Optical properties of porphyrazine functionalized dendrimers

Abstract

Phthalocyanine is a representative colorant, which have improved such various applications such as organic photo conductors (OPC), nonlinear optical materials (NLO), information storage for information technology, and photosensitizers and photodynamic therapy. Because of thermal stability and ability for absorbance of near infrared lights, phthalocyanines and their metal complexes have recently received considerable attention. Dendrimers are macromolecules with highly branched and regular structural units. In this study, tetrapropyrazinoporphyrazine, which contain pyrazines in their backbone instead of benzene rings, was synthesized by coordinate bonding between 2,3-dicyanpyrazine and metals. We were recently able to develop convenient methods for the synthesis of porphyrazines containing both flexible (linear) and more rigid (dendritic) groups. The synthesis of this type of completely aromatic dendrimers is unique in that it is based on the [2+4] Diels-Alder cycloaddition of the tetraphenylcyclopentadienone to an ethynyl compound, followed by the elimination of carbon monoxide. And phenylene groups can be connected each to supramolecule by intramolecular cyclodehydrogenation3, which have a planar structure, and strong electron donating effect. The UV-visible absorbance was characterized about synthesized compounds, which have a typical absorbance (Q-band) of phthalocyanine. The aggregation behaviors were occurred which solvents changed at the same molar concentration. In this study, It is experimented the solvatochromism, and sensitive changing of absorbance peak by adding base to application with chemosensor technology As shown Fig.1, in the polar solvent like DMF or DMSO, the porphyrazine shows high absorbance at the Q-band at the same concentration. It shows the aggregation behavior was less occurred relatively with non-polar solvents such as carbon tetrachloride. The optical change in anionic condition is extremely shown as Fig.2 The synthesized tetrapyrazinoporphyrazinato metal complexes were characterized by UV-visible spectroscopy, MALDI-TOF-Ms (matrix-assisted laser desorption ionization time-of-flight mass) spectroscopy, elemental analysis and 1H NMR spectroscopy