“…The experimentally determined maximum absorption wavelength of novel 2,7-naphthyridine derivatives have been reported in the range 443–485 nm. 72 Other 2,7-naphthyridine derivatives have experimental UV-visible spectral bands in the range 261–450 nm which is increased to 535–550 nm after nickel addition. 73 The designed compounds N1–N10 have maximum absorption wavelength in the range 352–502 nm and the compounds N6 , N7 , N10 and N9 show absorption peaks at 360.14 nm, 383.14 nm, 440.63 nm and 502.80 nm respectively (see Table 1).…”