki-Miyaura coupling in the preparation of hyperbranched polymers. |
