[摘要]：A series of 3,3'-polymethylene-2-(pyrid-2'-yl)benzo[b]-1,10-phenanthrolines were prepd. by the Friedlander reactions of 4-aminoacridine-3-carbaldehyde with pyrido[b]cycloalkanones as potential tridentate ligands. Dehydrogenation of dimethylene-bridged system afforded the corresponding fully aromatized system. Flexibility of annulated bridges is highly dependent on the length of the carbon chain, where the tetramethylene-bridge is rigid enough to differentiate eight bridge protons in 1H NMR time scale at rt.
