Synthesis and J-Dimer Formation of Tetrapyrazinoporphyrazines with Different Functional Groups for Potential...

Though tetrapyrazinoporphyrazines (TPyzPzs) are generally presented as universal dark quenchers for oligonucleotide probes, the availability of TPyzPzs bearing different functional groups suitable for attachment to 3', and 5' ends or intrastrand positions remains rather limited. Therefore, a synthetic route to hexa(bis(2-methoxyethyl)amino) or hexa(diethylamino) TPyzPzs functionalized by an azide, hydroxy, or carboxy group or their combinations was developed. Studies of self-assembly into J-dimers in nonpolar solvents and their stability upon titration with pyridine (association constants, K_P values, ranging 0.32-12.7×10²  M^-1 ) revealed that smaller peripheral substituents and functionalization of TPyzPzs improves the stability of J-dimers. Φ_Δ and Φ_F were low for the monomers (Φ_F <0.0001, Φ_Δ <0.008, DMF) due to quenching by intramolecular charge transfer; however, they increased in nonpolar solvents and after self-assembly into J-dimer (up to Φ_F =0.027, Φ_Δ =0.28).