Two families of "push-pull" phthalocyanines 1-3 having an unusually strong
dipole moment have been prepared. The syntheses of unsymmetrically substitu
ted phthalocyanines 1a,b and 2 bearing one or two electron-withdrawing 4-ni
trophenylethynyl moieties, respectively, and six alkoxy substituents were p
erformed by combination of a zinc or nickel templated cyclotetramerization
and cross-coupling palladium mediated methodologies. In a similar way, the
"push-pull" compounds 3a,b having a reversal substitution pattern, characte
rized by the presence of one electron-donor 4-(dimethylamino)phenylethynyl
unit and six strong acceptor alkylsulfonyl substituents were prepared. The
compounds show very large second-order nonlinear optical responses.