The influence of methoxy- group position on thermal stability and properties of novel isomeric 4-[(methoxy)phenoxy] phthalonitriles and phthalocyanine complexes based on them

Isomeric 4-[(methoxy)phenoxy]phthadinitriles were obtained and characterized in this work. The compounds showed high thermal stability, which is directly related to their structure. These features were revealed and described using X-ray diffraction analysis. For m-substituted structures during packing, the largest contribution was found from intermolecular interactions of the π-stacking type between nitrile fragments. In the packing of o-substituted analogs, this type of interaction is not realized due to geometry, and additional stabilization is realized due to the appearance of three-center intermolecular bonds between the bridging oxygen atoms of one nitrile molecule and the hydrogen atom of the nitrile fragment of another molecule. Based on the obtained phthalonitriles, novel metal complexes with tetrakis-4-[4-(o-/m-/p-methoxy)phenoxy]phthalocyanine ligands were synthesized. For the substituted phthalocyaninates obtained the structure was characterized, the spectroscopic and luminescent properties were determined, as well as the influence of the position of the methoxy-group in the peripheral fragments on them. It is shown that, on the one hand, the position of the methoxyl-group has a significant effect on the values of the fluorescence quantum yields of the compounds, and, on the other hand, has almost no effect on their fluorescence lifetimes.