Twisted One-Dimensional Charge Transfer and Related Y-Shaped Chromophores with a 4H-Pyranylidene Donor: Synthesis and Optical Properties

Synthesis and Studies of Pyridoneimine-Functionalized PETIM Dendrimers

Pyridinoimine-functionalized poly(ether imine) (PETIM) dendrimers of 1-3 generations, possessing 4-16 moieties at the peripheries, are synthesized. Chloride-functionalized dendrimers are reacted with N-methylamino pyridine, under basic conditions, which led to functionalization of the peripheries of a dendrimer with pyridoneimine moieties. Variable-temperature 1H NMR studies are performed to assess the contributing resonance forms of pyridoneimine in the dendrimers. Solvatochromism and 15N NMR studies aid further the assessment of the contributing resonance forms. Comparison with derivatives that possess 1 and 2 pyridoneimines illustrates the contributing resonance forms between nonaromatic pyridoneimine and zwitter ionic aromatic imidopyridinium species.