Reductive Aromatization of 5,7,12,14-Pentacenetetrone: Approach Towards Substituted Pentacenes?

Herein we report a convenient access to asymmetrically substituted, well soluble pentacene derivatives synthesized from commercially available 5,7,12,14-pentacenetetrone via reductive one step functionalization. Zinc or potassium are used as reducing agents and the reduced intermediates are trapped with electrophiles such as acetyl, triisopropylsilyl or cationic methyl synthons. The reduction allows for an unsymmetric functionalization whilst one dione moiety is maintained due to partial reduction.

An experimental and computational study on isomerically pure, soluble azaphthalocyanines and their complexes and boron azasubphthalocyanines of a varying number of aza units.

Herein, we present a series of isomerically pure, peripherally alkyl substituted, soluble and low aggregating azaphthalocyanines as well as their new, smaller hybrid homologues, azasubphthalocyanines. The focus lies on the effect of the systematically increasing number of aza building blocks [-N[double bond, length as m-dash]] replacing the non-peripheral [-CH[double bond, length as m-dash]] units and their influence on the physical and photophysical properties of these chromophores. The absolute and relative HOMO-LUMO energies of azaphthalocyanines were analyzed using UV-Vis and CV and compared to the density functional theory calculations (B3LYP, TD-DFT).