Synthesis and properties of benzo[b]-1,10-phenanthrolines and their ruthenium(II) complexes

Abstract

Friedländer reactions of 4-aminoacridine-3-carbaldehyde with 1,3-, 1,4-di-, and 1,3,5-triacetylbenzenes afforded a series of corresponding (benzo[b]-1,10-phenanthrolin-2-yl)benzenes as new N,N,C-polydentates. Reaction with 1,2-diacetylbenzene afforded 1,2-di(benzo[b]-1,10-phenanthrol-2-yl)benzene with unexpected benzo[b]-1,10-phenanthroline and 3-oxoindeno[1,2-b]benzo[j]-1, 10-phenanthroline in a ratio of 1:1.2:1. Metal complex formation of the ligands was examined to provide two isomeric Ru complexes, a pentaaza-coordinated (N5Cl) complex [Ru(tpy)(3aH)Cl](PF6) and a hexacoordinated (N5C) complex [Ru(tpy)(3a)](PF6) in a ratio of 1:4 with 71% overall yield, whereas 3b-eH afforded complex mixtures upon reactions with Ru(tpy)Cl3. © 2007 Wiley Periodicals, Inc.