Abstract
Heteroaromatic precursors to nitrogen substituted derivatives of Koelsch's free radical have been prepared by the condensation of 4,5-diazafluorene with a fluorenylidene or diazafluorenylidene. These compounds appear coloured and can exist in different tautomeric forms. An improved one pot synthesis of 4,5-diazafluorenone has been developed by the oxidative ring contraction of 1,10-phenanthroline with aqueous potassium permanganate. Aza derivatives of Koelsch's free radical are easily generated by oxidation of the appropriate precursors with K3Fe(CN)6. Treatment of 9-[(9H-4,5-diazafluoren-9-ylidene)phenylmethyl]-9H-fluoren-9-yl radical with CuCl2 in EtOH gives a brown precipitate of a 1:1 radical-ligand complex.
Original language | English |
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Pages (from-to) | 971-979 |
Number of pages | 9 |
Journal | Journal of the Chemical Society, Perkin Transactions 1 |
Issue number | 6 |
DOIs | |
Publication status | Published - 2000 |
Keywords
- RUTHENIUM(II) COMPLEXES
- BRIDGING LIGANDS
- PATHWAYS
- DIMERS